Intermediate Clusters Research Articles

High-resolution spectroscopy of red giants and ‘yellow stragglers’ in the southern open cluster NGC 2539

ABSTRACT We present a detailed high-resolution spectroscopic analysis of 12 red giant stars, in single and binaries or multiples systems, classified as members of the intermediate-age (631 Myr) open cluster NGC 2539. We used FEROS echelle spectra and the standard LTE analysis to derive the atmospheric parameters for the stars and the abundance ratios of light elements (Li, C, N), light odd-Z elements (Na, Al), α-elements (Mg, Si, Ca, Ti), Fe-group elements (Cr, Fe, Ni), and n-capture elements (Y, Zr, Ce, Nd, Eu). Our results show that the sample star of NGC 2539 has low projected rotational velocities and an almost solar metallicity, with a mean of [Fe/H] = −0.03 ± 0.07 dex. The abundance pattern displays for the analyzed stars are, in general, similar to those presented by solar neighborhood stars, including giant members of others open clusters. In particular, light elements and Na abundance pattern shows anomalies resulting from the appearance of enriched material on the stellar surface, produced by mechanisms like the first dredge-up and/or thermohaline and rotation-induced mixing. We also identified two of the spectroscopic binaries of our sample as ‘yellow stragglers’ and we determined the nature of their companions.

A systematic density-based clustering method using anchor points

Clustering is an important unsupervised learning method in machine learning and data mining. Many existing clustering methods may still face the challenge in self-identifying clusters with varying shapes, sizes and densities. To devise a more generic clustering method that considers all the aforementioned properties of the natural clusters, we propose a novel clustering algorithm named Anchor Points based Clustering (APC). The anchor points in APC are characterized by having a relatively large distance from data points with higher densities. We take anchor points as centers to obtain intermediate clusters, which can divide the whole dataset more appropriately so as to better facilitate further grouping. In essence, based on the analysis of the identified anchor points, the relationship among the corresponding intermediate clusters can be better revealed. In short, the difference in local densities (densities within neighboring data points) of the anchor points characterizes their different properties, that is to say, all the intermediate clusters may fall into one or multiple identified levels with different densities. Finally, based on the properties of anchor points, APC spontaneously chooses the appropriate clustering strategies and reports the final clustering results. To evaluate the performances of APC, we conduct experiments on twelve two-dimensional synthetic datasets and twelve multi-dimensional real-world datasets. Moreover, we also apply APC to the Olivetti Face dataset to further assess its effectiveness in terms of face recognition. All experimental results indicate that APC outperforms four classical methods and two state-of-the-art methods in most cases.

Effectiveness of Blended Learning in Nursing Education.

Currently, teaching in higher education is being heavily developed by learning management systems that record the learning behaviour of both students and teachers. The use of learning management systems that include project-based learning and hypermedia resources increases safer learning, and it is proven to be effective in degrees such as nursing. In this study, we worked with 120 students in the third year of nursing degree. Two types of blended learning were applied (more interaction in learning management systems with hypermedia resources vs. none). Supervised learning techniques were applied: linear regression and k-means clustering. The results indicated that the type of blended learning in use predicted 40.4% of student learning outcomes. It also predicted 71.9% of the effective learning behaviors of students in learning management systems. It therefore appears that blended learning applied in Learning Management System (LMS) with hypermedia resources favors greater achievement of effective learning. Likewise, with this type of Blended Learning (BL) a larger number of students were found to belong to the intermediate cluster, suggesting that this environment strengthens better results in a larger number of students. BL with hypermedia resources and project-based learning increase students´ learning outcomes and interaction in learning management systems. Future research will be aimed at verifying these results in other nursing degree courses.

A Hybrid Energy Efficient Cooperative Transmission Scheme in Multi‐Hop Wireless Sensor Networks

This letter proposes a hybrid cooperative transmission scheme for energy reduction in multi‐hop clustered wireless sensor networks (WSNs) where single‐input single‐output (SISO) and spatial modulation (SM)‐based cooperative MIMO (CMIMO‐SM) schemes are jointly used as the transmission candidates. In this work, we consider a linear all‐transmission scenario where the intermediate clusters act not only as forwarding clusters but also transmitting clusters. The numerical experiments demonstrate that the energy reduction of WSN is achieved by choosing the optimal hop length and appropriate transmission candidate. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

The Gaia-ESO Survey: a new approach to chemically characterising young open clusters

Context. Open clusters are recognised as excellent tracers of Galactic thin-disc properties. At variance with intermediate-age and old open clusters, for which a significant number of studies is now available, clusters younger than ≲150 Myr have been mostly overlooked in terms of their chemical composition until recently (with few exceptions). On the other hand, previous investigations seem to indicate an anomalous behaviour of young clusters, which includes (but is not limited to) slightly sub-solar iron (Fe) abundances and extreme, unexpectedly high barium (Ba) enhancements. Aims. In a series of papers, we plan to expand our understanding of this topic and investigate whether these chemical peculiarities are instead related to abundance analysis techniques. Methods. We present a new determination of the atmospheric parameters for 23 dwarf stars observed by the Gaia-ESO survey in five young open clusters (τ < 150 Myr) and one star-forming region (NGC 2264). We exploit a new method based on titanium (Ti) lines to derive the spectroscopic surface gravity, and most importantly, the microturbulence parameter. A combination of Ti and Fe lines is used to obtain effective temperatures. We also infer the abundances of Fe I, Fe II, Ti I, Ti II, Na I, Mg I, Al I, Si I, Ca I, Cr I, and Ni I. Results. Our findings are in fair agreement with Gaia-ESO iDR5 results for effective temperatures and surface gravities, but suggest that for very young stars, the microturbulence parameter is over-estimated when Fe lines are employed. This affects the derived chemical composition and causes the metal content of very young clusters to be under-estimated. Conclusions. Our clusters display a metallicity [Fe/H] between +0.04 ± 0.01 and +0.12 ± 0.02; they are not more metal poor than the Sun. Although based on a relatively small sample size, our explorative study suggests that we may not need to call for ad hoc explanations to reconcile the chemical composition of young open clusters with Galactic chemical evolution models.

Light Exposure Promotes Degradation of Intermediates and Growth of Phosphine-Ligated Gold Clusters

Subnanometer clusters exhibit unique properties not observed at the bulk or nanometer scale. Many applications, however, require clusters to be monodisperse in size and composition. While substantial progress has been made empirically on producing specific-sized gold clusters using different ligands, the mechanisms of cluster formation remain insufficiently understood. Using high mass-resolution electrospray ionization mass spectrometry, we characterized the formation of cationic triphenylphosphine-ligated gold clusters [Aux(PPh3)yz+] in solution. Our data provides evidence that small hydrogen-containing intermediate “building blocks” (i.e., Au2(PPh3)2H+, Au4(PPh3)4H+, and Au7(PPh3)7H52+) are responsible for the growth of larger gold clusters (i.e., Au6(PPh3)62+ and Au8(PPh3)72+) over several hours. In addition, intermediate degradation and cluster growth are shown to be dependent on irradiation of the reacting solution with light. Specifically, the rate of growth of large clusters is demonstrated to scale with the intensity of light exposure. Complementary theoretical calculations were also performed that provide molecular-level insight into the nature of the bonding between the hydrogens and gold atoms in the intermediate Au-phosphine clusters. Collectively, our joint experimental and theoretical findings advance the understanding of the factors at play in the size-selective synthesis of ligated gold clusters in solution.

Risk stratification for nasopharyngeal carcinoma: a real-world study based on locoregional extension patterns and Epstein-Barr virus DNA load.

Aim:The present study aimed to evaluate the combined value of locoregional extension patterns (LEPs) and circulating cell-free Epstein–Barr virus (cf EBV) DNA for risk stratification of locoregionally advanced nasopharyngeal carcinoma (LA-NPC) to better guide therapeutic strategies.Methods:A total of 7227 cases of LA-NPC were reviewed retrospectively and classified into six groups according to their LEP (ascending, descending, or mixed type) and pre-treatment cf EBV-DNA load (⩾ versus <4000 copy/ml). Using a supervised statistical clustering approach, patients in the six groups were clustered into low, intermediate, and high-risk clusters. Progression-free survival (PFS), overall survival (OS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS) were calculated using the Kaplan–Meier method and differences were compared using the log-rank test.Results:Survival curves for the low, intermediate, and high-risk clusters were significantly different for all endpoints. The 5-year survival rate for the low, intermediate, and high-risk clusters, respectively, were: PFS (83.5%, 73.2%, 62.6%, p < 0.001), OS (91.0%, 82.7%, 73.2%, p < 0.001), DMFS (92.3%, 83.0%, 73.4%, p < 0.001), and LRRFS (91.0%, 88.0%, 83.3%, p < 0.001). The risk clusters acted as independent prognostic factors for all endpoints. Among the patients in the high-risk cluster, neoadjuvant chemotherapy combined with concurrent chemoradiotherapy (CCRT) significantly improved the patients 5-year PFS (66.4% versus 57.9%, p = 0.014), OS (77.6% versus 68.6%; p < 0.002), and DMFS (76.6% versus 70.6%; p = 0.028) compared with those treated with CCRT.Conclusion:Our results could facilitate the development of risk-stratification and risk-adapted therapeutic strategies for patients with LA-NPC.

Socio-economic development, income differentiation and religious people: an empirical analysis of the relationship

The paper studies issues related to the relationship between indicators of socio-economic development, income differentiation and religiosity of the population in the country. Based on the assumption that the religiosity of the population can be a factor that has a significant impact on socio-economic development and the inequality of income distribution in society, this hypothesis is tested using correlation and cluster analysis methods based on empirical analysis. The results of a) a correlation analysis of indicators of the inequality of the income distribution of the country, its socio-economic development and the level of religiosity of the population are presented; b) analysis of the relationship between the Gini coefficient and the number of believers; c) clustering of sample objects (countries) by indicators of socio-economic development, income distribution and religiosity of the population. The analysis was carried out on a sample of 75 countries and indicators: per capita GDP, human development index (HDI), income differentiation (Gini coefficient), the number of religious population (in %). The results confirm the existence of relationships between these indicators. It is revealed that the nature of the relationship between the socio-economic development of the country and the level of religiosity of the population is non-linear, which can be presented in a parabolic form. An analysis conducted by groups of countries by income level (High income, Upper middle income, Lower middle income, Low income) showed that the closest positive relationship between the Gini index and religiosity of the population is observed in the countries of Lower middle income. To describe the diversity of combinations of indicators of socio-economic development, income differentiation and religiosity of the population, a cluster analysis was carried out on the basis of all 4 indicators. 3 clusters of countries were identified, of which groups with opposite values of attributes: countries with a high level of religiosity and income distribution inequality and low development rates; countries with low rates of inequality and religiosity and high levels of development. The intermediate cluster has indicator values that are closer to the first group.

The Rise (and Fall) of Tech Clusters

Tech clusters play a growing role in knowledge-based economies by accommodating high-tech firms and providing an environment that fosters location-dependent knowledge spillovers and promote R&D investments by .rms. Yet, not much is known about the economic conditions under which such entities may form in equilibrium without government interventions. This paper develops a spatial equilibrium model with a competitive final sector and a monopolistically competitive intermediate sector, which allows us to determine necessary and sufficient conditions for a tech cluster to emerge as an equilibrium outcome. We show that strongly localized knowledge spillovers, skilled labor abundance, and low commuting costs are key drivers for a tech cluster to form. Not only is the productivity of the final sector higher when intermediate firms cluster, but a tech cluster hosts more intermediate firms and more R&D and production activities, and yields greater worker welfare, compared to what a dispersed pattern would generate. With continual improvements in infrastructure and communication technology that lowers coordination costs, tech clusters will eventually be fragmented.

How stellar rotation shapes the colour−magnitude diagram of the massive intermediate-age star cluster NGC 1846

ABSTRACT We present a detailed study of stellar rotation in the massive 1.5 Gyr old cluster NGC 1846 in the Large Magellanic Cloud. Similar to other clusters at this age, NGC 1846 shows an extended main-sequence turn-off (eMSTO), and previous photometric studies have suggested it could be bimodal. In this study, we use MUSE integral-field spectroscopy to measure the projected rotational velocities (vsin i) of around $1400$ stars across the eMSTO and along the upper main sequence of NGC 1846. We measure vsin i values up to $\sim 250\, {\rm km\, s^{-1}}$ and find a clear relation between the vsin i of a star and its location across the eMSTO. Closer inspection of the distribution of rotation rates reveals evidence for a bimodal distribution, with the fast rotators centred around $v\sin i=140\, {\rm km\, s^{-1}}$ and the slow rotators centred around $v\sin i=60\, {\rm km\, s^{-1}}$. We further observe a lack of fast rotating stars along the photometric binary sequence of NGC 1846, confirming results from the field that suggest that tidal interactions in binary systems can spin-down stars. However, we do not detect a significant difference in the binary fractions of the fast and slowly rotating sub-populations. Finally, we report on the serendipitous discovery of a planetary nebula associated with NGC 1846.

Combined Effects of Rotation and Age Spreads on Extended Main-Sequence Turn Offs

Abstract The extended main-sequence turn offs (eMSTOs) of several young to intermediate age clusters are examined in the Magellanic Clouds and the Milky Way. We explore the effects of extended star formation (eSF) and a range of stellar rotation rates on the behavior of the color–magnitude diagram, paying particular attention to the MSTO. We create synthetic stellar populations based on MESA stellar models to simulate observed Hubble Space Telescope and Gaia star cluster data. We model the effect of rotation as a nonparametric distribution, allowing for maximum flexibility. In our models the slow rotators comprise the blueward, and fast rotators the redward portion of the eMSTO. We simulate data under three scenarios: nonrotating eSF, a range of rotation rates with a single age, and a combination of age and rotation effects. We find that two of the five clusters (the youngest and oldest) favor an age spread, but these also achieve the overall worst fits of all clusters. The other three clusters show comparable statistical evidence between rotation and an age spread. In all five cases, a rotation-rate distribution alone is capable of qualitatively matching the observed eMSTO structure. In future work, we aim to compare our predicted V sin i with observations in order to better constrain the physics related to stellar rotation.

The anatomo-functional organization of the hyperdirect cortical pathway to the subthalamic area using in vivo structural connectivity imaging in humans.

The subthalamic nucleus (STN) receives direct cortical inputs which constitute the so-called hyperdirect pathway. In monkeys, motor cortices innervate the whole extent of the STN whereas limbic cortices innervate only its anteromedial part extending more medially outside the nucleus. Tractography studies in humans have also identified motor cortical inputs to the STN, but little is known about the associative and limbic cortical projections. Therefore, the aim of this study was to investigate the anatomo-functional organization of the cortical projections to the STN and to the adjacent medial subthamic region (MSR). We used diffusion-weighted imaging-based tractography acquired from 30 subjects from the Human Connectome Project. We performed a whole-brain probabilistic tractography using MRTrixand extracted streamlines of interest between 39 cortical masks and both the STN and the MSR to provide track-density maps. Agglomerative clustering method was used to classify the voxels of the regions of interest. We found that the STN receives major inputs from the sensorimotor cortices and few inputs from the limbic cortices. On the other hand, the MSR receives mainly cortical limbic projections and few from the sensorimotor cortices. Weak connections were found between the associative cortices and both the STN and the MSR. We found a dominant motor cluster located in the posterolateral STN, a limbic cluster located medially in the MSR, and an intermediate motor-limbic cluster in between. Our findings show that the hyperdirect pathway is anatomo-functionally organized with a poor participation of associative cortices.

Structural analysis of disc super star clusters of M82: size and profile shape at intermediate ages

ABSTRACT We present the structural parameters of 99 super star clusters (SSCs) in the disc of M82. Moffat-EFF, King, and Wilson models were fitted using a χ2-minimization method to background-subtracted surface brightness profiles in the F435W (B), F555W (V), and F814W (I) bands of the Advanced Camera for Surveys (ACS) of the Hubble Space Telescope. The majority of the SSC profiles are best fitted by the Moffat-EFF profile. The scale parameter rd and the shape parameter γ in the three filters are identical within the measurement errors. The analysed sample is big enough to allow the characterization of the distributions of core radii Rc and γ. The obtained distribution of Rc follows a lognormal form, with centre and $\sigma \mathrm{ log}\big {(}\frac{R_{\rm c}}{pc}\big {)}$ being 1.73 pc and 0.25, respectively. The γ distribution is also lognormal with centre and σlog(γ) being 2.88 and 0.08, respectively. M82 is well known for the absence of current star formation in its disc, with all disc SSCs older than 50 Myr and hardly any cluster older than ∼300 Myr. The derived distributions compare very well with the distributions for intermediate-age clusters in the Large Magellanic Cloud (LMC), which is also a low-mass late-type galaxy similar to M82. On the other hand, the distributions of Rc in both these galaxies are shifted towards larger values as compared to SSCs of similar age in the giant spiral galaxy M83. M82 and LMC also span a narrower range of γ values as compared to that in M83.

Toward a New Multi-Dimensional Classification of Traumatic Brain Injury: A Collaborative European NeuroTrauma Effectiveness Research for Traumatic Brain Injury Study.

Traumatic brain injury (TBI) is currently classified as mild, moderate, or severe TBI by trichotomizing the Glasgow Coma Scale (GCS). We aimed to explore directions for a more refined multidimensional classification system. For that purpose, we performed a hypothesis-free cluster analysis in the Collaborative European NeuroTrauma Effectiveness Research for TBI (CENTER-TBI) database: a European all-severity TBI cohort (n = 4509). The first building block consisted of key imaging characteristics, summarized using principal component analysis from 12 imaging characteristics. The other building blocks were demographics, clinical severity, secondary insults, and cause of injury. With these building blocks, the patients were clustered into four groups. We applied bootstrap resampling with replacement to study the stability of cluster allocation. The characteristics that predominantly defined the clusters were injury cause, major extracranial injury, and GCS. The clusters consisted of 1451, 1534, 1006, and 518 patients, respectively. The clustering method was quite stable: the proportion of patients staying in one cluster after resampling and reclustering was 97.4% (95% confidence interval [CI]: 85.6-99.9%). These clusters characterized groups of patients with different functional outcomes: from mild to severe, 12%, 19%, 36%, and 58% of patients had unfavorable 6 month outcome. Compared with the mild and the upper intermediate cluster, the lower intermediate and the severe cluster received more key interventions. To conclude, four types of TBI patients may be defined by injury mechanism, presence of major extracranial injury and GCS. Describing patients according to these three characteristics could potentially capture differences in etiology and care pathways better than with GCS only.

An independent poor-prognosis subtype of breast cancer defined by a distinct tumor immune microenvironment

How mixtures of immune cells associate with cancer cell phenotype and affect pathogenesis is still unclear. In 15 breast cancer gene expression datasets, we invariably identify three clusters of patients with gradual levels of immune infiltration. The intermediate immune infiltration cluster (Cluster B) is associated with a worse prognosis independently of known clinicopathological features. Furthermore, immune clusters are associated with response to neoadjuvant chemotherapy. In silico dissection of the immune contexture of the clusters identified Cluster A as immune cold, Cluster C as immune hot while Cluster B has a pro-tumorigenic immune infiltration. Through phenotypical analysis, we find epithelial mesenchymal transition and proliferation associated with the immune clusters and mutually exclusive in breast cancers. Here, we describe immune clusters which improve the prognostic accuracy of immune contexture in breast cancer. Our discovery of a novel independent prognostic factor in breast cancer highlights a correlation between tumor phenotype and immune contexture.

Mass cytometry–based single-cell analysis of human stem cell reprogramming uncovers differential regulation of specific pluripotency markers

Human induced pluripotent stem cells (hiPSCs) are reprogrammed from somatic cells and are regarded as promising sources for regenerative medicine and disease research. Recently, techniques for analyses of individual cells, such as single-cell RNA-Seq and mass cytometry, have been used to understand the stem cell reprogramming process in the mouse. However, the reprogramming process in hiPSCs remains poorly understood. Here we used mass cytometry to analyze the expression of pluripotency and cell cycle markers in the reprogramming of human stem cells. We confirmed that, during reprogramming, the main cell population was shifted to an intermediate population consisting of neither fibroblasts nor hiPSCs. Detailed population analyses using computational approaches, including dimensional reduction by spanning-tree progression analysis of density-normalized events, PhenoGraph, and diffusion mapping, revealed several distinct cell clusters representing the cells along the reprogramming route. Interestingly, correlation analysis of various markers in hiPSCs revealed that the pluripotency marker TRA-1-60 behaves in a pattern that is different from other pluripotency markers. Furthermore, we found that the expression pattern of another pluripotency marker, octamer-binding protein 4 (OCT4), was distinctive in the pHistone-H3high population (M phase) of the cell cycle. To the best of our knowledge, this is the first mass cytometry-based investigation of human reprogramming and pluripotency. Our analysis elucidates several aspects of hiPSC reprogramming, including several intermediate cell clusters active during the process of reprogramming and distinctive marker expression patterns in hiPSCs.

Reliable data transmission method based on 6LoWPAN for building energy systems

The building energy internet of things is based on radio frequency technology and a wireless sensor network that can collect building energy consumption data in real time. However, with the increasing complexity of wireless sensor network topology, there is a problem of insufficient IP address space relying on IPv4 protocol. In this paper, a design scheme of a building energy system based on 6LoWPAN network is proposed. IPv4/IPv6 address conversion is used to realise the access of IP addresses to each other, so as to monitor building energy consumption information anytime and anywhere. In view of the shortcomings of existing wireless network data transmission methods in low energy consumption and high reliability in building energy monitoring applications, a reliable data transmission method based on multipath routing coding algorithm is proposed. This strategy improves the transmission reliability of the network by increasing the number of redundant packets, and reduces the energy consumption of the network by reducing the number of transmission paths. The simulation results show that the proposed method can effectively improve the success rate of data packet transmission, reduce the standard energy consumption of sensor networks, and provide an effective method for the application of wireless sensor networks in building energy monitoring systems. Practical application: This paper studies how to improve transmission reliability and energy efficiency in cluster-based WSN and proposes a multi-path transmission strategy for selective coding of intermediate cluster head nodes. The strategy improves the transmission reliability of the network by increasing the number of transmissions of redundant packets and reduces the network energy consumption by reducing the number of transmission paths. It has good use value for the actual development and application of the building energy consumption monitoring system.

DNA Methylation Profiling of AML Reveals Epigenetic Subgroups with Distinct Clinical Outcome

In acute myeloid leukemia (AML), DNA methylation is frequently altered and epigenetic regulators are commonly mutated. Here, we describe the effects of mutations in commonly mutated genes (NPM1, FLT3-ITD, DNMT3A, IDH1, IDH2, TET2, and WT1), including epigenetic regulators, on DNA methylation profiles and differential gene expression. Moreover, we show that subgroups of epigenetically homogeneous AML patients differ significantly in clinical outcome. We have characterized 212 AML patients treated on consecutive trials of the AMLCG study group using Illumina Infinium MethylationEPIC BeadChips, gene panel sequencing, and transcriptome sequencing. In order to detect differentially methylated CpG sites (dmCpGs) according to a particular mutation, we have selected sets of mutated and control samples for each gene of interest individually. We excluded samples with subclonal variants only and selected control samples based on matching karyotype and matching pattern of co-mutations. Mutations at the R882 hotspot of DNMT3A result in global hypomethylation while alterations of IDH1, IDH2, TET2, or WT1 lead to global hypermethylation. Still, subsets of dmCpGs are hypermethylated in DNMT3A-R882+ AML as well as hypomethylated in IDH1+, IDH2+, TET2+, and WT1+ AML. NPM1 mutations result both in hypo- and hypermethylation, while based on FLT3-ITD status, we could not detect significant changes in DNA methylation. Of note, we observed wildtype samples with a methylation profile highly matching that of mutated samples for most comparisons, suggesting alternative mechanisms. Moreover, mutations in IDH1, IDH2, TET2, and WT1 show substantial overlaps in dmCpGs, which is in line with their reported function, while the overlap with DNMT3A-R882 is rather small. Of note, we also detected overlaps in gene expression profiles by comparing test and control samples, in particular between AML with IDH1, IDH2, or WT1 mutations. The proto-oncogenes FOSB, FOSL2, and JUN are differentially expressed in IDH1+ AML, while in IDH2+ and WT1+ AML, members of the RPL and RPS gene families of ribosomal proteins are deregulated, known to alter FOS and JUN function. Unsupervised hierarchical clustering of all samples in our cohort results in two highly distinct epigenetic subgroups, each with three subclusters (Figure 1A). Of note, clusters are associated with distinct mutations. Most AML samples in clusters 1, 2, or 3 are mutated in NPM1, while clusters 4, 5, and 6 are mostly NPM1 wildtype. Still, the genetic profiles of subclusters differ based on the presence of mutations in IDH1/IDH2/TET2 (clusters 1 and 4), DNMT3A (cluster 2), and DNMT3A-R882/WT1 (cluster 3). Clusters 5 and 6 show only few mutations in DNMT3A, IDH1, IDH2, TET2, or WT1. Mutations in FLT3 are not associated with any cluster. Of note, epigenetic subgroups are also associated with differences in overall survival (OS) and event free survival (EFS) (Figure 1B). Clusters 1, 3, and 5 show significantly better outcome (median OS: 1113, 1046, and 1054 days; median EFS 513, 374, and 305 days) as compared to clusters 4 and 6 (median OS: 378 and 296 days; median EFS 103 and 70 days; p&lt;0.0001, log-rank test; Figure 1C). Moreover, clusters largely correlate with ELN-2017 classification, although cluster 3 also includes ELN intermediate patients and cluster 5 also includes ELN adverse patients. Still, these patients show better outcome as compared to other patients classified as intermediate or adverse, respectively. Cluster 6 largely includes ELN adverse patients, showing the overall worst outcome of all clusters (80% of samples with EFS &lt;180 days). Interestingly, Cluster 2 has intermediate OS and EFS (median OS: 710, median EFS: 437), including both ELN favorable and ELN adverse patients. Of note, within ELN favorable AML, samples of cluster 2 perform worst, while within ELN adverse AML, samples of cluster 2 perform the best. This points towards a subgroup of patients that might benefit from risk assessment based on DNA methylation profiles. Although the epigenetic landscape of AML is complex, we identified nearly homogeneous subgroups, which are associated with but not limited to mutations in epigenetic regulators. As epigenetic subgroups show differences in clinical outcome, DNA methylation profiling has the potential to refine AML risk stratification. Disclosures Metzeler: Otsuka: Honoraria; Celgene: Honoraria, Research Funding; Daiichi Sankyo: Honoraria. Hiddemann:Vector Therapeutics: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Research Funding; Bayer: Research Funding; Gilead: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria.

Theoretical study of the hydration effects on alkylamine and alkanolamine clusters and the atmospheric implication.

Amines are important atmospheric nucleation precursors in polluted areas. However, specific roles of various amines in enhancing the stability of pre-nucleation clusters are poorly understood. Herein, different roles of trimethylamine (TMA) and monoethanolamine (MEA) in the formation of sulfuric acid (SA)-based pre-nucleation clusters were investigated. The hydration effects of up to four water (W) molecules on the interaction of the acid-base pairs of (TMA)(SA) and (MEA)(SA) were computationally investigated at the M06-2X/6-311++G (3df, 3pd) level of theory. Results show that the formation thermodynamics of key intermediate clusters are different with amines. Besides, MEA-enhanced formation of pre-nucleation clusters plays an important role in environments with high humidity while TMA may be the dominant nucleation precursors in dry conditions. The concentration of dominant MEA-containing pre-nucleation cluster is at least three orders of magnitude higher than that of TMA and dimethylamine near emission sources at conditions of T=298.15K and RH=60%, indicating that alkanolamine may play an important role in atmospheric nucleation. Furthermore, the hydration of MEA is easier than that of alkylamines. Our results put forward the need to distinguish the performance of different types of amine under specific conditions to better model the new particle formation events in highly polluted areas. Besides, this study indicates that alkanolamines such as MEA are important participator in new particle formation.

‘Aversive’ democracy, ‘contentious’ politics and ‘agonistic’ populism: comparative experience and implications for contemporary North Africa

ABSTRACT There is a vast social science literature on the politics of protest and ‘bottom up’ mobilisation. One strand concerns peaceful protest is stable constitutional systems. Another deals with revolutionary mobilisation to overthrow repressive regimes. This article focuses on an intermediate cluster of recent contributions of more direct relevance to today’s Maghreb. These all concern mass movements seeking more inclusive democratic dispensations. Such mobilisations are voluntary and pluralist in spirit (not revolutionary) and so favour peaceful and inclusionary forms of expression. 1 But they confront regimes that lack constitutional legitimacy, and that in their insecurity may react with arbitrary repression. So these processes involve acute uncertainty and intense risk for participants. Three main approaches are outlined and compared. Aletta Norval draws from her South African experience in her formulation of ideas about ‘aversive’ democracy. Sidney Tarrow and Charles Tilly have produced ground breaking work on ‘contentious’ politics that partly reflects their base in the USA. The Essex school inspired by Ernesto Laclau and Chantal Mouffe is more attuned to Latin American and some European experiences of ‘agonistic’ mobilisation. While all three approaches have important ideas to contribute, each also displays conceptual and empirical limitations. This article aims to highlight the useful insights of each, and provide some guidance about how well they ‘travel’ to North Africa, and how lessons from this region might be fed back into the global debate about ‘informal’ political activism in the twenty-first century.