bluuebunny/crossref_metadata_2025 huggingface dataset:
Overview of Engineering Mathematics Education for STEM in Armenia
Authors: Hovhannisyan Ishkhan
Published: July 2018

The higher education system in Armenia consists of a number of higher education institutions (HEIs), both state and private. State higher education institutions operate under the responsibility of several ministries, but most of them are under the supervision of the Ministry of Education and Science. At present there are 26 state and 41 private higher education institutions operating in the Republic of Armenia (RA), of which 35 are accredited institutions, 6 are non-accredited institutions, 3 are branches of state HEIs and 4 are branches of private HEIs from the Commonwealth of Independent States (CIS). Higher education is provided by many types of institutions: institutes, universities, academies and a conservatory.
The Prognostic Value of Preoperative Neutrophil‐to‐Lymphocyte Ratio in Resected Patients with Pancreatic Adenocarcinoma
Authors: Fang Le‐ping , Xu Xiao‐yan , Ji Yu , Huang Pu‐wen
Published: July 2018

Purpose

This research aims to analyze neutrophil‐to‐lymphocyte ratio (NLR) for resectable pancreatic ductal adenocarcinoma (PDAC) patients and reveal its predictive value.

Methods

We enrolled 389 pancreatic adenocarcinoma patients who had undergone curative surgery between January 1, 2008 and August 15, 2015 in Jiangsu Provincial People’s Hospital, and they were followed up until December 20, 2016. Among them, 219 patients had definite recurrence record in our hospital. The appropriate cutoff value for the NLR was obtained from X‐tile software. The association between qualitative variables and NLR was analyzed by Chi‐square test or Fisher’s exact test, and for quantitative values, the association was analyzed by independent Student’s t test. Additionally, survival analysis was performed by Kaplan–Meier plots. Independent prognostic factors were found according to Cox regression analysis.

Results

Based on univariate analysis, the elevated preoperative NLR had an important influence on the decreased recurrence‐free survival (RFS) (8.2 vs. 14.9 months) and overall survival (OS) (13.7 vs. 22 months), and this result also counted in the multivariate analysis. Regarding OS, both patients with or without postoperative chemotherapy can obtain benefits from low NLR according to subgroup analysis. Stage I and II pancreatic adenocarcinoma patients can get longer OS and RFS from low NLR, while patients with stage III cancer cannot. Regarding recurrence site, high NLR level was also related to distant metastasis (P = 0.02).

Conclusion

Preoperative NLR level could be a useful prognostic indication for resectable pancreatic adenocarcinoma patients.
Postoperative Small Bowel Obstruction Following Laparoscopic or Open Fundoplication in Children: A Retrospective Analysis Using a Nationwide Database
Authors: Fujiogi Michimasa , Michihata Nobuaki , Matsui Hiroki , Fushimi Kiyohide , Yasunaga Hideo , Fujishiro Jun
Published: July 2018

Background

Postoperative small bowel obstruction (SBO) is one of the most serious adverse events resulting in deteriorated quality of life in children. Numerous studies have shown that laparoscopic surgery significantly reduces the occurrence of SBO compared with open surgery in adults. However, evidence of the advantages of laparoscopic surgery over open surgery in terms of reducing SBO is lacking in children. Fundoplication is a common abdominal procedure in children. This study was performed to compare the occurrence of SBO after laparoscopic fundoplication (LF) versus open fundoplication (OF).

Methods

Using the Diagnosis Procedure Combination database, a national inpatient database in Japan, we retrospectively identified patients aged 0–18 years who underwent LF or OF from July 2010 to March 2016. Propensity score adjustment was used to compare the occurrence of SBO between the groups.

Results

We identified 1838 eligible patients who underwent LF (n = 1362) or OF (n = 476). The median age at surgery was 4.0 and 1.5 years in the LF and OF group, respectively (P < 0.001). The median weight at admission was 11.4 and 7.5 kg, respectively (P < 0.001). Nineteen (1.4%) patients in the LF group and 13 (2.7%) in the OF group had at least one episode of SBO (P = 0.11, log‐rank test). In the propensity score‐adjusted Cox regression analysis, SBO was significantly less likely to occur in the LF than OF group (hazard ratio, 0.36; 95% confidence interval 0.16–0.82; P = 0.01).

Conclusions

In this retrospective nationwide study, LF was significantly associated with a reduction in SBO compared with OF in children.
Synaptic metabolism: a new approach to inborn errors of neurotransmission
Authors: Tristán‐Noguero Alba , García‐Cazorla Àngels
Published: July 2018

To date, inborn errors of neurotransmitters have been defined based on the classic concept of inborn error of metabolism (IEM), and they include defects in synthesis, catabolism, and transport pathways. However, the omics era is bringing insights into new diseases and is leading to an extended definition of IEM including new categories and mechanisms. Neurotransmission takes place at the synapse, the most specialized tight junction in the brain. The concept of “synaptic metabolism” would point to the specific chemical composition and metabolic functions of the synapse. Based on these specialized functions, we aim to provide a tentative overview about the major categories of IEM susceptible to affect neurotransmission. Small molecule defects (biogenic amines and amino acids) and energy defects are amongst the most prevalent diseases reported to disturb the concentration of CSF neurotransmitters. In these IEM, the neurological phenotypes have been largely described. Disorders of complex molecules are not typically considered as diseases affecting neurotransmission. However, most of them have been recently discovered and are involved in intracellular vesiculation, trafficking, processing, and quality control mechanisms. In this large group, neurotransmission is affected in disorders of chaperones and autophagy, disorders of the synaptic vesicle, and diseases affecting pre‐synaptic membranes (synthesis and remodeling of complex lipids, defects of glycosylation). Disorders of the vesicle pools, receptor trafficking, and the chronobiology of neurotransmission are potentially emerging new categories. Finally, although not considered as IEM, channelopathies are a large group of diseases disturbing neurotransmitter homeostasis. New CSF biomarkers will probably contribute to improve the diagnosis of these disorders and find new therapeutic targets.
Sequence stratigraphy of the Berriassian–Lower Aptian deposits of West Siberia
Authors: Ershov S.V.
Published: July 2018

The geological structure and conditions of formation of a Lower Cretaceous clinoform complex in West Siberia are examined based on sequence stratigraphy. The regional Berriasian–Hauterivian clinoforms are interpreted as third-order sequences, and their formation should be considered in terms of the Depositional Sequence III model. Productive beds of both shallow and deep marine as well as continental genesis formed mostly in a regressive basin and belong to the highstand systems tracts.
Monolithic high-average-power linearly polarized nanosecond pulsed fiber laser with near-diffraction-limited beam quality
Authors: Huang Long , Ma Pengfei , Meng Daren , Li Lei , Tao Rumao , Su Rongtao , Ma Yanxing , Zhou Pu
Published: July 2018

An all-fiberized high-average-power narrow linewidth ns pulsed laser with linear polarization is demonstrated. The laser system utilizes a typical master oscillator power amplifier (MOPA) configuration. The stimulated Brillouin scattering (SBS) is effectively suppressed due to the short fiber length and large mode area in the main amplifier, combined with the narrow pulse duration smaller than the phonon lifetime of SBS effect. A maximal output power of 466 W is obtained with a narrow linewidth of ${\sim}$203.6 MHz, and the corresponding slope efficiency is ${\sim}$80.3%. The pulse duration is condensed to be ${\sim}$4 ns after the amplification, corresponding to the peak power of 8.8 kW and the pulse energy of $46.6~\unicode[STIX]{x03BC}\text{J}$. Near-diffraction-limited beam quality with an $M^{2}$ factor of 1.32 is obtained at the output power of 442 W and the mode instability (MI) is observed at the maximal output power. To the best of our knowledge, this is the highest average output power of the all-fiberized narrow linewidth ns pulsed fiber laser with linear polarization and high beam quality, which is a promising source for the nonlinear frequency conversion, laser lidar, and so on.
Borderline personality disorder: resource utilisation costs in Ireland
Authors: Bourke J. , Murphy A. , Flynn D. , Kells M. , Joyce M. , Hurley J.
Published: July 2018

Objectives

Borderline personality disorder (BPD) is characterised by recurring crises, hospitalisations, self-harm, suicide attempts, addictions, episodes of depression, anxiety and aggression and lost productivity. The objective of this study is to determine the use of direct health care resources by persons with BPD in Ireland and the corresponding costs.

Methods

This prevalence-based micro-costing study was undertaken on a sample of 196 individuals with BPD attending publicly funded mental health services in Ireland. All health care costs were assessed using a resource utilisation questionnaire completed by mental health practitioners. A probabilistic sensitivity analysis, using a Monte Carlo simulation, was performed to examine uncertainty.

Results

Total direct healthcare cost per individual was €10 844 annually (ranging from 5228 to 20 609). Based on a prevalence of 1% and an adult population (18–65 years) of 2.87 million, we derived that there were 28 725 individuals with BPD in Ireland. Total yearly cost of illness was calculated to be up to €311.5 million.

Conclusions

There is a dearth of data on health care resource use and costs of community mental health services in Ireland. The absence of this data is a considerable constraint to research and decision-making in the area of community mental health services. This paper contributes to the limited literature on resource use and costs in community mental health services in Ireland. The absence of productivity loss data (e.g. absenteeism and presenteeism), non-health care costs (e.g. addiction treatment), and indirect costs (e.g. informal care) from study participants is a limitation of this study.
Older assistant nurses’ motivation for a full or extended working life
Authors: Gyllensten Kristina , Wentz Kerstin , Håkansson Carita , Hagberg Mats , Nilsson Kerstin
Published: July 2018

The aim of this study was to explore older workers’ motivation for a full or extended working life. With particular focus on assistant nurses aged 55–64 years, working in the elderly care sector. Focus group interviews were conducted with five different groups of assistant nurses. Inductive thematic analysis was used to analyse the interviews and five main themes were developed from the data: ‘Organisational issues’, ‘Health-related problems’, ‘Private issues’, ‘Meaningfulness and appreciation’ and ‘Social support’. Several of the main themes concerned problems with too high work demands of the assistant nurses. These findings suggest that it is important to improve the working conditions of assistant nurses in order to create a more sustainable working life. Increasing the number of staff and improving recovery opportunities and work–life balance could be important steps to improving the working conditions for this group. Finally, upgrading the competency and professionalism of assistant nurses could help to increase the motivation for a full or extended working life.
Non-coeliac gluten sensitivity and the spectrum of gluten-related disorders: an updated overview
Authors: Dale Hanna Fjeldheim , Biesiekierski Jessica R. , Lied Gülen Arslan
Published: July 2018

The spectrum of gluten-related disorders includes coeliac disease (CD), wheat allergy (WA) and the suggested entity of non-coeliac gluten sensitivity (NCGS). An increasing number of the world’s population are avoiding gluten due to the assumption of health benefits and self-diagnosed gastrointestinal and/or extra-intestinal symptoms. Unlike CD and WA, NCGS is a relatively new entity with an unknown prevalence and mechanisms, complicated by recent literature suggesting that gluten is not the only food component that may trigger symptoms experienced by this group of patients. The term ‘non-coeliac wheat sensitivity’ has been proposed as a more accurate term, allowing inclusion of other non-gluten wheat components such as fructans and amylase–trypsin inhibitors. There is inconsistent evidence when evaluating the effects of a gluten challenge in patients with suspected NCGS and there is a need for a standardised procedure to confirm the diagnosis, ultimately enabling the optimisation of clinical care. The present review will give an overview of the different gluten-related disorders and discuss the most recent scientific evidence investigating NCGS.
Association of direct and indirect aggression and victimization with self-harm in young adolescents: A person-oriented approach
Authors: Daukantaitė Daiva , Lundh Lars-Gunnar , Wångby-Lundh Margit
Published: July 2018

We sought to determine which patterns of direct and indirect aggression and victimization are most clearly associated with self-harm in adolescent girls and boys cross-sectionally at two time points, as well as prospectively over one year. A cluster analysis using the LICUR procedure (Bergman, 1998) was employed to identify stable patterns of aggression and victimization in a community cohort of 883 Swedish adolescents (51% girls; mean age 14.5). The results showed that a pattern combining high aggression with high victimization was consistently associated with high levels of self-harm in both genders, both cross-sectionally and prospectively. Additionally, this pattern of aggressive victims was a clear risk factor for the development of repetitive self-harm over a one-year period in both girls (odds ratio 13.58) and boys (odds ratio 5.72). We also found several gender differences: In girls, subgroups characterized by high victimization (aggressive victims and non-aggressive victims) had the highest levels of self-harm, whereas in boys the patterns characterized by high aggression (aggressive victims and aggressive non-victims) seemed more relevant. The findings concerning the aggressive victim cluster are clear warning signs of severe psychopathology and possible psychiatric diagnosis in this subgroup of girls and boys.
Allen–Cahn equation with strong irreversibility
Authors: AKAGI GORO , EFENDIEV MESSOUD
Published: July 2018

This paper is concerned with a fully non-linear variant of the Allen–Cahn equation with strong irreversibility, where each solution is constrained to be non-decreasing in time. The main purposes of this paper are to prove the well-posedness, smoothing effect and comparison principle, to provide an equivalent reformulation of the equation as a parabolic obstacle problem and to reveal long-time behaviours of solutions. More precisely, by derivingpartialenergy-dissipation estimates, a global attractor is constructed in a metric setting, and it is also proved that each solutionu(x,t) converges to a solution of an elliptic obstacle problem ast→ +∞.
The role of propofol on mouse oocyte meiotic maturation and early embryo development
Authors: Duan Xia-Guang , Huang Zai-Qing , Hao Chun-Guang , Zhi Xiao-Jun , Qi Xiao-Bing , Ren Ling , Luan Sheng-Hui , Liang Cheng-Guang
Published: July 2018

Propofol is a intravenous anaesthetic most commonly used in ultrasound oocyte retrieval. We studied if the use of propofol had an effect on mouse oocyte maturation, pregnancy, childbirth and progeny and investigated the correlation between propofol side effects and reproductive performance in mice. There was no statistical difference in mating, pregnancy, childbirth, litter size, the number of stillbirths and survival between each group (P>0.05). Propofol also had no effect on polar body extrusion in oocyte maturation as well as on pronucleus formation and, subsequently, early embryo development (P>0.05). An increased concentration of propofol had no effect on this result, although propofol at more than 0.01 mg/ml reduced polar body extrusion. Different concentrations of propofol had no effect on oocyte culture in vitro, pronucleus formation and early embryo development.
China’s Long March to Central and Eastern Europe
Authors: Song Weiqing
Published: July 2018

This essay provides a timely account of China’s recent initiatives in Central and Eastern Europe (CEE), centring on the ‘16+1’ format. It discusses China’s motivation in this part of Europe in relation to its ‘Go Global’ policy and, more recently and relevantly, the ‘One Road, One Belt’ initiative. It argues that China has made big efforts to strengthen its presence in CEE through state-driven commercialism. While there have been some meaningful outcomes, particularly in building institutional ties, China’s ambition in the CEE region faces some practical and deep-rooted obstacles. Put succinctly, there is still a long way to go before China becomes a mature global power.
Quality assurance of volumetric-modulated arc therapy head and neck cancer treatment using PRESAGE® dosimeter
Authors: ur Rehman Jalil , Isa Muhammad , Ahmad Nisar , Noor ul Huda Khan Asghar H. M. , Gilani Zaheer A. , Chow James C. L. , Afzal Muhammad , Ibbott Geoffrey S.
Published: July 2018

Background

Accurate three-dimensional dosimetry is essential in modern radiotherapy techniques such as volumetric-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). In this research work, the PRESAGE® dosimeter was used as quality assurance (QA) tool for VMAT planning for head and neck (H&N) cancer.

Material and method

Computer tomography (CT) scans of an Image Radiation Oncology Core (IROC) H&N anthropomorphic phantom with both IROC standard insert and PRESAGE® insert were acquired separately. Both CT scans were imported into the Pinnacle (9.4 version) TPS for treatment planning, where the structures [planning target volume (PTV), organs at risk) and thermoluminescent detectors (TLDs) were manually contoured and used to optimise a VMAT plan. Treatment planning was done using VMAT (dual arc: 182°–178°, 178°–182°). Beam profile comparisons and gamma analysis were used to quantify agreement with film, PRESAGE® measurement and treatment planning system (TPS) calculated dose distribution.

Results

The average ratio of TLD measured to calculated doses at the four PTV locations in the H&N phantom were between 0·95 to 0·99 for all three VMAT deliveries. Dose profiles were taken along the left–right, the anterior–posterior and superior–inferior axes, and good agreement was found between the PRESAGE® and Pinnacle profile. The mean value of gamma results for three VMAT deliveries in axial and sagittal planes were found to be 94·24 and 93·16% when compared with film and Pinnacle, respectively. The average values comparing the PRESAGE® results and dose values calculated on Pinnacle were observed to be 95·29 and 94·38% in the said planes, respectively, using a 5%/3 mm gamma criteria.

Conclusion

The PRESAGE® dose measurements and calculated dose of pinnacle show reasonable agreement in both axial and sagittal planes for complex dual arc VMAT treatment plans. In general, the PRESAGE® dosimeter is found to be a feasible QA tool of VMAT plan for H&N cancer treatment.
SMA, VLA and VLBA observations in a 105 L⊙ high mass star formation region IRAS 18360-0537
Authors: Wu Gang , Qiu Keping , Esimbek Jarken , Zheng Xingwu
Published: July 2018

We have observed a young stellar object, IRAS 18360-0537, with a far-infrared luminosity of 1.2 × 105 L⊙. It is perhaps the most promising candidate of a high-mass protostar associated with a Keplerian disk and a jet/outflow system in the regime of L > 105L⊙. We are conducting the SMA, VLA, and VLBA studies to provide a comprehensive understanding of this interesting high mass star formation scenario.
Statistical analysis of the physical properties of the 6.7 GHz methanol maser features based on VLBI data
Authors: Sarniak R. , Szymczak M. , Bartkiewicz A.
Published: July 2018

Methanol masers observed at high angular resolution are useful tool to investigate the processes of high-mass star formation. Here, we present the results of statistical analysis of the 6.7 GHz methanol maser structures in 60 sources observed with the EVN. The parameters of the maser clouds and exciting stars were derived. There is evidence that the emission structures composed of larger number of maser clouds are formed in the vicinity of more luminous exciting stars.
Missing flux in VLBI observations of SiO maser at 7 mm in IRC+10011
Authors: Desmurs J.-F. , Alcolea J. , Bujarrabal V. , Colomer F. , Soria-Ruiz R.
Published: July 2018

VLBI observations of SiO masers recover at most 40-50% of the total flux obtained by single dish observations at any spectral channel. Some previous studies seems to indicate that, at least, part of the lost flux is divided up into many weak components rather than in a large resolved emission area. Taking benefit of the high sensitivity and resolution of the HSA, we investigate the problem of the missing flux in VLBI observations of SiO maser emission at 7 mm in the AGB stars and obtain a high dynamic range map of IRC+10011. We conclude that the missing flux is mostly contained in many very weak maser components.
Masers as probes of the gas dynamics close to forming high-mass stars
Authors: Moscadelli Luca , Sanna Alberto , Goddi Ciriaco
Published: July 2018

Imaging the inner few 1000 AU around massive forming stars, at typical distances of several kpc, requires angular resolutions of better than 0″.1. Very Long Baseline Interferometry (VLBI) observations of interstellar molecular masers probe scales as small as a few AU, whereas (new-generation) centimeter and millimeter interferometers allow us to map scales of the order of a few 100 AU. Combining these informations all together, it presently provides the most powerful technique to trace the complex gas motions in the proto-stellar environment. In this work, we review a few compelling examples of this technique and summarize our findings.
Extragalactic class I methanol maser: A new probe for starbursts and feedback of galaxies
Authors: Chen Xi , Ellingsen Simon P.
Published: July 2018

We report progress on research relating to 36.2 GHz extragalactic class I methanol masers, including a review of published work and new observations at high angular resolution. These observations reveal that extragalactic class I masers are excited in shocked gas and maybe associated with starbursts, galactic-scale outflows from active galactic nuclei (AGNs) feedback, or the inner-end region of the galactic bar. The current observational results suggests that extragalactic class I methanol masers provide a new probe for starbursts and feedback in active galaxies.
How maser observations unravel the gas motions in the Galactic Center
Authors: Immer K. , Reid M. , Brunthaler A. , Menten K. , Zhang Q. , Lu X. , Mills E. A. C. , Ginsburg A. , Henshaw J. , Longmore S. , Kruijssen D. , Pillai T.
Published: July 2018

The Central Molecular Zone (CMZ), the inner 450 pc of our Galaxy, is an exceptional region where the volume and column densities, gas temperatures, velocity dispersions, etc. are much higher than in the Galactic plane. It has been suggested that the formation of stars and clusters in this area is related to the orbital dynamics of the gas. The complex kinematic structure of the molecular gas was revealed by spectral line observations. However, these results are limited to the line-of-sight-velocities. To fully understand the motions of the gas within the CMZ, we have to know its location in 6D space (3D location + 3D motion). Recent orbital models have tried to explain the inflow of gas towards and its kinematics within this region. With parallax and proper motion measurements of masers in the CMZ we can discriminate among these models and constrain how our Galactic Center is fed with gas.
A study on evolved stars by simultaneous observations of H2O and SiO masers using KVN
Authors: Cho Se-Hyung , Yun Youngjoo , Kim Jaeheon , Yoon Dong-Hwan , Kim Dong-Jin , Choi Yoon Kyung , Dodson Richard , Rioja María , Imai Hiroshi
Published: July 2018

The Korean VLBI Network (KVN) is a unique millimeter VLBI system which is consisted of three 21 m telescopes with relatively short baselines. We present the preliminary results of simultaneous monitoring observations of the 22.2 GHz H2O and 43.1/42.8/86.2/129.3 GHz SiO masers based on the KVN Key Science Project (KSP). We obtained the astrometrically registered maps of the H2O and SiO masers toward nine evolved stars using the source frequency phase referencing method (SFPR). The SFPR maps of the H2O and SiO masers enabled us to investigate the spatial structure and kinematics from the SiO to H2O maser regions including the development of an outward motion from the ring-like or elliptical structures of SiO masers to the asymmetric structures of the 22.2 GHz H2O maser features. In particular, the 86.2/129.3 GHz SiO (v=1, J=2–1 and J=3–2) masers were clearly imaged toward several objects for the first time. The SiO v=1, J=3–2 maser shows different distributions compared to those of the SiO v=1, 2, J=1–0 and v=1, J=2–1 masers implying a different physical condition.
Maser Emission in G 339.884−1.259
Authors: Krishnan V. , Moscadelli L. , Ellingsen S. P. , Bignall H. E. , Breen S. L. , Dodson R. , Hyland L. J. , Phillips C. J. , Reynolds C. , Stevens J.
Published: July 2018

We present multi–epoch VLBI observations of the methanol and water masers in the high–mass star formation region G 339.884−1.259, made using the Australian Long Baseline Array (LBA). Our sub–milliarcsecond precision measurements trace the proper motions of individual maser features in the plane of the sky. When combined with the direct line–of–sight radial velocity (vlsr), these measure the 3 D gas kinematics of the associated high–mass star formation region, allowing us to probe the dynamical processes to within 1000 AU of the core.
Maser, infrared and optical emission for late-type stars in the Galactic plane
Authors: Quiroga-Nuñez L. H. , van Langevelde H. J. , Sjouwerman L. O. , Pihlström Y. M. , Reid M. J. , Brown A. G. A. , Green J. A.
Published: July 2018

Radio astrometric campaigns using VLBI have provided distances and proper motions for masers associated with young massive stars (BeSSeL survey). The ongoing BAaDE project plans to obtain astrometric information of SiO maser stars located in the inner Galaxy. These stars are associated with evolved, mass-losing stars. By overlapping optical (Gaia), infrared (2MASS, MSX and WISE) and radio (BAaDE) sources, we expect to obtain important clues on the intrinsic properties and population distribution of late-type stars. Moreover, a comparison of the Galactic parameters obtained with Gaia and VLBI can be done using radio observations on different targets: young massive stars (BeSSeL) and evolved stars (BAaDE).
On the origin of methanol maser variability: Clues from long-term monitoring
Authors: Szymczak M. , Olech M. , Sarniak R. , Wolak P. , Bartkiewicz A.
Published: July 2018

High-mass young stellar objects (HMYSO) displaying methanol maser flux variability probably trace a variety of phenomena such as accretion events, magnetospheric activity, stellar flares and stellar wind interactions in binary systems. A long-term monitoring of the 6.7 GHz methanol line in a large sample of HMYSOs has been undertaken to characterize the variability patterns and examine their origins. The majority of the masers show significant variability on time-scales between a week and a few years. High amplitude short flares of individual features occurred in several HMYSOs. The maser features with low luminosity tend to be more variable than those with high luminosity. The variability of the maser features increases when the bolometric luminosity the powering star decreases. Statistical analysis of basic properties of exciting objects and the variability measures supports an idea that burst activity of methanol masers is driven mainly by changes in the infrared pumping rate.
The Structure of the Radio Recombination Line Maser Emission in the Envelope of MWC349A
Authors: Moran James M. , Zhang Qizhou , Emery Deanna L.
Published: July 2018

The Submillimeter Array (SMA) has been used to image the emission from radio recombination lines of hydrogen at subarcsecond angular resolution from the young high-mass star MWC349A in the H26α, H30α, and H31α transitions at 353, 232, and 211 GHz, respectively. Emission was seen over a range of 80 km s−1 in velocity and 50 mas (corresponding to 60 AU for a distance of 1200 pc). The emission at each frequency has two distinct components, one from gas in a nearly edge-on annular disk structure in Keplerian motion, and another from gas lifted off the disk at distances of up to about 25 AU from the star. The slopes of the position-velocity (PV) curves for the disk emission show a monotonic progression of the emission radius with frequency with relative radii of 0.85 ± 0.04, 1, and 1.02 ± 0.01 for the H26α, H30α, and H31α transitions, respectively. This trend is consistent with theoretical excitation models of maser emission from a region where the density decreases with radius and the lower transitions are preferentially excited at higher densities. The mass is difficult to estimate from the PV diagrams because the wind components dominate the emission at the disk edges. The mass estimate is constrained to be only in the range of 10–30 solar masses. The distribution of the wind emission among the transitions is surprisingly different, which reflects its sensitivity to excitation conditions. The wind probably extracts significant angular momentum from the system.
Registration of H2O and SiO masers in the Calabash Nebula, to confirm the Planetary Nebula paradigm
Authors: Dodson R. , Rioja M. , Bujarrabal V. , Kim J. , Cho S. H. , Choi Y. K. , Youngjoo Y.
Published: July 2018

We report on the astrometric registration of VLBI images of the SiO and H2O masers in OH 231.8+4.2, the iconic Proto-Planetary Nebula also known as the Calabash nebula, using the KVN and Source/Frequency Phase Referencing. This, for the first time, robustly confirms the alignment of the SiO masers, close to the AGB star, which drives the bi-lobe structure with the water masers in the out-flow.
Masers and ALMA
Authors: Peck Alison B. , Impellizzeri C. M. Violette
Published: July 2018

Masers have been well-known phenomena for decades, but water masers at 183, 321, 325 and 658 GHz have only been detected since the 1990s. Early detections came from single-dish telescopes with follow-up observations from the PdBI and the Submillimeter Array. Detecting them at these short wavelengths has been very difficult due to water in our atmosphere, meaning that even in very good weather, one can only detect very bright masers, such as those in stellar atmospheres. In the last 7 years, a new window on submillimeter water masers, both Galactic and now extragalactic, has opened. Located at high altitude, above a large fraction of the Earth’s atmosphere, ALMA sits on the edge of the driest desert on the planet, meaning that the air that does remain above the telescope is frequently extremely low in water vapor content. Combine this with sensitive, stable receivers covering a number of masing transitions from 183-658 GHz and you have an excellent machine for detecting and characterizing submillimeter water masers. In addition, other molecules also exhibit maser emission in the ALMA observing bands, such as SiO and HCN.
Class II 6.7 GHz Methanol Maser Association with Young Massive Cores Revealed by ALMA
Authors: Chibueze James O. , Csengeri Timea , Tatematsu Ken’ichi , Hasegawa Tetsuo , Iguchi Satoru , Alhassan Jibrin A. , Higuchi Aya E. , Bontemps Sylvain , Menten Karl M.
Published: July 2018

The association of 6.7 GHz class II methanol (CH3OH) masers with ATLASGAL/ ALMA 0.9 mm massive dense cores is presented in this work from a statistical viewpoint. 42 of the 112 cores (37.5%) detected with the Atacama Compact Array (ACA) excite 6.7 GHz CH3OH masers. ACA cores have offsets 0\rlap.″17 to 4\rlap.″79 from the methanol multibeam survey (MMB), with a median of 2.″19. Approximately 90% of the MMB-associated cores are of masses > 40 M⊙. Because all the cores show evidence of outflow activity, and only a fraction of the cores excited CH3OH masers, we suggest that outflows precede the emergence of maser emission. This first ALMA survey of massive dense cores combined with the MMB survey along with other maser specie surveys is a promising tool to trace the evolutionary sequence of high-mass stars.
Constraining Theories of SiO Maser Polarization: Analysis of a π/2 EVPA Change
Authors: Tobin T. L. , Kemball A. J. , Gray M. D.
Published: July 2018

The full theory of polarized SiO maser emission from the near-circumstellar environment of Asymptotic Giant Branch stars has been the subject of debate, with theories ranging from classical Zeeman origins to predominantly non-Zeeman anisotropic excitation or propagation effects. Features with an internal electric vector position angle (EVPA) rotation of ∼π/2 offer unique constraints on theoretical models. In this work, results are presented for one such feature that persisted across five epochs of SiO ν = 1, J = 1 − 0 VLBA observations of TX Cam. We examine the fit to the predicted dependence of linear polarization and EVPA on angle (θ) between the line of sight and the magnetic field against theoretical models. We also present results on the dependence of mc on θ and their theoretical implications. Finally, we discuss potential causes of the observed differences, and continuing work.
Interferometric and single-dish observations of 44, 84 and 95 GHz Class I methanol masers
Authors: Rodríguez-Garza Carolina B. , Kurtz Stanley E. , Gómez-Ruiz Arturo I. , Hofner Peter , Araya Esteban D. , Kalenskii Sergei V.
Published: July 2018

We present observations of massive star-forming regions selected from the IRAS Point Source Catalog. The observations were made with the Very Large Array and the Large Millimeter Telescope to search for Class I methanol masers. We made interferometric observations of 125 massive star-forming regions in the 44 GHz methanol maser transition; 53 of the 125 fields showed emission. The data allow us to demonstrate associations, at arcsecond precision, of the Class I maser emission with outflows, HII regions and shocks traced by 4.5 μm emission. We made single-dish observations toward 38 of the 53 regions with 44 GHz masers detected to search for the methanol transitions at 84.5, 95.1, 96.7, 107.0, and 108.8 GHz. We find detection rates of 74, 55, 100, 3, and 45%, respectively. We used a wide-band receiver which revealed many other spectral lines that are common in star-forming regions.
The innermost regions of massive protostars traced by masers, high-resolution radio continuum, and near-infrared imaging
Authors: Massi Fabrizio , Moscadelli Luca , Arcidiacono Carmelo , Bacciotti Francesca
Published: July 2018

Whether high-mass stars (M > 7M⊙) emerge from a scaled-up version of the low-mass star formation scenario, i. e. through disk-mediated accretion, is still debated. We present the first results of an observational programme aimed to map the innermost regions of high-mass stellar objects by combining together high-spatial resolution maser and radio continuum observations, and near-infrared imaging.
X-Ray Characteristics of Water Megamaser Galaxies
Authors: Leiter K. , Kadler M. , Wilms J. , Braatz J. , Grossberger C. , Krauß F. , Kreikenbohm A. , Langejahn M. , Litzinger E. , Markowitz A. , Müller C.
Published: July 2018

We have compiled the X-ray characteristic properties for a unique and homogeneous sample of Type 2 AGN with water megamaser activity observed by XMM-Newton and for a control sample of non-maser galaxies, both analyzed in a uniform way. A comparison of the luminosity distributions confirms previous results (from smaller and/or less systematic studies) that water maser galaxies appear more luminous than non-maser sources. In addition, the maser phenomenon is associated with more complex X-ray spectra, higher column densities and higher equivalent widths of the Fe Kα line. Both a sufficiently luminous X-ray source and a high absorbing column density in the line of sight favor the appearance of the water megamaser phenomenon in AGN.
Measuring Magnetic Fields from Water Masers Associated with a Synchrotron Protostellar Jet
Authors: Goddi Ciriaco , Surcis Gabriele
Published: July 2018

The Turner-Welch Object in the W3(OH) high-mass star forming complex drives a synchrotron jet, which is quite exceptional for a high-mass protostar, and is associated with a strongly polarized water maser source, W3(H2O), making it an optimal target to investigate the role of magnetic fields on the innermost scales of protostellar disk-jet systems. We report here full polarimetric VLBA observations of water masers. The linearly polarized emission from water masers provides clues on the orientation of the local magnetic field, while the measurement of the Zeeman splitting from circular polarization provides its strength. By combining the information on the measured orientation and strength of the magnetic field with the knowledge of the maser velocities, we infer that the magnetic field evolves from having a dominant component parallel to the outflow velocity in the pre-shock gas (with field strengths of the order of a few tens of mG), to being mainly dominated by the perpendicular component (of order of a few hundred of mG) in the post-shock gas where the water masers are excited. The general implication is that in the undisturbed (i.e. not-shocked) circumstellar gas, the flow velocities would follow closely the magnetic field lines, while in the shocked gas the magnetic field would be re-configured to be parallel to the shock front as a consequence of gas compression.
OH masers as probes: How does the variability fade away during the AGB - post-AGB transition?
Authors: Engels D. , Etoka S. , West M. , Gérard E.
Published: July 2018

We are currently performing a monitoring program of the 1612 MHz OH maser emission of several dozen Galactic disk OH/IR stars with the Nancay Radio Telescope (NRT). They are complemented by several OH/IR stars toward the Galactic center, which were monitored with the Hartebeesthoek radio telescope. We use the maser variations to probe the underlying stellar variability. As early monitoring programs already have shown, some stars are large amplitude variables with periods up to 7 years, others show small or even no amplitude variations. This dichotomy in the variability behaviour is assumed to mark the border between the AGB and the post-AGB stages. With the current program, we wish to find objects in transition and to describe their variability properties. We consider the fading out of pulsations with steadily declining amplitudes as a viable process. Promising candidates in the disk are the small-amplitude variables OH 138.0+7.2 and OH 51.8−0.2. ’Non-variable’ OH/IR stars in the Galactic center region may be as frequent as in the disk.
Malcolm Walmsley’s Maser Science
Authors: Menten Karl M.
Published: July 2018

Charles Malcolm Walmsley passed away on 1 May 2017. Over a long and highly productive career, Malcolm made numerous and fundamental contributions to the science of the interstellar medium and star formation. These have recently been summarized elsewhere (Menten & Cesaroni 2017). Here I would like to describe some of his work related to masers.
A Systematic Review on the Role of Natural Products in Modulating the Pathways in Alzheimer’s Disease
Authors: Auti Sandip T. , Kulkarni Yogesh A.
Published: July 2018

Abstract. Alzheimer’s disease (AD) is the most common neurodegenerative disorder to date, with no cure or preventive therapy. Histopathological hallmarks of AD include deposition of β-amyloid plaques and formation of neurofibrillary tangles in brain. Despite extensive research, only five approved drugs are available for the management of AD. Hence, there is a need to look for alternative therapies and new drugs. Use of natural products in medicine has gained popularity in recent years and several natural compounds with neuroprotective effects have been studied in detail. Some of them target the disease pathways and improve cognition by directly affecting amyloidogenesis, programmed cell death and increase neuronal cell survival. Currently, phytochemicals like polyphenols, alkaloids, terpenes, flavonoids, tannins, saponins and vitamins from plants have received a special attention from the scientific community against the pathological processes in conditions like cancer, cardiovascular diseases and neurodegenerative diseases. Many efforts have been made to unravel the molecular mechanisms and the specific interactions of phytochemicals, which targets disease pathways in the AD. Further studies on these natural products and their mechanism of action, target specific effect in disease pathology parallel with the use of novel pharmaceutical drug design and delivery techniques, enable us to offer an addition to conventional medicine in treatment of AD. This review presents detailed information on natural products like polyphenols, alkaloids and terpenes with their potential effects in Alzheimer’s disease.
Serotonin concentration enhancers at clinically relevant doses reduce [11C]AZ10419369 binding to the 5-HT1B receptors in the nonhuman primate brain
Authors: Yang Kai-Chun , Takano Akihiro , Halldin Christer , Farde Lars , Finnema Sjoerd J.
Published: July 2018

The serotonin (5-HT) system plays an important role in the pathophysiology and treatment of several major psychiatric disorders. Currently, no suitable positron emission tomography (PET) imaging paradigm is available to assess 5-HT release in the living human brain. [11C]AZ10419369 binds to 5-HT1B receptors and is one of the most 5-HT-sensitive radioligands available. This study applied 5-HT concentration enhancers which can be safely studied in humans, and examined their effect on [11C]AZ10419369 binding at clinically relevant doses, including amphetamine (1 mg/kg), 3,4-methylenedioxymethamphetamine (MDMA; 1 mg/kg) or 5-hydroxy-L-tryptophan (5-HTP; 5 mg/kg). Twenty-six PET measurements (14 for amphetamine, 6 for MDMA and 6 for 5-HTP) using a bolus and constant infusion protocol were performed in four cynomolgus monkeys before or after drug administration. Binding potential (BPND) values were determined with the equilibrium method (integral interval: 63–123 min) using cerebellum as the reference region. BPND values were significantly decreased in several examined brain regions after administration of amphetamine (range: 19–31%), MDMA (16–25%) or 5-HTP (13–31%). Reductions in [11C]AZ10419369 binding were greater in striatum than cortical regions after administration of 5-HTP, while no prominent regional differences were found for amphetamine and MDMA. In conclusion, [11C]AZ10419369 binding is sensitive to changes in 5-HT concentration induced by amphetamine, MDMA or 5-HTP. The robust changes in BPND, following pretreatment drugs administered at clinically relevant doses, indicate that the applied PET imaging paradigms hold promise to be successfully used in future human studies.
Suppression of AURKA alleviates p27 inhibition on Bax cleavage and induces more intensive apoptosis in gastric cancer
Authors: Hou Daisen , Che Zhihui , Chen Ping , Zhang Wenli , Chu Yiwei , Yang Dongqin , Liu Jie
Published: July 2018

Bax is a key molecule in mitochondria-apoptosis pathway, however it is not always an efficient apoptosis inducer in chemotherapeutic agents-treated cancer cells. Here, we found that specific inhibition of AURKA by MLN8237-induced calpain-mediated Bax cleavage at N-terminal 33th asparagine (c-Bax) to promote apoptosis. The c-Bax, as Bax, could also efficiently located to mitochondria but c-Bax is a stronger apoptosis inducer than Bax. Morever, c-Bax-induced apoptosis could not be blocked by the canonical Bax inhibitor, Bcl-2. Further study found p27 was degraded and subsequently Bax was transformed to c-Bax through calpain. Also, p27 efficiently inhibited Bax cleavage and p27 knockdown sensitized apoptosis through Bax cleavage when cancer cells were treated with MLN8237. It is also demonstrated that the anti-apoptotic role of p27 lies its cytoplasmic localization. Finally, we found that the positive correlation between AURKA and p27 in advanced gastric cancer patients. In conclusion, we found that MNL8237 suppressed cell growth by regulating calpain-dependent Bax cleavage and p27 dysregulation in gastric cancer cells.
Correction: Ubiquitylation of MFHAS1 by the ubiquitin ligase praja2 promotes M1 macrophage polarization by activating JNK and p38 pathways
Authors: Zhong Jing , Wang Huihui , Chen Wankun , Sun Zhirong , Chen Jiawei , Xu Yajun , Weng Meilin , Shi Qiqing , Ma Duan , Miao Changhong
Published: July 2018

The PDF and HTML versions of the article have been updated to include the Creative Commons Attribution 4.0 International License information.
Microscopic mechanism of biphasic interface relaxation in lithium iron phosphate after delithiation
Authors: Kobayashi Shunsuke , Kuwabara Akihide , Fisher Craig A. J. , Ukyo Yoshio , Ikuhara Yuichi
Published: July 2018

Charge/discharge of lithium-ion battery cathode material LiFePO4 is mediated by the structure and properties of the interface between delithiated and lithiated phases. Direct observations of the interface in a partially delithiated single crystal as a function of time using scanning transmission electron microscopy and electron energy-loss spectroscopy help clarify these complex phenomena. At the nano-scale, the interface comprises a thin multiphase layer whose composition varies monotonically between those of the two end-member phases. After partial delithiation, the interface does not remain static, but changes gradually in terms of orientation, morphology and position, as Li ions from the crystal bulk diffuse back into the delithiated regions. First-principles calculations of a monoclinic crystal of composition Li2/3FePO4 suggest that the interface exhibits higher electronic conductivity than either of the end-member phases. These observations highlight the importance of the interface in enabling LiFePO4 particles to retain structural integrity during high-rate charging and discharging.
Dissecting myosin-5B mechanosensitivity and calcium regulation at the single molecule level
Authors: Gardini Lucia , Heissler Sarah M. , Arbore Claudia , Yang Yi , Sellers James R. , Pavone Francesco S. , Capitanio Marco
Published: July 2018

Myosin-5B is one of three members of the myosin-5 family of actin-based molecular motors. Despite its fundamental role in recycling endosome trafficking and in collective actin network dynamics, the molecular mechanisms underlying its motility are inherently unknown. Here we combine single-molecule imaging and high-speed laser tweezers to dissect the mechanoenzymatic properties of myosin-5B. We show that a single myosin-5B moves processively in 36-nm steps, stalls at ~2 pN resistive forces, and reverses its directionality at forces >2 pN. Interestingly, myosin-5B mechanosensitivity differs from that of myosin-5A, while it is strikingly similar to kinesin-1. In particular, myosin-5B run length is markedly and asymmetrically sensitive to force, a property that might be central to motor ensemble coordination. Furthermore, we show that Ca2+ does not affect the enzymatic activity of the motor unit, but abolishes myosin-5B processivity through calmodulin dissociation, providing important insights into the regulation of postsynaptic cargoes trafficking in neuronal cells.