bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of metabolites of anticancer candidate salinomycin using liquid chromatography coupled with quadrupole time‐of‐flight and hybrid triple quadrupole linear ion trap mass spectrometry
Authors: Olejnik Małgorzata , Radko Lidia , Jedziniak Piotr
Published: February 2018

Rationale

Salinomycin is an ionophore antibiotic with potential anticancer activity. The history of its use in veterinary medicine shows large differences in species susceptibility to its toxicity. At the same time, the results of research to date suggest a correlation between the extent and pathways of ionophore biotransformation and its toxicity. The biotransformation pattern of salinomycin has not been studied so far.

Methods

Extracts from culture media of human hepatoma cells (HepG2) exposed to salinomycin were analysed with two mass spectrometry techniques. For the first one, micro‐liquid chromatography coupled with a quadrupole time‐of‐flight (Q‐TOF) mass spectrometer was used. In the second approach, high‐performance liquid chromatography was coupled with a hybrid triple quadrupole linear ion trap. Both experiments were operated in positive electrospray ionization mode. To identify unknown salinomycin metabolites, information‐dependent acquisition was applied.

Results

Metabolites identified with tandem mass spectrometry included hydroxylated, demethylated and hydroxylated–demethylated derivatives, in total 14 compounds. Using high resolution, only eight isomers of hydroxysalinomycin were detected. The efficiency of biotransformation was low, and so was the abundance of the signals; only for two metabolites did the signal exceed 1% of the salinomycin signal. The analysis of fragmentation patterns narrowed the structure combinations but the actual modification site could not be specified.

Conclusions

Tandem mass spectrometry was more sensitive in the identification of salinomycin metabolites in comparison to the Q‐TOF approach. Because of low efficiency of biotransformation of the applied model, the obtained fragmentation data are not sufficient to fully characterize the detected compounds. A study with more metabolically active primary hepatocytes is needed.
Simultaneous small‐sample comparisons in longitudinal or multi‐endpoint trials using multiple marginal models
Authors: Pallmann Philip , Ritz Christian , Hothorn Ludwig A.
Published: February 2018

Simultaneous inference in longitudinal, repeated‐measures, and multi‐endpoint designs can be onerous, especially when trying to find a reasonable joint model from which the interesting effects and covariances are estimated. A novel statistical approach known as multiple marginal models greatly simplifies the modelling process: the core idea is to “marginalise” the problem and fit multiple small models to different portions of the data, and then estimate the overall covariance matrix in a subsequent, separate step. Using these estimates guarantees strong control of the family‐wise error rate, however only asymptotically. In this paper, we show how to make the approach also applicable to small‐sample data problems. Specifically, we discuss the computation of adjusted P values and simultaneous confidence bounds for comparisons of randomised treatment groups as well as for levels of a nonrandomised factor such as multiple endpoints, repeated measures, or a series of points in time or space. We illustrate the practical use of the method with a data example.
Validation of the Japanese Version of the Low Anterior Resection Syndrome Score
Authors: Akizuki Emi , Matsuno Hiroshi , Satoyoshi Tetsuta , Ishii Masayuki , Usui Akihiro , Ueki Tomomi , Nishidate Toshihiko , Okita Kenji , Mizushima Tsunekazu , Mori Masaki , Takemasa Ichiro
Published: February 2018

Background

The low anterior resection syndrome (LARS) score is a patient‐reported outcome measure to evaluate the severity of bowel dysfunction after rectal cancer surgery by scoring the major symptoms of LARS. The aim of this study was to translate the English version of the LARS score into Japanese and to investigate the validity and reliability of the LARS score.

Methods

The LARS score was translated in Japanese following current international recommendations. A total of 149 rectal cancer patients completed the LARS score questionnaire and were also asked a single question assessing the impact of bowel function on quality of life (QoL). A total of 136 patients answered the LARS score questionnaire twice.

Results

The Japanese LARS score showed high convergent validity, based on its good correlation between the LARS score and QoL (p < 0.001). The LARS score was able to discriminate between patients according to the tumor distance to anal verge (p < 0.001), type of surgery (p < 0.001), and time since surgery (p = 0.001). Patients after ultra‐low anterior resection and intersphincteric resection showed especially high scores. The score also had high test–retest reliability (intraclass correlation coefficient: 0.87).

Conclusion

The Japanese LARS score is a valid and reliable tool for measuring LARS. The LARS score is appropriate for assessments in postoperative bowel function and international comparison. Using this score, patient‐reported outcome measures of LARS in Japanese patients can be shared internationally. Additional validation reports from non‐English speaking countries can support the LARS score as a worldwide assessment tool for postoperative bowel dysfunction.
Maturation of the [Ni–4Fe–4S] active site of carbon monoxide dehydrogenases
Authors: Merrouch Mériem , Benvenuti Martino , Lorenzi Marco , Léger Christophe , Fourmond Vincent , Dementin Sébastien
Published: February 2018

Nickel-containing enzymes are diverse in terms of function and active site structure. In many cases, the biosynthesis of the active site depends on accessory proteins which transport and insert the Ni ion. We review and discuss the literature related to the maturation of carbon monoxide dehydrogenases (CODH) which bear a nickel-containing active site consisting of a [Ni–4Fe–4S] center called the C-cluster. The maturation of this center has been much less studied than that of other nickel-containing enzymes such as urease and NiFe hydrogenase. Several proteins present in certain CODH operons, including the nickel-binding proteins CooT and CooJ, still have unclear functions. We question the conception that the maturation of all CODH depends on the accessory protein CooC described as essential for nickel insertion into the active site. The available literature reveals biological variations in CODH active site biosynthesis.
The functional genomics laboratory: functional validation of genetic variants
Authors: Rodenburg Richard J.
Published: February 2018

Currently, one of the main challenges in human molecular genetics is the interpretation of rare genetic variants of unknown clinical significance. A conclusive diagnosis is of importance for the patient to obtain certainty about the cause of the disease, for the clinician to be able to provide optimal care to the patient and to predict the disease course, and for the clinical geneticist for genetic counseling of the patient and family members. Conclusive evidence for pathogenicity of genetic variants is therefore crucial. This review gives an introduction to the problem of the interpretation of genetic variants of unknown clinical significance in view of the recent advances in genetic screening, and gives an overview of the possibilities for functional tests that can be performed to answer questions about the function of genes and the functional consequences of genetic variants (“functional genomics”) in the field of inborn errors of metabolism (IEM), including several examples of functional genomics studies of mitochondrial disorders and several other IEM.
Emergency Management of Priapism in the United Kingdom: A Survey of Current Practice
Authors: Bullock Nicholas , Steggall Martin , Brown Gareth
Published: February 2018

Background

Despite its importance, current practice in the emergency management of priapism in the United Kingdom is unknown.

Aim

To evaluate current practice in the emergency management of priapism in the United Kingdom.

Methods

All “full,” “associate urological specialist,” and “trainee” members of the British Association of Urological Surgeons (BAUS; leading membership-based organization for practitioners of urologic surgery in the United Kingdom) were invited to participate in an online survey. Questions related to the emergency management of priapism, access to tertiary andrology services, and use of guidelines.

Outcomes

Key outcome measures included frequency of encountered cases, access to specialist andrology support, confidence in key management steps, and use of current guidelines.

Results

213 of 1,304 (16.3%) eligible members completed the survey. Most reported managing 1 case annually (median = 1, range = 0–>10). Only 7.0% transferred patients to a tertiary center and 87.8% believed they could access specialist andrology advice if required. Respondents were less confident in performing intracavernosal phenylephrine instillation (88.7%) compared with corporal aspiration (98.1%), with confidence lowest among trainee members. Only 68.5% reported performing the distal shunt procedure. Of the 212 respondents that chose to answer questions relating to guidelines, only 155 (73.1%) were aware of their existence, with those published by the European Association of Urology being most popular (53.8%). 205 (96.2%) respondents expressed an interest in the development of a UK-specific guideline, with 162 of 212 (76.4%) stating they would use this in practice.

Clinical Implications

Urologists in the United Kingdom support the development of UK-specific guidance on the emergency management of priapism for use within the context of the National Health Service.

Strengths and Limitations

This is the first study to assess current practice in the emergency management of priapism in the United Kingdom. Its strength is that most UK urologists were invited to participate through collaboration with the BAUS. Although the response rate of 16.3% is acceptable for a national survey of this nature, responses were self-reported, rendering them susceptible to bias.

Conclusion

This study demonstrates that some UK urologists lack confidence in key steps in the emergency management of priapism and identifies a strong level of support for the development of up-to-date UK-specific guidance.
Soviet legacies, organized crime, and economic gangsterism: Russia, 1995–2010
Authors: Belokurova Galina
Published: February 2018

In countries like Russia, where legal institutions providing political accountability and protection of property rights are weak, some elite actors accept the use of violence as a tool in political and economic competition. The intensity of this violent exposure may vary depending on the position the province had had in the Soviet administrative hierarchy. The higher the province’s position before 1991, the greater the intensity of business violence one is likely to observe there in post-communist times, because the Soviet collapse left a more gaping power vacuum and lack of working informal rules in regions with limited presence of traditional criminal organizations. Post-Soviet entrepreneurs also often find it worthwhile to run for office or financially back certain candidates in order to secure a privileged status and the ability to interpret the law in their favor. Businessmen-candidates themselves and their financial backers behind the scenes may become exposed to competitive pressures resulting in violence during election years, because their competitors may find it hard to secure their position in power through the existing legal or informal non-violent means. To test whether Soviet legacies and Provincial elections indeed cause spikes in commerce-motivated violence, this project relies on an original dataset of more than 6000 attacks involving business interests in 74 regions of Russia, in 1991e2010. The results show that only legislative elections cause increases in violence while there is no firm evidence that executive polls have a similar effect.
A strategy to represent impacts of subgrid-scale topography on snow evolution in the Canadian Land Surface Scheme
Authors: Younas Waqar , Hay Rachel W. , MacDonald Matt K. , Islam Siraj ul , Déry Stephen J.
Published: February 2018

This sensitivity study applies the offline Canadian Land Surface Scheme (CLASS) version 3.6 to simulate snowpack evolution in idealized topography using observations at Likely, British Columbia, Canada over 1 July 2008 to 30 June 2009. A strategy for a subgrid-scale snow (SSS) parameterization is developed to incorporate two key features: ten elevation bands at 100 m intervals to capture air temperature lapse rates, and five slope angles on four aspects to resolve solar radiation impacts on the evolution of snow depth and SWE. Simulations reveal strong elevational dependencies of snow depth and SWE when adjusting temperatures using a moist adiabatic lapse rate with elevation, with 26% peak SWE differences between that at the average elevation versus the mean of the remainder of the elevation bands. Differences in peak SWE on north- and south-facing slopes increase from 3.0 mm at 10° slope to 17.9 mm at 50° slope. When applied to elevation, slope and aspect combinations derived from a high-resolution digital elevation model, elevation dominates the control of peak SWE values. Inclusion of the range of SSS effects into a regional climate model will improve snowpack and hydrological simulations of western North America's snow-dominated, mountainous watersheds.
In Search of the Black Women's History Archive
Authors: Farmer Ashley D.
Published: February 2018

Questions of evidence have sat at the center of black women's history since the field entered the academy over thirty years ago. Historians of black women's lives and labors have filled bookshelves by “mining the forgotten” to render them visible. Scholarship pioneered in the 1980s and 1990s established black women as prominent and indispensable historical actors, and key to understanding such eras as slavery, the Civil War, and the Civil Rights movement. Subsequent works built upon the bedrock that these initial studies provided, incorporating nuanced gender analyses into the history of black women's thought, experiences, and political action. The past ten years have seen a proliferation of publications that have extended the reach of the field to include such genres and approaches as girlhood studies, intellectual history, and black internationalism. This groundswell of research has foregrounded a persistent methodological quandary for scholars of black women's history: how should they address the paradox of simultaneously finding copious archival records on some black women, while also accounting for the deafening archival silence on others?
Socially Engaged Social Psychology in Asia: Sustaining Research Progress in Diverse Directions
Authors: Bernardo Allan B. I. , Liu James H.
Published: February 2018

The final thematic special issue in the series ‘The Social Psychology of Social Change: Science and Practice in Asia’ features 10 empirical studies that apply diverse social psychological theories and approaches to understand and to address a wide range of social concerns in Asian societies. The articles in the special issue align more to mainstream social psychological approaches to studying social phenomena, and as such are mainly derivative of Western social psychological paradigms, with the exception of a couple of studies that adopt emic indigenous approaches. Nevertheless, the various studies display a clear motivation to use social psychology to engage particular societal concerns, representing incremental progress towards using social psychology in the service of social change.
Seed dispersal syndromes in the Madagascan flora: the unusual importance of primates
Authors: Albert-Daviaud Aurélie , Perillo Sarah , Stuppy Wolfgang
Published: February 2018

Madagascar is one of the most threatened biodiversity hotspots, and protection of its biodiversity is becoming increasingly urgent as deforestation of the island continues. For the long-term success of conservation efforts it is essential that key ecological processes, such as seed dispersal, are protected and restored. Therefore, the identification of ecological gaps is a vital task. For Madagascar, only little is known about plant–animal interactions, and traditional methods of ecological research are too time-consuming to provide crucial information about breakdowns in these interactions. To identify likely dispersal gaps we therefore used a theoretical approach to analyse plant–disperser interactions in Madagascar. We used data science tools to impute missing data on relevant plant traits to subsequently predict the most likely dispersal agents for each of Madagascar's endemic plant species. We found that 38% of the endemic species (N = 8,784) are endozoochorous, and among these 26–41% display a primate syndrome and 17–19% a bird syndrome (depending on the definition of syndromes). This lower percentage of endozoochorous species and higher percentage of species with a primate syndrome in Madagascar compared to other tropical areas reflects the unusual disperser guild on the island. Only five bird species but 20 lemur species are frugivorous, and 16 of those lemur species are currently threatened with extinction. The disappearance of frugivorous lemurs would significantly change the vegetation dynamics of Madagascar's ecosystems, and a high proportion of Madagascar's endemic plants would enter an extinction vortex.
Are sacred caves still safe havens for the endemic bats of Madagascar?
Authors: Fernández-Llamazares Álvaro , López-Baucells Adrià , Rocha Ricardo , Andriamitandrina Santatra F. M. , Andriatafika Zo Emmanuel , Burgas Daniel , Temba Eric Marcel , Torrent Laura , Cabeza Mar
Published: February 2018

Despite conservation discourses in Madagascar increasingly emphasizing the role of customary institutions for wildlife management, we know relatively little about their effectiveness. Here, we used semi-structured interviews with 54 adults in eight villages to investigate whether sacred caves and taboos offer conservation benefits for cave-dwelling bats in and around Tsimanampetsotsa National Park, south-west Madagascar. Although some caves were described as sites of spiritual significance for the local communities, most interviewees (c. 76%) did not recognize their present-day sacred status. Similarly, only 22% of the interviewees recognized taboos inhibiting bat hunting and consumption. Legal protection of bats and caves through protected areas was often more widely acknowledged than customary regulations, although up to 30% of the interviewees reported consumption of bats within their communities. Guano extraction was often tolerated in sacred caves in exchange for economic compensation. This may benefit bat conservation by creating incentives for bat protection, although extraction is often performed through destructive and exploitative practices with little benefit for local communities. In view of these results our study questions the extent to which sacred sites, taboos and protected areas offer protection for bats in Madagascar. These results support previous studies documenting the erosion of customary institutions in Madagascar, including the loss of the spiritual values underpinning sacred sites. Given that many Malagasy bats are cave-dwelling species and that most depend on the customary protection of these sites, it is important to obtain a better understanding of the complex interactions between spiritual practices, taboos and protected areas in sustaining bat diversity.
THE SMALL IMPROVEMENT ARGUMENT, EPISTEMICISM AND INCOMPARABILITY
Authors: Flanigan Edmund Tweedy , Halstead John
Published: February 2018

The Small Improvement Argument (SIA) is the leading argument for value incomparability. All vagueness-based accounts of the SIA have hitherto assumed the truth of supervaluationism, but supervaluationism has some well-known problems. This paper explores the implications of epistemicism, a leading rival theory. We argue that if epistemicism is true, then options are comparable in small improvement cases. Moreover, even if SIAs do not exploit vagueness, if epistemicism is true, then options cannot be on a par. The epistemicist account of the SIA has an advantage over leading existing rival accounts of the SIA because it accounts for higher-order hard cases.
Rehabilitation bei chronischen Kopfschmerzen
Authors: Gantenbein Andreas R. , Romano Sylvia K. , Zemp Monika , Benz Thomas , Sandor Peter S.
Published: February 2018

Zusammenfassung. Chronische Kopfschmerzen stellen ein häufiges Problem in der Praxis dar. Die Behandlung beinhaltet eine Kombination von medikamentösen und nichtmedikamentösen Therapieverfahren im Rahmen eines multimodalen Settings. Neben der chronischen Migräne steht der Medikamentenübergebrauchskopfschmerz im Vordergrund. Hierbei ist ein zusätzliches Ziel, die Patienten vorausgehend im ambulanten oder stationären Setting von den übermässig konsumierten Schmerz- und Migränemittel zu entziehen. Mit der Kombination von einem Medikamentenentzug mit der nachfolgenden Optimierung der Migränebehandlung akut und prophylaktisch lässt sich in den allermeisten Fällen eine Verminderung der Kopfschmerzfrequenz und dadurch eine Verbesserung der Lebensqualität erreichen.
Lenalidomide regulates CNS autoimmunity by promoting M2 macrophages polarization
Authors: Weng Qinjie , Wang Jiaying , Wang Jiajia , Wang Jing , Sattar Fahmida , Zhang Zhikang , Zheng Jiahuan , Xu Zijie , Zhao Mengting , Liu Xuan , Yang Lijun , Hao Guifeng , Fang Liang , Lu Q. Richard , Yang Bo , He Qiaojun
Published: February 2018

Multiple sclerosis (MS) is a chronic and debilitating neurological disorder of the central nervous system (CNS), characterized by infiltration of leukocytes into CNS and subsequent demyelination. Emerging evidences have revealed the beneficial roles of M2 macrophages in ameliorating experimental autoimmune encephalomyelitis (EAE), a model for MS. Here, we identify that lenalidomide alone could promote macrophages M2 polarization to prevent the progression of EAE, which is associated with subsequent inhibition of proinflammatory Th1 and Th17 cells both in peripheral lymph system and CNS. Depletion of macrophages by pharmacology treatment of clodronate liposomes or transferring lenalidomide-induced BMDMs in EAE mice completely abolished the therapeutic effect of lenalidomide or prevented EAE development, respectively. The macrophages-derived IL10 was upregulated both in vivo and in vitro after lenalidomide treatment. Moreover, lenalidomide-treated IL10-dificient EAE mice had higher clinical scores and more severe CNS damage, and intravenous injection of lenalidomide-treated IL10−/− BMDMs into mice with EAE at disease onset did not reverse disease severity, implying IL10 may be essential in lenalidomide-ameliorated EAE. Mechanistically, lenalidomide significantly increased expression and autocrine secretion of IL10, subsequently activated STAT3-mediated expression of Ym1. These studies facilitate the development of potential novel therapeutic application of lenalidomide for the treatment of MS.
Mechanism of inhibition of Shiga-toxigenic Escherichia coli SubAB cytotoxicity by steroids and diacylglycerol analogues
Authors: Yahiro Kinnosuke , Nagasawa Sayaka , Ichimura Kimitoshi , Takeuchi Hiroki , Ogura Kohei , Tsutsuki Hiroyasu , Shimizu Takeshi , Iyoda Sunao , Ohnishi Makoto , Iwase Hirotaro , Moss Joel , Noda Masatoshi
Published: February 2018

Shiga toxigenic Escherichia coli (STEC) are responsible for a worldwide foodborne disease, which is characterized by severe bloody diarrhea and hemolytic uremic syndrome (HUS). Subtilase cytotoxin (SubAB) is a novel AB5 toxin, which is produced by Locus for Enterocyte Effacement (LEE)-negative STEC. Cleavage of the BiP protein by SubAB induces endoplasmic reticulum (ER) stress, followed by induction of cytotoxicity in vitro or lethal severe hemorrhagic inflammation in mice. Here we found that steroids and diacylglycerol (DAG) analogues (e.g., bryostatin 1, Ingenol-3-angelate) inhibited SubAB cytotoxicity. In addition, steroid-induced Bcl-xL expression was a key step in the inhibition of SubAB cytotoxicity. Bcl-xL knockdown increased SubAB-induced apoptosis in steroid-treated HeLa cells, whereas SubAB-induced cytotoxicity was suppressed in Bcl-xL overexpressing cells. In contrast, DAG analogues suppressed SubAB activity independent of Bcl-xL expression at early time points. Addition of Shiga toxin 2 (Stx2) with SubAB to cells enhanced cytotoxicity even in the presence of steroids. In contrast, DAG analogues suppressed cytotoxicity seen in the presence of both toxins. Here, we show the mechanism by which steroids and DAG analogues protect cells against SubAB toxin produced by LEE-negative STEC.
Warm blood cardioplegia versus cold crystalloid cardioplegia for myocardial protection during coronary artery bypass grafting surgery
Authors: Nardi Paolo , Pisano Calogera , Bertoldo Fabio , Vacirca Sara R. , Saitto Guglielmo , Costantino Antonino , Bovio Emanuele , Pellegrino Antonio , Ruvolo Giovanni
Published: February 2018

We retrospectively analyzed early results of coronary artery bypass grafting (CABG) surgery using two different types of cardioplegia for myocardial protection: antegrade intermittent warm blood or cold crystalloid cardioplegia. From January 2015 to October 2016, 330 consecutive patients underwent isolated on-pump CABG. Cardiac arrest was obtained with use of warm blood cardioplegia (WBC group, n = 297) or cold crystalloid cardioplegia (CCC group, n = 33), according to the choice of the surgeon. Euroscore II and preoperative characteristics were similar in both groups, except for the creatinine clearance, slightly lower in WBC group (77.33 ± 27.86 mL/min versus 88.77 ± 51.02 mL/min) (P < 0.05). Complete revascularization was achieved in both groups. In-hospital mortality was 2.0% (n = 6) in WBC group, absent in CCC group. The required mean number of cardioplegia’s doses per patient was higher in WBC group (2.3 ± 0.8) versus CCC group (2.0 ± 0.7) (P = 0.045), despite a lower number of distal coronary artery anastomoses (2.7 ± 0.8 versus 3.2 ± 0.9) (P = 0.0001). Cardiopulmonary and aortic cross-clamp times were similar in both groups. The incidence of perioperative myocardial infarction (WBC group 3.4% versus CCC group 3.0%) and low cardiac output syndrome (4.4% versus 3.0%) were similar in both groups. As compared with WBC group, in CCC group CK-MB/CK ratio >10% was lower during each time points of evaluation, with a statistical significant difference at time 0 (4% ± 1.6% versus 5% ± 2.5%) (P = 0.021). In presence of complete revascularization, despite the value of CK-MB/CK ratio >10% was less in the CCC group, clinical results were not affected by both types of cardioplegia adopted to myocardial protection. As compared with cold crystalloid, warm blood cardioplegia requires a shorter interval of administration to achieve better myocardial protection.
Hardware-efficient fermionic simulation with a cavity–QED system
Authors: Zhu Guanyu , Subaşı Yiğit , Whitfield James D. , Hafezi Mohammad
Published: February 2018

In digital quantum simulation of fermionic models with qubits, non-local maps for encoding are often encountered. Such maps require linear or logarithmic overhead in circuit depth which could render the simulation useless, for a given decoherence time. Here we show how one can use a cavity–QED system to perform digital quantum simulation of fermionic models. In particular, we show that highly nonlocal Jordan–Wigner or Bravyi–Kitaev transformations can be efficiently implemented through a hardware approach. The key idea is using ancilla cavity modes, which are dispersively coupled to a qubit string, to collectively manipulate and measure qubit states. Our scheme reduces the circuit depth in each Trotter step of the Jordan–Wigner encoding by a factor of N2, comparing to the scheme for a device with only local connectivity, where N is the number of orbitals for a generic two-body Hamiltonian. Additional analysis for the Fermi–Hubbard model on an N × N square lattice results in a similar reduction. We also discuss a detailed implementation of our scheme with superconducting qubits and cavities.
Heat transfer across a nanoscale pressurized air gap and its application in magnetic recording
Authors: Zheng Jinglin , Chen Yung-Kan , Zhou Qin
Published: February 2018

In this study, we investigated how a thermally actuated air bearing slider heats up a fast-spinning storage disk through a highly pressurized nanoscale air gap in a magnetic recording system. A Eulerian-description-based computational approach is developed considering heat conduction through a pressurized air film and near-field radiation across the gap. A set of field equations that govern the air bearing dynamics, slider thermo-mechanics and disk heat dissipation are solved simultaneously through an iterative approach. A temperature field on the same order as the hot slider surface itself is found to be established in the disk. The effective local heat transfer coefficient is found to vary substantially with disk materials and linear speeds. This approach quantifies the magnitude of different thermal transport schemes and the accuracy is verified by an excellent agreement with our experiment, which measures the local slider temperature rise with a resistance temperature sensor. It also demonstrates an effective computational approach to treat transient thermal processes in a system of components with fast relative speed and different length scales. Finally, the investigated thermal transport mechanism leads to a substantial spacing change that has a significant impact on the spacing margin of today’s magnetic storage systems.
An exotic band structure of a supramolecular honeycomb lattice formed by a pancake π–π interaction between triradical trianions of triptycene tribenzoquinone
Authors: Shuku Yoshiaki , Mizuno Asato , Ushiroguchi Ryo , Hyun Chang Seok , Ryu Young Jun , An Byeong-Kwan , Kwon Ji Eon , Park Soo Young , Tsuchiizu Masahisa , Awaga Kunio
Published: February 2018

Triradical trianions of triptycene tribenzoquinone form a supramolecular honeycomb lattice.
A “peak cut” procedure of column separation for calcium isotope measurement using the double spike technique and thermal ionization mass spectrometry (TIMS)
Authors: Zhu Hongli , Liu Fang , Li Xin , An Yajun , Wang Guiqin , Zhang Zhaofeng
Published: February 2018

We propose a “peak cut” procedure of column separation for calcium isotope measurement using the double spike technique and thermal ionization mass spectrometry (TIMS).
The influence of the double spike proportion effect on stable isotope (Zn, Mo, Cd, and Sn) measurements by multicollector-inductively coupled plasma-mass spectrometry (MC-ICP-MS)
Authors: Zhang Le , Li Jie , Xu Yi-Gang , Ren Zhong-Yuan
Published: February 2018

This study investigates the double spike (DS) proportion effect on measurements of stable Zn, Mo, Cd, and Sn isotopes by multicollector-inductively coupled plasma-mass spectrometry (MC-ICP-MS).
Atomic Spectrometry Update: review of advances in the analysis of clinical and biological materials, foods and beverages
Authors: Taylor Andrew , Barlow Nicola , Day Martin P. , Hill Sarah , Martin Nicholas , Patriarca Marina
Published: February 2018

This review discusses developments in elemental mass spectrometry, atomic absorption, emission and fluorescence, XRF and LIBS, as applied to the analysis of specimens of clinical interest, foods and beverages. Sample preparation procedures and quality assurance are also included.
Passband reconstruction from photometry
Authors: Weiler M. , Jordi C. , Fabricius C. , Carrasco J. M.
Published: February 2018

Context. Based on an initial expectation from laboratory measurements or instrument simulations, photometric passbands are usually subject to refinements. These refinements use photometric observations of astronomical sources with known spectral energy distribution.

Aims. This work investigates the methods for and limitations in determining passbands from photometric observations. A simple general formalism for passband determinations from photometric measurements is derived. The results are applied to the passbands of HIPPARCOS, Tycho, and Gaia DR1.

Methods. The problem of passband determination is formulated in a basic functional analytic framework. For the solution of the resulting equations, functional principal component analysis is applied.

Results. We find that, given a set of calibration sources, the passband can be described with respect to the set of calibration sources as the sum of two functions, one which is uniquely determined by the set of calibration sources, and one which is entirely unconstrained. The constrained components for the HIPPARCOS, Tycho, and Gaia DR1 passbands are determined, and the unconstrained components are estimated.
Online Event Reconstruction in the CBM Experiment at FAIR
Authors: Akishina Valentina , Kisel Ivan
Published: February 2018

Targeting for rare observables, the CBM experiment will operate at high interaction rates of up to 10 MHz, which is unprecedented in heavy-ion experiments so far. It requires a novel free-streaming readout system and a new concept of data processing. The huge data rates of the CBM experiment will be reduced online to the recordable rate before saving the data to the mass storage. Full collision reconstruction and selection will be performed online in a dedicated processor farm. In order to make an efficient event selection online a clean sample of particles has to be provided by the reconstruction package called First Level Event Selection (FLES).

The FLES reconstruction and selection package consists of several modules: track finding, track fitting, event building, short-lived particles finding, and event selection. Since detector measurements contain also time information, the event building is done at all stages of the reconstruction process. The input data are distributed within the FLES farm in a form of time-slices. A time-slice is reconstructed in parallel between processor cores. After all tracks of the whole time-slice are found and fitted, they are collected into clusters of tracks originated from common primary vertices, which then are fitted, thus identifying the interaction points. Secondary tracks are associated with primary vertices according to their estimated production time. After that short-lived particles are found and the full event building process is finished. The last stage of the FLES package is a selection of events according to the requested trigger signatures. The event reconstruction procedure and the results of its application to simulated collisions in the CBM detector setup are presented and discussed in detail.
Shape Approximation Based on Higher-Degree Polynomials
Authors: Dikusar Nikolay
Published: February 2018

The planar shape (contour) of an object is a fundamental source of information in a pattern recognition problem. Obtaining the relevant information set rests on difficult procedures and is a key problem in pattern recognition. A method is proposed for the segmentation of contours with a complex geometrical form. It is based on a parametric piecewise approximation of 12th order spanned by a polynomial model defined by basic elements. Higher-order polynomial approximation allows to optimize the number of segments on the contour and to obtain analytically the dependence of the curvature for more exact calculation of informative signs that are invariant to geometrical transformations. The algorithm based on this method as well as specific examples are described in detail.
Application of Power Geometry and Normal Form Methods to the Study of Nonlinear ODEs
Authors: Edneral Victor
Published: February 2018

This paper describes power transformations of degenerate autonomous polynomial systems of ordinary differential equations which reduce such systems to a non-degenerative form. Example of creating exact first integrals of motion of some planar degenerate system in a closed form is given.
Two-Stage Approach to Image Classification by Deep Neural Networks
Authors: Ososkov Gennady , Goncharov Pavel
Published: February 2018

The paper demonstrates the advantages of the deep learning networks over the ordinary neural networks on their comparative applications to image classifying. An autoassociative neural network is used as a standalone autoencoder for prior extraction of the most informative features of the input data for neural networks to be compared further as classifiers. The main efforts to deal with deep learning networks are spent for a quite painstaking work of optimizing the structures of those networks and their components, as activation functions, weights, as well as the procedures of minimizing their loss function to improve their performances and speed up their learning time. It is also shown that the deep autoencoders develop the remarkable ability for denoising images after being specially trained. Convolutional Neural Networks are also used to solve a quite actual problem of protein genetics on the example of the durum wheat classification. Results of our comparative study demonstrate the undoubted advantage of the deep networks, as well as the denoising power of the autoencoders. In our work we use both GPU and cloud services to speed up the calculations.
On the Relativistic Separable Functions for the Breakup Reactions
Authors: Bondarenko Serge G. , Burov Valery V. , Rogochaya Elena P.
Published: February 2018

In the paper the so-called modified Yamaguchi function for the Bethe-Salpeter equation with a separable kernel is discussed. The type of the functions is defined by the analytic stucture of the hadron current with breakup - the reactions with interacting nucleon-nucleon pair in the final state (electro-, photo-, and nucleon-disintegration of the deuteron).
Splitting of Potential Curves in the Two-Coulomb-Centre Problem
Authors: Hnatič Michal , Khmara Viktor M. , Lazur Volodymyr Yu. , Reity Oleksandr K.
Published: February 2018

The quasiclassical expression for the exchange interaction ∆E of potential curves at the points of their quasicrossing in the two-Coulomb-centre problem is found. It can be used for the calculation of cross sections of charge exchange processes between hydrogen or hydrogen-like atoms and bare nuclei.
On the Stratifications of 2-Qubits X-State Space
Authors: Khvedelidze Arsen , Torosyan Astghik
Published: February 2018

The 7-dimensional family ℬX of the so-called mixed X-states of 2-qubits is considered. Two versions of stratifications of ℬX , i.e., its decomposition into strata according to orbit types of the adjoint actions of two groups, are described. The first stratification is due to the action of global unitary group GX ⊂ S U(4), while the second one corresponds to the action of the local unitary group LGX ⊂ GX . The equations and in-equalities in the invariants of the corresponding groups, determining each stratification component, are given.
Minimum Period of Rotation of Millisecond Pulsars and Pulsar Matter Equations of State
Authors: Mikheev Sergey , Tsvetkov Victor
Published: February 2018

Based on the findings of our previous studies of fast-rotating Newtonian polytropes, we found the relation between the minimum pulsar rotation period, the value of pulsar central density, and the polytropic index. From this relation we come to the conclusion that the value of minimum central density of a pulsar with a peak period is 2.5088 • 1014 g/cm3.
Generalized Darcy’s Law in Filtration Theory
Authors: Rybakov Yuri P. , Semenova Natalya V.
Published: February 2018

We study the hydrodynamics of flow in a porous medium modeling the grain filling in filters. Using the lattice approximation, we derive the structure of the current in porous media and obtain the transverse diffusion coefficient D which proves to be proportional to the diameter d of the grains as constituents of the medium. We consider the axially-symmetric stationary flow in a cylindrical filter and show that the vertical velocity takes its maximal value at the wall, this effect being known as the “near-wall” one. We analyze the solution to the Euler equation with the modified Darcy force, which depends not only on the velocity but also on the gradient of the pressure included in the Darcy coefficient. Finally, within the scope of the perturbation method, we derive the main filtration equation and discuss the influence of modifying the Darcy’s law on the efficiency of the filtration process.
Modeling Static Electric Field Effect on Nematic Liquid Crystal Director Orientation in Side-Electrode Cell
Authors: Ayriyan Alexander , Ayryan Edik , Egorov Alexandre , Dencheva-Zarkova Maria , Hadjichristov Georgi , Marinov Yordan , Maslyanitsyn Igor , Petrov Alexander , Popova Lidia , Shigorin Vladimir , Strigazzi Alfredo , Torgova Sofia
Published: February 2018

A two-dimensional model of Fredericks effect was used for the investigation of the static electric field influence on nematic liquid crystal director orientation in the side-electrode cell. The solutions of the equations describing the model were obtained by finite-difference methods. Fredericks transition threshold for the central part of the cell, as well as dependencies of the distribution of the director orientation patterns on the electric field and location, were obtained. The numerical results are found to agree qualitatively with the experiment. Further investigations are needed to elucidate completely the Fredericks effect.
High-Accuracy Finite Element Method: Benchmark Calculations
Authors: Gusev Alexander , Vinitsky Sergue , Chuluunbaatar Ochbadrakh , Chuluunbaatar Galmandakh , Gerdt Vladimir , Derbov Vladimir , Góźdź Andrzej , Krassovitskiy Pavel
Published: February 2018

We describe a new high-accuracy finite element scheme with simplex elements for solving the elliptic boundary-value problems and show its efficiency on benchmark solutions of the Helmholtz equation for the triangle membrane and hypercube.
Generating Function Approach to the Derivation of Higher-Order Iterative Methods for Solving Nonlinear Equations
Authors: Zhanlav Tugal , Chuluunbaatar Ochbadrakh , Ulziibayar Vandandoo
Published: February 2018

In this paper we propose a generating function method for constructing new two and three-point iterations withp(p= 4, 8) order of convergence. This approach allows us to derive a new family of optimal order iterative methods that include well known methods as special cases. Necessary and sufficient conditions forp-th (p= 4, 8) order convergence of the proposed iterations are given in terms of parameters τnand αn. We also propose some generating functions for τnand αn. We develop a unified representation of all optimal eighth-order methods. The order of convergence of the proposed methods is confirmed by numerical experiments.
Time-based Reconstruction of Free-streaming Data in CBM
Authors: Akishina Valentina , Kisel Ivan , Vassiliev Iouri , Zyzak Maksym
Published: February 2018

Traditional latency-limited trigger architectures typical for conventional experiments are inapplicable for the CBM experiment. Instead, CBM will ship and collect time-stamped data into a readout buffer in a form of a time-slice of a certain length and deliver it to a large computer farm, where online event reconstruction and selection will be performed. Grouping measurements into physical collisions must be performed in software and requires reconstruction not only in space, but also in time, the so-called 4-dimensional track reconstruction and event building. The tracks, reconstructed with 4D Cellular Automaton track finder, are combined into event-corresponding clusters according to the estimated time in the target position and the errors, obtained with the Kalman Filter method. The reconstructed events are given as inputs to the KF Particle Finder package for short-lived particle reconstruction. The results of time-based reconstruction of simulated collisions in CBM are presented and discussed in details.
Fitting by Orthonormal Polynomials of Silver Nanoparticles Spectroscopic Data
Authors: Bogdanova Nina , Koleva Mihaela
Published: February 2018

Our original Orthonormal Polynomial Expansion Method (OPEM) in one-dimensional version is applied for first time to describe the silver nanoparticles (NPs) spectroscopic data. The weights for approximation include experimental errors in variables. In this way we construct orthonormal polynomial expansion for approximating the curve on a non equidistant point grid. The corridors of given data and criteria define the optimal behavior of searched curve. The most important subinterval of spectra data is investigated, where the minimum (surface plasmon resonance absorption) is looking for. This study describes the Ag nanoparticles produced by laser approach in a ZnO medium forming a AgNPs/ZnO nanocomposite heterostructure.
Mock Data Challenge for the MPD/NICA Experiment on the HybriLIT Cluster
Authors: Gertsenberger Konstantin , Rogachevsky Oleg
Published: February 2018

Simulation of data processing before receiving first experimental data is an important issue in high-energy physics experiments. This article presents the current Event Data Model and the Mock Data Challenge for the MPD experiment at the NICA accelerator complex which uses ongoing simulation studies to exercise in a stress-testing the distributed computing infrastructure and experiment software in the full production environment from simulated data through the physical analysis.
Heavy Ion Fragmentation Reactions at Energies of 35–140 MeV in a Combined Transport and Statistical Approach
Authors: Mikhailova Tatiana , Erdemchimeg Batchuluun , Artukh Anatoliy , Sereda Yuriy , Toro Massimo Di , Wolter Hermann H.
Published: February 2018

Fragment formation in heavy ion collisions at low to intermediate energy is described by a combined application of transport theory of the Boltzmann type and of a statistical program for the decay of the fragments at the late stage. The transport equations are solved by simulations using the test particle method as a finite element representation of the phase space distribution. The description of experimental data is reasonable overall, but the fragment velocity distributions point to the presence of other mechanisms and the role of fluctuations.
Simulation of Radiation Damage to Neural Cells with the Geant4-DNA Toolkit
Authors: Bayarchimeg Lkhagvaa , Batmunkh Munkhbaatar , Belov Oleg , Lkhagva Oidov
Published: February 2018

To help in understanding the physical and biological mechanisms underlying effects of cosmic and therapeutic types of radiation on the central nervous system (CNS), we have developed an original neuron application based on the Geant4 Monte Carlo simulation toolkit, in particular on its biophysical extension Geant4-DNA. The applied simulation technique provides a tool for the simulation of physical, physico-chemical and chemical processes (e.g. production of water radiolysis species in the vicinity of neurons) in realistic geometrical model of neural cells exposed to ionizing radiation. The present study evaluates the microscopic energy depositions and water radiolysis species yields within a detailed structure of a selected neuron taking into account its soma, dendrites, axon and spines following irradiation with carbon and iron ions.
Parallel Implementation of Numerical Solution of Few-Body Problem Using Feynman’s Continual Integrals
Authors: Naumenko Mikhail , Samarin Viacheslav
Published: February 2018

Modern parallel computing algorithm has been applied to the solution of the few-body problem. The approach is based on Feynman’s continual integrals method implemented in C++ programming language using NVIDIA CUDA technology. A wide range of 3-body and 4-body bound systems has been considered including nuclei described as consisting of protons and neutrons (e.g., 3,4He) and nuclei described as consisting of clusters and nucleons (e.g., 6He). The correctness of the results was checked by the comparison with the exactly solvable 4-body oscillatory system and experimental data.