bluuebunny/crossref_metadata_2025 huggingface dataset:
Negligible senescence in naked mole rats may be a consequence of well-maintained splicing regulation
Authors: Lee B. P. , Smith M. , Buffenstein R. , Harries L. W.
Published: January 2020

Naked mole-rats (NMRs) have amongst the longest lifespans relative to body size of any known, non-volant mammalian species. They also display an enhanced stress resistance phenotype, negligible senescence and very rarely are they burdened with chronic age-related diseases. Alternative splicing (AS) dysregulation is emerging as a potential driver of senescence and ageing. We hypothesised that the expression of splicing factors, important regulators of patterns of AS, may differ in NMRs when compared to other species with relatively shorter lifespans. We designed assays specific to NMR splicing regulatory factors and also to a panel of pre-selected brain-expressed genes known to demonstrate senescence-related alterations in AS in other species, and measured age-related changes in the transcript expression levels of these using embryonic and neonatal developmental stages through to extreme old age in NMR brain samples. We also compared splicing factor expression in both young mouse and NMR spleen and brain samples. Both NMR tissues showed approximately double the expression levels observed in tissues from similarly sized mice. Furthermore, contrary to observations in other species, following a brief period of labile expression in early life stages, adult NMR splicing factors and patterns of AS for functionally relevant brain genes remained remarkably stable for at least two decades. These findings are consistent with a model whereby the conservation of splicing regulation and stable patterns of AS may contribute to better molecular stress responses and the avoidance of senescence in NMRs, contributing to their exceptional lifespan and prolonged healthspan.
Field and CFD Study of Fuel Distribution in Pulverized Fuel (PF) Boilers
Authors: Ciukaj Szymon , Hernik Bartłomiej
Published: January 2020

The article presents both field and CFD results of a new concept of a mechanical pulverized fuel (PF) distributor. The goal of the study was to improve the pulverized coal-air mixture separation in PF boilers where the fuel preparation and feeding system was operated in a combined coal and biomass grinding conditions. The numerical analysis was preceded after a field study, where measurements were carried out in a pulverized coal-fired (PC) boiler equipped with a technology of NOx reduction by means of primary methods. Proper distribution of a pulverized coal-air mixture to the individual burners is one of the fundamental tasks of the combustion systems where the primary methods are implemented to control the NOx emission. Problems maintaining the proper distribution of fuel to the burners related primarily to the boilers where the coal and biomass co-grinding is used. Changing the load of coal-mills and fuel type at the same time (i.e., different types of biomass) could result in less effective separation of pulverized fuel particles in PF distributors. Selection of an appropriate construction of a distributor will allow the better control of the combustion process which results in decreased NOx emission while keeping the proper combustion efficiency, i.e., less unburned carbon (UBC) in the fly ash. The results of the field measurements made it possible to create a CFD distribution base model, which was used for the analysis of a new splitter construction to be used in a PF distributor. Subsequent analysis of the numerical splitter enables precise analysis of its construction, including the efficiency of separation and the prediction of conveying of the coal and biomass particles.
Generating Substantially Complete Landslide Inventory using Multiple Data Sources: A Case Study in Northwest Himalayas, India
Authors: Ghosh T. , Bhowmik S. , Jaiswal P. , Ghosh S. , Kumar D.
Published: January 2020

Landslide inventory contains basic information about landslides such as location, classification, morphometry, volume, run-out distance, activity, date of occurrence, damages caused etc. In most landslide inventory maps only spatio-temporal distribution of slope failures is shown. A complete portrayal of landslide inventory, both in number of landslides mapped and associated attributes such as morphometry, classification etc. is a must as it has bearing on the estimation of landslide susceptibility, hazard and risk. Despite of its enormous importance, landslide inventory is rarely found to be complete. This can be attributed to limited availability of requisite data and the inherent uncertainties in landslide inventory mapping from different sources and importantly the insufficient field inputs. In the present work in the Mandakini valley of Uttarakhand Himalayas attempts have been made to prepare a substantially complete landslide inventory, both in terms of number of landslides and attributes, using multifarious data sources substantiated with thorough field checks. Supplementary historical data sources along with the conventional data sources have been used to prepare the inventory. The approach followed includes pre-field mapping of landslides from different Earth Observation (EO) data followed by interpretation of archival records and detailed field surveys. The data available for the period 1962 to 2013 were used to build up the inventory database in GIS. A total of 644 landslides have been mapped and attributed using conventional EO data and also the different supplementary data sources for an area covering 400 sq. km. An inventory of 151 landslides prepared from EO data have been confirmed and updated during the field study. Finally, the detailed landslide inventory prepared during the course of this study was analysed to understand the behaviour of landslides and role of triggering factors in susceptibility mapping and the geo-environmental conditions governing the magnitude of the event.
Pedogenesis and Mineralogy of Alluvial Soils from Semi-arid Southeastern Part of Rajasthan in Aravalli Range, India
Authors: Sharma R. P. , Raja P. , Bhaskar B. P.
Published: January 2020

Three representative alluvial soils were studied from Kothari river basin of Bhilwara district in southeast Rajasthan to assess degree of chemical weathering and pedogenesis. Morphological, geochemical, mineralogical and other analytical investigations were carried out. Soils were classified as Entisols and Inceptisols. These soils are mostly sandy with more than 50% of fine and medium sand fractions, silt to clay ratio more than 0.45 and little textural variation suggesting more uniform weathering. These soils are slight to strongly alkaline with high exchangeable sodium (>15%) and cation exchange capacity less than 10 cmol(+)kg-1. Mineralogical investigations showed the dominance of micas and smectites in Pedon 1 (P1) and Pedon 2 (P2) and increase of smectites and micas in Bw3 horizon of P3 under strong alkalinity and high silica activity with limited lessivage. The low chemical index of alteration (CIA) in soils further indicated an incipient pedogenesis with a relative proportion of mica-smectite composition. The A-CNK-FM diagram shows abundance of CaO + Na2O + K2O as against Fe2O3+ MgO components under limited leaching environment and chemical weathering. The results of bivariate plot of SiO2 to (Al2O3 + K2O + Na2O) indicated the past weathering which influenced by prevailing arid climate in the region.
Prediction of local scour around bridge piers: artificial-intelligence-based modeling versus conventional regression methods
Authors: Abd El-Hady Rady Reda
Published: January 2020

This paper presents the use of two artificial intelligence modeling methods, namely genetic programming (GP) and adaptive neuro-fuzzy inference system (ANFIS), to predict pier scour depth based on clear water conditions of 320 data sets of laboratory and field data measurements. The scour depth was modeled as a function of five main dimensionless parameters: pier width, approaching flow depth, Froude number, standard deviation of grain size distribution, and channel open ratio. A functional relationship was established using the trained GP model, and its performance was verified by comparing the results with those obtained by the ANFIS model and seven conventional regression-based formulas. Numerical tests indicated that the GP model yielded much superior agreement than the ANFIS model or any other empirical equation. The advantage of the GP model was confirmed by applying the derived GP equation to predict the scour depth around the piers of Imbaba Bridge, Egypt.
Co-spraying of carriers (mannitol-lactose) as a method to improve aerosolization performance of salbutamol sulfate dry powder inhaler
Authors: Ferdynand Mickey Socrates , Nokhodchi Ali
Published: January 2020

Although in dry powder inhaler (DPI) formulations a single carrier is used, a single carrier is not able to provide an excellent aerosolization performance when it is used in DPI formulations. Thereby, the aim of this study was to engineer a suitable ternary mixture of mannitol-lactose-leucine to be used in a DPI formulation with enhanced aerosolization performance. To this end, binary mixtures of mannitol:lactose containing a constant amount of leucine (5% w/w of carriers) were spray-dried as a single solution. Spray-dried samples were blended with salbutamol sulfate to determine the efficiency of their aerosolization performance. Interestingly, note that lactose was in its amorphous state stabilized by the presence of mannitol in the samples. Spray-dried mannitol without lactose showed a combination of the α- and β-polymorphic forms which was the case in all other ratios of mannitol:lactose. It was shown that the highest fine particle fraction (FPF) was 62.42 ± 4.21% which was obtained for the distinct binary mixtures (1:3 mannitol:lactose) compared to a single carrier. This study opens a new window to investigate further the implementation of binary mixtures of sugar carriers containing leucine in DPI formulations to overcome poor aerosolization performance the mentioned DPI formulations.
UFLC-PDA-MS/MS Profiling of Seven Uncaria Species Integrated with Melatonin/5-Hydroxytryptamine Receptors Agonistic Assay
Authors: Zhang Jian-Gang , Huang Xiao-Yan , Ma Yun-Bao , Chen Ji-Jun , Geng Chang-An
Published: January 2020

Uncariae Ramulus Cum Uncis (Gou-Teng), the dried hook-bearing stems of several Uncaria plants (Rubiaceae), is a well-known herbal medicine in China. The clinical application of Gou-Teng is bewildered for the morphological and chemical similarity between different species. In order to discern their chemical and biological difference, an ultra-fast liquid chromatography equipped with ion trap time-of-flight mass spectrometry (UFLC-IT/TOF-MS) combining with melatonin (MT1 and MT2) and 5-hydroxytryptamine (5-HT1A and 5-HT2C) receptors agonistic assay in vitro was conducted on seven Uncaria species. As a result, 57 compounds including 35 indole alkaloids, ten flavonoids, five triterpenoids, five chlorogenic analogues, and two other compounds were characterized based on their MS/MS patterns and UV absorptions. Specifically, cadambine-type and corynanthein-type alkaloids were exclusively present in U.rhynchophylla and U.scandens, whereas corynoxine-type alkaloids were commonly detected in all the seven Uncaria plants. Three Uncaria species, U. rhynchophylla, U. macrophylla, and U. yunnanensis showed obviously agnostic activity on four neurotransmitter receptors (MT1, MT2, 5-HT1A, and 5-HT2C). This first-time UFLCMS-IT-TOF analyses integrated with biological assay on seven Uncaria plants will provide scientific viewpoints for the clinical application of Gou-Teng.

Graphic Abstract
Evaluation of the cost of producing wind-generated electricity in Chad
Authors: Soulouknga Marcel Hamda , Oyedepo Sunday Olayinka , Doka Serge Yamigno , Kofane Timoleon Crépin
Published: January 2020

This paper presents an economic analysis of the electricity produced by different types of wind turbines selected for Chad. Thus, the data considered for the analysis in this study are the average monthly wind speeds at selected locations, as well as the altitude value. Statistical analysis was performed using the Weibull distribution. The same energy factor allowed determining the Weibull parameters. The results obtained show that the average annual wind speed varies from 1 m/s in Am-Timan to 4.2 m/s in N'Djamena, at a height of 10 m from the ground. Weibull statistical parameters (k and c) were determined at 10, 30, 50, and 70 m. These were obtained by extrapolation using a power law based on Weibull parameters. Three models of wind turbines available on the market were used in this study: Bonus 300 kW/33, Bonus 1 MW/54, and Vestas 2 MW/V80. The performance of these wind turbines was evaluated using the calculation of the capacity factor and the annual energy produced by each type of wind turbine at 12 sites. The PVC (present value) method was used to perform an economic analysis. The lowest cost of wind power generation was obtained with the Vestas 2 MW/V80 model, with a cost per kilowatt-hour (kWh) of approximately $143.08/kWh/year in Moundou and 132343$89/kWh/year in Am-Timan. Therefore, it is recommended the use of a Vestas 2 MW/80 wind turbine in Chad.
Uncertainty Analysis in Life Cycle Assessments Applied to Biorefineries Systems: A Critical Review of the Literature
Authors: Lima Richardson Silva , de Azevedo Caldeira-Pires Armando , Cardoso Alexandre Nunes
Published: January 2020

The aim of the present article was to investigate the relationship between uncertainty analysis and life cycle assessment (LCA) in scientific publications that address the application of LCA in biorefineries systems. Uncertainty analysis and its relationship with environmental impact assessment studies, especially those that address the application of LCA, is a research topic that requires attention because of its possible influence on results. A reference base was defined using a systematic approach and bibliometric analysis, with 64 scientific publications extracted from the Web of Science (WoS) and Scopus® databases, which were analyzed using two computational tools: VOSviewer and SciMAT. This group of publications helped establish the correlation and evolution over the last 10 years of the three key themes: “uncertainty analysis,” “LCA,” and “biorefineries.” The results of bibliometric analysis for the established framework pointed to a close and important relationship among these themes. The results were presented quantitatively and qualitatively, and the latter were visualized using infographics, co-occurrence networks, and strategic keyword diagrams. Although the study confirmed the relevance of uncertainties analysis to support LCA studies, it was identified a secondary role for scientific studies analyzed. The study also presents the analysis and discussions of the main publications found in the scientific literature. Future studies should conduct a more in-depth analysis of advanced knowledge representation and reasoning strategies about uncertainty, such as probabilistic ontologies.
G-Networks and the Performance of ICT with Renewable Energy
Authors: Zhang Yunxiao
Published: January 2020

As a consequence of developing information and communication technology that is playing a significant role in our society and has changed our life dramatically, we witnessed a significant increase in energy consumption in computer systems and networks. Subsequently, energy harvesting technologies with renewable energy are of great interest in the field of computer systems and networks, and thus lead to abundant research which has been carried out to address energy harvesting from different aspects. However, the majority of them focuses on wireless or small-scale networks, which left wired networks with a general structure neglected. We first present a comprehensive systemic review of the trends of overall energy consumption, and energy and quality of service optimization in computer systems and networks. Then, this paper reviews the recent research progress in G-networks and energy packet networks with renewable and intermittent energy from both the system paradigms and the performance optimization and energy reduction algorithms for the wired networks.
Antidepressant Use During Development May Impair Women's Sexual Desire in Adulthood
Authors: Lorenz Tierney K.
Published: January 2020

Introduction

Although antidepressants are well known to cause sexual side effects in adults, the long-term effects of antidepressant use during development on adult sexual function is unknown.

Aim

To explore differences in sexual desire and sexual behavior between adults who did vs did not use antidepressants during childhood or adolescence.

Methods

An online survey of 610 young adults (66% women) assessed childhood and current mental health and use of antidepressants and other psychiatric medications before the age of 16 years and currently, partnered and solitary sexual desire, and frequency of masturbation and partnered sexual activity. Antidepressants were coded into either selective serotonin reuptake inhibitors (SSRIs) or non-SSRI antidepressants.

Main Outcome Measure

Scores on the Sexual Desire Inventory, and self-reported frequency of masturbation and partnered sexual activity.

Results

For women, childhood SSRI use was associated with significantly lower solitary sexual desire, desire for an attractive other, and frequency of masturbation. This was true even when controlling for childhood mental health concerns, current mental health, and current antidepressant use. However, there was no effect of childhood SSRI use on women's partnered sexual desire or partnered sexual activity. There was no significant effect of childhood antidepressant use on men's sexual desire or masturbation. However, in men, childhood use of non-SSRI antidepressants was associated with significantly higher frequency of partnered sexual activity. Childhood use of non-SSRI antidepressants, or nonantidepressant psychiatric medication, was not associated with adult sexual desire or behavior in either women or men.

Clinical Implications

It is possible that SSRI use during childhood interrupts the normal development of sexual reward systems, which may be a risk factor for sexual desire dysfunction in adult women.

Strengths & Limitations

Strengths include a large sample, use of attention checks and validated measures, and careful assessment of childhood mental health history; however, generalizability is limited by a predominantly white, young adult sample. These data are cross-sectional, and therefore, causal explanations for the association between childhood SSRI use and adult sexual well-being should be considered preliminary, warranting replication.

Conclusion

These findings point to a critical need for well-controlled, prospective research on possible long-term effects of antidepressant use, particularly SSRI use, on the development of adult sexual well-being.
Composite technologies to the fore at K
Authors: Holmes Mark
Published: January 2020

Alongside the many mainstream plastics technologies on show at the triennial K 2019 show gathering in Düsseldorf, Germany, a number of new composite manufacturing processes and materials were presented. Reinforced Plastics highlights some examples.
Current Status of Pain Management in Parkinson’s Disease
Authors: Karnik Vikram , Farcy Nicole , Zamorano Carolina , Bruno Veronica
Published: January 2020

Background:

Pain is a non-motor symptom in Parkinson’s disease (PD) which commonly goes underreported. Adequate treatment for pain in PD remains challenging, and to date, no clear guidelines for management are available.

Methods:

With the goal of understanding and organizing the current status of pain management in PD, we conducted a review of pharmacological and non-pharmacological treatments for pain in patients with PD. Suitable studies cataloged in PubMed and the Cochrane database up to October 31, 2019, were included prioritizing randomized controlled trials.Post-hocanalyses and open-label studies were also included.

Results:

Treatment with levodopa increases pain thresholds in patients with PD. Apomorphine did not have similar efficacy. Duloxetine provided benefit in an open-label trial. Oxycodone-naloxone PR did not have a significant improvement in pain, but per-protocol analysis showed a reduction in pain when adherence was strong. Rotigotine patch had numerical improvement on pain scales with no statistical significance. Safinamide significantly improved the “bodily discomfort” domain in the PDQ-39 questionnaire. Botulinum toxin A had a non-significant signal toward improving dystonic limb pain in PD. DBS to the subthalamic nucleus may modulate central pain thresholds, and a pilot study of cranioelectric therapy warrants future research in the area.

Conclusion:

After optimizing dopaminergic therapy, understanding the type of pain a patient is experiencing is essential to optimizing pain control in PD. While recommendations can be made regarding the treatment options in each domain, evidence remains weak and future randomized controlled studies are needed.
Existence, non-existence and blow-up behaviour of minimizers for the mass-critical fractional non-linear Schrödinger equations with periodic potentials
Authors: Dinh Van Duong
Published: January 2020

We consider the minimizing problem for the energy functional with prescribed mass constraint related to the fractional non-linear Schrödinger equation with periodic potentials. Using the concentration-compactness principle, we show a complete classification for the existence and non-existence of minimizers for the problem. In the mass-critical case, under a suitable assumption of the potential, we give a detailed description of blow-up behaviour of minimizers once the mass tends to a critical value.
Age stage, two-sex life table ofHabrobracon hebetor(Braconidae) onSpodoptera exigua(Noctuidae) reared on different sugar beet genotypes
Authors: Fathipour Yaghoub , Talaee Ladan , Bagheri Abdoolnabi , Talebi Ali Asghar , Khajehali Jahangir
Published: January 2020

The present study was carried out to unveil interactive relevance among consecutive and alternate members of a tritrophic system comprised of sugar beet genotypes, beet armyworm,Spodoptera exigua(Hübner), and its parasitoid,Habrobracon hebetor(Say) using demographic parameters. To do so,H. hebetorwas reared onS. exiguafed on 10 sugar beet genotypes, including SB26; SB27; SB29; SB33; SB34; (7112*SB36)*Sh-1-HSF-5; FC220; FC301; SBSI006; and HM 1339RZ in a growth chamber at 25 ± 1 °C, 60 ± 5% RH, and 16:8 (L: D) h photoperiod. The data was analyzed based on the age-stage, two-sex life table theory. Our results revealed high variation in duration of different life stages ofH. hebetoronS. exiguareared on different sugar beet genotypes examined. The shortest (10.605 days) and longest (13.721 days) pre-adult period ofH. hebetorwas onS. exiguareared on SB26 and SB34, respectively. The longest (17.2 days) and shortest adult longevity (7.5 days) was onS. exiguareared on SB26 and SB27, respectively. The highest values of the intrinsic rate of increase (r) (0.209 day−1) and finite rate of increase (λ) (1.233 day−1) were observed onS. exiguareared on SB34 and their lowest values (0.159 and 1.172 day−1, respectively) were recorded on SB27. Resistant and susceptible genotypes toS. exigua, FC301 and (7112*SB36)*Sh-1-HSF-5, respectively, were only genotypes on whichH. hebetorhad greater and approximately equalrcompared withS. exigua. This finding indicates high capability ofH. hebetorto be successfully employed againstS. exiguaon sugar beet genotypes which are extremely different in resistance to this pest.
Adjoint approach to calculating shape gradients for three-dimensional magnetic confinement equilibria. Part 2. Applications
Authors: Paul Elizabeth J. , Antonsen Thomas , Landreman Matt , Cooper W. Anthony
Published: January 2020

The shape gradient is a local sensitivity function defined on the surface of an object which provides the change in a characteristic quantity, or figure of merit, associated with a perturbation to the shape of the object. The shape gradient can be used for gradient-based optimization, sensitivity analysis and tolerance calculations. However, it is generally expensive to compute from finite-difference derivatives for shapes that are described by many parameters, as is the case for typical stellarator geometry. In an accompanying work (Antonsen, Paul & Landreman J. Plasma Phys., vol. 85 (2), 2019), generalized self-adjointness relations are obtained for magnetohydrodynamic (MHD) equilibria. These describe the relation between perturbed equilibria due to changes in the rotational transform or toroidal current profiles, displacements of the plasma boundary, modifications of currents in the vacuum region or the addition of bulk forces. These are applied to efficiently compute the shape gradient of functions of MHD equilibria with an adjoint approach. In this way, the shape derivative with respect to any perturbation applied to the plasma boundary or coil shapes can be computed with only one additional MHD equilibrium solution. We demonstrate that this approach is applicable for several figures of merit of interest for stellarator configuration optimization: the magnetic well, the magnetic ripple on axis, the departure from quasisymmetry, the effective ripple in the low-collisionality

$1/\unicode[STIX]{x1D708}$

regime

$(\unicode[STIX]{x1D716}_{\text{eff}}^{3/2})$

(Nemov et al. Phys. Plasmas, vol. 6 (12), 1999, pp. 4622–4632) and several finite-collisionality neoclassical quantities. Numerical verification of this method is demonstrated for the magnetic well figure of merit with the VMEC code (Hirshman & Whitson Phys. Fluids, vol. 26 (12), 1983, p. 3553) and for the magnetic ripple with modification of the ANIMEC code (Cooper et al. Comput. Phys. Commun., vol. 72 (1), 1992, pp. 1–13). Comparisons with the direct approach demonstrate that, in order to obtain agreement within several per cent, the adjoint approach provides a factor of

$O(10^{3})$

in computational savings.
Bootstrap current and parallel ion velocity in imperfectly optimized stellarators
Authors: Catto Peter J. , Helander Per
Published: January 2020

A novel derivation of the parallel ion velocity, and the bootstrap and Pfirsch–Schlüter currents in an imperfectly optimized (that is, almost omnigenous) stellarator magnetic field,

$\boldsymbol{B}$

, is presented that somewhat more generally recovers expressions completely consistent with previous analytic results. However, it is also shown that, when the conventional radially local form of the drift kinetic equation is employed, the flow velocity and the bootstrap current acquire a spurious contribution proportional to

$\unicode[STIX]{x1D714}/\unicode[STIX]{x1D708}$

, where

$\unicode[STIX]{x1D714}$

denotes the

$\boldsymbol{E}\times \boldsymbol{B}$

rotation frequency (due to the radial electric field

$\boldsymbol{E}$

) and

$\unicode[STIX]{x1D708}$

the collision frequency. This contribution is particularly large in the

$\sqrt{\unicode[STIX]{x1D708}}$

regime and at smaller collisionalities, where

$\unicode[STIX]{x1D714}/\unicode[STIX]{x1D708}\gtrsim 1$

, and is presumably present in most numerical calculations, but it disappears if a more accurate drift kinetic equation is used.
What if God commanded something horrible? A pragmatics-based defence of divine command metaethics
Authors: KREMERS PHILIPP
Published: January 2020

The objection of horrible commands claims that divine command metaethics is doomed to failure because it is committed to the extremely counterintuitive assumption that torture of innocents, rape, and murder would be morally obligatory if God commanded these acts. Morriston, Wielenberg, and Sinnott-Armstrong have argued that formulating this objection in terms of counterpossibles is particularly forceful because it cannot be simply evaded by insisting on God's necessary perfect moral goodness. I show that divine command metaethics can be defended even against this counterpossible version of the objection of horrible commands because we can explain the truth-value intuitions about the disputed counterpossibles as the result of conversational implicatures. Furthermore, I show that this pragmatics-based defence of divine command metaethics has several advantages over Pruss'sreductiocounterargument against the counterpossible version of the objection of horrible commands.
History of Health Technology Assessment in Iran
Authors: Arab-Zozani Morteza , Sokhanvar Mobin , Kakemam Edris , Didehban Tahereh , Hassanipour Soheil
Published: January 2020

This article describes the characteristics of the health system and reviews the history of health technology assessment (HTA) in Iran, including its inception, processes, challenges, and lessons learned. This study was conducted by analyzing existing documents, reports, and guidelines related to HTA and published articles in the field. HTA in Iran has been established since the late 2000s and was first introduced as a secretariat by the Deputy of Health at the Ministry of Health and Medical Education. The mission of the HTA office is to systematically assess technologies to improve evidence-informed decision making. Despite its 10 years of existence, HTA in Iran still faces some challenges. The most pressing problems currently facing HTA in Iran include conflicts of interest among researchers performing the HTAs, the absence of a systematic structure for identifying and introducing new technologies, the lack of interest in HTA results among high-level policy makers, and the lack of external oversight for HTA projects.
Commissioning experience of the X-ray volume imaging system of an image-guided radiotherapy capable linear accelerator
Authors: Raina Payal , Sahoo Susanta Kumar
Published: January 2020

Aim:

An image-guided radiotherapy capable linear accelerator was installed at our hospital which is equipped with an X-ray volumetric imaging (XVI) system. The aim of this study was to describe the results of acceptance tests which were carried out on the XVI facility to verify the manufacturer’s specification.

Materials and methods:

The commissioning test had six elements: system safety, geometric accuracy, image quality, registration and correction accuracy, X-ray tube and generator performance, and quality assurance (QA) procedures.

Results:

We had satisfactory results for all the tests. The system passed the safety testes, and the agreement of isocentres was found to be within the tolerance limit. Imaging quality was acceptable. Registration and correction accuracy was tasted with indigenously developed phantom and positioned accurately at isocentre. X-ray tube and generator test results showed that the tube was performing properly.

Findings:

The described tests represent that the performance of the system is maintained at acceptable levels.
Gravitational fragmentation and formation of giant protoplanets on orbits of tens of AU
Authors: Elbakyan Vardan G. , Vorobyov Eduard I.
Published: January 2020

Migration of dense gaseous clumps that form in young protostellar disks via gravitational fragmentation is investigated to determine the likelihood of giant-planet formation. We show that gaseous clumps that form in the outer regions of the disk (> 100 au) through disk fragmentation often migrate toward the central star on timescales from a few thousand to few tens of thousands of years. The tidal mass loss helps the clumps to significantly slow down or even halt their inward migration at a distance of a few tens of AU from the protostar.
Towards Realistic Understandings of Gas Dynamics in Protoplanetary Disks
Authors: Bai Xue-Ning
Published: January 2020

The gas dynamics of protoplanetary disks (PPDs) plays a crucial role in almost all stages of planet formation, yet it is far from being well understood largely due to the complex interplay among various microphysical processes. Primarily, PPD gas dynamics is likely governed by magnetic fields, and their coupling with the weakly ionized gas is described by non-ideal magnetohydrodynamic (MHD) effects. Incorporating these effects, I will present the first fully global simulations of PPDs that include the most realistic disk microphysics. Accretion and disk evolution is primarily driven by magnetized disk winds with significant mass loss comparable to accretion rate. The overall disk gas dynamics strongly depends on the polarity of large-scale poloidal magnetic field threading the disk owing to the Hall effect. The flow structure in the disk is highly unconventional with major implications on planet formation.
Analysis of KOI 2700b, the second exoplanet with a comet-like dusty tail – selected results
Authors: Garai Zoltán , Dolinský Peter
Published: January 2020

The Kepler object KOI 2700b was discovered recently as the second exoplanet with a comet-like dusty tail. We aimed at verifying the disintegrating-planet scenario of KOI 2700b by modeling its light curve and to put constraints on various tail and planet properties, as was done in the case of KIC 12557548b. Here, we describe some selected results of our analysis.
Kinematics of OB-associations in the 3-kpc solar neighborhood
Authors: Melnik Anna M. , Dambis Andrei K. , Glushkova Elena V. , Rautiainen Pertti
Published: January 2020

We use Gaia (DR1, DR2) stellar proper motions to study the kinematics of OB-associations. The average one-dimensional velocity dispersion inside 18 OB-associations with more than 10 Gaia DR1 stars is σv = 3.9 km s−1. The median virial and stellar masses of OB-associations are equal to 7×105 and 9 × 103 solar masses, respectively. The median star-formation efficiency is ε = 2.1%. We have found the expansion in several OB-associations. Models of the Galaxy with a two-component outer ring R1R2 can reproduce the average residual velocities of OB-associations in the Perseus, Sagittarius and Local System complexes.
A physically motivated core definition applied to dust emission observations of the Pipe nebula
Authors: Hasenberger Birgit , Alves João
Published: January 2020

Dense cores represent a critical stage in the star-formation process, but are not physically well-defined entities. We present a new technique to define core boundaries in observations of molecular clouds based on the physical properties of the cloud medium. Applying this technique to regions in the Pipe nebula, we find that our core boundaries differ from previous analyses, with potentially crucial implications for the statistical properties of the core sample.
Tracing the early planet formation with molecular lines: chemistry of vortex in the protoplanetary disks
Authors: Dzyurkevich Natalia , Lyra Wladimir , Majumdar Liton
Published: January 2020

The millimeter observations of dust in protoplanetary disks show us spectacular structures like numerous gaps, vortices and spirals. In particular, IRS 48 disk demonstrates a large vortex-like structure. Molecular lines provide information about disks that is complementary to dust continuum observations: formaldehyde was found on the inner edge of the IRS 48 vortex, along with detections of SO2 and CS isotopes.

We use a reduced chemical network containing main carbon- and sulfur-bearing species to find the molecular species which can be sensitive to the gaps in dust, as well as to accumulation of the dust grains in the vortex. We find that SO molecule is the main reservoir for sulfur in IRS 48, for adopted disk model as in Bruderer et al. 2014. While SO is very sensitive to the gap edge, it cannot trace the vortex as it is weakly responding to the local increase in dust. Instead, SO2 molecule abundance can be expected to drop quickly within the vortex, making it an interesting tracer of dust-trapping structure.
Obliquity Variability of Terrestrial Planets in the Habitable Zone
Authors: Shan Yutong , Li Gongjie
Published: January 2020

Obliquity (axial tilt) and its variability could play an important role in the climate and habitability of a planet. We explore the spin-axis dynamics of two specific habitable zone exoplanets, Kepler-62f and Kepler-186f, using numerical and analytical techniques. Based on our current understanding of their orbital architecture, we find that, in contrast with the typical conditions in the Solar System, Kepler-62f and 186f should have low obliquity variations except in fine-tuned conditions. Extra undetected planetary companions and/or the existence of a satellite could either stabilize or destabilize obliquities at a variety of values.
Problems with exoplanets around sdBV and sdO stars from primary Kepler field
Authors: Krzesinski Jerzy , Blokesz A. , Ogłoza W. , Dróżdż M.
Published: January 2020

The existence of exoplanets around evolved objects is one of the most interesting subjects from the viewpoint of planetary system evolution and its fate. What happens to the exoplanets engulfed in the host star envelope during red giant branch (RGB) phase? Can planets survive this evolutionary stage of the host star? Here, we are showing that at least some of the exoplanetary candidates recently found around a couple of sdBV stars, KIC 5807616 and KIC 10001893, might not be exoplanets after all. One “exoplanetary signal” visible in the light curve FT of KIC 10001893 can be just a frequency combination of stellar pulsation modes, while others are likely artifacts. Similarly, low frequency signals found in KIC 5807616 light curve FT, are beating frequencies of stellar oscillations, rather than resulting from the exoplanetary radiation. We also analyzed frequency and amplitude changes of the signal around 0.256 c/d (∼3.9 day) visible in the light curve FT of the KIC 10449976 sdO star. Our simulations show that it is difficult to reproduce the observed signal frequency variations by the weather changes in the exoplanet atmosphere.
Global Protoplanetary Disk Simulations: Dead Zone Formation and FUor Outbursts
Authors: Kadam Kundan , Vorobyov E. , Regály Zs. , Kóspál Á. , Ábráham P.
Published: January 2020

We conducted global hydrodynamic simulations of protoplanetary disk evolution with an adaptive Shakura-Sunyaev α prescription to represent the layered disk structure, and starting with the collapse phase of the molecular cloud. With the canonical values of model parameters, self-consistent dead zones formed at the scale of a few au. The instabilities associated with the dead zone and corresponding outbursts, similar to FUor eruptions, were also observed in the simulations.
The implications of clustered star formation for (proto)planetary systems and habitability
Authors: Kruijssen J. M. Diederik , Longmore Steven N.
Published: January 2020

Star formation is spatially clustered across a range of environments, from dense stellar clusters to unbound associations. As a result, radiative or dynamical interactions with neighbouring stars disrupt (proto)planetary systems and limit their radii, leaving a lasting impact on their potential habitability. In the solar neighbourhood, we find that the vast majority of stars form in unbound associations, such that the interaction of (proto)planetary systems with neighbouring stars is limited to the densest sub-regions. However, the fraction of star formation occurring in compact clusters was considerably higher in the past, peaking at ∼50% in the young Milky Way at redshift z ∼ 2. These results demonstrate that the large-scale star formation environment affects the demographics of planetary systems and the occupation of the habitable zone. We show that planet formation is governed by multi-scale physics, in which Mpc-scale events such as galaxy mergers affect the AU-scale properties of (proto)planetary systems.
Magnetic geometry and activity of cool stars
Authors: Boro Saikia Sudeshna , Lüftinger Theresa , Guedel Manuel
Published: January 2020

Stellar magnetic field manifestations such as stellar winds and EUV radiation are the key drivers of planetary atmospheric loss and escape. To understand how the central star influences habitability, it is very important to perform detailed investigation of the star’s magnetic field. We investigate the surface magnetic field geometry and chromospheric activity of 51 sun-like stars. The magnetic geometry is reconstructed using Zeeman Doppler imaging. Chromospheric activity is measured using the Ca II H& K lines. We confirm that the Sun’s large-scale geometry is dominantly poloidal, which is also true for slowly rotating stars. Contrary to the Sun, rapidly rotating stars can have a strong toroidal field and a weak poloidal field. This separation in field geometry appears at Ro=1. Our results show that detailed investigation of stellar magnetic field is important to understand its influence on planetary habitability.
Nitrogen-included Carbonaceous Compounds (NCC): Laboratory-synthesized organics as the probable candidate for the carrier of the UIR bands observed in dusty classical novae
Authors: Endo Izumi , Sakon Itsuki , Onaka Takashi , Helton Andrew L. , Lau Ryan M. , Kimura Seiji , Wada Setsuko , Ogawa Nanako , Ohkouchi Naohiko , Kebukawa Yoko
Published: January 2020

The unidentified infrared (UIR) bands have been ubiquitously observed in various astrophysical environments and consist of a series of emission features arising from aromatic and/or aliphatic C-C and C-H bonds [1]. Therefore, their carriers are thought to be related to interstellar organics. However, our knowledge on the true carriers of the UIR bands is still limited. Recently [4] has proposed Mixed Aromatic Aliphatic Organic Nanoparticles, which contains hetero atoms in addition to conventional hydrocarbon models, as a more realistic interpretation of the band carriers. The challenges toward identifying the carriers of the UIR bands are still ongoing. Past studies have shown that the UIR bands observed around classical novae, which characterized by the presence of broad feature around 8μm[2], are somewhat different from those observed in other astrophysical environment. Here we report the success of experimentally synthesizing the organics called Nitrogen-included Carbonaceous Compounds (NCC; [7]) whose infrared properties can reproduce the UIR bands observed in classical novae.
Unveiling the whole from its parts or to see the forest for the trees
Authors: Janot-Pacheco Eduardo , Rachid Marina , Bendjoya Philippe , Domiciano Armando , Antunes-Rosa Caroline , Emilio Marcelo , Lage Claudia
Published: January 2020

If biologically complex molecules as DNA were present in the extraterrestrial targets, their spectral signatures would be rather difficult to be unambiguously identified. As a matter of fact, the molecular array of a single nucleobasis will generate a tangled spectral signature. On the other hand, a part of it, e.g. bands due to the group of HNCO of guanine may have been detected but associated to smaller molecules, e.g. isocianic acid (HNCO). However, if comprised in a nucleobasis, its detection would be misinterpreted. Five key transitions were preliminarly selected for either purines and pyrimidines that should be observed together in the same target. If this happens, it may be that we are detecting the whole from its parts.
Pre- and protostellar cores in the Rosette Nebula
Authors: Bögner R. , Csengeri T. , Wienen M. , Schneider N. , Montillaud J. , Tóth L. V.
Published: January 2020

Recent theories on the formation of the Solar System turned the attention to the study of low mass cloud cores in massive star forming regions. The Rosette Molecular Cloud is a well-known star forming area having highly filamentary structure with dense cores covering a wide range of masses. These pre- and protostellar cores were observed by Herschel and key core properties were derived from its data. With the Effelsberg 100m telescope a sample of these cores with masses ranging between 3-40 M⊙ were observed in ammonia inversion lines. In this work we are examining the correlations between these two datasets with the aim of gaining insight of the processes behind the star formation of the region.
Brightness variations of young Sun-like stars from ground-based and space telescopes
Authors: Zsidi G. , Kóspál Á. , Ábrahám P. , Szabó R. , Cseh B. , Sárneczky K. , Sódor Á. , Szakáts R. , Vida K. , Vinkó J.
Published: January 2020

Young stellar objects often show photometric variability, which is well examined at optical wavelengths, but more and more infrared data are also available. The wavelength dependence of the variability carries information on the physical cause of the changing brightness. Here, we examine seven T Tauri-type stars known for their large amplitude variability selected from the Campaign 13 field of the Kepler K2 mission. We complemented the K2 light curves by multifilter optical monitoring observations made with the 90 cm Schmidt telescope of Konkoly Observatory, and by 3.6 and 4.5 μm infrared photometry with a 20 hours cadence using the Spitzer Space Telescope. We found that the wavelength dependence of the observed variability is not consistent with changing interstellar extinction. We suggest that the brightness changes are due to variable accretion, causing a variable illumination of the inner disk.
An UXor among FUors: extinction-related brightness variations of the young eruptive star V582 Aur
Authors: Ábrahám P. , Kóspál Á. , Kun M. , Fehér O. , Zsidi G. , Acosta-Pulido J. A.
Published: January 2020

The early evolution of Sun-like stars may be interspersed by energetic FU Orionis (FUor) type accretion outbursts. We analysed eight years of photometric and spectroscopic variability of V582 Aur, a bona fide FUor, in outburst. While the accretion rate derived from near-infrared measurements was constant, radical brightness changes occurred due to dust clumps crossing the line of sight. The brightness minima resemble the variability patterns of the UXor phenomenon. Orbiting density enhancements or short-lived clumps moving in and out of the line-of-sight may explain these observations. Our message is that during FUor outbursts the inner disk is a dynamically active place, affecting the initial conditions for planet formation.
Possibility to locate the position of the H2O snowline in protoplanetary disks through spectroscopic observations
Authors: Notsu Shota , Nomura Hideko , Walsh Catherine , Honda Mitsuhiko , Hirota Tomoya , Akiyama Eiji , Tsukagoshi Takashi , Booth Alice S. , Millar T. J.
Published: January 2020

Observationally locating the position of the H2O snowline in protoplanetary disks is crucial for understanding planetesimal and planet formation processes, and the origin of water on the Earth. In our studies, we conducted calculations of chemical reactions and water line profiles in protoplanetary disks, and identified that ortho/para-H216O, H218O lines with small Einstein A coefficients and relatively high upper state energies are dominated by emission from the hot midplane region inside the H2O snowline. Therefore, through analyzing their line profiles the position of the H2O snowline can be located. Moreover, because the number density of the H218O is much smaller than that of H216O, the H218O lines can trace deeper into the disk and thus they are potentially better probes of the exact position of the H2O snowline in disk midplane.