bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Hypothermia in the Emergency Department on the Outcome of Trauma Patients: A Cross-Sectional Analysis
Authors: Hsieh Ting-Min , Kuo Pao-Jen , Hsu Shiun-Yuan , Chien Peng-Chen , Hsieh Hsiao-Yun , Hsieh Ching-Hua
Published: August 2018

This study aimed to assess whether hypothermia is an independent predictor of mortality in trauma patients in the condition of defining hypothermia as body temperatures of <36 °C. Data of all hospitalized adult trauma patients recorded in the Trauma Registry System at a level I trauma center between 1 January 2009 and 12 December 2015 were retrospectively reviewed. A multivariate logistic regression analysis was performed in order to identify factors related to mortality. In addition, hypothermia and normothermia were defined as temperatures <36 °C and from 36 °C to 38 °C, respectively. Propensity score-matched study groups of hypothermia and normothermia patients in a 1:1 ratio were grouped for mortality assessment after adjusting for potential confounders such as age, sex, preexisting comorbidities, and injury severity score (ISS). Of 23,705 enrolled patients, a total of 401 hypothermic patients and 13,368 normothermic patients were included in this study. Only 3.0% of patients had hypothermia upon arrival at the emergency department (ED). Compared to normothermic patients, hypothermic patients had a significantly higher rate of abbreviated injury scale (AIS) scores of ≥3 in the head/neck, thorax, and abdomen and higher ISS. The mortality rate in hypothermic patients was significantly higher than that in normothermic patients (13.5% vs. 2.3%, odds ratio (OR): 6.6, 95% confidence interval (CI): 4.86–9.01, p < 0.001). Of the 399 well-balanced propensity score-matched pairs, there was no significant difference in mortality (13.0% vs. 9.3%, OR: 1.5, 95% CI: 0.94–2.29, p = 0.115). However, multivariate logistic regression analysis revealed that patients with low body temperature were significantly associated with the mortality outcome. This study revealed that low body temperature is associated with the mortality outcome in the multivariate logistic regression analysis but not in the propensity score matching (PSM) model that compared patients with hypothermia defined as body temperatures of <36 °C to those who had normothermia. These contradicting observations indicated the limitation of the traditional definition of body temperature for the diagnosis of hypothermia. Prospective randomized control trials are needed to determine the relationship between hypothermia following trauma and the clinical outcome.
Association of Bisphenol A Exposure with LINE-1 Hydroxymethylation in Human Semen
Authors: Tian Youping , Zhou Xiaoyu , Miao Maohua , Li De-kun , Wang Ziliang , Li Runsheng , Liang Hong , Yuan Wei
Published: August 2018

Bisphenol A (BPA), an exogenous endocrine-disrupting chemical, has been shown to alter DNA methylation. However, little information is available about the effect of BPA exposure on DNA hydroxymethylation in humans. The objective of the present study was to examine whether BPA exposure was associated with DNA hydroxymethylation in human semen samples. We measured urine BPA levels and LINE-1 hydroxymethylation in 158 male factory workers selected from an occupational cohort study conducted in China between 2004 and 2008. Among them, there were 72 male workers with occupational BPA exposure (BPA-exposed group) and 86 male workers without occupational BPA exposure (unexposed group). Multivariate linear regression models were used to examine the association of exposure to BPA with LINE-1 hydroxymethylation. LINE-1 was more highly hydroxymethylated in the BPA-exposed group than in the unexposed group (median 12.97% vs. 9.68%, respectively; p < 0.05), after adjusting for the potential confounders. The medians of 5-hydroxymethylcytosine (5hmC) generally increased with increasing urine BPA levels: 8.79%, 12.16%, 11.53%, and 13.45%, for undetected BPA and corresponding tertiles for the detected BPA, respectively. After analysis using data at individual level, our findings indicated that BPA exposure was associated with alterations of sperm LINE-1 hydroxymethylation, which might have implications for understanding the mechanisms underlying BPA-induced adverse effects on male reproductive function.
Analysis of Surface Extraction Methods Based on Gradient Operators for Computed Tomography in Metrology Applications
Authors: Ontiveros Sinué , Jiménez Roberto , Yagüe-Fabra José A. , Torralba Marta
Published: August 2018

Among the multiple factors influencing the accuracy of Computed Tomography measurements, the surface extraction process is a significant contributor. The location of the surface for metrological applications is generally based on the definition of a gray value as a characteristic of similarity to define the regions of interest. A different approach is to perform the detection or location of the surface based on the discontinuity or gradient. In this paper, an adapted 3D Deriche algorithm based on gradient information is presented and compared with a previously developed adapted Canny algorithm for different surface types. Both algorithms have been applied to nine calibrated workpieces with different geometries and materials. Both the systematic error and measurement uncertainty have been determined. The results show a significant reduction of the deviations obtained with the Deriche-based algorithm in the dimensions defined by flat surfaces.
A Mini-System Integrated with Metal-Oxide-Semiconductor Sensor and Micro-Packed Gas Chromatographic Column
Authors: Sun Jianhai , Geng Zhaoxin , Xue Ning , Liu Chunxiu , Ma Tianjun
Published: August 2018

In this work, a mini monitoring system integrated with a microfabricated metal oxide array sensor and a micro packed gas chromatographic (GC) column was developed for monitoring environmental gases. The microfabricated packed GC column with a 1.6 m length was used to separate the environmental gas, and the metal oxide semiconductor (MOS) array sensor, fabricated with nano-sized SnO-SnO2 sensitive materials, was able to effectively detect each component separated by GC column. The results demonstrate that the monitoring system can detect environmental gas with high precision.
Nutrient Intake and Physical Exercise Significantly Impact Physical Performance, Body Composition, Blood Lipids, Oxidative Stress, and Inflammation in Male Rats
Authors: Bloomer Richard J. , Schriefer John Henry M. , Gunnels Trint A. , Lee Sang-Rok , Sable Helen J. , Van der Merwe Marie , Buddington Randal K. , Buddington Karyl K.
Published: August 2018

Background: Humans consuming a purified vegan diet known as the "Daniel Fast" realize favorable changes in blood lipids, oxidative stress, and inflammatory biomarkers, with subjective reports of improved physical capacity. Objective: We sought to determine if this purified vegan diet was synergistic with exercise in male rats. Methods: Long–Evans rats (n = 56) were assigned to be exercise trained (+E) by running on a treadmill three days per week at a moderate intensity or to act as sedentary controls with normal activity. After the baseline physical performance was evaluated by recording run time to exhaustion, half of the animals in each group were fed ad libitum for three months a purified diet formulated to mimic the Daniel Fast (DF) or a Western Diet (WD). Physical performance was evaluated again at the end of month 3, and body composition was assessed using dual-energy x-ray absorptiometry. Blood was collected for measurements of lipids, oxidative stress, and inflammatory biomarkers. Results: Physical performance at the end of month 3 was higher compared to baseline for both exercise groups (p < 0.05), with a greater percent increase in the DF + E group (99%) than in the WD + E group (51%). Body fat was lower in DF than in WD groups at the end of month 3 (p < 0.05). Blood triglycerides, cholesterol, malondialdehyde, and advanced oxidation protein products were significantly lower in the DF groups than in the WD groups (p < 0.05). No significant differences were noted in cytokines levels between the groups (p > 0.05), although IL-1β and IL-10 were elevated three-fold and two-fold in the rats fed the WD compared to the DF rats, respectively. Conclusions: Compared to a WD, a purified diet that mimics the vegan Daniel Fast provides significant anthropometric and metabolic benefits to rats, while possibly acting synergistically with exercise training to improve physical performance. These findings highlight the importance of macronutrient composition and quality in the presence of ad libitum food intake.
Maternal and Paternal Caffeine Intake and ART Outcomes in Couples Referring to an Italian Fertility Clinic: A Prospective Cohort
Authors: Ricci Elena , Noli Stefania , Cipriani Sonia , La Vecchia Irene , Chiaffarino Francesca , Ferrari Stefania , Mauri Paola Agnese , Reschini Marco , Fedele Luigi , Parazzini Fabio
Published: August 2018

Caffeine intake, a frequent lifestyle exposure, has a number of biological effects. We designed a cohort study to investigate the relation between lifestyle and assisted reproduction technique (ART) outcomes. From September 2014 to December 2016, 339 subfertile couples referring to an Italian fertility clinic and eligible for ART procedures were enrolled in our study. Sociodemographic characteristics, smoking, and usual alcohol and caffeine consumption in the year prior to ART were recorded. The mean age of participants was 36.6 ± 3.6 years in women and 39.4 ± 5.2 years in men. After oocytes retrieval, 293 (86.4%) underwent implantation, 110 (32.4%) achieved clinical pregnancy, and 82 (24.2%) live birth. Maternal age was the main determinant of ART outcome. In a model including women’s age and college degree, smoking habits, calorie and alcohol intake for both partners, previous ART cycles, and partner’s caffeine intake, we did not observe any association between caffeine intake and ART outcome. Using the first tertile of caffeine intake by women as a reference, the adjusted rate ratio (ARR) for live birth was 1.09 (95% confidence interval (CI) 0.79–1.50) in the second and 0.99 (95% CI 0.71–1.40) in the third tertiles. In conclusion, a moderate caffeine intake by women and men in the year prior to the ART procedure was not associated with negative ART outcomes.
Embedding Carbon Dots in Superabsorbent Polymers for Additive Manufacturing
Authors: Zhou Yiqun , Mintz Keenan J. , Oztan Cagri Y. , Hettiarachchi Sajini D. , Peng Zhili , Seven Elif S. , Liyanage Piumi Y. , De La Torre Sabrina , Celik Emrah , Leblanc Roger M.
Published: August 2018

A type of orange carbon dots (O-CDs) synthesized via an ultrasonication route with citric acid and 1,2-phenylenediamine as precursors was embedded into sodium polyacrylate (SPA) as the ink for 3D printing. Characterizations of these spherical O-CDs revealed an ultra-small size (~2 nm) and excitation-independent, but solvent dependent, emission. The O-CDs were evenly distributed with low degree of aggregation in sodium polyacrylate (SPA), which was achieved due to the property that SPA can absorb water together with O-CDs. The 3D printed photoluminescent objective with the ink revealed a great potential for high yield application of these materials for additive manufacturing. This also represents the first time, bare CDs have been reported as a photoluminescent material in 3D printing, as well as the first time SPA has been reported as a material for 3D printing.
Experimental Study on the Reinforcement Mechanism of Segmented Split Grouting in a Soft Filling Medium
Authors: Li Zhipeng , Li Shucai , Liu Haojie , Zhang Qingsong , Liu Yanan
Published: August 2018

Subsection split grouting technology can effectively improve the grouting efficiency and homogeneity of grouting in a target reinforcement area. It is therefore necessary to clarify the reinforcement mechanism and characteristics of the soft filling medium under the condition of split grouting. A three-dimensional grouting simulation test of segmented split grouting in a soft filling medium was conducted. The distribution characteristics and thicknesses of the grouting veins were obtained under the condition of segmented grouting. The mechanical mechanism of segmented split grouting reinforcement, based on the distribution characteristics of different grouting veins, was revealed. After grouting, a uniaxial compression test and an indoor permeation test were conducted. Based on the method of the region-weighted average, the corresponding permeability coefficient and the elastic modulus of each splitting-compaction region were obtained. The quantitative relationship between the mechanical properties and the impermeability of the soft filling medium before and after grouting was established. The results revealed that three different types of veins were formed as the distance from the grouting holes increased; namely, skeleton veins, cross-grid grouting veins, and parallel dispersed grouting veins. The thicknesses of the grouting veins decreased gradually, whereas the number of grouting veins increased. Moreover, the strikes of the grouting vein exhibited increased randomness. The reinforcement effect of segmental split grouting on soft filling media was mainly confirmed by the skeleton support and compaction. The elastic modulus of the grouting reinforcement solid increased on average by a factor that was greater than 100, and the permeability coefficient decreased on average by a factor that was greater than 40 in the direction of the parallel grouting vein with the most impermeable solid. The research results may be helpful in the investigation of the split grouting reinforcement mechanism under the condition of segmented grouting.
Dynamic Sequence Specific Constraint-Based Modeling of Cell-Free Protein Synthesis
Authors: Dai David , Horvath Nicholas , Varner Jeffrey
Published: August 2018

Cell-free protein expression has emerged as an important approach in systems and synthetic biology, and a promising technology for personalized point of care medicine. Cell-free systems derived from crude whole cell extracts have shown remarkable utility as a protein synthesis technology. However, if cell-free platforms for on-demand biomanufacturing are to become a reality, the performance limits of these systems must be defined and optimized. Toward this goal, we modeled E. coli cell-free protein expression using a sequence specific dynamic constraint-based approach in which metabolite measurements were directly incorporated into the flux estimation problem. A cell-free metabolic network was constructed by removing growth associated reactions from the iAF1260 reconstruction of K-12 MG1655 E. coli. Sequence specific descriptions of transcription and translation processes were then added to this metabolic network to describe protein production. A linear programming problem was then solved over short time intervals to estimate metabolic fluxes through the augmented cell-free network, subject to material balances, time rate of change and metabolite measurement constraints. The approach captured the biphasic cell-free production of a model protein, chloramphenicol acetyltransferase. Flux variability analysis suggested that cell-free metabolism was potentially robust; for example, the rate of protein production could be met by flux through the glycolytic, pentose phosphate, or the Entner-Doudoroff pathways. Variation of the metabolite constraints revealed central carbon metabolites, specifically upper glycolysis, tricarboxylic acid (TCA) cycle, and pentose phosphate, to be the most effective at training a predictive model, while energy and amino acid measurements were less effective. Irrespective of the measurement set, the metabolic fluxes (for the most part) remained unidentifiable. These findings suggested dynamic constraint-based modeling could aid in the design of cell-free protein expression experiments for metabolite prediction, but the flux estimation problem remains challenging. Furthermore, while we modeled the cell-free production of only a single protein in this study, the sequence specific dynamic constraint-based modeling approach presented here could be extended to multi-protein synthetic circuits, RNA circuits or even small molecule production.
Bank Stress Testing: A Stochastic Simulation Framework to Assess Banks’ Financial Fragility †
Authors: Montesi Giuseppe , Papiro Giovanni
Published: August 2018

We present a stochastic simulation forecasting model for stress testing that is aimed at assessing banks’ capital adequacy, financial fragility, and probability of default. The paper provides a theoretical presentation of the methodology and the essential features of the forecasting model on which it is based. Also, for illustrative purposes and to show in practical terms how to apply the methodology and the types of outcomes and analysis that can be obtained, we report the results of an empirical application of the methodology proposed to the Global Systemically Important Banks (G-SIB) banks. The results of the stress test exercise are compared with the results of the supervisory stress tests performed in 2014 by the Federal Reserve and EBA/ECB.
A Landscape-Scale Adjoining Conservation (LAC) Approach for Efficient Habitat Expansion: The Case of Changbai Mountain, Northeast China
Authors: Bai Jianwei , Tang Lina , Wang Qingchun , Li Fengri
Published: August 2018

The biodiversity crisis and ecosystem degradation caused by habitat destruction and human activities can be reduced by organizing protected areas. However, many protected areas currently take the form of “green islands,” which has led to serious habitat isolation in many places. We thus introduce herein a landscape-scale adjoining conservation (LAC) approach for the protection and restoration of ecosystems across the boundaries between protected areas and surrounding non-protected areas. The strategy of the LAC approach is to effectively expand conservation areas by connecting isolated areas of important ecosystems or habitats outside of protected areas. The methodology of the LAC approach involves integrated analyses that consider both habitat quality and landscape patterns. Forest-habitat quality is characterized by species composition and stand structure, and habitat connectivity is quantified by the max patch area of habitat and total habitat area. The focal statistic is useful for examining habitat clumps that result from landscape fragmentation. As a case study, we apply the LAC approach to adjoining restoration of broadleaf Korean pine mixed forest on the Changbai Mountain in northeastern China. We developed a metric called the Restoration Efficiency of Landscape Expansion (RELE) to evaluate the LAC approach. The results indicate that a minimal restoration effort can produce significant effects in terms of the expansion of contiguous habitat, as quantified by RELE.
The Small World of the Alternative Food Network
Authors: Brinkley Catherine
Published: August 2018

This research offers the first use of graph theory mathematics in social network analysis to explore relationships built through an alternative food network. The local food system is visualized using geo-social data from 110 farms and 224 markets around Baltimore County, Maryland, with 699 connections between them. Network behavior is explored through policy document review and interviews. The findings revealed a small-world architecture, with system resiliency built-in by diversified marketing practices at central nodes. This robust network design helps to explain the long-term survival of local food systems despite the meteoric rise of global industrial food supply chains. Modern alternative food networks are an example of a movement that seeks to reorient economic power structures in response to a variety of food system-related issues not limited to consumer health but including environmental impacts. Uncovering the underlying network architecture of this sustainability-oriented social movement helps reveal how it weaves systemic change more broadly. The methods used in this study demonstrate how social values, social networks, markets, and governance systems embed to transform both physical landscapes and human bodies. Network actors crafted informal policy reports, which were directly incorporated in state and local official land-use and economic planning documents. Community governance over land-use policy suggests a powerful mechanism for further localizing food systems.
Online and Offline Communities in the Sharing Economy
Authors: Vaskelainen Taneli , Piscicelli Laura
Published: August 2018

The online community is crucial to sharing economy platforms because without it, no transactions can take place. Online communities have been studied extensively, but so far, little attention has been paid to how they link to different offline communities, such as geographic (e.g., neighborhoods) and relational communities (e.g., friends and colleagues). In this study, we address this gap by examining the importance of communities to the users and the entrepreneurs of the goods-sharing platform Ecomodo. We conduct a qualitative content analysis of archival and interview data to uncover the importance of different communities and the relationships among them. We discover that the platform design aimed to facilitate lending and borrowing in relational communities. However, geographic communities were more important to the users since most of them joined the platform to be acquainted with their neighbors. We also find that the platform entrepreneurs underestimated the behavioral changes needed to use the platform. The producers were not used to asking for money to lend their possessions, and it was difficult to teach consumers to borrow instead of buying. We use these findings to offer recommendations to practitioners and discuss some avenues for further research.
Green Production Planning and Control Model with ABC under Industry 4.0 for the Paper Industry
Authors: Tsai Wen-Hsien , Lai Shang-Yu
Published: August 2018

In the last 20 years, with the liberalization of the economy, and the trend of industrial globalization, people have gradually paid more attention to environmental protection. With the tremendous advances in information technology, enterprises facing such a severe impact on the business operations, business administrative models must be innovative and adaptable in order to survive and flourish. The paper industry is not only a highly polluting industry, but in the case of long-term overcapacity, the price of paper products is often suppressed, which lowers profitability. The purpose of this study, which is based on the production data of a paper company, is to pose a mathematical programming decision model which integrates green manufacturing technologies, activity-based costing (ABC), and the theory of constraint (TOC); this model should assist in preparing the best production plans, and achieve the optimal profitable product mix. In addition, this study also proposes that the most popular related technologies developed by Industry 4.0 be applied to production control in recent years in order to enhance production efficiency and quality. The findings of this study should contribute to the improvement of the competitiveness of the paper industry, and provide insights into the value of an integrated mathematical programming model applied for product-mix decision. At the same time, we have also applied the related technologies developed by Industry 4.0 to machine maintenance and quality control in manufacturing workshops. With its tremendous benefits, we can actively arouse the industry’s understanding of, and attention to, Industry 4.0, thereby increasing the interest in industrial 4.0-related technology investments.
A Neutrosophic Set Based Fault Diagnosis Method Based on Multi-Stage Fault Template Data
Authors: Jiang Wen , Zhong Yu , Deng Xinyang
Published: August 2018

Fault diagnosis is an important issue in various fields and aims to detect and identify the faults of systems, products, and processes. The cause of a fault is complicated due to the uncertainty of the actual environment. Nevertheless, it is difficult to consider uncertain factors adequately with many traditional methods. In addition, the same fault may show multiple features and the same feature might be caused by different faults. In this paper, a neutrosophic set based fault diagnosis method based on multi-stage fault template data is proposed to solve this problem. For an unknown fault sample whose fault type is unknown and needs to be diagnosed, the neutrosophic set based on multi-stage fault template data is generated, and then the generated neutrosophic set is fused via the simplified neutrosophic weighted averaging (SNWA) operator. Afterwards, the fault diagnosis results can be determined by the application of defuzzification method for a defuzzying neutrosophic set. Most kinds of uncertain problems in the process of fault diagnosis, including uncertain information and inconsistent information, could be handled well with the integration of multi-stage fault template data and the neutrosophic set. Finally, the practicality and effectiveness of the proposed method are demonstrated via an illustrative example.
Prospects in Innate Immune Responses as Potential Control Strategies against Non-Primate Lentiviruses
Authors: De Pablo-Maiso Lorena , Doménech Ana , Echeverría Irache , Gómez-Arrebola Carmen , De Andrés Damián , Rosati Sergio , Gómez-Lucia Esperanza , Reina Ramsés
Published: August 2018

Lentiviruses are infectious agents of a number of animal species, including sheep, goats, horses, monkeys, cows, and cats, in addition to humans. As in the human case, the host immune response fails to control the establishment of chronic persistent infection that finally leads to a specific disease development. Despite intensive research on the development of lentivirus vaccines, it is still not clear which immune responses can protect against infection. Viral mutations resulting in escape from T-cell or antibody-mediated responses are the basis of the immune failure to control the infection. The innate immune response provides the first line of defense against viral infections in an antigen-independent manner. Antiviral innate responses are conducted by dendritic cells, macrophages, and natural killer cells, often targeted by lentiviruses, and intrinsic antiviral mechanisms exerted by all cells. Intrinsic responses depend on the recognition of the viral pathogen-associated molecular patterns (PAMPs) by pathogen recognition receptors (PRRs), and the signaling cascades leading to an antiviral state by inducing the expression of antiviral proteins, including restriction factors. This review describes the latest advances on innate immunity related to the infection by animal lentiviruses, centered on small ruminant lentiviruses (SRLV), equine infectious anemia virus (EIAV), and feline (FIV) and bovine immunodeficiency viruses (BIV), specifically focusing on the antiviral role of the major restriction factors described thus far.
Correction of Precipitation Records through Inverse Modeling in Watersheds of South-Central Chile
Authors: Muñoz Enrique , Acuña Mauricio , Lucero Juan , Rojas Ignacio
Published: August 2018

Precipitation is the main input in the water balance of watersheds; therefore, correct estimates are necessary for water resources management and decision making. In south-central Chile there is a low density of precipitation gauges (~1 station/675 km2), most of which are located in low-altitude areas. The spatial distribution of precipitation is, therefore, not properly recorded. In this study an inverse modeling approach is used to estimate the extent to which precipitation amounts must be corrected. Using a lumped water balance model, a factor for correcting precipitation data is calculated for 41 watersheds located in south-central Chile. Then, based on a geo-statistical interpolation, a map for correcting the precipitation amounts is proposed and a validation of these corrections is achieved. The results show that in gently sloping areas, the precipitation records are more representative than in steep mountain areas. In addition, the higher the mountains, the less representative the precipitation records become.
New Insights on Land Surface-Atmosphere Feedbacks over Tropical South America at Interannual Timescales
Authors: Bedoya-Soto Juan Mauricio , Poveda Germán , Sauchyn David
Published: August 2018

We present a simplified overview of land-atmosphere feedbacks at interannual timescales over tropical South America as structural sets of linkages among surface air temperature (T), specific humidity at 925 hPa (q925), volumetric soil water content (Θ), precipitation (P), and evaporation (E), at monthly scale during 1979–2010. Applying a Maximum Covariance Analysis (MCA), we identify the modes of greatest interannual covariability in the datasets. Time series extracted from the MCAs were used to quantify linear and non-linear metrics at up to six-month lags to establish connections among variables. All sets of metrics were summarized as graphs (Graph Theory) grouped according to their highest ENSO-degree association. The core of ENSO-activated interactions is located in the Amazon River basin and in the Magdalena-Cauca River basin in Colombia. Within the identified multivariate structure, Θ enhances the interannual connectivity since it often exhibits two-way feedbacks with the whole set of variables. That is, Θ is a key variable in defining the spatiotemporal patterns of P and E at interannual time-scales. For both the simultaneous and lagged analysis, T activates non-linear associations with q925 and Θ. Under the ENSO influence, T is a key variable to diagnose the dynamics of interannual feedbacks of the lower troposphere and soil interfaces over tropical South America. ENSO increases the interannual connectivity and memory of the feedback mechanisms.
Combining Grey Relational Analysis and a Bayesian Model Averaging Method to Derive Monthly Optimal Operating Rules for a Hydropower Reservoir
Authors: Fang Guohua , Guo Yuxue , Huang Xianfeng , Rutten Martine , Yuan Yu
Published: August 2018

Various regression models are currently applied to derive functional forms of operating rules for hydropower reservoirs. It is necessary to analyze and evaluate the model selecting uncertainty involved in reservoir operating rules for efficient hydropower generation. Moreover, selecting the optimal input variables from a large number of candidates to characterize an output variable can lead to a more accurate operation simulation. Therefore, this paper combined the Grey Relational Analysis (GRA) method and the Bayesian Model Averaging (BMA) method to select input variables and derive the monthly optimal operating rules for a hydropower reservoir. The monthly input variables were first filtered according to the relationship between the preselected output and input variables based on the reservoir optimal deterministic trajectory using GRA. Three models, Particle Swarm Optimization-Least Squares Support Vector Machine (PSO-LSSVM), Adaptive Neural Fuzzy Inference System (ANFIS), and Multiple Linear Regression Analysis (MLRA) model, were further implemented to derive individual monthly operating rules. BMA was applied to determine the final monthly operating rules by analyzing the uncertainty of selecting individual models with different weights. A case study of Xinanjiang Reservoir in China shows that the combination of the two methods can achieve high-efficiency hydropower generation and optimal utilization of water resources.
HST Astrometry in the 30 Doradus Region. II. Runaway Stars from New Proper Motions in the Large Magellanic Cloud
Authors: Platais Imants , Lennon Daniel J. , van der Marel Roeland P. , Bellini Andrea , Sabbi Elena , Watkins Laura L. , Sohn Sangmo T. , Walborn Nolan R. , Bedin Luigi R. , Evans Christopher J. , de Mink Selma E. , Sana Hugues , Herrero Artemio , Langer Norbert , Crowther Paul
Published: August 2018

We present a catalog of relative proper motions for 368,787 stars in the 30 Doradus region of the Large Magellanic Cloud (LMC), based on a dedicated two-epoch survey with the Hubble Space Telescope and supplemented with proper motions from our pilot archival study. We demonstrate that a relatively short epoch difference of three years is sufficient to reach a level of precision of ∼0.1 mas yr−1 or better. A number of stars with relative proper motions exceeding a 3σ error threshold represent a mixture of Milky Way denizens and 18 potential LMC runaway stars. Based upon 183 VFTS OB stars with the best proper motions, we conclude that none of them moves faster than ∼0.3 mas yr−1 in each coordinate—equivalent to ∼70 km s−1. Among the remaining 351 VFTS stars with less accurate proper motions, only one candidate OB runaway can be identified. We rule out any OB star in our sample moving at a tangential velocity exceeding ∼120 km s−1. The most significant result of this study is finding 10 stars over a wide range of masses that appear to have been ejected from the massive star cluster R136 in the tangential plane to angular distances from 35″ out to 407″, equivalent to 8–98 pc. The tangential velocities of these runaways appear to be correlated with apparent magnitude, indicating a possible dependence on the stellar mass. Lastly, a comparison to proper motions from Gaia DR 2 shows that for several relatively bright stars the DR 2 has an unexpected scatter that cannot be accounted for by the formal errors.
A Study of Hα Line Profile Variations in β Lyr
Authors: Ignace Richard , Gray Sharon K. , Magno Macon A. , Henson Gary D. , Massa Derck
Published: August 2018

We examine over 160 archival Hα spectra from the Ritter Observatory for the interacting binary β Lyr obtained between 1996 and 2000. The emission is characteristically double-peaked, but asymmetric, and with an absorption feature that is persistently blueshifted. Using a set of simplifying assumptions, phase varying emission line profiles are calculated for Hα formed entirely in a Keplerian disk, and separately for the line formed entirely from an off-center bipolar flow. However, a dynamic spectrum of the data indicates that the blueshifted feature is not always present, and the data are even suggestive of a drift of the feature in velocity shift. We explore whether a circumbinary envelope, hot spot on the accretion disk, or accretion stream could explain the observations. While none are satisfactory, an accretion stream explanation is somewhat promising.
Investigating the Nature of Late-time High-energy GRB Emission through Joint Fermi/Swift Observations
Authors: Ajello M. , Baldini L. , Barbiellini G. , Bastieri D. , Bellazzini R. , Bissaldi E. , Blandford R. D. , Bonino R. , Bottacini E. , Bregeon J. , Bruel P. , Buehler R. , Cameron R. A. , Caputo R. , Caraveo P. A. , Chiaro G. , Ciprini S. , Cohen-Tanugi J. , Costantin D. , D’Ammando F. , de Palma F. , Di Lalla N. , Di Mauro M. , Di Venere L. , Domínguez A. , Favuzzi C. , Franckowiak A. , Fukazawa Y. , Funk S. , Fusco P. , Gargano F. , Gasparrini D. , Giglietto N. , Giordano F. , Giroletti M. , Green D. , Grenier I. A. , Guiriec S. , Holt C. , Horan D. , Jóhannesson G. , Kocevski D. , Kuss M. , Mura G. La , Larsson S. , Li J. , Longo F. , Loparco F. , Lubrano P. , Magill J. D. , Maldera S. , Manfreda A. , Mazziotta M. N. , Michelson P. F. , Mizuno T. , Monzani M. E. , Morselli A. , Negro M. , Nuss E. , Omodei N. , Orienti M. , Orlando E. , Paliya V. S. , Perkins J. S. , Persic M. , Pesce-Rollins M. , Piron F. , Principe G. , Racusin J. L. , Rainò S. , Rando R. , Razzano M. , Razzaque S. , Reimer A. , Reimer O. , Sgrò C. , Siskind E. J. , Spandre G. , Spinelli P. , Tak D. , Thayer J. B. , Torres D. F. , Tosti G. , Valverde J. , Vogel M. , Wood K.
Published: August 2018

We use joint observations by the Swift X-ray Telescope (XRT) and the Fermi Large Area Telescope (LAT) of gamma-ray burst (GRB) afterglows to investigate the nature of the long-lived high-energy emission observed by Fermi LAT. Joint broadband spectral modeling of XRT and LAT data reveals that LAT nondetections of bright X-ray afterglows are consistent with a cooling break in the inferred electron synchrotron spectrum below the LAT and/or XRT energy ranges. Such a break is sufficient to suppress the high-energy emission so as to be below the LAT detection threshold. By contrast, LAT-detected bursts are best fit by a synchrotron spectrum with a cooling break that lies either between or above the XRT and LAT energy ranges. We speculate that the primary difference between GRBs with LAT afterglow detections and the nondetected population may be in the type of circumstellar environment in which these bursts occur, with late-time LAT detections preferentially selecting GRBs that occur in low wind-like circumburst density profiles. Furthermore, we find no evidence of high-energy emission in the LAT-detected population significantly in excess of the flux expected from the electron synchrotron spectrum fit to the observed X-ray emission. The lack of excess emission at high energies could be due to a shocked external medium in which the energy density in the magnetic field is stronger than or comparable to that of the relativistic electrons behind the shock, precluding the production of a dominant synchrotron self-Compton (SSC) component in the LAT energy range. Alternatively, the peak of the SSC emission could be beyond the 0.1–100 GeV energy range considered for this analysis.
Effect of Upstream ULF Waves on the Energetic Ion Diffusion at the Earth’s Foreshock. II. Observations
Authors: Kis Arpad , Matsukiyo Shuichi , Otsuka Fumiko , Hada Tohru , Lemperger Istvan , Dandouras Iannis , Barta Veronika , Facsko Gabor
Published: August 2018

This study reports observations of energetic ions upstream of the Earth’s quasi-parallel bow shock by Cluster at times when interspacecraft separation distances were large. We analyze two individual upstream ion events during high solar wind velocity conditions to compare the spatial evolution of partial energetic ion densities in front of the Earth’s bow shock along the magnetic field line. Using a bow shock model, we determine the distance of SC1 and SC3 to the bow shock surface parallel to the magnetic field. The CIS-HIA instrument on board Cluster provides partial energetic ion densities in four energy channels between 10 and 32 keV. Using the differences of the partial energetic ion densities observed on SC1 and SC3, and the distances of the spacecraft to the bow shock, we determine the spatial gradient of partial energetic ion densities at various distances from the bow shock. We show, for the first time, that the e-folding distance and the diffusion coefficient of the diffuse ions become unusually small when these ions interact with high-intensity waves generated by a strong field-aligned beam.
Enhanced Rates of Fast Radio Bursts from Galaxy Clusters
Authors: Fialkov Anastasia , Loeb Abraham , Lorimer Duncan R.
Published: August 2018

Fast radio bursts (FRBs) have so far been detected serendipitously across the sky. We consider the possible enhancement in the FRB rate in the direction of galaxy clusters, and compare the predicted rate from a large sample of galaxy clusters with the expected cosmological mean rate. We show that clusters offer better prospects for a blind survey if the faint end of the FRB luminosity function is steep. We find that for a radio telescope with a ∼1 deg2 beam, the best targets would be either nearby clusters such as Virgo, or clusters at intermediate cosmological distances of few hundred Mpc, which offer maximal number of galaxies per beam. We identify several galaxy clusters which are expected to have a significant excess FRB yield compared with the cosmic mean. The two most promising candidates are the Virgo cluster containing 1598 galaxies and is located 16.5 Mpc away and the S 34 cluster, which contains 3175 galaxies and is located at a distance of 486 Mpc.
The SLUGGS Survey: The Inner Dark Matter Density Slope of the Massive Elliptical Galaxy NGC 1407
Authors: Wasserman Asher , Romanowsky Aaron J. , Brodie Jean , Dokkum Pieter van , Conroy Charlie , Villaume Alexa , Forbes Duncan A. , Strader Jay , Alabi Adebusola , Bellstedt Sabine
Published: August 2018

We investigate the dark matter density profile of the massive elliptical galaxy, NGC 1407, by constructing spherically symmetric Jeans models of its field star and globular cluster systems. Two major challenges in such models are the degeneracy between the stellar mass and the dark matter halo profiles, and the degeneracy between the orbital anisotropy of the tracer population and the total mass causing the observed motions. We address the first issue by using new measurements of the mass-to-light ratio profile from stellar population constraints that include a radially varying initial mass function. To mitigate the mass–anisotropy degeneracy, we make use of multiple kinematic tracers, including two subpopulations of globular clusters in addition to the galaxy’s field stars. We create a hierarchical Bayesian model that addresses several often-neglected systematic uncertainties, such as the statistical weight given to various data sets and the adopted distance. After sampling the posterior probability distribution with a Markov chain Monte Carlo method, we find evidence for a central cusp with a log slope of

, with the quantified systematic uncertainty dominated by choice of anisotropy profile. This is lower than expected for dark matter halos that have undergone adiabatic contraction, supporting inferences from gravitational lensing that some process has suppressed the steepening of halos in massive galaxies. We also confirm radially biased orbits for the metal-rich globular clusters and tangentially biased orbits for the metal-poor globular clusters, which remains a puzzling finding for an accretion-dominated halo.
Laboratory Photochemistry of Pyrene Clusters: An Efficient Way to Form Large PAHs
Authors: Zhen Junfeng , Chen Tao , Tielens Alexander G. G. M.
Published: August 2018

In this work, we study the photodissociation processes of small PAH clusters (e.g., pyrene clusters). The experiments are carried out using a quadrupole ion trap in combination with time-of-flight (QIT-TOF) mass spectrometry. The results show that pyrene clusters are converted into larger PAHs under the influence of a strong radiation field. Specifically, pyrene dimer cations (e.g., [C16H10 −C16H9]+ or C32H19
+), will photodehydrogenate and photo-isomerize to fully aromatic cations (PAHs) (e.g., C32H16
+) with laser irradiation. The structure of new formed PAHs and the dissociation energy for these reaction pathways are investigated with quantum chemical calculations. These studies provide a novel efficient evolution routes for the formation of large PAHs in the interstellar medium in a bottom-up process that will counteract the top-down conversion of large PAHs into rings and chains, and provide a reservoir of large PAHs that can be converted into C60 and other fullerenes and large carbon cages.
Production of Silicon on Mass-increasing White Dwarfs: Possible Origin of High-velocity Features in Type Ia Supernovae
Authors: Kato Mariko , Saio Hideyuki , Hachisu Izumi
Published: August 2018

Type Ia supernovae (SNe Ia) often show high-velocity absorption features (HVFs) in their early phase spectra; however, the origin of the HVFs is unknown. We show that a near-Chandrasekhar-mass white dwarf (WD) develops a silicon-rich layer on a carbon–oxygen (CO) core before it explodes as an SN Ia. We calculated the nuclear yields in successive helium shell flashes for 1.0 M
☉, 1.2 M
☉, and 1.35 M
☉ CO WDs accreting helium-rich matter with several mass-accretion rates, ranging from 1 × 10−7 M
☉ yr−1 to 7.5 × 10−7 M
☉ yr−1. For the 1.35 M
☉ WD with the accretion rate of 1.6 × 10−7 M
☉ yr−1, the surface layer developed as helium burning ash and consisted of 40% 24Mg, 33% 12C, 23% 28Si, and a few percent of 20Ne by weight. For a higher mass-accretion rate of 7.5 × 10−7 M
☉ yr−1, the surface layer consisted of 58% 12C, 31% 24Mg, and 0.43% 28Si. For the 1.2 M
☉ WDs, silicon is produced only for lower mass-accretion rates (2% for 1.6 × 10−7 M
☉ yr−1). No substantial silicon (<0.07%) is produced on the 1.0 M
☉ WD independently of the mass-accretion rate. If the silicon-rich surface layer is the origin of Si ii HVFs, its characteristics are consistent with that of mass-increasing WDs. We also discuss possible Ca production on very massive WDs (≳1.38 M
☉).
Extremely Large Extreme-ultraviolet Late Phase Powered by Intense Early Heating in a Non-eruptive Solar Flare
Authors: Dai Yu , Ding Mingde , Zong Weiguo , Yang Kai E.
Published: August 2018

We analyzed and modeled an M1.2 non-eruptive solar flare on 2011 September 9. The flare exhibited a strong late-phase peak of extreme-ultraviolet (EUV) warm coronal emissions (∼3 MK), with peak emission over 1.3 times that of the main flare peak. Multiple flare ribbons are observed, whose evolution indicates a two-stage energy release process. A nonlinear force-free field extrapolation reveals the existence of a magnetic null point, a fan-spine structure, and two flux ropes embedded in the fan dome. Magnetic reconnections involved in the flare are driven by the destabilization and rise of one of the flux ropes. In the first stage, the fast ascending flux rope drives reconnections at the null point and the surrounding quasi-separatrix layer (QSL), while in the second stage, reconnection mainly occurs between the two legs of the field lines stretched by the eventually stopped flux rope. The late-phase loops are mainly produced by the first-stage QSL reconnection, while the second-stage reconnection is responsible for the heating of main flaring loops. The first-stage reconnection is believed to be more powerful, leading to an extremely strong EUV late phase. We find that the delayed occurrence of the late-phase peak is mainly due to the long cooling process of the long late-phase loops. Using the model enthalpy-based thermal evolution of loops, we model the EUV emissions from a late-phase loop. The modeling reveals a peak heating rate of 1.1 erg cm−3 s−1 for the late-phase loop, which is obviously higher than previous values.
First Results of an ALMA Band 10 Spectral Line Survey of NGC 6334I: Detections of Glycolaldehyde (HC(O)CH2OH) and a New Compact Bipolar Outflow in HDO and CS
Authors: McGuire Brett A. , Brogan Crystal L. , Hunter Todd R. , Remijan Anthony J. , Blake Geoffrey A. , Burkhardt Andrew M. , Carroll P. Brandon , van Dishoeck Ewine F. , Garrod Robin T. , Linnartz Harold , Shingledecker Christopher N. , Willis Eric R.
Published: August 2018

We present the first results of a pilot program to conduct an Atacama Large Millimeter Array (ALMA) band 10 spectral line survey of the high-mass star-forming region NGC 6334I. The observations were taken in exceptional weather conditions (0.19 mm precipitable water) with typical system temperatures T
sys < 950 K at ∼890 GHz. A bright, bipolar north–south outflow is seen in HDO and CS emission, driven by the embedded massive protostar MM1B. This has allowed, for the first time, a direct comparison of the thermal water in this outflow to the location of water maser emission from prior 22 GHz Very Large Array observations. The maser locations are shown to correspond to the sites along the outflow cavity walls, where high-velocity gas impacts the surrounding material. We also compare our new observations to prior Herschel Heterodyne Instrument for the Far-infrared (HIFI) spectral line survey data of this field, detecting an order of magnitude more spectral lines (695 versus 65) in the Atacama Large Millimeter/submillimeter Array (ALMA) data. We focus on the strong detections of the complex organic molecule glycolaldehyde (HC(O)CH2OH) in the ALMA data that is not detected in the heavily beam-diluted HIFI spectra. Finally, we stress the need for dedicated THz laboratory spectroscopy to support and exploit future high-frequency molecular line observations with ALMA.