bluuebunny/crossref_metadata_2025 huggingface dataset:
State Estimation for Robotics
Authors: Barfoot Timothy D.
Published: August 2017

A key aspect of robotics today is estimating the state, such as position and orientation, of a robot as it moves through the world. Most robots and autonomous vehicles depend on noisy data from sensors such as cameras or laser rangefinders to navigate in a three-dimensional world. This book presents common sensor models and practical advice on how to carry out state estimation for rotations and other state variables. It covers both classical state estimation methods such as the Kalman filter, as well as important modern topics such as batch estimation, the Bayes filter, sigmapoint and particle filters, robust estimation for outlier rejection, and continuous-time trajectory estimation and its connection to Gaussian-process regression. The methods are demonstrated in the context of important applications such as point-cloud alignment, pose-graph relaxation, bundle adjustment, and simultaneous localization and mapping. Students and practitioners of robotics alike will find this a valuable resource.
REGIONAL ARCHAEOLOGY AND LOCAL INTERESTS IN COIXTLAHUACA, OAXACA
Authors: Kowalewski Stephen A. , Brannan Stefan P. , Vilchis Marisol Yadira Cortés , Luna Laura Diego , Ayala Gabriela García , Zárate José Leonardo López , Sobel Fernando Méndez , Walsh Laura R. Stiver , Turck Ellen B. , Turck John A. , Vepretskiy Sergei
Published: August 2017

The Recorrido Arqueológico de Coixtlahuaca (RAC) presents period-by-period settlement pattern maps for the valley of Coixtlahuaca in the northern Mixteca Alta. The RAC project made improvements in full-coverage survey methods. We identify limitations and suggest that similar projects in the future need to resolve several management and budget problems. The survey revealed two periods of heavy occupation, 700–300 BC and AD 1200–1520, separated by a long period of lower population. Archaeological and historical data indicate that during the AD 1200–1520 period, and probably earlier, small landholders organized in strong communities managed an intensive agroecosystem, investing in landesque capital. Urbanization was impressive, yet cities were aggregations of communities and barrios. Today local citizens pose questions about how the large prehispanic population could have organized and sustained itself; these questions coincide with anthropological interest in collective agency, property, landesque capital, and collapse.
Cropping system intensification: vegetable pea can replace fallow between rainfed monsoon rice and irrigated spring rice
Authors: MALIK A. I. , NASIM M. , FLOWER K. , HOSSAIN M. A. , RAHMAN M. S. , ANWAR B. , ALI M. O. , RAHMAN M. M. , ERSKINE W.
Published: August 2017

The Eastern Gangetic Plain is among the world's most intensively farmed regions, where rainfed and irrigated agriculture coexist. While the region and especially Bangladesh is a major producer of rice (Oryza sativaL. ssp.indica), there is potential to further develop sustainable rice production systems. Specifically, there is scope to include a replacement crop for the short fallow between rice crops in the dominant cropping pattern of rainfed monsoon rice harvest followed by irrigated spring rice. The aim of the current research was to identify a suitable cool-season legume crop – pea (Pisum sativumL.) or lentil (Lens culinarisMedik. ssp.culinaris) – that could be grown in the brief period between rice crops. The study comprised four crop sequence experiments comparing legume cultivars differing in maturity grown in between both long and short duration rice cultivars. These experiments were done at the Bangladesh Rice Research Institute regional station at Rajshahi over three cropping cycles. This was followed by an evaluation of pea vs. fallow between rice crops on three farmers’ fields in one cropping cycle. Here it is demonstrated that green pod vegetable pea is one of the best options to intensify the rainfed monsoon rice–fallow–spring irrigated rice cropping system, notwithstanding other remunerative rabi cropping options that could displace boro rice. The inclusion of an extra crop, pea as green pod vegetable, increased farm productivity by 1·4-fold over the dominant cropping sequence (rice–fallow–rice) and farm net income by fourfold. The study highlighted the advantages in total system productivity and monetary return of crop intensification with the inclusion of a pea crop between successive rice crops instead of a fallow period.
The word(s) the Spirit gives: Lutheran and Reformed exegesis of 1 Corinthians 2:13
Authors: Harris Steven Edward
Published: August 2017

Distinctive Lutheran and Reformed theologies of the relationship between Word and Spirit influenced the history of Protestant exegesis of 1 Corinthians 2:13, which states, ‘we speak not in words taught by human wisdom, but in those taught by the Spirit’. The interpretation of the time of the Spirit's teaching (past or present) and the identity of the words taught (scripture or preaching/teaching) are seen to depend upon and develop these respective Lutheran and Reformed theologies. The essay concludes with a brief evaluation of the adequacy of these interpretations in light of the divine economy and some ecumenical considerations.
Neither Centre nor Local: Community-Driven Experimentalist Governance in China
Authors: Shin Kyoung
Published: August 2017

Based on findings from three years of site-intensive fieldwork at the local level, this article presents evidence to suggest that binary governance frameworks like centre–local relations are insufficient to understand certain local regulatory outcomes in contemporary China. I seek to specify a distinct type of local governance that has been emerging in recent years, which blurs existing binary concepts. It can be distinguished along two main dimensions: ostensible structure and modalities of governance. Two cases are analysed to illustrate the ways in which it impacts local regulatory outcomes. The analyses point to the need for expanding our portfolio of approaches to understanding local governance in contemporary China.
Implementation of Pollution Control Targets in China: Has a Centralized Enforcement Approach Worked?
Authors: Zhang Xuehua
Published: August 2017

The scholarly work on China's environmental regulations in the context of “central–local” relations is dominated by the preference for a centralized approach. This article examines a centrally imposed and executed verification programme of locally reported pollution data, a rare and sustained central effort to enforce an environmental policy, namely the national pollution reduction target system. The programme was established in 2007 to curtail perceived widespread data falsification and to enhance the quality of emission data, the basis for assessing local compliance with targets. Based on an analysis of official documents and interviews with environmental officials and industry representatives, this article found that the verification programme appears to have reduced the overreporting problem with emission data, enhanced local monitoring and enforcement capacity, and to a certain degree deterred violations due to the increased frequency of national and local inspections. Nevertheless, significant challenges remain. Verification is highly resource intensive, it has involved little external oversight and public participation, the central authority has exerted significant yet unchecked discretionary powers, and poor data quality has remained an issue. Over time, the verification programme appears to have turned into essentially a “numbers game.” All those challenges indicate that a centralized enforcement approach is arguably ineffective in addressing China's long-standing problem of weak environmental policy implementation. This study also sheds lights on the classical “principal-agent” theory in the study of public bureaucracy. Not only does the principal distrust the agent, which is the main concern of the theory, but the agent also distrusts the principal.
Periurban outbreaks of bovine calf scours in Northern India caused byCryptosporidiumin association with other enteropathogens
Authors: BRAR A. P. S. , SOOD N. K. , KAUR P. , SINGLA L. D. , SANDHU B. S. , GUPTA K. , NARANG D. , SINGH C. K. , CHANDRA M.
Published: August 2017

Bovine calf scours reported to be caused by multiple aetiologies resulting in heavy mortality in unweaned calves and huge economic loss to the dairy farmers. Among these, cryptosporidiosis is an emerging waterborne zoonoses and one of the important causes of neonatal calf diarrhoea. Poor immune response coupled with primary cryptosporidial infections predispose neonatal calves to multiple secondary infections resulting in their deaths. In the present study, faecal samples from 100 diarrhoeic calves randomly picked up out of 17 outbreaks of bovine calf diarrhoea in periurban Ludhiana, Punjab in Northern India were subjected to conventional (microscopy, modified Zeihl–Neelsen (mZN) staining) and immunological and molecular techniques (faecal antigen capture ELISA and PCR) for detection of primaryCryptosporidium parvuminfection as well as other frequently reported concurrent pathogens,viz. rotavirus and coronavirus,Salmonellaspp.,Escherichia coli,Clostridium perfringensandEimeriaspp. The faecal antigen capture ELISA and PCR revealed 35% prevalence ofC. parvumin contrast to 25% by mZN staining with a relatively higher prevalence (66·7%) in younger (8–14-day-old) calves. The detection rate of the other enteropathogens associated withC. parvumwas 45·71% forC. perfringensfollowed bySalmonellaspp (40·0%), rotavirus (36·0%), coronavirus (16·0%),E. coli(12·0%) andEimeriaspp (4·0%) The sensitivity for detection ofC. parvumby ELISA and mZN staining in comparison to PCR was 97·14% and 72·72%, respectively. An important finding of the study was thatC. parvumalone was found in only 10% of the diarrhoeic faecal samples, whereas, majority of the samples (90%) showed mixed infections ranging from a combination of two to five agents. This is the first documentary proof ofC. parvumand associated pathogens responsible for severe periurban outbreaks of bovine calf diarrhoea culminating in heavy mortality from Northern India.
Genital HPV infection among heterosexual and homosexual male attendees of sexually transmitted diseases clinic in Beijing, China
Authors: XIN H.N. , LI H.J. , LI Z. , LI X.W. , LI M.F. , ZHANG H.R. , FENG B.X. , LUN W.H. , YAN H.W. , LONG J. , GAO L.
Published: August 2017

Human papillomavirus (HPV) has been identified as etiologic agent of various cancers for both men and women. However, HPV vaccine has not been recommended for men in China by far. To provide more evidences to promote HPV vaccination among males at high-risk of infection, this study investigated genital HPV genotypes among male attendees of sexually transmitted disease (STD) clinic. Male attendees (⩾18 years old) were recruited from STD clinic of Beijing Ditan Hospital. Data on sociodemographic characteristics and self-reported sexual behaviors were collected based on questionnaire. Genital swab specimens were collected for HPV genotypes. Finally, a total of 198 eligible participants were included in the study. Nearly half of them were infected with at least one type of HPV. The prevalence of genital infection among participants with only heterosexual behaviors (50·91%, 56/110) was significantly higher than those with only homosexual behaviors (36·36%, 32/88) (P< 0·001). However, the distribution pattern of the most frequently observed HPV subtypes were found to be similar between these two subgroups. HPV31, HPV18, HPV16 and HPV58 were the most frequently identified high-risk types and HPV11, HPV6, HPV81 and HPV61 were the most frequently observed low-risk types. Our results, although need further verification by larger sample size, suggested that currently available HPV vaccines covered most prevalent HPV types observed in Chinese men. As HPV vaccine has been approved for application in females in China, molecular epidemiological studies and intervention studies among high-risk males should be promoted as well.
Pulmonary vasodilator therapy in tetralogy of Fallot with pulmonary atresia and major aortopulmonary collaterals: case series and review of literature
Authors: Apostolopoulou Sotiria C. , Vagenakis George , Rammos Spyridon
Published: August 2017

We present the use of pulmonary vasodilators in three adult patients with unrepaired tetralogy of Fallot, pulmonary atresia, aortopulmonary collaterals, and segmental pulmonary arterial hypertension. Patients improved by 1–2 NYHA classes with modest exercise-tolerance increase, and remained stable without side effects during 2.5, 10, and 14 years. Literature review revealed five studies with pulmonary vasodilators in heterogeneous, mostly repaired patient populations.
Perinatal and early postnatal outcomes for fetuses with prenatally diagnosed d-transposition of the great arteries: a prospective cohort study assessing the effect of standardised prenatal consultation
Authors: Qu Yanji , Wen Shusheng , Liu Xiaoqing , Pan Wei , Han Fengzhen , Mai Jinzhuang , Ou Yanqiu , Nie Zhiqiang , Gao Xiangmin , Wu Yong , Ohye Richard G. , Chen Jimei , Zhuang Jian
Published: August 2017

Background

The aim of this study was to explore perinatal and early postnatal outcomes in fetuses with prenatally diagnosed d-transposition of the great arteries and impacts of standardised prenatal consultation.

Methods

All fetuses with prenatally diagnosed d-transposition of the great arteries prospectively enrolled at South China cardiac centre from 2011 to 2015. Standardised prenatal consultation was introduced in 2013 and comprehensive measures were implemented, such as establishing fetal CHD Outpatient Consultation Service, performing standard prenatal consultation according to specifications, and establishing a multidisciplinary team with senior specialists performing in-person consultations. Continuous follow-up investigation was conducted. Perinatal and postnatal outcomes were compared before and after consultation including live birth, elective termination of pregnancy, spontaneous fetal death, stillbirths, referral for surgery, and survival.

Results

In all, 146 fetuses were enrolled with 41 (28%) lost to follow-up. Among 105 remaining fetuses, 29 (28%) were live births and 76 (72%) were terminated. After consultation, live birth rate was higher (50 versus 33%) and termination rate was lower (50 versus 76%), although there was no statistical significance. Excluding three live births without postnatal d-transposition of the great arteries, 65% (17/26) underwent arterial switch operation within 30 days. A total of three in-hospital deaths occurred and during the 10-month follow-up period, one death was observed. In one case, the switch procedure was performed at 13 months and the infant survived. Out of eight infants without arterial switch operation, two died.

Conclusions

Live birth rate increased after consultation; however, termination remained high. Combining termination, patients without arterial switch operation, and operative mortality, outcomes of d-transposition of the great arteries infants can be improved. Standard consultation, multidisciplinary collaboration, and improved perinatal care are important to improve outcomes.
Coronary artery spasm in a neonate with transposition of great arteries: a rare complication and reason for heart transplant
Authors: Bansal Neha , Delius Ralph E. , Aggarwal Sanjeev
Published: August 2017

Arterial switch operation has become the standard of care for d-transposition of great arteries and has excellent short- and long-term outcomes. We report the case of a newborn with a diagnosis of d-transposition of great arteries with intact ventricular septum and a low-risk coronary artery anatomy who developed coronary artery vasospasm while coming off bypass following arterial switch operation in the operating room. The coronary artery spasm led to severe biventricular dysfunction and need for extracorporeal membranous oxygenation support. Despite extracorporeal membranous oxygenation and inotropic support, there was no improvement in the left ventricular function, and cardiac transplantation was performed after 8 days. The explanted heart showed extensive infarction of both ventricles. Both the coronary ostei were patent with no evidence of thrombus, suggesting coronary artery vasospasm rather than embolus or thrombus formation. This is the first case of coronary artery vasospasm in a neonate with d-transposition of great arteries leading to cardiac transplantation. We speculate that early identification of patients who are at a high risk for coronary vasospasm and prophylactic or timely infusion of papaverine directly into the coronary arteries may be beneficial in this condition.
Nurse prescribing in primary care: a metasynthesis of the literature
Authors: Nuttall Dilyse
Published: August 2017

Aim

The aim of this metasynthesis was to develop an understanding of the existing theoretical perspectives around nurse prescribing and to identify any gaps in knowledge, which would support further research into the lived experience of the nurse prescriber in the primary care setting.

Background

Nurse prescribing has been the focus of many research studies since its introduction, with many benefits to the patient, the prescriber and service identified; however, there remains variation in the utilisation of the prescribing qualification, particularly in primary care settings. Although a range of quantitative and qualitative studies have been undertaken, which aimed to explore the influences on prescribing, few have used a research methodology that supports the in-depth exploration of the nurse prescriber’s experience.

Methods

An extensive literature search was undertaken in April 2015 (20–24), which included UK and non-UK studies since 1999. Inclusion and exclusion criteria were applied to search for studies in which participants included nurse prescribers who practiced in primary or community care settings. Studies that only used a quantitative methodology and those not available in English were excluded. The literature search yielded 124 papers, with 50 papers remaining after the initial screen of full papers against the inclusion/exclusion criteria. The papers were reviewed and graded for their quality, with a further 13 papers excluded.

A three-step qualitative analysis technique of metasynthesis was applied to the remaining 37 papers. Identification of similarities and differences enabled first-order interpretations to be identified, which were grouped into broader themes (second-order interpretations) by identifying concepts that applied to two or more studies. Further interpretation through synthesis of translation enabled third-order interpretations to emerge.

Findings

From the metasynthesis of the 37 papers, nine themes emerged: patient-centred care; benefits to the service; the need for knowledge; professional accountability and boundary setting; safety consciousness; barriers to effective prescribing; role preservation; power-shifts and inter-professional relationships; and culture of prescribing.
Molecular studies of Planetary Nebulae
Authors: Zhang Yong
Published: August 2017

Circumstellar envelopes (CEs) around evolved stars are an active site for the production of molecules. After evolving through the Asymptotic Giant Branch (AGB), proto-planetary nebula (PPN), to planetary nebula (PN) phases, CEs ultimately merge with the interstellar medium (ISM). The study of molecules in PNe, therefore, is essential to understanding the transition from stellar to interstellar materials. So far, over 20 molecular species have been discovered in PNe. The molecular composition of PNe is rather different from those of AGB and PPNe, suggesting that the molecules synthesized in PN progenitors have been heavily processed by strong ultraviolet radiation from the central star. Intriguingly, fullerenes and complex organic compounds having aromatic and aliphatic structures can be rapidly formed and largely survive during the PPN/PN evolution. The similar molecular compositions in PNe and diffuse clouds as well as the detection of C60+ in the ISM reinforce the view that the mass-loss from PNe can significantly enrich the ISM with molecular species, some of which may be responsible for the diffuse interstellar bands. In this contribution, I briefly summarize some recent observations of molecules in PNe, with emphasis on their implications on circumstellar chemistry.
Understanding Galactic planetary nebulae with precise/reliable nebular abundances
Authors: García-Hernández D. A. , Ventura P. , Delgado-Inglada G. , Dell'Agli F. , Di Criscienzo M. , Yagüe A.
Published: August 2017

We compare recent precise/reliable nebular abundances - as derived from high-quality optical spectra and the most recent ICFs - in a sample of Galactic planetary nebulae (PNe) with nucleosynthesis predictions (HeCNOCl) from asymptotic giant branch (AGB) ATON models in the metallicity range Z⊙/4 < Z < 2Z⊙. According to the infrared dust features, the sample is divided among carbon-, oxygen-, and double-dust chemistry (CC, OC, and DC, respectively), providing an independent proxy for the nature of the PNe progenitors. Our AGB models, with diffusive overshooting from all the convective borders, nicely reproduce the O overabundances observed in CC PNe, indicating that they evolve from low-Z low-mass (∼1 −3 M⊙) AGB stars. This indicates that O is not always a good indicator of the original ISM metallicity and that the O production by low-mass stars should be considered in galactic-evolution models. The lowest metallicity OC PNe evolve from low-mass (∼1 M⊙) O-rich AGBs, while the higher metallicity ones (all with uncertain dust classifications) display a chemical pattern similar to the DC PNe. In agreement with the recent literature, the DC PNe mostly descend from high-mass (M > 3.5 M⊙) solar/supersolar metallicity AGBs that experience hot bottom burning (HBB), but other formation channels in low-mass AGBs like extra mixing, stellar rotation, binary interaction, or He pre-enrichment cannot be disregarded until more accurate C/O ratios can be obtained. Two DC PNe show the imprint of advanced CNO processing and deep second dredge-up, suggesting progenitors masses close to the limit to evolve as core collapse supernovae (above 6 M⊙). Their actual C/O ratios, if confirmed, indicate contamination from the third dredge-up, rejecting the hypothesis that the chemical composition of such high-metallicity massive AGBs is modified exclusively by HBB.
Photoionisation effects in hydrodynamical simulations of planetary nebulae
Authors: Hernández-Martínez L. , Estrella D. , Velázquez P. F. , Esquivel A. , Raga A. C.
Published: August 2017

We explored the photoionisation effects on both the proper motion and emission of planetary nebulae NGC 6302, by means of hydrodynamical simulations. We used the GUACHO code, which includes the photoionisation due to central source (Esquivel et al. 2009, Esquivel & Raga 2013). We model these PNe considering an interacting stellar fast wind with and ejected toroidally shaped slow wind (Uscanga et al. 2014). Synthetic Hα emission maps were obtained from our numerical results in order to do a comparison between the cases with and without photoionisation. Using a wavelets fittering method on our results for the ionisation case, we do not find an increase in the proper motion velocities, however we can see an accelerated expansion in both cases. For the ionisation case the Hα emission presents an increase.
Abundances and Gradients in M31 – A Chemical Study of Planetary Nebulae in the Substructures
Authors: Fang Xuan , García-Benito Rubén , Guerrero Martín A. , Liu Xiaowei , Zhang Yong , Yuan Haibo
Published: August 2017

We present deep optical spectroscopy of seven planetary nebulae (PNe) in the substructures of M31, three in the Northern Spur and four associated with the Giant Stream. The spectra were obtained with the OSIRIS spectrograph on the 10.4 m GTC. The detection of the [O iii] λ4363 auroral line in all PNe of our sample enables reliable abundance determinations. Our targets have low N/O (<0.5) and He/H ratios, indicating that they are probably Type II PNe. The PNe in our sample have rather homogeneous oxygen abundances, with an average value of 8.56±0.10. Based on the abundances as well as the spatial and kinematical information of our targets, we speculate that the Northern Spur and the Giant Stream might have the same origin. We raise a hypothesis that the dwarf satellite M32 might be responsible for these two substructures. New observations have recently been made to assess this hypothesis.
The halo of M49 and its environment as traced by planetary nebulae
Authors: Hartke Johanna , Arnaboldi Magda , Longobardi Alessia , Gerhard Ortwin , Freeman Ken , Okamura Sadanori
Published: August 2017

We investigate the stellar halo of the nearby elliptical Virgo-cluster galaxy M49 using Planetary Nebulae (PNe). M49 is the second-brightest galaxy of the Virgo cluster and is at the center of the Virgo subcluster B. We present an extended catalogue extracted from a narrow-band survey carried out with Subaru’s Suprime Cam, consisting of 735 PNe down to a limiting magnitude of m5007 = 29.3. This PNe population traces the halo out to 155 kpc from the galaxy’s center, which provides accurate measurement of the luminosity-specific PN-number (α-parameter) in the inner and outer regions of M49’s halo. We are also able to determine the morphological variation of the planetary nebulae luminosity function (PNLF), that may trace different parent stellar populations. This enables us to identify the transition from the PN-scarce, possibly metal-rich, galaxy halo to the PN-rich, metal-poor, outer component.
Herschel spectroscopic observations of PPNe and PNe
Authors: García-Lario Pedro , Ramos-Medina J. , Sánchez-Contreras C.
Published: August 2017

We are building a catalogue of interactively reprocessed observations of evolved stars observed with Herschel. The catalogue will offer not only the PACS and SPIRE spectroscopic data for each observation, but also complementary information from other infrared space observatories. As a first step, we are concentrating our efforts on two main activities: 1) the interactive data-reduction of more than 500 individual spectra obtained with PACS in the 55-210 μm range, available in the Herschel Science Archive; 2) the creation of a catalogue, accesible via a web-based interface and through the Virtual Observatory. Our ultimate goal is to carry out a comprehensive and systematic study of the far infrared properties of low-and intermediate-mass evolved stars using these data and enable science based on Herschel archival data. The objects cover the whole range of possible evolutionary stages in this short-lived phase of stellar evolution, from the AGB to the PN stage, displaying a wide variety of chemical and physical properties.
Expansion parallaxes and intrinsic stellar properties for 15 simple planetary nebulae
Authors: Schönberner Detlef , Jacob Ralf , Balick Bruce
Published: August 2017

We determined individual distances to a small number of rather round, quite regularly shaped planetary nebulae by combining their angular expansion in the plane of the sky with a spectroscopically measured expansion along the line of sight. For this goal, we combined up to three epochs of Hubble Space Telescope imaging data and determined the respective proper motions of rim and shell edges, and of other features as well. Ground-based radial velocities are assigned separately to the nebular rims and shells and used to determine individual distances, thereby assuming that the expansions in the line-of-sight and in the plane of sky are equal. We employed 1D radiation-hydrodynamics simulations of planetary nebulae evolution to correct for the difference between the spectroscopically measured expansion velocities of rim and shell and the expansion speeds of their respective shock fronts.
Central Stars of Planetary Nebulae
Authors: Jones David
Published: August 2017

In this brief invited review, I will attempt to summarise some of the key areas of interest in the study of central stars of planetary nebulae which (probably) will not be covered by other speakers’ proceedings. The main focus will, inevitably, be on the subject of multiplicity, with special emphasis on recent results regarding triple central star systems as well as wide binaries which avoid a common-envelope phase. Furthermore, in light of the upcoming release of Kepler’s Campaign 11 data, I will discuss a few of the prospects from that data including the unique possibility to detect merger products.
Spitzer IRS spectroscopy of planetary nebulae
Authors: Ramos-Larios G. , Guerrero M. A. , Mata H. , Fang X. , Nigoche-Netro A. , Toalá J. A. , Rubio G.
Published: August 2017

We present Spitzer Space Telescope archival mid-infrared (mid-IR) spectroscopy of a sample of eleven planetary nebulae (PNe). The observations, acquired with the Spitzer Infrared Spectrograph (IRS), cover the spectral range 5.2-14.5 μm that includes the H2 0-0 S(2) to S(7) rotational emission lines. This wavelength coverage has allowed us to derive the Boltzmann distribution and calculate the H2 rotational excitation temperature (Tex). The derived excitation temperatures have consistent values ≃ 900 ±70 K for different sources despite their different structural components. We also report the detection of mid-IR ionic lines of [Ar iii], [S iv], and [Ne ii] in most objects, and polycyclic aromatic hydrocarbon (PAH) features in a few cases.
Post-AGB nebular studies
Authors: Lagadec Eric
Published: August 2017

This review presents the latest advances in the nebular studies of post-AGB objects. Post-AGB stars are great tools to test nucleosynthesis and evolution models for stars of low and intermediate masses, and the evolution of dust in harsh environment. I will present the newly discovered class of post-RGB stars, formed via binary interaction on the RGB. Binary systems can also lead to the formation of two class of aspherical post-AGB, the Proto-Planetary Nebulae and the naked post-AGBs (dusty RV Taus, a.k.a. Van Winckel’s stars).
X-ray Studies of Planetary Nebulae
Authors: Montez Rodolfo
Published: August 2017

X-ray emission from planetary nebulae (PNe) provides unique insight on the formation and evolution of PNe. Past observations and the ongoing Chandra Planetary Nebulae Survey (ChanPlaNS) provide a consensus on the two types of X-ray emission detected from PNe: extended and compact point-like sources. Extended X-ray emission arises from a shocked “hot bubble” plasma that resides within the nebular shell. Cooler than expected hot bubble plasma temperatures spurred a number of potential solutions with one emerging as the likely dominate process. The origin of X-ray emission from compact sources at the location of the central star is less clear. These sources might arise from one or combinations of the following processes: self-shocking stellar winds, spun-up binary companions, and/or accretion, perhaps from mass transfer, PN fallback, or debris disks. In the discovery phase, X-ray studies of PNe have mainly focused on the origin of the various emission processes. New directions incorporate multi-wavelength observations to study the influence of X-ray emission on the rest of the electromagnetic spectrum.
Progress and Application of The Initial-Final Mass Relation
Authors: Cummings Jeffrey D.
Published: August 2017

The stellar life cycle is dominated by phases such as the hydrogen-burning stage and the remnant white dwarf cooling phase. However, between these two stages, stars dramatically transform themselves by losing the bulk of their mass. Planetary nebulae (PNe) provide a powerful clue to the processes involved in this transformation, but they are very complex. Over the past 15 years, a new wave of imaging and spectroscopy programs have uncovered the remnants of PNe, white dwarfs, in a wide range of well-measured environments. With this we can map the masses and temperatures of the stellar remnants to the properties of their progenitors. This work has now led to the first uniform mapping of the initial-final mass relation from 1.5 to 7 M⊙. The resulting relation is a fundamental input to our understanding of stellar evolution for low and intermediate-mass stars that produce PNe and has a wide range of applications.
Resolving the Disk-Halo Degeneracy using Planetary Nebulae
Authors: Aniyan S. , Freeman K. C. , Arnaboldi M. , Gerhard O. , Coccato L. , Fabricius M. , Kuijken K. , Merrifield M.
Published: August 2017

The decomposition of the 21 cm rotation curve of galaxies into contribution from the disk and dark halo depends on the adopted mass to light ratio (M/L) of the disk. Given the vertical velocity dispersion (σz) of stars in the disk and its scale height (hz), the disk surface density and hence the M/L can be estimated. Earlier works have used this technique to conclude that galaxy disks are submaximal. Here we address an important conceptual problem: star-forming spirals have an old (kinematically hot) disk population and a young cold disk population. Both of these populations contribute to the integrated light spectra from which σz is measured. The measured scale height hz is for the old disk population. In the Jeans equation, σz and hz must pertain to the same population. We have developed techniques to extract the velocity dispersion of the old disk from integrated light spectra and from samples of planetary nebulae. We present the analysis of the disk kinematics of the galaxy NGC 628 using IFU data in the inner regions and planetary nebulae as tracers in the outer regions of the disk. We demonstrate that using the scale height of the old thin disk with the vertical velocity dispersion of the same population, traced by PNe, results in a maximal disk for NGC 628. Our analysis concludes that previous studies underestimate the disk surface mass density by ~ 2, sufficient to make a maximal disk for NGC 628 appear like a submaximal disk.
GTC/CanariCam mid-IR imaging of the fullerene-rich planetary nebula IC 418
Authors: Díaz-Luis J. J. , García-Hernández D. A. , Manchado A. , García-Lario P. , Villaver E. , García-Segura G.
Published: August 2017

The formation process(es) of fullerenes in space is still uncertain and several mechanisms have been proposed in the literature. In particular, the most accepted idea to explain the simultaneous presence of fullerenes and PAH-like emission in the H-rich circumstellar envelopes of PNe is that these molecular species may be formed from the photochemical processing of a carbonaceous compound with a mixture of aromatic and aliphatic structures, which should be a major constituent of their circumstellar envelopes. Here we present seeing-limited narrow-band mid-IR GTC/CanariCam images of the fullerene-containing PN IC 418. The narrow-band images cover the 9−13, 11.3, and 17.4 μm emission features (and their adjacent continua) in this extended PN. We study the relative sub-arcsecond spatial distribution of the nebula in these filters with the intention of getting some clues about the formation process of fullerenes in H-rich circumstellar environments.
Mid-Infrared Studies of the Cool Dust Distribution in Bipolar Planetary Nebulae
Authors: Asano Kentaro , Miyata Takashi , Kamizuka Takafumi , Ueta Toshiya
Published: August 2017

To understand mass loss history and mass loss and dust formation history of massive AGB stars, we carried out observations of three bipolar planetary nebulae (BPNe) in 30 micron bands from a ground-based telescope. All of our targets have a compact strong emission source in the mid-infrared (MIR) around the position of the central star of planetary nebula (CSPN). These detected emissions can be originated from cool dust. Our results show that the cool dust component is compactly distributed and much more massive than previous studies indicated. These findings suggest that they experienced a strong mass loss into the equatorial direction in past.
The systematic uncertainties introduced by atomic data in nebular abundance determinations
Authors: de Dios Leticia Juan , Rodríguez Mónica
Published: August 2017

Atomic data selection is one important source of systematic uncertainty since there are important variations between the values provided by different authors. We explore the effect of using different atomic data in the determination of physical conditions and chemical abundances in a sample of Galactic planetary nebulae and Hii regions. We find that the available datasets introduce significant differences in the results, especially at densities above 104 cm−3, where O/H and N/O reach uncertainties higher than a factor of 4.
The VIRGO PN population and the mass assembly in M87
Authors: Longobardi Alessia , Arnaboldi Magda , Gerhard Ortwin
Published: August 2017

Cosmological simulations allow us to study in detail the evolution of galaxy halos in cluster environments, but the extremely low surface brightness of such components makes it difficult to gather observational constraints. Planetary nebulas (PNs) offer a unique tool to investigate these environments owing to their strong [OIII] emission line. We study the light and kinematics of the Virgo cluster and its central galaxy, M87, prime targets to address the topic of galaxy formation and evolution in dense environments. We make use of a deep and extended PN sample (~300 objects) that extends out to 150 kpc in radius from M87’s centre. We show that at all distance the galaxy halo overlaps with the Virgo intracluster light (ICL). Halo and ICL are dynamically distinct components with different parent stellar populations, consistent with the halo of M87 being redder and more metal rich than the ICL. The synergy between PN kinematic information and deep V/B-band photometry made it possible to unravel an ongoing accretion process in the outskirt of M87. This accretion event represents a non-negligible perturbation of the halo light, showing that this galaxy is still growing by accretion of smaller systems.
Shaping planetary nebulae with jets in inclined triple stellar systems
Authors: Akashi Muhammad , Soker Noam
Published: August 2017

We conduct three-dimensional hydrodynamical simulations of two opposite jets launched obliquely to the orbital plane around an asymptotic giant branch (AGB) star and within its dense wind, and demonstrate the formation of a ‘messy’ planetary nebula (PN), namely, a PN lacking any type of symmetry (highly irregular). In building the initial conditions we assume that a tight binary system orbits the AGB star, and that the orbital plane of the tight binary system is inclined to the orbital plane of binary system and the AGB star. We further assume that the accreted mass onto the tight binary system forms an accretion disk around one of the stars, and that the plane of the disk is in between the two orbital planes. The highly asymmetrical lobes that we obtain support the notion that messy PNe might be shaped by triple stellar systems.
Herschel observations of planetary nebulae
Authors: Van de Steene Griet C.
Published: August 2017

This article presents an overview of the published results for planetary nebulae based on images and spectroscopy from the PACS, SPIRE, and HIFI instruments on board the Herschel satellite.
Circumstellar spirals/shells/arcs: the message from binary stars
Authors: Kim Hyosun
Published: August 2017

A consensus has grown in the past few decades that binarity is key to understanding the morphological diversities of the circumstellar envelopes (CSEs) surrounding stars in the Asymptotic Giant Branch (AGB) to Planetary Nebula (PN) phase. The possible roles of binaries in their shaping have, however, yet to be confirmed. Meanwhile, recurrent patterns are often found in the CSEs of AGB stars and the outer halos of PNe, providing a fossil record of the mass loss during the AGB phase. In this regard, recent molecular line observations using interferometric facilities have revealed the spatio-kinematics of such patterns. Numerical simulations of binary interactions producing spiral-shells have been extensively developed, revealing new probes for extracting the stellar and orbital properties from these patterns. I review recent theoretical and observational investigations on the circumstellar spiral-shell patterns and discuss their implications in linking binary properties to the asymmetric ejection events in the post-AGB phase.
A New Model of NGC 6210 to Solve its Abundance Discrepancy Problem
Authors: Escalante V. , Toalá J. A.
Published: August 2017

We present a model that solves the abundance discrepancy problem for NGC 6210. The model proposes a high abundance of CNONe elements that lowers the temperature of the central parts of the nebula. The colder gas model reproduces the observed intensity of the strong [N ii] and [O iii] emission lines, and increases the predicted weak recombination lines towards their observed values. We examine how the usual nebular diagnostic line ratios depend on model abundances.
Galactic planetary nebulae as absolute probes: The view from Gaia
Authors: Stanghellini Letizia , Bucciarelli Beatrice , Lattanzi Mario G. , Morbidelli Roberto
Published: August 2017

We searched the first Gaia data release for Galactic central stars of planetary nebulae (CSPNe) for parallaxes in order to determine the distances of the hosting PNe. For the small sample of PNe for which a comparison is available, we show that distances derived from Gaia parallaxes agree, within the uncertainties, with the individual PN distances derived by other reliable methods. While Gaia parallaxes available for Galactic CSPNe are still few, and with high uncertainties, we studied the possibility of building a PN distance scale by using the Gaia distances as calibrators. We found that a scale built on the relation between the linear nebular radius and its surface brightness has promising future applications.
Common Envelope Evolution: Implications for Post-AGB Stars and Planetary Nebulae
Authors: Nordhaus J.
Published: August 2017

Common envelopes (CE) are of broad interest as they represent one method by which binaries with initially long-period orbits of a few years can be converted into short-period orbits of a few hours. Despite their importance, the brief lifetimes of CE phases make them difficult to directly observe. Nevertheless, CE interactions are potentially common, can produce a diverse array of nebular shapes, and can accommodate current post-AGB and planetary nebula outflow constraints. Here, I discuss ongoing theoretical and computational work on CEs and speculate on what lies ahead for determining accurate outcomes of this elusive phase of evolution.
Revealing the Location of the Mixing Layer in a Hot Bubble
Authors: Guerrero M. A. , Fang X. , Chu Y.-H. , Toalá J. A. , Gruendl R. A.
Published: August 2017

The fast stellar winds can blow bubbles in the circumstellar material ejected from previous phases of stellar evolution. These are found at different scales, from planetary nebulae (PNe) around stars evolving to the white dwarf stage, to Wolf-Rayet (WR) bubbles and up to large-scale bubbles around massive star clusters. In all cases, the fast stellar wind is shock-heated and a hot bubble is produced. Processes of mass evaporation and mixing of nebular material and heat conduction occurring at the mixing layer between the hot bubble and the optical nebula are key to determine the thermal structure of these bubbles and their evolution. In this contribution we review our current understanding of the X-ray observations of hot bubbles in PNe and present the first spatially-resolved study of a mixing layer in a PN.
The LAMOST spectroscopic survey of planetary nebulae in M31 and M33
Authors: Xiang Maosheng , Liu Xiaowei , Zhang Meng , Yuan Haibo , Huo Zhiying
Published: August 2017

We present LAMOST observations and radial velocity measurements of about 1500 planetary nebulae (PNe) in M31 and M33. Most of the PNe are previously known, but 36 of them are newly discovered in the outskirts of M31, and the furthest one has a projected distance larger than 50 kpc away from the galaxy center. Eighteen objects in the area of M33 are probably newly discovered PNe, and quite a few of them are associated with previously known clusters. For all the 1500 PNe, homogeneous radial velocities are measured from the LAMOST spectra, with a typical uncertainty of a few km s−1.
The Origins of Planetary Nebulae in the Inner and Outer Disks of M 31
Authors: Balick Bruce , Kwitter Karen , Corradi Romano , Rosillo Rebeca Galera , Henry Richard
Published: August 2017

The planetary nebulae (PNe) of M 31 are receiving considerable attention as probes of its structure and chemical evolution in a galactic environment that is putatively similar to the Milky Way. We have obtained deep spectra for about 30 luminous PNe in M 31’s inner disk and beyond (Rgal < 105 kpc). The entire ensemble of PNe exhibit O/H ~ 2/3 solar with no discernible radial gradient, in stark contrast to the H ii regions of M 31. This suggests that the outer PNe in M 31 formed from a common O-rich ISM at least 5 GY ago. We infer that the outer PNe and the underlying stellar population have little common history in M 31, and that the formation of the O-rich PNe preceded any putative encounter with M 33 ~2–3 Gy ago.
The origin of the most luminous Planetary Nebulae
Authors: Galera-Rosillo Rebeca , Corradi Romano L. M. , Balick Bruce , Kwitter Karen , Mampaso Antonio , García-Rojas Jorge
Published: August 2017

As part of a systematic effort to characterize the properties and progenitors of the most luminous planetary nebulae (PNe), we obtained a sample among the brightest PNe in two stellar systems of different metallicities: LMC (Z/Z⊙~0.5) and M31 (Z/Z⊙~1) by means of a combined effort with the VLT and the 10mGTC. Modelling of these data will allow us to infer the masses of the stellar progenitors, gaining insights into the controversial origin of the universal cutoff of the Planetary Nebulae Luminosity Function (PNLF).
BELIEVING EPISTEMIC CONTRADICTIONS
Authors: BEDDOR BOB , GOLDSTEIN SIMON
Published: August 2017

What is it to believe something might be the case? We develop a puzzle that creates difficulties for standard answers to this question. We go on to propose our own solution, which integrates a Bayesian approach to belief with a dynamic semantics for epistemic modals. After showing how our account solves the puzzle, we explore a surprising consequence: virtually all of our beliefs about what might be the case provide counterexamples to the view that rational belief is closed under logical implication.
A novel uniplanar wideband magneto-electric dipole antenna element
Authors: Shuai Chen-Yang , Wang Guang-Ming , Wang Ya-Wei
Published: August 2017

A novel uniplanar wideband magneto-electric dipole antenna element is proposed in this paper. The proposed antenna is composed of the conventional bow-tie radiation patch as an electric dipole, a semi-circular loop, which works as a magnetic dipole, a coplanar ground plane, two directors with different lengths for enhancing gain, and a microstrip-to-coplanar stripline transition balun. The designed antenna adopts a small-size coplanar ground plane to achieve a uniplanar structure. Consequently, this method reduces the space size immensely and makes the antenna suitable for the array application. In addition, a tapered slot structure is utilized to improve impedance matching. The prototype of the proposed antenna was fabricated and measured. The measured results keep in good accordance with the simulated ones. The simulated results show that the proposed antenna obtains a broad impedance bandwidth of 60.5% from 2.25 to 4.20 GHz (voltage standing wave ratio [VSWR] ≤ 2) which can be applied for wireless local area network (WLAN) (2.4–2.484 GHz), worldwide interoperability for microwave access (WiMAX) (2.5–2.69/3.4–3.69 GHz), and long term evolution (LTE) (2.5–2.69 GHz). Meanwhile, the stable gain, low cross-polarization, stable unidirectional radiation patterns, and low back lobe are obtained within the operating frequency band. The array composed of the proposed antenna elements is also investigated in this paper.