bluuebunny/crossref_metadata_2025 huggingface dataset:
Percutaneous Microwave Ablation of Metastatic Lymph Nodes from Papillary Thyroid Carcinoma: Preliminary Results
Authors: Zhou Wei , Chen Yudong , Zhang Lu , Ni Xiaofeng , Xu Shangyan , Zhan Weiwei
Published: December 2018

Background

Our purpose is to assess the effectiveness and safety of ultrasound‐guided percutaneous microwave ablation (MWA) for lymph node metastases (LNMs) from papillary thyroid carcinomas (PTC).

Methods

In total, 14 patients with recurrent PTC were enrolled in this retrospective study. The vascularity within the ablation zone was evaluated by contrast‐enhanced ultrasonography (CEUS) after MWA. Patients were followed up with measurement of the size and volume of tumor, serum thyroglobulin, and clinical evaluation at 7 days, 1, 3, 6 months, and every 6 months thereafter.

Results

Twenty‐one LNMs were confirmed by biopsy and successfully treated by MWA in a single session. No incomplete ablation was detected by CEUS after treatment. The average largest diameter and volume of the tumors were reduced from 10.1 ± 4.7 mm (range, 3.1–20.0 mm) and 291.9 ± 255.6 mm3 (range, 11.6–766.6 mm3) to 0.9 ± 1.6 mm (range, 0–4.1 mm; p < 0.05) and 4.0 ± 9.0 mm3 (range, 0–31.6 mm3; p < 0.05) at the final follow‐up. Neither progression of treated tumors nor newly suspicious LNMs could be detected after treatment. The overall complication rate was 7.1% (1/14).

Conclusions

Ultrasound‐guided MWA can effectively control LNMs from PTC, but it is less safe for tumors in the central compartment. MWA may become an alternative therapy in selected PTC patients, who were ineligible or refused to undergo repeated neck explorations.
EDITORIAL: YES, WE CANN!
Authors: Wüthrich Mario V. , Merz Michael
Published: December 2018

The aim of this editorial is to increase the acceptance of neural net modeling in the actuarial community. Neural nets may substantially improve classical actuarial models, if appropriately applied. We illustrate this on a toy example but, in fact, this should be understood as a universal concept. Assume we have a classical regression problem where the distribution of a response Y = Y(x) can be described by covariates x. A common actuarial problem is to determine the premium $\mu ({\textit{\textbf{x}}}) = {\mathbb E} [Y({\textit{\textbf{x}}})]$ as a function of the covariates x. Actuaries have developed excellent skills to solve such problems through finding appropriate regression functions x ↦ μ(x). This editorial shows how these skills can further be improved using the toolbox of neural nets.
Effect of dietary reduction and sex class on nutrient digestibility, nitrogen balance, excreted purine derivatives and infrared thermography of hair lambs
Authors: Pereira E. S. , Campos A. C. N. , Heinzen E. L. , Barbosa Filho J. A. D. , Carneiro M. S. S. , Fernandes D. R. , Bezerra L. R. , Oliveira R. L.
Published: December 2018

An experiment was conducted to evaluate whether dietary reduction and sex class affect nutrient intake, digestibility, purine derivative (PD) excretion and heat tolerance coefficient in lambs. Thirty-five hair lambs (14.5 ± 0.89 kg initial body weight (BW), 2 months old) were used in a completely randomized study with a 3 × 3 factorial arrangement, three sex classes (11 intact males, 12 castrated males and 12 females) and three levels of feeding (ad libitum, 300 and 600 g/kg/dry matter (DM) feed restriction) for 120 days. Intact and castrated males showed higher intakes of DM and neutral detergent fibre corrected for ash and protein (NDFap) than females. At 300 g/kg/DM feed restriction, NDFap digestibility was lower in intact males than in other classes; however, no differences were found between classes when subjected toad libitumfeeding or 600 g/kg/DM. The basal endogenous nitrogen and endogenous urinary losses were highest in intact males. Allantoin, uric acid and PD excretion, as well as PD absorption and microbial protein production were lowest in the animals subjected to 600 g/kg/DM feed restriction. Microbial protein synthesis (MPS) was highest in animals subjected to 600 g/kg/DM feed restriction. The lowest temperatures were observed in animals subjected to 600 g/kg/DM feed restriction. The heat tolerance coefficient was highest in animals subjected to 600 g/kg/DM feed restriction. In conclusion, feed restriction reduced the time spent on feeding and rumination but increased the digestibility of DM. The restriction level of 600 g/kg/DM maximized MPS and infrared thermography indicated an elevated heat tolerance coefficient.
The Eruption and Ruination of ‘Rising India’: Rana Dasgupta's Capital and the temporalities of Delhi in the 2010s
Authors: MENDES ANA CRISTINA
Published: December 2018

In 2000, the writer Rana Dasgupta moved from New York to Delhi, reversing his father's act of migration in the 1960s, to find a new, but already obsolescent, ‘rising India’. This was the India of the economic boom, whose extent and import have been increasingly under scrutiny. With reference to the temporalities of ‘rising India’, the purpose of this article is to examine the representation of globalization's multiple temporalities in Dasgupta's non-fiction work Capital: The Eruption of Delhi (2014). Capital is a returnee author's personal attempt to inhabit the multiple temporalities of Delhi, wherein the pull of globalization—here understood as neo-liberal corporate economic globalization—is alternatively embraced and resisted. This article argues that the conceptual limitations of the multiple-modernities framework are reflected in Dasgupta's representation of the multiple temporalities of globalization. It is through politicized and territorialized genealogies of ‘imperial debris’ such as Dasgupta's that we can arrive at new critiques of modernity. At the same time, this article is concerned with the ways in which Dasgupta's fractured and multi-temporal present of Delhi, inhabited by the old and the new, is being captured by a returnee from the United States of America to India who is concurrently the ‘other’ from ‘abroad’ and the ‘same’ at ‘home’. Ultimately, the book's re-Orientalist frame underscores, from the outset, the difficulty in decoupling ideas of modernity and progress from a Eurocentric, Enlightenment project.
Reimagining Asia: Indian and Australian women crossing borders
Authors: GOODALL HEATHER , GHOSH DEVLEENA
Published: December 2018

The decades from the 1940s to the 1960s were ones of increasing contacts between women of India and Australia. These were not built on a shared British colonial history, but on commitments to visions circulating globally of equality between races, sexes, and classes. Kapila Khandvala from Bombay and Lucy Woodcock from Sydney were two women who met during such campaigns. Interacting roughly on an equal footing, they were aware of each other's activism in the Second World War and the emerging Cold War. Khandvala and Woodcock both made major contributions to the women's movements of their countries, yet have been largely forgotten in recent histories, as have links between their countries. We analyse their interactions, views, and practices on issues to which they devoted their lives: women's rights, progressive education, and peace. Their beliefs and practices on each were shaped by their respective local contexts, although they shared ideologies that were circulating internationally. These kept them in contact over many years, during which Kapila built networks that brought Australians into the sphere of Indian women's awareness, while Lucy, in addition to her continuing contacts with Kapila, travelled to China and consolidated links between Australian and Chinese women in Sydney. Their activist world was centred not in Western Europe, but in a new Asia that linked Australia and India. Our comparative study of the work and interactions of these two activist women offers strategies for working on global histories, where collaborative research and analysis is conducted in both colonizing and colonized countries.
Monitoring norms: a multi-disciplinary perspective
Authors: Dastani Mehdi , Torroni Paolo , Yorke-Smith Neil
Published: December 2018

The concept of anormis found widely across fields including artificial intelligence, biology, computer security, cultural studies, economics, law, organizational behaviour and psychology. The concept is studied with different terminology and perspectives, including individual, social, legal and philosophical. If a norm is an expected behaviour in a social setting, then this article considers how it can be determined whether an individual is adhering to this expected behaviour. We call this processmonitoring, and again it is a concept known with different terminology in different fields. Monitoring of norms is foundational for processes of accountability, enforcement, regulation and sanctioning. Starting with a broad focus and narrowing to the multi-agent systems literature, this survey addresses four key questions: what is monitoring, what is monitored, who does the monitoring and how the monitoring is accomplished.
Ethical Dilemmas in Cyberspace
Authors: Finnemore Martha
Published: December 2018

This essay steps back from the more detailed regulatory discussions in other contributions to this roundtable on “Competing Visions for Cyberspace” and highlights three broad issues that raise ethical concerns about our activity online. First, the commodification of people—their identities, their data, their privacy—that lies at the heart of business models of many of the largest information and communication technologies companies risks instrumentalizing human beings. Second, concentrations of wealth and market power online may be contributing to economic inequalities and other forms of domination. Third, long-standing tensions between the security of states and the human security of people in those states have not been at all resolved online and deserve attention.
Feeling Like It Wasn't
Authors: Greiner Rae
Published: December 2018

In “Is There a Problem with Historical Fiction (or with Scott's Redgauntlet)?”—an essay, as it happens, on Sir Walter Scott's great counterfactual novel—Harry E. Shaw calls on literary critics more fully to register “the remarkable variety of things history can do in novels, by short-circuiting the assumption that the representation of history in fiction is really always doing the same sort of work, or should be.” History might be a source of imaginative energy, a sort of launching pad for a book about timeless truths, as in Charles Dickens's A Tale of Two Cities (“ultimately about individual sacrifice and transcendence, not about the French Revolution in the way in which Scott's Waverley is about the Forty-Five”); or the past might function as “a pastoral,” which is to say, as a field onto which authors project the concerns of their own times, as in Romola (depicting problems “in definitively Victorian terms and then project[ing them] back on to Renaissance Italy,” where they would have been understood quite differently [176–77]). Or history, what Shaw calls “objective history,” might be a work's actual subject (180). An historical novel of this last sort tells it like it was, or tries to. But even that novel is only doing so much, only making a use of history. Georg Lukács is therefore wrong in thinking that “a sufficiently dialectical mode of representation could capture everything” (Shaw 175). No one mode can capture all of even a highly delimited history at once.
NONPARTY PARTICIPATION AS A (PARTIAL) REMEDY TO PROCEDURALIST CONCERNS OVER JUDICIAL REVIEW
Authors: Callaghan Geoffrey D.
Published: December 2018

The argument I defend in this paper takes for granted that the proceduralist indictment against judicial review is at least partly justifiable, and that a complete theory of democratic legitimacy will therefore attempt to address it to the greatest possible degree. I examine how the indictment can be addressed via the practice of nonparty participation, whereby members of the general public may seek participatory involvement in a court proceeding despite not being directly implicated by the dispute at issue. Through this practice, courts acquire a means to expose themselves to a cross-section of societal influences, which in turn can be said to improve the legitimacy of the decisions they render from a procedural perspective. Importantly, however, such legitimacy will not be transmitted spontaneously, as if the mere fact that courts allow nonparties to participate is all that is needed to address the proceduralist's concern. The crux of my argument is that only when the practice is conceived in a particular way, and is subjected to the appropriate conditions, does it have a genuine chance of realizing its legitimating promise.
Sharing is caring: the role of voter-candidate similarities in intra-party electoral competition
Authors: van Erkel Patrick F. A.
Published: December 2018

Previous studies have found similarities with presidential candidates or party leaders to be an important factor in explaining voting behaviour. However, with the exception of gender, few studies have structurally studied voter-candidate similarities in intra-party electoral competition. This study investigates the Belgian case and argues that voter-candidate similarities play a role in the decision-making process of citizens when casting preferential votes. Moreover, it investigates whether underrepresented groups, and especially women, are more guided by these voter-candidate similarities than overrepresented groups. To achieve this aim voter and candidate characteristics are modelled simultaneously. This enables an investigation of the decision-making process of voters while taking into account structural inequalities at the supply side. The results demonstrate that citizens are indeed more likely to cast preferential votes for candidates similar to themselves and that these effects are stronger for underrepresented groups. Hence, preferential voting could ultimately pave the way for better descriptive representation.
Effort-Reward Imbalance and Burnout in German Kindergarten	Educators
Authors: Backhaus Olaf , Hampel Petra , Dadaczynski Kevin
Published: December 2018

Abstract. Effort-reward imbalance and overcommitment are increasingly identified as work-related risk factors for burnout and somatic symptoms. In order to explore the situation in German kindergarten educators, a cross-sectional study based on questionnaire responses from N = 1,933 was carried out. Burnout was found in 24.4% and somatic symptoms in 47.3% of the study participants. Binary logistic regressions were used to identify effort-reward imbalance (OR = 3.75, 95% CI: 2.85–4.95) and overcommitment (OR = 1.41, 95% CI: 1.34–1.47) as independent predictors for burnout. Results confirm the high relevance of the effort-reward imbalance concept for the health status of kindergarten educators.
The Internal Cycling of Zinc in the Ocean
Authors: Roshan Saeed , DeVries Tim , Wu Jingfeng , Chen Gedun
Published: December 2018

The internal cycling of zinc (Zn) in the ocean has been a longstanding mystery. Particularly puzzling is the strong correlation between Zn and silicate (SiO44−), but not phosphate (PO43−), even though Zn is involved with cell functions that regulate PO43− uptake and are unrelated to SiO44− uptake. To help solve this mystery, we use an artificial neural network to produce global maps of dissolved Zn, and then use a diagnostic model to infer rates of uptake and regeneration for Zn, SiO44−, and PO43−. We find that plankton in the Southern Ocean account for 62 (±32)% of global Zn uptake. The plankton Zn:PO43− uptake ratio increases by more than tenfold from the low latitudes to the Southern Ocean, a much larger range than expected from culture studies, suggesting controls from factors such as iron availability. Reconstruction of particulate Zn (PZn), phosphorus (PP), and biogenic silica (PSi) fluxes reveals that PZn remineralizes like PP, and not like PSi. However, a small flux of PZn into the deep ocean is not matched by an equivalent flux of PP, which is likely due to the combined effects of desorption of scavenged Zn and the input of hydrothermal Zn in the deep ocean. This small difference in the remineralization of PZn and PP, combined with the patterns of surface uptake, eliminates the correlation between Zn and PO43− in the deep ocean and causes a tight correlation between Zn and SiO44−. This coincidental correlation cannot be expected to hold for past and future states of the ocean.
The Development of a Space Climatology: 3. Models of the Evolution of Distributions of Space Weather Variables With Timescale
Authors: Lockwood Mike , Bentley Sarah N. , Owens Mathew J. , Barnard Luke A. , Scott Chris J. , Watt Clare E. , Allanson Oliver , Freeman Mervyn P.
Published: December 2018

We study how the probability distribution functions of power input to the magnetosphere Pα and of the geomagnetic ap and Dst indices vary with averaging timescale, τ, between 3 hr and 1 year. From this we develop and present algorithms to empirically model the distributions for a given τ and a given annual mean value. We show that lognormal distributions work well for ap, but because of the spread of Dst for low activity conditions, the optimum formulation for Dst leads to distributions better described by something like the Weibull formulation. Annual means can be estimated using telescope observations of sunspots and modeling, and so this allows the distributions to be estimated at any given τ between 3 hr and 1 year for any of the past 400 years, which is another important step toward a useful space weather climatology. The algorithms apply to the core of the distributions and can be used to predict the occurrence rate of large events (in the top 5% of activity levels): they may contain some, albeit limited, information relevant to characterizing the much rarer superstorm events with extreme value statistics. The algorithm for the Dst index is the more complex one because, unlike ap, Dst can take on either sign and future improvements to it are suggested.
Measuring Single-Cell Phenotypic Growth Heterogeneity Using a Microfluidic Cell Volume Sensor
Authors: Jing Wenyang , Camellato Brendan , Roney Ian J. , Kaern Mads , Godin Michel
Published: December 2018

An imaging-integrated microfluidic cell volume sensor was used to evaluate the volumetric growth rate of single cells from a Saccharomyces cerevisiae population exhibiting two phenotypic expression states of the PDR5 gene. This gene grants multidrug resistance by transcribing a membrane transporter capable of pumping out cytotoxic compounds from the cell. Utilizing fluorescent markers, single cells were isolated and trapped, then their growth rates were measured in two on-chip environments: rich media and media dosed with the antibiotic cycloheximide. Approximating growth rates to first-order, we assessed the fitness of individual cells and found that those with low PDR5 expression had higher fitness in rich media whereas cells with high PDR5 expression had higher fitness in the presence of the drug. Moreover, the drug dramatically reduced the fitness of cells with low PDR5 expression but had comparatively minimal impact on the fitness of cells with high PDR5 expression. Our experiments show the utility of this imaging-integrated microfluidic cell volume sensor for high-resolution, single-cell analysis, as well as its potential application for studies that characterize and compare the fitness and morphology of individual cells from heterogeneous populations under different growth conditions.
Noninvasive evaluation of 18F-FDG/18F-FMISO-based Micro PET in monitoring hepatic metastasis of colorectal cancer
Authors: Zhang Mingyu , Jiang Huijie , Zhang Rongjun , Xu Hailong , Jiang Hao , Pan Wenbin , Li Xin , Wang Yiqiao , Wang Song
Published: December 2018

This study aimed to explore the application of two radiotracers (18F-fluorodeoxyglucose (FDG) and 18F-fluoromisonidazole (FMISO)) in monitoring hepatic metastases of human colorectal cancer (CRC). Mouse models of CRC hepatic metastases were established by implantation of the human CRC cell lines LoVo and HT29 by intrasplenic injection. Wound healing and Transwell assays were performed to examine cell migration and invasion abilities. Radiotracer-based cellular uptake in vitro and micro-positron emission tomography imaging of liver metastases in vivo were performed. The incidence of liver metastases in LoVo-xenografted mice was significantly higher than that in HT29-xenografted ones. The SUVmax/mean values of 18F-FMISO, but not 18F-FDG, in LoVo xenografts were significantly greater than in HT29 xenografts. In vitro, LoVo cells exhibited stronger metastatic potential and higher radiotracer uptake than HT29 cells. Mechanistically, the expression of HIF-1α and GLUT-1 in LoVo cells and LoVo tumor tissues was remarkably higher than in HT29 cells and tissues. Linear regression analysis demonstrated correlations between cellular 18F-FDG/18F-FMISO uptake and HIF-1α/GLUT-1 expression in vitro, as well as between 18F-FMISO SUVmax and GLUT-1 expression in vivo. 18F-FMISO uptake may serve as a potential biomarker for the detection of liver metastases in CRC, whereas its clinical use warrants validation.
A DNA minimachine for selective and sensitive detection of DNA
Authors: Lyalina Tatiana A. , Goncharova Ekaterina A. , Prokofeva Nadezhda Y. , Voroshilina Ekaterina S. , Kolpashchikov Dmitry M.
Published: December 2018

Synthetic molecular machines have been explored to manipulate matter at the molecular level.
Fast and sensitive fluorescent probe for ratiometric detection of hydrogen sulfide in mitochondria
Authors: Jiang Na , Wang Bin , Liu Tao , Liu Qingyu , Wei Qin , Xing Yujing , Zheng Gengxiu
Published: December 2018

A hemicyanine-based fluorescent dye, Mito-BT, was developed to ratiometrically detect H2S. This dye was of high selectivity, photostability and sensitivity with a rapid response time of 10 seconds. In addition, Mito-BT was localized in mitochondria, making it a promising probe for detecting H2S in cells.
Prussian blue coupling with zinc oxide as a protective layer: an efficient cathode for high-rate sodium-ion batteries
Authors: Qiao Yun , Wei Gangya , Cui Jiabao , Zhang Mingming , Cheng Xiaoguang , He Dandan , Li Shuan , Liu Yang
Published: December 2018

Prussian blue coupled with zinc oxide has been synthesized via a facial heat treatment process.
The solid state forms of the sex hormone 17-β-estradiol
Authors: Stevenson Erin L. , Lancaster Robert W. , Buanz Asma B. M. , Price Louise S. , Tocher Derek A. , Price Sarah L.
Published: December 2018

The crystal structure of the female sex hormone has been established despite its high affinity for water.
The influence of cholesterol on melittin lipidation in neutral membranes
Authors: Britt Hannah M. , Mosely Jackie A. , Sanderson John M.
Published: December 2018

Cholesterol inclusion in membranes influences the rate and selectivity of acyl transfer from lipids to a membrane-embedded peptide.
Pt-Based electrocatalysts with high atom utilization efficiency: from nanostructures to single atoms
Authors: Zhang Lei , Doyle-Davis Kieran , Sun Xueliang
Published: December 2018

This review presents recent developments in the design and synthesis of Pt-based catalysts with high atom utilization efficiency and their enhanced catalytic performance in electrochemical catalytic reactions.
Stimuli-responsive materials: a web themed collection
Authors: Huang Feihe , Zhang Xi , Tang Ben Zhong
Published: December 2018

Feihe Huang, Xi Zhang and Ben Zhong Tang introduce this Materials Chemistry Frontiers themed collection on stimuli-responsive materials.
A facile and efficient [4 + 2] annulation reaction of sulfur ylides: access to N-fused benzimidazoles
Authors: Qin Hui , Miao Yuanyuan , Xu Jian , Bi Qirui , Qu Wei , Liu Wenyuan , Feng Feng , Sun Haopeng
Published: December 2018

The synthesis of N-fused benzimidazoles via sulfur ylides is first reported. The reaction system is facile and mild without a metal catalyst.
Photo-induced Au–Pd alloying at TiO2 {101} facets enables robust CO2 photocatalytic reduction into hydrocarbon fuels
Authors: Chen Qian , Chen Xianjie , Fang Minling , Chen Jiayu , Li Yongjian , Xie Zhaoxiong , Kuang Qin , Zheng Lansun
Published: December 2018

Au–Pd alloy catalytic sites were specifically constructed on anatase TiO2 {101} facets for promoting CO2 conversion to hydrocarbons.
Considerations for hydrogel applications to neural bioelectronics
Authors: Goding Josef , Vallejo-Giraldo Catalina , Syed Omaer , Green Rylie
Published: December 2018

Hydrogels have garnered interest as materials in bioelectronics due to the capacity to tailor their properties. Appropriate selection and design of hydrogel systems for this application requires an understanding of the physical, chemical and biological properties as well as their structure–property relationships.
Photo-activated bimorph composites of Kapton and liquid-crystalline polymer towards biomimetic circadian rhythms of Albizia julibrissin leaves
Authors: Li Xiao , Ma Shudeng , Hu Jing , Ni Yue , Lin Zhiqun , Yu Haifeng
Published: December 2018

Bimorph structure composing of photoresponsive LCP layer was designed to mimic plant's circadian rhythm behaviors.
Electrical resonance mitigation scheme based on damping controller for wind farm integration through VSC‐HVDC system
Authors: Hu Xiaobao , Wang Xiao , Wu Linlin , Liu Hui , Sheng Siqing
Published: December 2018

Voltage Source Converter based High Voltage Direct Current Transmission (VSC‐HVDC) technology promotes the development and utilisation of large‐scale wind power, but the power oscillation might occur due to the interaction between two control systems. In order to avoid the high cost of wind turbines transformation, an additional damping scheme on the VSC‐HVDC converter for power oscillation mitigation is proposed in this article. On the basis of the additional damping control principle, the concrete transformation method of islanding control is given. Under the time domain simulation and impedance analysis, the validity of the proposed oscillation mitigation method is verified.
AGILE, Fermi, Swift, and GASP/WEBT multi-wavelength observations of the high-redshift blazar 4C +71.07 in outburst
Authors: Vercellone S. , Romano P. , Piano G. , Vittorini V. , Donnarumma I. , Munar-Adrover P. , Raiteri C. M. , Villata M. , Verrecchia F. , Lucarelli F. , Pittori C. , Bulgarelli A. , Fioretti V. , Tavani M. , Acosta-Pulido J. A. , Agudo I. , Arkharov A. A. , Bach U. , Bachev R. , Borman G. A. , Butuzova M. S. , Carnerero M. I. , Casadio C. , Damljanovic G. , D’Ammando F. , Di Paola A. , Doroshenko V. T. , Efimova N. V. , Ehgamberdiev Sh. A. , Giroletti M. , Gómez J. L. , Grishina T. S. , Järvelä E. , Klimanov S. A. , Kopatskaya E. N. , Kurtanidze O. M. , Lähteenmäki A. , Larionov V. M. , Larionova L. V. , Mihov B. , Mirzaqulov D. O. , Molina S. N. , Morozova D. A. , Nazarov S. V. , Orienti M. , Righini S. , Savchenko S. S. , Semkov E. , Slavcheva-Mihova L. , Strigachev A. , Tornikoski M. , Troitskaya Yu. V. , Vince O. , Cattaneo P. W. , Colafrancesco S. , Longo F. , Morselli A. , Paoletti F. , Parmiggiani N.
Published: December 2018

Context. The flat-spectrum radio quasar 4C +71.07 is a high-redshift (z = 2.172), γ-loud blazar whose optical emission is dominated by thermal radiation from the accretion disc.

Aims. 4C +71.07 has been detected in outburst twice by the AGILE γ-ray satellite during the period from the end of October to mid-November 2015, when it reached a γ-ray flux of the order of F(E >  100 MeV)=(1.2 ± 0.3)×10−6 photons cm−2 s−1 and F(E > 100 MeV)=(3.1 ± 0.6)×10−6 photons cm−2 s−1, respectively, allowing us to investigate the properties of the jet and the emission region.

Methods. We investigated its spectral energy distribution by means of almost-simultaneous observations covering the cm, mm, near-infrared, optical, ultraviolet, X-ray, and γ-ray energy bands obtained by the GASP-WEBT Consortium and the Swift, AGILE, and Fermi satellites.

Results. The spectral energy distribution of the second γ-ray flare (whose energy coverage is more dense) can be modelled by means of a one-zone leptonic model, yielding a total jet power of about 4 × 1047 erg s−1.

Conclusions. During the most prominent γ-ray flaring period our model is consistent with a dissipation region within the broad-line region. Moreover, this class of high-redshift, flat-spectrum radio quasars with high-mass black holes might be good targets for future γ-ray satellites such as e-ASTROGAM.
Characterization of the in-flight properties of the Planck telescope
Authors: Tauber J. A. , Nielsen P. H. , Martín-Polegre A. , Crill B. , Cuttaia F. , Ganga K. , Gudmundsson J. , Jones W. , Lawrence C. , Meinhold P. , Norgaard-Nielsen H. U. , Oxborrow C. A. , Partridge B. , Roudier G. , Sandri M. , Scott D. , Terenzi L. , Villa F. , Bernard J. P. , Burigana C. , Franceschi E. , Kurki-Suonio H. , Mandolesi N. , Puget J. L. , Toffolatti L.
Published: December 2018

The European Space Agency’s Planck satellite was launched on 14 May 2009, and surveyed the sky stably and continuously between August 2009 and October 2013. The scientific analysis of the Planck data requires understanding the optical response of its detectors, which originates partly from a physical model of the optical system. In this paper, we use in-flight measurements of planets within ∼1° of boresight to estimate the geometrical properties of the telescope and focal plane. First, we use observed grating lobes to measure the amplitude of mechanical dimpling of the reflectors, which is caused by the hexagonal honeycomb structure of the carbon fibre reflectors. We find that the dimpling amplitude on the two reflectors is larger than expected from the ground, by 20% on the secondary and at least a factor of 2 on the primary. Second, we use the main beam shapes of 26 detectors to investigate the alignment of the various elements of the optical system, as well as the large-scale deformations of the reflectors. We develop a metric to guide an iterative fitting scheme, and are able to determine a new geometric model that fits the in-flight measurements better than the pre-flight prediction according to this metric. The new alignment model is within the mechanical tolerances expected from the ground, with some specific but minor exceptions. We find that the reflectors contain large-scale sinusoidal deformations most probably related to the mechanical supports. In spite of the better overall fit, the new model still does not fit the beam measurements at a level compatible with the needs of cosmological analysis. Nonetheless, future analysis of the Planck data would benefit from taking into account some of the features of the new model. The analysis described here exemplifies some of the limitations of in-flight retrieval of the geometry of an optical system similar to that of Planck, and provides useful information for similar efforts in future experiments.
Detection of He I λ10830 Å absorption on HD 189733 b with CARMENES high-resolution transmission spectroscopy
Authors: Salz M. , Czesla S. , Schneider P. C. , Nagel E. , Schmitt J. H. M. M. , Nortmann L. , Alonso-Floriano F. J. , López-Puertas M. , Lampón M. , Bauer F. F. , Snellen I. A. G. , Pallé E. , Caballero J. A. , Yan F. , Chen G. , Sanz-Forcada J. , Amado P. J. , Quirrenbach A. , Ribas I. , Reiners A. , Béjar V. J. S. , Casasayas-Barris N. , Cortés-Contreras M. , Dreizler S. , Guenther E. W. , Henning T. , Jeffers S. V. , Kaminski A. , Kürster M. , Lafarga M. , Lara L. M. , Molaverdikhani K. , Montes D. , Morales J. C. , Sánchez-López A. , Seifert W. , Zapatero Osorio M. R. , Zechmeister M.
Published: December 2018

We present three transit observations of HD 189733 b obtained with the high-resolution spectrograph CARMENES at Calar Alto. A strong absorption signal is detected in the near-infrared He I triplet at 10830 Å in all three transits. During mid-transit, the mean absorption level is 0.88 ± 0.04% measured in a ±10 km s−1 range at a net blueshift of − 3.5 ± 0.4 km s−1 (10829.84–10830.57 Å). The absorption signal exhibits radial velocities of + 6.5 ± 3.1 km s−1 and − 12.6 ± 1.0 km s−1 during ingress and egress, respectively; all radial velocities are measured in the planetary rest frame. We show that stellar activity related pseudo-signals interfere with the planetary atmospheric absorption signal. They could contribute as much as 80% of the observed signal and might also affect the observed radial velocity signature, but pseudo-signals are very unlikely to explain the entire signal. The observed line ratio between the two unresolved and the third line of the He I triplet is 2.8 ± 0.2, which strongly deviates from the value expected for an optically thin atmospheres. When interpreted in terms of absorption in the planetary atmosphere, this favors a compact helium atmosphere with an extent of only 0.2 planetary radii and a substantial column density on the order of 4 × 1012 cm−2. The observed radial velocities can be understood either in terms of atmospheric circulation with equatorial superrotation or as a sign of an asymmetric atmospheric component of evaporating material. We detect no clear signature of ongoing evaporation, like pre- or post-transit absorption, which could indicate material beyond the planetary Roche lobe, or radial velocities in excess of the escape velocity. These findings do not contradict planetary evaporation, but only show that the detected helium absorption in HD 189733 b does not trace the atmospheric layers that show pronounced escape signatures.
Deriving star cluster parameters with convolutional neural networks
Authors: Bialopetravičius J. , Narbutis D. , Vansevičius V.
Published: December 2018

Context. Convolutional neural networks (CNNs) have been proven to perform fast classification and detection on natural images and have the potential to infer astrophysical parameters on the exponentially increasing amount of sky-survey imaging data. The inference pipeline can be trained either from real human-annotated data or simulated mock observations. Until now, star cluster analysis was based on integral or individual resolved stellar photometry. This limits the amount of information that can be extracted from cluster images.

Aims. We aim to develop a CNN-based algorithm capable of simultaneously deriving ages, masses, and sizes of star clusters directly from multi-band images. We also aim to demonstrate CNN capabilities on low-mass semi-resolved star clusters in a low-signal-to-noise-ratio regime.

Methods. A CNN was constructed based on the deep residual network (ResNet) architecture and trained on simulated images of star clusters with various ages, masses, and sizes. To provide realistic backgrounds, M 31 star fields taken from The Panchromatic Hubble Andromeda Treasury (PHAT) survey were added to the mock cluster images.

Results. The proposed CNN was verified on mock images of artificial clusters and has demonstrated high precision and no significant bias for clusters of ages ≲3 Gyr and masses between 250 and 4000 M⊙. The pipeline is end-to-end, starting from input images all the way to the inferred parameters; no hand-coded steps have to be performed: estimates of parameters are provided by the neural network in one inferential step from raw images.
Is there a left-handed magnetic field in the solar neighborhood?
Authors: Bracco A. , Candelaresi S. , Del Sordo F. , Brandenburg A.
Published: December 2018

Context. The analysis of the full-sky Planck polarization data at 850 μm revealed unexpected properties of the E- and B-mode power spectra of dust emission in the interstellar medium (ISM). The positive cross-correlations over a wide range of angular scales between the total dust intensity, T, and both E and (most of all) B modes has raised new questions about the physical mechanisms that affect dust polarization, such as the Galactic magnetic field structure. This is key both to better understanding ISM dynamics and to accurately describing Galactic foregrounds to the polarization of the cosmic microwave background (CMB). In particular, in the quest to find primordial B modes of the CMB, the observed positive cross-correlation between T and B for interstellar dust requires further investigation towards parity-violating processes in the ISM.

Aims. In this theoretical paper we investigate the possibility that the observed cross-correlations in the dust polarization power spectra, and specifically the one between T and B, can be related to a parity-odd quantity in the ISM such as the magnetic helicity.

Methods. We produce synthetic dust polarization data, derived from 3D analytical toy models of density structures and helical magnetic fields, to compare with the E and B modes of observations. We present several models. The first is an ideal fully helical isotropic case, such as the Arnold-Beltrami-Childress field. Second, following the nowadays favored interpretation of the T–E signal in terms of the observed alignment between the magnetic field morphology and the filamentary density structure of the diffuse ISM, we design models for helical magnetic fields wrapped around cylindrical interstellar filaments. Lastly, focusing on the observed T–B correlation, we propose a new line of interpretation of the Planck observations advocating the presence of a large-scale helical component of the Galactic magnetic field in the solar neighborhood.

Results. Our analysis shows that: I) the sign of magnetic helicity does not affect E and B modes for isotropic magnetic-field configurations; II) helical magnetic fields threading interstellar filaments cannot reproduce the Planck results; and III) a weak helical left-handed magnetic field structure in the solar neighborhood may explain the T–B correlation seen in the Planck data. Such a magnetic-field configuration would also account for the observed large-scale T–E correlation.

Conclusions. This work suggests a new perspective for the interpretation of the dust polarization power spectra that supports the imprint of a large-scale structure of the Galactic magnetic field in the solar neighborhood.
Discovery of short-term activity cycles in F-type stars
Authors: Mittag M. , Schmitt J. H. M. M. , Hempelmann A. , Schröder K.-P.
Published: December 2018

Previous studies have revealed a 120 day activity cycle in the F-type star τ Boo, which represents the shortest activity cycle discovered until now. The question arises as to whether or not short-term activity cycles are a common phenomenon in F-type stars. To address this question, we analyse S-index time series of F-type stars taken with the TIGRE telescope to search for periodic variations with a maximal length of 2 years using the generalised Lomb-Scargle periodogram method. In our sample, we find four F-type stars showing periodic variations shorter than one year. However, the amplitude of these variations in our sample of F-star type stars appears to be smaller than that of solar-type stars with well-developed cyclic activity, and apparently represents only a part of the total activity. We conclude that among F-stars, the time-behaviour of activity differs from that of the Sun and cooler main sequence stars, as short-term cyclic variations with shallow amplitude of the cycle seem to prevail, rather than cycles with 10+ years periods and a larger cycle amplitude.
A deep X-ray view of the bare AGN Ark 120
Authors: Marinucci A. , Porquet D. , Tamborra F. , Bianchi S. , Braito V. , Lobban A. , Marin F. , Matt G. , Middei R. , Nardini E. , Reeves J. , Tortosa A.
Published: December 2018

Context. The spectral shape of the hard X-ray continuum of Active Galactic Nuclei (AGN) can be ascribed to inverse Compton scattering of optical/UV seed photons from the accretion disc by a hot corona of electrons. This physical process produces a polarization signal which is strongly sensitive to the geometry of the scattering medium (i.e. the hot corona) and of the radiation field.

Aims. MoCA (Monte Carlo code for Comptonisation in Astrophysics) is a versatile code which allows for different geometries and configurations to be tested for Compton scattering in compact objects. A single photon approach is considered as well as polarisation and Klein–Nishina effects. In this work, we selected four different geometries for the scattering electrons cloud above the accretion disc, namely an extended slab, an extended spheroid and two compact spheroids.

Methods. We discuss the first application of the MoCA model to reproduce the hard X-ray primary continuum of the bare Seyfert 1 galaxy Ark 120, using different geometries for the hot corona above the accretion disc. The lack of extra-Galactic absorption along the line of sight makes it an excellent target for studying the accretion disc-corona system. We report on the spectral analysis of the simultaneous 2013 and 2014 XMM-Newton and NuSTAR observations of the source.

Results. A general agreement is found between the best fit values of the hot coronal parameters obtained with MoCA and the ones inferred using other Comptonisation codes from the literature. The expected polarization signal from the best fits with MoCA is then presented and discussed, in view of the launch in 2021 of the Imaging X-ray Polarimetry Explorer (IXPE).

Conclusions. We find that none of the tested geometries for the hot corona (extended slab and extended/compact spheroids) can be statistically preferred, based on spectroscopy solely. In the future, an IXPE observation less than 1 Ms long will clearly distinguish between an extended slab or a spherical hot corona.
Accurate fitting functions for peculiar velocity spectra in standard and massive-neutrino cosmologies
Authors: Bel J. , Pezzotta A. , Carbone C. , Sefusatti E. , Guzzo L.
Published: December 2018

We estimate the velocity field in a large set ofN-body simulations including massive neutrino particles, and measure the auto-power spectrum of the velocity divergence field as well as the cross-power spectrum between the cold dark matter density and the velocity divergence. We perform these measurements at four different redshifts and within four different cosmological scenarios, covering a wide range in neutrino masses. We find that the nonlinear correction to the velocity power spectra largely depends on the degree of nonlinear evolution with no specific dependence on the value of neutrino mass. We provide a fitting formula based on the value of the rms of the matter fluctuations in spheres of 8 h−1Mpc, describing the nonlinear corrections with 3% accuracy on scales belowk = 0.7 h Mpc−1.
Investigation the stability of reservoir sediments in the lab and field
Authors: Noack Markus , Beckers Felix , Haun Stefan , Wieprecht Silke
Published: December 2018

To investigate the erosion stability of reservoir sediments, two measuring strategies were applied. Next to in situ measurements, sediment cores were extracted and analysed in the laboratory. At several sampling points at a reservoir in Germany, the in situ device was used to determine the critical bed shear stresses at the sediment surface. At the same time, sediment cores were withdrawn at each site to perform depth-orientated investigations in the hydraulic laboratory. The objective of this study is to investigate the remobilisation potential of the deposited fine sediments and to compare different methods to determine the erosion threshold. Next to critical shear stresses and erosion rates, additional sedimentary and biological parameters were examined such as bulk densities, particle size distributions, TOC-contents and chlorophylla concentrations. The results show generally a very low erosion stability, especially at the sediment surface and in the upper sediment layers. Deeper sediment layers are characterised by consolidation effects and show a higher erosion resistance. High clay contents result in increased stability while high sand contents show a high remobilisation potential. No significant relation to the parameters TOC-content or chlorophylla concentration are identified. A comparison between the different applied techniques to determine the critical bed shear stresses reveals values in the same order of magnitude; however, some significant variations occur because of different hydromorphological conditions and the different limitations for each device.
Discussion on Reservoir dispatch during a sudden accident of water pollution in a long distance river
Authors: Fang Shen-guang , Cui Li-qin , Yong He
Published: December 2018

A mathematical model of river hydrodynamics with cascade reservoirs and pollutant has been established and verified by using analytic solutions of partial differential equation for transportation and diffusion. Ten dispatch schedules of single or multi- reservoirs have been set up and executed according to that a pollution accident occurred upstream or downstream to a reservoir. It shows that which dispatch schedule should be selected was decided by sensitive factors of a target river segment downstream. A dispatch model of large flux with short time duration by utilizing a reservoir nearest to the segment was more appropriate for which was more sensitive to concentration than other factors, while a model of appropriate flux discharge with long time duration was more suitable for those being more sensitive to extra concentration retention of pollutants. Compared with a single reservoir dispatch, multi-reservoirs have larger effective storage capacity to reduce the loss by a sudden water pollution accident better by supplement water step by step from upstream to downstream.
The Design and Check of Regional Typical Rainfall Processes: A Case Study of Yongnian District, China
Authors: Man Zihao , Luan Qinghua , Xu Dan , Sun Congwu , Niu Yongzhen
Published: December 2018

Observing and analyzing runoff process is an important method to study the principle of runoff yield and concentration. However, natural rainfall is random and difficult to monitor the related runoff process timely, so most of the runoff processes analysis is based on the artificial rainfall experiments. In this study, the selected test site is located in Yongnian district, Hebei Province, China. Rainfall volume, rainfall peak, rainfall duration and peak ratio were considered as the key factors of designed rainfall type. Based on regional historical observed rainfall data from 1980 to 2012, the two mainly representative processes which was in flood season and non-flood season respectively, were calculated. The most typical rainfall process in each period was screened through two methods of characteristic frequency distribution. Furthermore, accuracy of rainfall intensity and uniformity of spatial and temporal distribution were selected as the criteria for correcting the artificial rainfall devices. This research is the foundation of the artificial runoff experiment and provide reference to regional climate change research and local water resources assessment.