bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methanol fixed fibroblasts serve as feeder cells to maintain stem cells in the pluripotent state in vitro
Authors: Ren Yahui , Ma Ziyu , Yu Tong , Ling Min , Wang Huayan 
Published: May 2018

AbstractPreparation of mouse embryonic fibroblast (MEF) feeder cells to maintain pluripotent stem cells (PSCs) is time consuming and involved in animal issues. Here, we demonstrated a novel method to prepare feeder cells with high efficiency, timesaving, and low costs. MEFs in 3 × 104 cell/cm2 were fixed by methanol for 5 min and air drying for 5 min. Thereafter, the methanol fixed MEF cells (MT-MEF) were able to be used directly to culture PSCs or stored at room temperature for the future usage. PSCs cultured on MT-MEF could be continuously expanded for over 40 passages with the naïve pluripotency. MT-MEFs could also be used to maintain human and pig iPSCs. Moreover, methanol fixed MEFs’ culture dish was able to be reused for at least 4 times, and to be applied for antibiotic resistant screening assay to establishing stable transfected PSC lines. Alternatively, the immortalized cell lines, for instance NIH3T3 cells, could also be fixed by methanol and used as feeder cells to maintain PSCs. Thus, this novel means of methanol fixed feeder cells can completely replace the mitomycin C and gamma radiation treated MEF feeder cells, and be used to maintain PSCs derived from mouse as well as other animal species.
The Crotone Megalandslide, southern Italy: Architecture, timing and tectonic control
Authors: Zecchin Massimo , Accaino Flavio , Ceramicola Silvia , Civile Dario , Critelli Salvatore , Da Lio Cristina , Mangano Giacomo , Prosser Giacomo , Teatini Pietro , Tosi Luigi 
Published: May 2018

AbstractLarge-scale submarine gravitational land movements involving even more than 1,000 m thick sedimentary successions are known as megalandslides. We prove the existence of large-scale gravitational phenomena off the Crotone Basin, a forearc basin located on the Ionian side of Calabria (southern Italy), by seismic, morpho-bathymetric and well data. Our study reveals that the Crotone Megalandslide started moving between Late Zanclean and Early Piacenzian and was triggered by a contractional tectonic event leading to the basin inversion. Seaward gliding of the megalandslide continued until roughly Late Gelasian, and then resumed since Middle Pleistocene with a modest rate. Interestingly, the onshore part of the basin does not show a gravity-driven deformation comparable to that observed in the marine area, and this peculiar evidence allows some speculations on the origin of the megalandslide.
Three dynamically distinct stellar populations in the halo of M49
Authors: Hartke J. , Arnaboldi M. , Gerhard O. , Agnello A. , Longobardi A. , Coccato L. , Pulsoni C. , Freeman K. C. , Merrifield M. 
Published: May 2018

Context. M49 (NGC 4472) is the dominant galaxy in subcluster B of the Virgo Cluster, and a benchmark for studying the build-up of the extended halos of brightest group galaxies in the outskirts of galaxy clusters.
Aims. We investigate the kinematics in the outer halo of M49, look for substructures, and describe the transition to the surrounding intra-group light.
Methods. As kinematic tracers, we use planetary nebulae (PNe), combining kinematics from the extended Planetary Nebula Spectrograph (PN.S) early-type galaxy survey with our recent deep photometric sample. We study the position-velocity-plane for bright and faint PN populations out to 95 kpc radius, and employ a multi-Gaussian model for the velocity distribution to identify stellar populations with distinct kinematics and histories.
Results. We report the detection of stellar-kinematic substructure associated with the interaction of M49 with the dwarf irregular galaxy VCC 1249. We find two kinematically distinct PN populations associated with the main M49 halo and the extended intra-group light (IGL). These have velocity dispersions σhalo ≃ 170 km s−1 and σIGL ≃ 400 km s−1 at 10–80 kpc radii. The overall luminosity profile and velocity dispersion at ~80 kpc are consistent with a flat circular velocity curve extrapolated from X-ray observations. The dispersion of the PNe associated with the IGL joins onto that of the satellite galaxies in subcluster B at ~100 kpc radius. This is the first time that the transition from halo to IGL is observed based on the velocities of individual stars.
Conclusions. Therefore the halo of M49, consisting of at least three distinct components, has undergone an extended accretion history within its parent group potential. The blue colours of the IGL component are consistent with a population of stars formed in low-mass galaxies at redshift ~0.5 that has since evolved passively, as suggested by other data.
K2 space photometry reveals rotational modulation and stellar pulsations in chemically peculiar A and B stars
Authors: Bowman D. M. , Buysschaert B. , Neiner C. , Pápics P. I. , Oksala M. E. , Aerts C. 
Published: May 2018

Context. The physics of magnetic hot stars and how a large-scale magnetic field affects their interior properties is largely unknown. Few studies have combined high-quality observations and modelling of magnetic pulsating stars, known as magneto-asteroseismology, primarily because of the dearth of detected pulsations in stars with a confirmed and well-characterised large-scale magnetic field.
Aims. We aim to characterise observational signatures of rotation and pulsation in chemically peculiar candidate magnetic stars using photometry from the K2 space mission. Thus, we identify the best candidate targets for ground-based, optical spectropolarimetric follow-up observations to confirm the presence of a large-scale magnetic field.
Methods. We employed customised reduction and detrending tools to process the K2 photometry into optimised light curves for a variability analysis. We searched for the periodic photometric signatures of rotational modulation caused by surface abundance inhomogeneities in 56 chemically peculiar A and B stars. Furthermore, we searched for intrinsic variability caused by pulsations (coherent or otherwise) in the amplitude spectra of these stars.
Results. The rotation periods of 38 chemically peculiar stars are determined, 16 of which are the first determination of the rotation period in the literature. We confirm the discovery of high-overtone roAp pulsation modes in HD 177765 and find an additional 3 Ap and Bp stars that show evidence of high-overtone pressure modes found in roAp stars in the form of possible Nyquist alias frequencies in their amplitude spectra. Furthermore, we find 6 chemically peculiar stars that show evidence of intrinsic variability caused by gravity or pressure pulsation modes.
Conclusions. The discovery of pulsations in a non-negligible fraction of chemically peculiar stars make these stars high-priority targets for spectropolarimetric campaigns to confirm the presence of their expected large-scale magnetic field. The ultimate goal is to perform magneto-asteroseismology and probe the interior physics of magnetic pulsating stars.
Unanticipated Difficulty in an Anticipated Difficult Airway in the Neurointervention Suite: A Case Report
Authors: Gandhe Rajashree Uday , Bhave Chinmaya Pradeep , Kakde Avinash Sahebarav , Sathe Kalyani Anand 
Published: May 2018

AbstractAirway management of patients with craniofacial vascular malformations poses many challenges. Establishment of a secure airway is a prerequisite for safe anesthetic management of these patients. We report a case of a 45-year-old man presenting with a facial vascular malformation involving the tongue, parapharynx, and extending into the neck, resulting in airway compromise scheduled for endovascular embolization.
A neural pathway controlling motivation to exert effort
Authors: Proulx Christophe D. , Aronson Sage , Milivojevic Djordje , Molina Cris , Loi Alan , Monk Bradley , Shabel Steven J. , Malinow Roberto 
Published: May 2018

Significance
The lateral habenula, a brain region that has been implicated in depression, receives inputs from brain nuclei associated with basic emotions and drives. In this report, using fiber photometry and optogenetics on behaving rats, we show that one major lateral habenula output pathway controls the motivation to exert effort in both aversive and appetitive contexts. Overactivity of this pathway could contribute to the reduced motivation seen in human depression.
A network of invasion hypotheses.
Authors: Enders M. , Jeschke J. M. 
Published: May 2018

Abstract

Hypotheses of research disciplines are typically not isolated from each other but share similarities. In a broad sense as defined here, they form an important part of the theoretical-conceptual understanding of a given topic, e.g. invasion hypotheses sensu lato represent an important part of our understanding of biological invasions. Dynamic research disciplines such as invasion biology have so many hypotheses that it is even hard for experts to keep track, and researchers from other disciplines as well as policy-makers, managers and other interested people find it extremely complicated to get to grips with invasion hypotheses. To tackle this situation, we argue that it is useful to define key hypotheses and visualize their relationships. We define 35 of the arguably most common invasion hypotheses and outline three approaches to create hypothesis networks that visualize the similarities and dissimilarities between hypotheses: (i) the bibliometric approach; (ii) the survey approach; and (iii) the matrix approach. The latter approach is in the focus of this chapter. It is centred around a matrix that represents the characteristics or traits of each hypothesis. Here we assigned such traits to 35 invasion hypotheses based on 13 trait categories. We then calculated the similarities between them and created a hypothesis network visualizing these similarities. With the same trait matrix, we created a smaller network focused on the 12 hypotheses featured in this book. This network thus illustrates the relationships between these 12 hypotheses and can be used as a map for the following chapters.
Biotic resistance and island susceptibility hypotheses.
Authors: Jeschke J. M. , Debille S. , Lortie C. J. 
Published: May 2018

Abstract

The biotic resistance hypothesis sensu stricto is also known as the diversity-invasibility hypothesis. It proposes that ecosystems with high biodiversity are more resistant against non-native species than ecosystems with lower biodiversity. It is a classic hypothesis of the field and our systematic literature search identified 155 empirical studies that examined it. Most of these studies question the hypothesis. The frequency of supportive observational field studies is only about 15%. Although the frequency of supportive experimental studies, which are typically done at smaller spatial scales, is significantly higher, it is still below 50%. The island susceptibility hypothesis is topically similar and posits that continents are more resistant against non-native species than islands. In more specific terms, the island susceptibility hypothesis states that non-native species are more likely to become established and have major ecological impacts on islands than on continents. Our literature search only identified 17 empirical tests of this hypothesis with five of them being supportive. Thus, the biotic resistance and island susceptibility hypotheses are not frequently supported by existing empirical evidence. Most studies addressing them examined the number of non-native species or their establishment success, whereas relatively few studies measured impacts of non-native species. Studies that measured abundance, biomass or cover of non-native species - which are related to impact - more frequently supported the resistance hypothesis than other studies. A promising way forward might thus be to narrow the definition and scope of both hypotheses (and possibly rename them), so that 'resistance' and 'susceptibility' are related to impact of nonnative species. The next steps will then be to critically test these revised hypotheses and further refine the relevant ecological contexts that mediate the importance or magnitude of resistance.
Disturbance hypothesis.
Authors: Nordheimer R. , Jeschke J. M. 
Published: May 2018

Abstract

The disturbance hypothesis posits that the invasion success of non-native species is higher in highly disturbed than in relatively undisturbed ecosystems. A synonymous formulation is that highly disturbed ecosystems show lower resistance against nonnative species than relatively undisturbed ecosystems. On the basis of a systematic literature search, we identified 126 studies addressing the disturbance hypothesis. Applying the hierarchy-of-hypotheses approach, we classified these studies according to: (i) the cause of disturbance (direct anthropogenic vs indirect or non-anthropogenic disturbances); (ii) the type of disturbance; and (iii) the measure of invasion success. The majority of studies reported evidence supporting the disturbance hypothesis (59%, with 21% of the studies questioning the hypothesis and another 21% being undecided). Most subhypotheses were supported as well, only studies focusing on conservation management or fire as disturbances frequently reported questioning evidence. There was also consistent support for the hypothesis across taxonomic groups and terrestrial as well as aquatic systems. However, experimental field studies showed a lower level of support than observational or laboratory studies. Overall, this hypothesis is relatively well, but not very strongly supported by currently available studies. Given that human disturbances will further increase in the foreseeable future, we can predict that these will tend to further promote biological invasions.
Phenotypic plasticity hypothesis.
Authors: Torchyk O. , Jeschke J. M. 
Published: May 2018

Abstract

The phenotypic plasticity hypothesis - or, in short, plasticity hypothesis - posits that invasive species are more phenotypically plastic than non-invasive or native ones. On the basis of a systematic review, we identified 115 relevant empirical tests of the plasticity hypothesis. Most of these empirical studies focused on terrestrial plants; only some have been carried out on animals or in aquatic habitats. The plasticity hypothesis is largely empirically supported, including most of its sub-hypotheses - focusing on phenotypic plasticity in morphology, physiology and life history - and across taxonomic groups and habitats. There are relatively few experimental field and enclosure studies available, and these showed significantly lower support than observational studies. Similarly, recent studies showed slightly lower support of the plasticity hypothesis than early ones but this difference was not statistically significant. Thus overall, this invasion hypothesis is largely supported by currently available evidence; however, more studies are needed on organisms other than plants and in aquatic habitats, and it seems important to perform more experimental field and enclosure studies in the future to scrutinize this hypothesis.
Propagule pressure hypothesis.
Authors: Jeschke J. M. , Starzer J. 
Published: May 2018

Abstract

Propagule pressure is a composite measure of introduction effort consisting of: (i) the number of individuals introduced per introduction event (propagule size); and (ii) the frequency of introduction events (propagule frequency or number). The propagule pressure hypothesis posits that a high propagule pressure is a cause of invasion success; in other words, non-native species with a high propagule pressure have a higher invasion success than non-native species with a low propagule pressure. On the basis of a systematic review, we identified 92 relevant empirical studies testing the propagule pressure hypothesis. These studies have addressed different aspects - that is, suband sub-sub-hypotheses - of the overall hypothesis. Independently of the specific aspects considered by each study, the propagule pressure hypothesis is largely supported by currently available evidence. About 80% of the 92 studies reported supporting evidence. Similarly, the propagule pressure hypothesis is empirically supported across major taxonomic groups, habitats and methodological approaches. This hypothesis is among the most influential ones in the field and represents the recognition that in order to understand biological invasions, one must consider humans and their actions as key underlying drivers.
Synthesis.
Authors: Jeschke J. M. , Heger T. 
Published: May 2018

Abstract

About 1100 studies focusing on 12 major invasion hypotheses have been analysed in Chapters 8-16 of this book. A network of these 12 hypotheses, in which topically similar hypotheses are connected, was presented in Chapter 7. We here combine and synthesize these previous chapters, colour coding the hypothesis network depending on the level of empirical support of each hypothesis. Overall, six of the 12 hypotheses were supported by the majority of available empirical studies, three hypotheses were questioned by the majority of studies, and empirical studies were undecided for the three remaining hypotheses. The three questioned hypotheses were: evolution of increased competitive ability (EICA), biotic resistance and the tens rule. On the basis of these findings, we propose an alternative hypothesis network in which the biotic resistance hypothesis and the tens rule are replaced by revised hypotheses that are better empirically supported, and the EICA hypothesis is abandoned because the better empirically supported shifting defence hypothesis already is a refinement of this hypothesis. The revised hypothesis network therefore consists of 11 major hypotheses. Most studies analysed in this book focused on terrestrial plants in affluent countries, whereas other taxonomic groups, habitats and other countries are underrepresented in the invasion literature. Observational studies currently dominate the field. We further found that the level of empirical support has declined over time for some but not all focal hypotheses. The hypothesis network featured here is provided online, where it is also connected to the empirical data analysed in this book. This website is envisioned as the initiation of an advanced online tool that grows beyond invasion biology and should cover different scientific disciplines such as community ecology, biodiversity science and evolutionary biology. It is meant to visualize the major concepts, ideas and hypotheses in these disciplines including their links and connections, thus featuring a large structured network that is connected to the data generated in these disciplines.
Conclusions and outlook.
Authors: Heger T. , Jeschke J. M. 
Published: May 2018

Abstract

In Chapters 8-16, the hierarchy-of-hypotheses (HoH) toolbox has been applied in various ways. The results displayed as HoHs and additional bar graphs in most chapters, and as networks in Chapter 17, can now be used to identify knowledge gaps and promising paths for future research. We suggest some further steps that could be taken, making use of the data gathered for this book (which are freely available at www. hi-knowledge.org) and possible avenues for more general methodological advancements. To strengthen research in invasion biology, we specifically suggest four steps: (i) a more efficient provision and use of existing data and knowledge; (ii) a stronger focus on experiments or ideally research projects combining field studies with experiments; (iii) the development of sets of conceptually based 'case-sensitive' generalizations; and (iv) continuous integration of newly gained data and knowledge into a growing and developing atlas of invasion biology, which could potentially be expanded into an atlas of science. In this final chapter, we will first discuss how the chapters in Part II of the book made use of the HoH approach, what we think was achieved and which further methodological steps can be taken. The second section of this chapter, and final section of the book, will be an overall brief conclusion about the current state of invasion biology and possible ways forward.
From colonisation to globalisation: a history of state capture by the tobacco industry in Malawi
Authors: Smith Julia , Lee Kelley 
Published: May 2018

ABSTRACT
Malawi, the world’s most tobacco-dependent country, has long defended the tobacco industry as essential to its economy. The impoverished living conditions of tobacco farmers, however, raise questions about the true benefits accruing to the country. While the government and industry often blame public health advocates for declining leaf prices, and thus lower returns to farmers, this article scrutinises these claims from a historical perspective. It argues that a context of state capture has characterised Malawi’s tobacco industry, originating with colonisation and evolving since to become increasingly entrenched. The analysis is divided into four periods: colonial (1890s–1964); national (1964–1981); liberalisation (1981–2004) and accelerated globalisation (2004 to present). Each period demonstrates how industry interests influenced government institutions and policies in ways that increased dependence on a crop that only benefits a minority of Malawians. Today, a transnational elite prospers at the expense of local growers.
Development of methods for the analysis of multi-mode TFM images
Authors: Sy K , Bredif P , Iakovleva E , Roy O , Lesselier D 
Published: May 2018

Abstract
TFM (Total Focusing Method) is an advanced post-processing imaging algorithm of ultrasonic array data that shows good potential in defect detection and characterization. It can be employed using an infinite number of paths between transducer and focusing point. Depending upon the geometry and the characteristics of the defect in a given part, there are not the same modes that are appropriate for the defect reconstruction. Furthermore, non-physical indications can be observed, prone to misinterpretation. These imaging artifacts are due to the coexistence of several contributions involving several modes of propagation and interactions with possible defects and/or the geometry of the part. Two methods for filtering artifacts and reducing the number of TFM images are developed and illustrated.
Coastal management strategy for small island: ecotourism potency development in Karimata Island, West Kalimantan
Authors: Rudiastuti A W , Munawaroh  , Setyawan I E , Pramono G H 
Published: May 2018

Abstract
Sustainable coastal management is playing an important role in coastal resources conservation, particularly on small islands. Karimata archipelago has unique characteristics and great potential to be developed as a tourism object, one of which is Karimata Island as the largest island and also reserve area. The concept of ecotourism focuses on the ecology conservation, economic benefits, and social life. Ecotourism aims to build sustainable tourism that provides economically viable and social benefits to the community. This study aims to develop coastal management strategy based on ecotourism at Karimata Island. Spatial approaching through coastal type was done. Qualitative descriptive analysis and SWOT are used to develop sustainable management strategies for the coast of Karimata Island, where the opportunities and challenges to the development of coastal ecotourism Karimata Island also included. If this potential is optimally utilized, it can be relied as an economic opportunity for local communities. Structurally shaped coast, marine depositional coast and coast build by organism are several of coastal types found at Karimata Island. Coastal ecosystems inhabited Karimata Island are mangroves, coral reefs, and macro-algae. Karimata Island have not been optimally utilized for tourist destinations. The biggest obstacle encountered is the accessibility from Kalimantan or other island at Karimata islands. Several problems related to the utilization of coastal resources were found such as mangrove and coral reef damage, also regulation that less supportive. The results of this study are expected to provide an overview of solutions for the development of coastal tourism potentials in Karimata Island.