bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Scale Thermal Analysis for Design of SiC-Based Medium Voltage Motor Drive
Authors: Cousineau J. Emily , Bennion Kevin , Potty Karun , Li He , Na Risha , Xu Longya , Wang Jin
Published: December 2019

This paper describes a multi-scale thermal analysis approach for the design of an air-cooled 1.7-kV SiC MOSFET-based medium-voltage variable-speed motor drive. The scope of the models and required efficient and flexible thermal models to be developed. Two modeling techniques are described that significantly reduced model run time and enabled more complex models to be run faster while retaining needed accuracy. The first technique uses the effectiveness-NTU method to extract convection boundary conditions from a CFD model that can be applied to a fast-running FEA model. The second is a porous media technique that enables system-level CFD simulations that incorporate effects from heat exchangers (e.g., pin fin heat sinks) that run in a fraction of the time required for fully resolved CFD simulations. The multi-scale approach to the thermal analysis enabled fast and accurate simulation for the converter design ranging from the die level up to the full system with 36 submodules. The modeling results were validated against experimental data from system tests performed by OSU.
Mass spectra database of polymers for bismuth-cluster ToF-SIMS
Authors: Kern Stefanie , Kern Christine , Rohnke Marcus
Published: December 2019

Contamination and pollution of the environment by plastic and especially microplastic debris has become a major research interest in recent years. Microplastics are, by definition, polymer fragments less than 5 mm in length and are either that size before entering or created from degradation of larger polymer products after entering the environment. Suitable analytical methods are required for the study of these small sized polymer particles. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is such a suitable analytical method with its high spatial resolution, which has the ability to detect molecular species, and 3D analysis option. However, there is a lack of ToF-SIMS reference spectra of polymers for state-of-the-art primary ion species such as bismuth-cluster Bi3+. Therefore, this study provides a database of reference spectra for the most abundantly used commercial polymers for bismuth cluster ToF-SIMS in positive and negative polarity. This database is an important tool for further microplastic analysis and classification.
The Effects of Aerobic Exercise on Postconcussion Symptoms in Patients With Persistent Symptoms: A Critically Appraised Topic
Authors: Kulpa Timothy A. , Mansell Jamie , Russ Anne , Tierney Ryan
Published: December 2019

Context: Patients who do not fully recover from a concussion in 7–14 days may require an impairment-based rehabilitation program. Recent evidence indicates improved outcomes with active rehabilitation compared to passive physical and cognitive rest. Clinical Question: In patients with persistent symptoms (greater than 4 weeks) following concussion, how does aerobic exercise affect postconcussion symptoms? Clinical Bottom Line: There is moderate and sufficient SORT Level B evidence to support the inclusion of subsymptom threshold (SST) exercise in the multimodal treatment plan for patients suffering from persistent symptoms after concussion. All five included studies reported moderate to very large effects ranging from d = 0.72 to d = 10.64 in reducing symptoms after the implementation of SST aerobic exercise. Additionally, two studies also identified moderate and very large effects (d = 0.77, d = 2.56) favoring aerobic exercise over stretching interventions. These results indicate that this treatment has potential clinical utility and is a viable option to reduce symptoms in patients with postconcussion syndrome and persistent symptoms following concussion.
Depression Following Concussion in Retired Professional Football Players
Authors: Thomson Ryan , Carabello Danielle , Mansell Jamie , Russ Anne
Published: December 2019

Clinical Question: In retired National Football League (NFL) players, what is the prevalence of depression after sustaining concussions? Clinical Bottom Line: There is emerging evidence to support the clinical question that retired NFL players with a history of concussion may be diagnosed with depression.
Detectability of HIV Residual Viremia despite Therapy Is Highly Associated with Treatment with a Protease Inhibitor-Based Combination Antiretroviral Therapy
Authors: Darcis Gilles , Maes Nathalie , Pasternak Alexander O. , Sauvage Anne-Sophie , Frippiat Frédéric , Meuris Christelle , Uurlings Françoise , Lecomte Marianne , Léonard Philippe , Elmoussaoui Majdouline , Fombellida Karine , Vaira Dolores , Moutschen Michel
Published: December 2019

HIV persistence despite therapy contributes to chronic immune activation and inflammation, increasing the risk of aging-associated events in HIV-infected individuals. We sought here to better understand the complex link between clinical and treatment features and HIV persistence despite therapy.
Comparative Analysis of the Capsid Structures of AAVrh.10, AAVrh.39, and AAV8
Authors: Mietzsch Mario , Barnes Candace , Hull Joshua A. , Chipman Paul , Xie Jun , Bhattacharya Nilakshee , Sousa Duncan , McKenna Robert , Gao Guangping , Agbandje-McKenna Mavis
Published: December 2019

Recombinant adeno-associated virus vectors (rAAVs), based on AAV8 and AAVrh.10, have been utilized in multiple clinical trials to treat different monogenetic diseases. The closely related AAVrh.39 has also shown promise
in vivo
. As recently attained for other AAV biologics, e.g., Luxturna and Zolgensma, based on AAV2 and AAV9, respectively, the vectors in this study will likely gain U.S. Food and Drug Administration approval for commercialization in the near future. This study characterized the capsid structures of these clinical vectors at atomic resolution using cryo-electron microscopy and image reconstruction for comparative analysis. The analysis suggested two key residues, S269 and N472, as determinants of BBB crossing for AAVrh.10 and AAVrh.39, a feature utilized for central nervous system delivery of therapeutic genes. The structure information thus provides a platform for engineering to improve receptor retargeting or tissue specificity. These are important challenges in the field that need attention. Capsid structure information also provides knowledge potentially applicable for regulatory product approval.
The Emergence of Successful Streptococcus pyogenes Lineages through Convergent Pathways of Capsule Loss and Recombination Directing High Toxin Expression
Authors: Turner Claire E. , Holden Matthew T. G. , Blane Beth , Horner Carolyne , Peacock Sharon J. , Sriskandan Shiranee
Published: December 2019

Streptococcus pyogenes
is a genetically diverse pathogen, with over 200 different genotypes defined by
emm
typing, but only a minority of these genotypes are responsible for the majority of human infection in high-income countries. Two prevalent genotypes associated with disease rose to international dominance following recombination of a toxin locus that conferred increased expression. Here, we found that recombination of this locus and promoter has occurred in other diverse genotypes, events that may allow these genotypes to expand in the population. We identified an association between the loss of hyaluronic acid capsule synthesis and high toxin expression, which we propose may be associated with an adaptive advantage. As
S. pyogenes
pathogenesis depends both on capsule and toxin production, new variants with altered expression may result in abrupt changes in the molecular epidemiology of this pathogen in the human population over time.
Duration of Persistent Atrial Fibrillation Is Associated with Alterations in Human Gut Microbiota and Metabolic Phenotypes
Authors: Zuo Kun , Li Jing , Wang Pan , Liu Ye , Liu Zheng , Yin Xiandong , Liu Xiaoqing , Yang Xinchun
Published: December 2019

Atrial fibrillation was associated with a disordered gut microbiota in previous research. However, the gut microbiota signature of patients at different stages of atrial fibrillation remains largely unknown. We sought to determine whether the shift in the gut microbiota and metabolic profiles occurs early and remains stable or develops gradually during atrial fibrillation. We found that patients with persistent atrial fibrillation of <12 months and persistent atrial fibrillation of >12 months shared most of the common features of gut microbiota dysbiosis. However, some distinctive and progressive alterations in the gut microbiota and metabolic structure, which may contribute to the progression of atrial fibrillation, were identified. The present study provides a comprehensive description of the dysbiotic gut microbiota and metabolic profiles in patients of short and long persistent atrial fibrillation, and our findings may help identify therapeutic strategies targeting the gut microbiota to treat atrial fibrillation at an early stage.
Marine Metabolomics: a Method for Nontargeted Measurement of Metabolites in Seawater by Gas Chromatography–Mass Spectrometry
Authors: Sogin Emilia M. , Puskás Erik , Dubilier Nicole , Liebeke Manuel
Published: December 2019

Nontargeted approaches using metabolomics to analyze metabolites that occur in the oceans is less developed than those for terrestrial and limnic ecosystems. One of the challenges in marine metabolomics is that salt limits metabolite analysis in seawater to methods requiring salt removal. Building on previous sample preparation methods for metabolomics, we developed SeaMet, which overcomes the limitations of salt on metabolite detection. Considering that the oceans contain the largest dissolved organic matter pool on Earth, describing the marine metabolome using nontargeted approaches is critical for understanding the drivers behind element cycles, biotic interactions, ecosystem function, and atmospheric CO
2
storage. Our method complements both targeted marine metabolomic investigations as well as other “omics” (e.g., genomics, transcriptomics, and proteomics) approaches by providing an avenue for studying the chemical interaction between marine microbes and their habitats.
Sea level, carbonate mineralogy, and early diagenesis controlled δ13C records in Upper Ordovician carbonates
Authors: Jones David S. , Brothers R. William , Crüger Ahm Anne-Sofie , Slater Nicholas , Higgins John A. , Fike David A.
Published: December 2019

Stratigraphic variability in the geochemistry of sedimentary rocks provides critical data for interpreting paleoenvironmental change throughout Earth history. However, the vast majority of pre-Jurassic geochemical records derive from shallow-water carbonate platforms that may not reflect global ocean chemistry. Here, we used calcium isotope ratios (δ44Ca) in conjunction with minor-element geochemistry (Sr/Ca) and field observations to explore the links among sea-level change, carbonate mineralogy, and marine diagenesis and the expression of a globally documented interval of elevated carbon isotope ratios (δ13C; Hirnantian isotopic carbon excursion [HICE]) associated with glaciation in Upper Ordovician shallow-water carbonate strata from Anticosti Island, Canada, and the Great Basin, Nevada and Utah, USA. The HICE on Anticosti is preserved in limestones with low δ44Ca and high Sr/Ca, consistent with aragonite as a major component of primary mineralogy. Great Basin strata are characterized by lateral gradients in δ44Ca and δ13C that reflect variations in the extent of early marine diagenesis across the platform. In deep-ramp settings, deposition during synglacial sea-level lowstand and subsequent postglacial flooding increased the preservation of an aragonitic signature with elevated δ13C produced in shallow-water environments. In contrast, on the mid- and inner ramp, extensive early marine diagenesis under seawater-buffered conditions muted the magnitude of the shift in δ13C. The processes documented here provide an alternative explanation for variability in a range of geochemical proxies preserved in shallow-water carbonates at other times in Earth history, and challenge the notion that these proxies necessarily record changes in the global ocean.
Isolated uterine metastasis from a lung adenocarcinoma
Authors: Knox Benita , Dobrotwir Andrew , Ades Alex
Published: December 2019

A 65-year-old woman was referred with an incidental finding of a flurodeoxyglucose-avid uterine lesion, following excision of a local lung adenocarcinoma. MRI had features concerning for an atypical fibroid or smooth muscle tumour of uncertain malignant potential. She underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy. Histopathology demonstrated a leiomyoma infiltrated with adenocarcinoma consistent with a secondary lesion from the lung cancer. Among the small number of cases of uterine metastases of extra-pelvic primary cancers reported in the literature, those from lung cancers are very rare. Concerning features for an atypical fibroid included the patient’s age and postmenopausal status, as well as positron emission tomography and MRI findings. A metastatic secondary cancer was not suspected. Diagnosis was only made after histopathological examination. This case represents a very unusual cause of a uterine mass. It demonstrates the importance of thorough preoperative work-up and accurate histopathological assessment.
Trichoblastoma of lid: a masquerading tumour
Authors: Subudhi Praveen , Agarwal Prateek , Patro Sweta , Subudhi Nageswar Rao
Published: December 2019

A 62-year-old woman came to our hospital with complaints of painless gradual increase in dark coloured mass along inner canthus of the right eye. The surface of the mass was rough with a well-defined margin. No other systemic abnormality was detected. Wide margin excision was done and the excised mass was sent for histopathological examination. No skin grafting was done and the raw area was left for self-healing. In the next 3 weeks, skin growth over the raw area was observed and it was cosmetically acceptable. Histopathological examination revealed well-circumscribed tissue composed of aggregation of basaloid cells suggestive of trichoblastoma. Immunohistochemistry revealed positive staining of CD34 and CD10. Trichoblastoma is a rare entity seen in our clinical practice. Hence, a patient presenting with darker masses trichoblastoma can be considered as differential diagnosis.
Chronic pleuritis leading to severe pulmonary restriction: a rare complication of Degos disease
Authors: Saha Biplab Kumar , Beegle Scott
Published: December 2019

This case demonstrates chronic fibrosing pleuritis, as a rare pulmonary aetiology for mortality in patients with Degos disease or malignant atrophic papulosis (MAP). Knowledge of this unusual complication will help physicians identify this entity early and provide appropriate treatment.

Patients with MAP die from gastrointestinal and brain involvement within 2–3 years of diagnosis. This case is unique as the patient survived for 9 years and died secondary to respiratory failure, which had not been reported before. Our patient was a young man, diagnosed with MAP at the age of 17. His skin and gastrointestinal disease were controlled with eculizumab and parenteral treprostinil. The patient developed severe restrictive pulmonary disease, required ventilatory support, and died from respiratory failure. An autopsy revealed chronic fibrosis pleuritis. Longer surviving patients with MAP might suffer from significant respiratory disease. Pulmonary function test should be obtained to identify subclinical respiratory limitation.
Association between same day discharge total knee and total hip arthroplasty and risks of cardiac/pulmonary complications and readmission: a population-based observational study
Authors: Liu Jiabin , Elkassabany Nabil , Poeran Jashvant , Gonzalez Della Valle Alejandro , Kim David H , Maalouf Daniel , Memtsoudis Stavros
Published: December 2019

Objective

To determine if same-day discharge total knee arthroplasty (TKA) or total hip arthroplasty (THA) is not associated with increased risk of unplanned readmission and adverse outcomes within 30 days of surgery.

Design

This is a population-based observational study.

Setting

Patients from 708 participating institutions who underwent primary TKA or primary THA between 2011 and 2017 were divided into three groups by length of stay (LOS 0, 1 and 2–3 days). All patients with LOS>3 days were excluded from the current study. Regression analysis and propensity score matching were performed.

Data sources

American College of Surgeons—National Surgical Quality Improvement Programme database.

Main outcomes and measures

Primary outcomes included unplanned readmission and cardiac/pulmonary complications within 30 days of surgery.

Results

We identified 226 481 TKA (LOS 0=3118, LOS 1=31 404, and LOS 2–3=1 91 959) and 140 557 THA patients (LOS 0=2652, LOS 1=29 617, and LOS 2–3=1 08 288). There were no differences in 30-day mortality. After adjusting for relevant covariates, LOS 0 (compared with LOS 1) was associated with higher odds of cardiac/pulmonary complications in both TKA (OR 1.95, 95% CI 1.20 to 3.16; 0.67% vs 0.37%) and THA (OR 1.96, 95% CI 1.05 to 3.64; 0.57% vs 0.26%). There were no statistical differences in unplanned readmissions between LOS 0 and LOS 1 groups in TKA (2.41% vs 2.31%) and THA (1.62% vs 2.04%).

Conclusions

LOS 0 discharge after TKA and THA was associated with higher odds of cardiac/pulmonary complications compared with LOS 1 discharge. While the overall burden of complications is relatively low, until future studies can confirm or challenge our findings, a measured approach is advisable when recommending discharge of patients on the same day of surgery.
Finding ‘the inner drive’ for a rehabilitation process: a small-scale qualitative investigation among male patients with primary glioma
Authors: Fahrenholtz Mette Lysdahl , Hansen Anders , Søgaard Karen , Andersen Lotte Nygaard
Published: December 2019

Objective

Brain tumours are relatively rare but hold a significant place in cancer rehabilitation due to their pronounced disabling capacity to promote physical, cognitive and psychosocial sequelae. This small-scale qualitative study used coping and motivational theories to gain understanding and knowledge of patients’ experience of being diagnosed with a severe disease and of their view of a rehabilitation process.

Design

Qualitative interview study.

Setting

Odense University Hospital, Denmark.

Informants

Five patients (men, aged 30–79 years) with primary glioma who had participated in a rehabilitation intervention.

Methods

Semi-structured interviews were conducted. The phenomenological interpretive analysis was used to analyse the interviews.

Results

The analysis revealed three main themes: (1) coping with a new life situation, (2) motivating and maintaining elements and (3) experience of the benefit of the rehabilitation programme.

Conclusion

The study concluded that interviewed informants use problem-solving coping strategies, which make them more active in their health behaviour. However, passive and emotion-focused strategies related to confronting diagnosis may be used in some cases. The motivational aspect is multifaceted. Personal and interpersonal elements alongside a competitive setting are crucial to self-efficacy and benefit. The intervention’s impact on health-related quality of life also has the potential to increase patients’ resources to manage their situation.

Trial registration number

NCT02221986
Systematic meta-analyses, field synopsis and global assessment of the evidence of genetic association studies in colorectal cancer
Authors: Montazeri Zahra , Li Xue , Nyiraneza Christine , Ma Xiangyu , Timofeeva Maria , Svinti Victoria , Meng Xiangrui , He Yazhou , Bo Yacong , Morgan Samuel , Castellví-Bel Sergi , Ruiz-Ponte Clara , Fernández-Rozadilla Ceres , Carracedo Ángel , Castells Antoni , Bishop Timothy , Buchanan Daniel , Jenkins Mark A , Keku Temitope O , Lindblom Annika , van Duijnhoven Fränzel J B , Wu Anna , Farrington Susan M , Dunlop Malcolm G , Campbell Harry , Theodoratou Evropi , Zheng Wei , Little Julian
Published: December 2019

Objective

To provide an understanding of the role of common genetic variations in colorectal cancer (CRC) risk, we report an updated field synopsis and comprehensive assessment of evidence to catalogue all genetic markers for CRC (CRCgene2).

Design

We included 869 publications after parallel literature review and extracted data for 1063 polymorphisms in 303 different genes. Meta-analyses were performed for 308 single nucleotide polymorphisms (SNPs) in 158 different genes with at least three independent studies available for analysis. Scottish, Canadian and Spanish data from genome-wide association studies (GWASs) were incorporated for the meta-analyses of 132 SNPs. To assess and classify the credibility of the associations, we applied the Venice criteria and Bayesian False-Discovery Probability (BFDP). Genetic associations classified as ‘positive’ and ‘less-credible positive’ were further validated in three large GWAS consortia conducted in populations of European origin.

Results

We initially identified 18 independent variants at 16 loci that were classified as ‘positive’ polymorphisms for their highly credible associations with CRC risk and 59 variants at 49 loci that were classified as ‘less-credible positive’ SNPs; 72.2% of the ‘positive’ SNPs were successfully replicated in three large GWASs and the ones that were not replicated were downgraded to ‘less-credible’ positive (reducing the ‘positive’ variants to 14 at 11 loci). For the remaining 231 variants, which were previously reported, our meta-analyses found no evidence to support their associations with CRC risk.

Conclusion

The CRCgene2 database provides an updated list of genetic variants related to CRC risk by using harmonised methods to assess their credibility.
Characterising risk of homicide in a population-based cohort
Authors: O’Neill Meghan , Buajitti Emmalin , Donnelly Peter D , Lewis Jeremy , Kornas Kathy , Rosella Laura C
Published: December 2019

Background

Homicide is an extreme expression of violence that has attracted less attention from public health researchers and policy makers interested in prevention. The purpose of this study was to examine the socioeconomic gradient of homicide and to determine whether risk differs by immigration status.

Methods

We conducted a population-based cohort study using linked vital statistics, census and population data sets that included all deaths by homicide from 1992 to 2012 in Ontario, Canada. We calculated age-adjusted death rates for homicide by material deprivation quintiles, stratified by immigration status. Count-based negative binomial regression models were used to calculate unadjusted and adjusted rate ratios with predictors of interest being age, urban residence, material deprivation and immigration status. A subanalysis containing immigrants only examined the effect of time since immigration and immigration class.

Results

There were 3345 homicide deaths registered between 1992 and 2012. Relative to low material deprivation areas, age-adjusted rates of homicide deaths in high materially deprived areas were similar among refugees (RR: 48.49; 95% CI 36.99 to 62.45) and long-term residents (RR: 47.67; 95% CI 44.66 to 50.83), but were slightly lower for non-refugee immigrants (RR: 38.53; 95% CI 32.42 to 45.45). Female refugees experienced a 1.31 (95% CI 0.88 to 1.94) higher rate and male refugees experienced a 1.23 (95% CI 0.90 to 1.67) higher rate of homicide victimisation compared with long-term residents. In an immigrant only analysis, the risk of homicide among refugees increased with duration of residence.

Conclusions

Given the large area-level, socioeconomic status gradients observed in homicides among refugees, community-level and culturally appropriate prevention approaches are important.
Finite lifespan of solutions of the semilinear wave equation in the Einstein–de Sitter spacetime
Authors: Galstian Anahit , Yagdjian Karen
Published: December 2019

We examine the solutions of the semilinear wave equation, and, in particular, of the [Formula: see text] model of quantum field theory in the curved spacetime. More exactly, for [Formula: see text] we prove that the solution of the massless self-interacting scalar field equation in the Einstein–de Sitter universe has finite lifespan.
A Note on the Connectivity of m-Ary n-Dimensional Hypercubes
Authors: Wang Shiying , Wang Mujiangshan
Published: December 2019

Connectivity plays an important role in measuring the fault tolerance of interconnection networks. As a topology structure of interconnection networks, the m-ary n-dimensional hypercube [Formula: see text] has many good properties. In this paper, we prove, by elementary method, that [Formula: see text] is tightly [Formula: see text] super connected [Formula: see text] and super edge-connected [Formula: see text].
LOW-FREQUENCY VOLATILITY AND MACROECONOMIC DYNAMICS: CONVENTIONAL VERSUS ISLAMIC STOCK MARKETS
Authors: KIM HONG-BAE , SOHEL AZAD A.S.M.
Published: December 2019

This study investigates the relationship between macroeconomic risk and low-frequency volatility of conventional and Islamic stock markets from around the world. Using a panel of 36 countries, representing developed, emerging and Islamic countries for the period from 2000 to 2016, the study finds that low-frequency market volatility is lower for Islamic countries and, markets with more number of listed companies, higher market capitalization relative to GDP and larger variability in industrial production. The study also finds that low-frequency component of volatility is greater when the macroeconomic factors of GDP, unemployment, short-term interest rates, inflation, money supply and foreign exchange rates are more volatile. The empirical results are robust to various alternative specifications and split sample analyses. The findings imply that religiosity has an influence on the correction of market volatility and investors may consider the Islamic stocks to diversify their risks.
Performance of Bridges Isolated with Sliding-Lead Rubber Bearings Subjected to Near-Fault Earthquakes
Authors: Zheng Wenzhi , Wang Hao , Hao Hong , Bi Kaiming , Shen Huijun
Published: December 2019

This paper investigates the seismic performance of bridges installed with a sliding-lead rubber bearing (LRB) isolation system subjected to near-fault earthquakes. A three-span continuous bridge isolated with sliding-LRB system is used as an example. Nonlinear time history analyses are conducted to investigate the sensitivity effects of isolation period, friction coefficient and sliding displacement limit on the bridge responses. The responses of the sliding-LRB system are compared with those of the conventional LRB system. The results show that the base forces of the piers can be reduced by employing proper friction coefficients. However, the residual displacement of the sliding-LRB system may be larger compared with that of the conventional LRB system. To overcome this disadvantage, an improved solution to reduce the residual displacement is proposed with its effectiveness investigated. It was also demonstrated that the residual displacement and peak displacement can be effectively reduced by employing the shape memory alloy devices in the sliding-LRB system without significantly increasing the base forces.
Algebraic constructions of rotated unimodular lattices and direct sum of Barnes–Wall lattices
Authors: Strapasson João Eloir , Ferrari Agnaldo José , Jorge Grasiele Cristiane , Costa Sueli Irene Rodrigues
Published: December 2019

In this paper, we construct some families of rotated unimodular lattices and rotated direct sum of Barnes–Wall lattices [Formula: see text] for [Formula: see text] and [Formula: see text] via ideals of the ring of the integers [Formula: see text] for [Formula: see text] and [Formula: see text]. We also construct rotated [Formula: see text] and [Formula: see text]-lattices via [Formula: see text]-submodules of [Formula: see text]. Our focus is on totally real number fields since the associated lattices have full diversity and then may be suitable for signal transmission over both Gaussian and Rayleigh fading channels. The minimum product distances of such constructions are also presented here.
Global Diffusion of Innovation during the Fourth Industrial Revolution: The Case of Additive Manufacturing or 3D Printing
Authors: Steenhuis Harm-Jan , Fang Xin , Ulusemre Tolga
Published: December 2019

Additive manufacturing can be considered an innovative and high-technology and one of its characteristics is that it has limited dependency on the location. The purpose of this study is to examine this aspect by investigation how additive manufacturing is spreading globally. The focus is on established manufacturers of industrial additive manufacturing machines. It was found that the early-stage diffusion of this technology is primarily in advanced economies. Furthermore, many of the currently established companies that manufacture industrial 3D printers come from already existing companies that expanded into AM or that led to spin-off companies. The complexity of AM which requires expert knowledge across a range of fields may be the key reason for this finding. Recommendations for further research are provided.
Steady state charge conduction through solution processed liquid crystalline lanthanide bisphthalocyanine films
Authors: Pal Chandana , Chambrier Isabelle , Cammidge Andrew N. , Sharma A. K. , Ray Asim K.
Published: December 2019

In-plane electrical characteristics of non-peripherally octyl(C[Formula: see text]H[Formula: see text]- and hexyl(C[Formula: see text]H[Formula: see text]-substituted liquid crystalline (LC) double decker lanthanide bisphthalocyanine (LnPc[Formula: see text] complexes with central metal ions lutetium (Lu), and gadolinium (Gd) have been measured in thin film formulations on interdigitated gold (Au) electrodes for the applied voltage ([Formula: see text] range of [Formula: see text]. The conduction mechanism is found to be Ohmic within the bias of [Formula: see text] while the bulk limited Poole–Frenkel mechanism is responsible for the higher bias. The compounds show individual characteristics depending on the central metal ions, substituent chain lengths and their mesophases. Values of 67.55 [Formula: see text]cm[Formula: see text] and 42.31 [Formula: see text]cm[Formula: see text] have been obtained for room temperature in-plane Ohmic conductivity of as-deposited octyl lutetium (C[Formula: see text]LuPc[Formula: see text] and hexyl gadolinium (C[Formula: see text]GdPc[Formula: see text] films, respectively while C[Formula: see text]GdPc[Formula: see text] films exhibit nearly two orders of magnitude smaller conductivity. On annealing at 80[Formula: see text]C, Ohmic conductivities of C[Formula: see text]LuPc[Formula: see text] and C[Formula: see text]GdPc[Formula: see text] are found to have increased but the conductivity of C[Formula: see text]GdPc[Formula: see text] decreased by more than one order of magnitude to 1.5 [Formula: see text]cm[Formula: see text]. For physical interpretation of the charge transport behavior of these three molecules, their UV-vis optical absorption spectra in the solution and in as-deposited and annealed solid phases and atomic force microscopy study have been performed. It is believed that both orientation and positional reorganizations are responsible, depending upon the size of the central ion and side chain length.
PERCEPTIONS AND ACCEPTANCE OF CCUS ENVIRONMENTAL RISK ASSESSMENT, BY EXPERTS AND GOVERNMENT OFFICERS, IN CHINA
Authors: LIU GUIZHEN , CAI BOFENG , LI QI , LEAMON GREGORY , CAO LIBIN , ZHOU YING
Published: December 2019

In May 2017, Department of Science, Technology and Standards, MEP, China held the first training conference of “2017 CCUS environmental risk assessment technology”. After the conference, specially designed questionnaires were sent to the participants so as to collect the professional opinions to improve the guideline in the next revision. Basic information of participants, knowledge of capture, utilization and geological storage (CCUS), and attitude to the CCUS environmental risk are contained in the questionnaires. The 82 questionnaires were issued to the participants, and 77 valid questionnaires were collected with the response rate of 93.9%. According to the data mining, (a) nearly one third of the participants had not heard of the CCUS before the training; (b) the attitude to CCUS environmental impact and risk is influenced by the knowledge of CCUS; (c) the severities of the three aspects of capture component are medium; (d) for onshore CCUS projects, underground water, atmosphere, soil, and human health were considered the highest sensitivity receptors; (e) the enterprises were very concerned of the CCUS environmental management policies, three most important policies were conducting environmental monitoring across the whole chain, clarifying the environmental management responsibilities, and establishing emergency plans for environmental accidents. The result of this survey would provide the guidance for the improvement of the technical guideline which planned to be released during the official version in 2020.
Algorithm 1002
Authors: Kara Gökçehan , Özturan Can
Published: December 2019

The maximum flow problem is one of the most common network flow problems. This problem involves finding the maximum possible amount of flow between two designated nodes on a network with arcs having flow capacities. The push-relabel algorithm is one of the fastest algorithms to solve this problem. We present a shared memory parallel push-relabel algorithm. Graph coloring is used to avoid collisions between threads for concurrent push and relabel operations. In addition, excess values of target nodes are updated using atomic instructions to prevent race conditions. The experiments show that our algorithm is competitive for wide graphs with low diameters. Results from three different data sets are included, computer vision problems, DIMACS challenge problems, and KaHIP partitioning problems. These are compared with existing push-relabel and pseudoflow implementations. We show that high speedup rates are possible using our coloring based parallelization technique on sparse networks. However, we also observe that the pseudoflow algorithm runs faster than the push-relabel algorithm on dense and long networks.
VISE
Authors: Usman Mahmud Ahmed , Antonacopoulos Apostolos
Published: December 2019

This article presents VISE, an interface that enables VIsual Search and Exploration across collections of approximately 836,000 museum objects extracted from the websites of the National Museums Scotland and the Rijksmuseum in the Netherlands. VISE provides an interactive visual summary of information relating to the museum to address online users with no domain knowledge challenges of exploring large museum collection. User satisfaction evaluation was conducted to measure the user satisfaction level for using VISE as the interface for search and exploration of information from large museum collection when compared to non-visual search interface. The evaluation of the visual interface revealed that users are more satisfied and attracted to explore museum objects via VISE than via the system with no visual search interface. Users with little or no domain knowledge find it easier to explore collections and find objects of interest while using VISE in contrast to the system with no visual interface.
A Wolfe Line Search Algorithm for Vector Optimization
Authors: Lucambio Pérez L. R. , Prudente L. F.
Published: December 2019

In a recent article, Lucambio Pérez and Prudente extended the Wolfe conditions for the vector-valued optimization. Here, we propose a line search algorithm for finding a step size satisfying the strong Wolfe conditions in the vector optimization setting. Well definedness and finite termination results are provided. We discuss practical aspects related to the algorithm and present some numerical experiments illustrating its applicability. Codes supporting this article are written in Fortran 90 and are freely available for download.
A Practical Guide for the Effective Evaluation of Twitter User Geolocation
Authors: Mourad Ahmed , Scholer Falk , Magdy Walid , Sanderson Mark
Published: December 2019

Geolocating Twitter users—the task of identifying their home locations—serves a wide range of community and business applications such as managing natural crises, journalism, and public health. Many approaches have been proposed for automatically geolocating users based on their tweets; at the same time, various evaluation metrics have been proposed to measure the effectiveness of these approaches, making it challenging to understand which of these metrics is the most suitable for this task. In this article, we propose a guide for a standardized evaluation of Twitter user geolocation by analyzing 15 models and two baselines in a controlled experimental setting. Models are evaluated using 10 metrics over four geographic granularities. We use rank correlations to assess the effectiveness of these metrics.

Our results demonstrate that the choice of effectiveness metric can have a substantial impact on the conclusions drawn from a geolocation system experiment, potentially leading experimenters to contradictory results about relative effectiveness. We show that for general evaluations, a range of performance metrics should be reported, to ensure that a complete picture of system effectiveness is conveyed. Given the global geographic coverage of this task, we specifically recommend evaluation at micro vs. macro levels to measure the impact of the bias in distribution over locations. Although a lot of complex geolocation algorithms have been applied in recent years, a majority class baseline is still competitive at coarse geographic granularity. We propose a suite of statistical analysis tests, based on the employed metric, to ensure that the results are not coincidental.
1
Space-Time Drift Point Detection in Mobility Patterns
Authors: Souza Roberto C. S. N. P. , Oliveira Derick M. , Brito Denise E. F. de , Assunção Renato M. , Jr. Wagner Meira
Published: December 2019

Location-aware information is now commonplace, as the ubiquity and pervasiveness of technology enabled its generation and storage at large scale. These data constitute a rich representation of entities’ whereabouts and behavior as they move on the map. Although several studies reported considerable predictability of such mobility patterns, several factors may impose significant changes on moving behavior. Being able to detect these changes can benefit several applications. In this article, we formalize and address the problem of detecting mobility drifts in mobility patterns. This problem is particularly challenging due to the noisy and incomplete nature of the data. We design non-parametric tests and present two algorithms to detect mobility drifts when the putative drift point is known in advance and there is no previous knowledge about the existence of potential changes, and we need to search for the most likely drift point rigorously. To evaluate our algorithms, we perform an extensive experimental study with real-world data coming from a variety of scenarios, such as geo-tagged social media data and GPS traces of connected vehicles. The results show the effectiveness of our algorithms, being able to identify existing drift points on spatial mobility patterns correctly.
Events
Authors: Rovatsos Michael
Published: December 2019

This section features information about upcoming events relevant to the readers of AI Matters, including those supported by SIGAI. We would love to hear from you if you are are organizing an event and would be interested in cooperating with SIGAI. For more information about conference support visit sigai.acm.org/activities/requesting_sponsor-ship.html.
AI education matters
Authors: Guerzhoy Michael , Zhang Lisa , Noarov Georgy
Published: December 2019

Fake news is a salient societal issue, the subject of much recent academic research, and, as of 2019, a ubiquitous catchphrase.
Considerations for AI fairness for people with disabilities
Authors: Trewin Shari , Basson Sara , Muller Michael , Branham Stacy , Treviranus Jutta , Gruen Daniel , Hebert Daniel , Lyckowski Natalia , Manser Erich
Published: December 2019

In society today, people experiencing disability can face discrimination. As artificial intelligence solutions take on increasingly important roles in decision-making and interaction, they have the potential to impact fair treatment of people with disabilities in society both positively and negatively. We describe some of the opportunities and risks across four emerging AI application areas: employment, education, public safety, and healthcare, identified in a workshop with participants experiencing a range of disabilities. In many existing situations, non-AI solutions are already discriminatory, and introducing AI runs the risk of simply perpetuating and replicating these flaws. We next discuss strategies for supporting fairness in the context of disability throughout the AI development lifecycle. AI systems should be reviewed for potential impact on the user in their broader context of use. They should offer opportunities to redress errors, and for users and those impacted to raise fairness concerns. People with disabilities should be included when sourcing data to build models, and in testing, to create a more inclusive and robust system. Finally, we offer pointers into an established body of literature on human-centered design processes and philosophies that may assist AI and ML engineers in innovating algorithms that reduce harm and ultimately enhance the lives of people with disabilities.
An Analysis of the Consequences of the General Data Protection Regulation on Social Network Research
Authors: Kotsios Andreas , Magnani Matteo , Vega Davide , Rossi Luca , Shklovski Irina
Published: December 2019

This article examines the principles outlined in the General Data Protection Regulation in the context of social network data. We provide both a practical guide to General Data Protection Regulation--compliant social network data processing, covering aspects such as data collection, consent, anonymization, and data analysis, and a broader discussion of the problems emerging when the general principles on which the regulation is based are instantiated for this research area.
On the Role of Clustering in Personalized PageRank Estimation
Authors: Vial Daniel , Subramanian Vijay
Published: December 2019

Personalized PageRank (PPR) is a measure of the importance of a node from the perspective of another (we call these nodes the
target
and the
source
, respectively). PPR has been used in many applications, such as offering a Twitter user (the source) recommendations of whom to follow (targets deemed important by PPR); additionally, PPR has been used in graph-theoretic problems such as community detection. However, computing PPR is infeasible for large networks like Twitter, so efficient estimation algorithms are necessary.

In this work, we analyze the relationship between PPR estimation complexity and clustering. First, we devise algorithms to estimate PPR for many source/target pairs. In particular, we propose an enhanced version of the existing single pair estimator Bidirectional-PPR that is more useful as a primitive for many pair estimation. We then show that the common underlying graph can be leveraged to efficiently and jointly estimate PPR for many pairs rather than treating each pair separately using the primitive algorithm. Next, we show the complexity of our joint estimation scheme relates closely to the degree of clustering among the sources and targets at hand, indicating that estimating PPR for many pairs is easier when clustering occurs. Finally, we consider estimating PPR when several machines are available for parallel computation, devising a method that leverages our clustering findings, specifically the quantities computed
in situ
, to assign tasks to machines in a manner that reduces computation time. This demonstrates that the relationship between complexity and clustering has important consequences in a practical distributed setting.
A Framework for Allocating Server Time to Spot and On-Demand Services in Cloud Computing
Authors: Wu Xiaohu , Pellegrini Francesco De , Gao Guanyu , Casale Giuliano
Published: December 2019

Cloud computing delivers value to users by facilitating their access to servers at any time period needed. An approach is to provide both on-demand and spot services on shared servers. The former allows users to access servers on demand at a fixed price and users occupy different time periods on servers. The latter allows users to bid for the remaining unoccupied time periods via dynamic pricing; however, without appropriate design, such time periods may be arbitrarily short since on-demand users arrive randomly. This is also the current service model adopted by Amazon Elastic Cloud Compute. In this article, we provide the first integral framework for sharing time on servers between on-demand and spot services while optimally pricing spot service. It guarantees that on-demand users can get served quickly while spot users can stably use servers for a properly long period once accepted, which is a key feature in making both on-demand and spot services accessible. Simulation results show that, by complementing the on-demand market with a spot market, a cloud provider can improve revenue by up to 461.5%. The framework is designed under assumptions that are met in real environments. It is a new tool that other cloud operators can use to quantify the advantage of a hybrid spot and on-demand service, making the case for eventually integrating this service model into their own infrastructures.
FloatX
Authors: Flegar Goran , Scheidegger Florian , Novaković Vedran , Mariani Giovani , Tomás Andrés E. , Malossi A. Cristiano I. , Quintana-Ortí Enrique S.
Published: December 2019

We present FloatX (Float eXtended), a C
++
framework to investigate the effect of leveraging customized floating-point formats in numerical applications. FloatX formats are based on binary IEEE 754 with smaller significand and exponent bit counts specified by the user. Among other properties, FloatX facilitates an incremental transformation of the code, relies on hardware-supported floating-point types as back-end to preserve efficiency, and incurs no storage overhead. The article discusses in detail the design principles, programming interface, and datatype casting rules behind FloatX. Furthermore, it demonstrates FloatX’s usage and benefits via several case studies from well-known numerical dense linear algebra libraries, such as BLAS and LAPACK; the Ginkgo library for sparse linear systems; and two neural network applications related with image processing and text recognition.
Common Vulnerabilities Enumeration (CVE), Common Weakness Enumeration (CWE), and Common Quality Enumeration (CQE)
Authors: Martin Bob
Published: December 2019

PDF of Powerpoint Slides
Approaches to Cyber-Resilience through Language System Design
Authors: Wheeler David A.
Published: December 2019

Software doesn't do what users wish due to defects, including security vulnerabilities Especially focus on vulnerabilities Defect categories for our purposes: Unintentional defects Security-related defects Non-security-related defects Intentional defects from malicious individual or subversion appearing to be from individual Need to help organization counter underhanded code Malicious organization: Hard to deal with Organization's goal & might not be considered defects Mechanisms to support independent review can help