135 research outputs found

    Understanding Collective Learning and Human Agency in Diverse Social, Cultural and Material Settings

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    The significance of environment and sustainability education research and practice, and its potential contribution to a sustainable future for humanity, is conveyed by the International Social Science Council (n.d.), which explains: People everywhere will need to learn how to create new forms of human activity and new social systems that are more sustainable and socially just. However, we have limited knowledge about the type of learning that creates such change, how such learning emerges, or how it can be scaled-up to create transformations at many levels.Here, the important shift is towards considering what social systems, forms of knowledge, learning processes and questions of justice are associated with perpetuating or halting the decline of Earth’s bio-geo-chemical systems. This edition of the Southern African Journal of Environmental Education contributes three research papers and a themed Think Piece collection to these international deliberations about the role of education in enabling transformations to sustainability. Collectively, the articles highlight how relationality and the formation of human agency in socio-cultural and material settings in past–present–future configurations underpin all environment-oriented learning processes. The three research papers constituting the first part of this volume offer glimpses into how current unsustainable socio-cultural and material configurations might be transformed to address social inequalities and damaged people–nature relations. The Think Piece collection, introduced by Lotz-Sisitka, Læssøe and Jørgensen later in this editorial, focuses on how learning can foster and contribute to the development of change agents and collective agency for climate-resilient development

    Galaxy morphology and star formation in the Illustris Simulation at

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    We study how optical galaxy morphology depends on mass and star formation rate (SFR) in the Illustris Simulation. To do so, we measure automated galaxy structures in 10 808 simulated galaxies at z = 0 with stellar masses 10[superscript 9.7] < M*/Mȯ < 10[superscript12.3]. We add observational realism to idealized synthetic images and measure non-parametric statistics in rest-frame optical and near-IR images from four directions. We find that Illustris creates a morphologically diverse galaxy population, occupying the observed bulge strength locus and reproducing median morphology trends versus stellar mass, SFR, and compactness. Morphology correlates realistically with rotation, following classification schemes put forth by kinematic surveys. Type fractions as a function of environment agree roughly with data. These results imply that connections among mass, star formation, and galaxy structure arise naturally from models matching global star formation and halo occupation functions when simulated with accurate methods. This raises a question of how to construct experiments on galaxy surveys to better distinguish between models. We predict that at fixed halo mass near 10[superscript 12] Mȯ, disc-dominated galaxies have higher stellar mass than bulge-dominated ones, a possible consequence of the Illustris feedback model. While Illustris galaxies at M* ∼ 10[superscript 11] Mȯ have a reasonable size distribution, those at M* ∼ 10[superscript 10] Mȯ have half-light radii larger than observed by a factor of 2. Furthermore, at M* ∼ 10[superscript 10.5]–10[superscript 11] Mȯ, a relevant fraction of Illustris galaxies have distinct ‘ring-like’ features, such that the bright pixels have an unusually wide spatial extent

    Health outcomes in offspring born to survivors of childhood cancers following assisted reproductive technologies

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    Purpose: An increasing number of childhood cancer survivors are using assisted reproductive technologies (ART) to overcome treatment-related fertility impairment. We report perinatal and health outcomes of offspring born to survivors following ART. Methods: The FeCt Multicenter Offspring Study surveyed the health of offspring of childhood cancer survivors. Health outcomes in offspring born to survivors following ART (n = 57, 4.6%) or after spontaneous conception (n = 1182) were assessed in the German cohort (n = 1239) using bivariate analysis. Findings were put into the context of the general German population by health outcome assessment in 1:1 matched-pair analysis (n = 2478). Results: Nearly twice the survivors used ART compared with numbers reported for the German general population (4.6% vs. 2.6%). Successful pregnancies were achieved after a median of two cycles, mainly using non-cryopreserved oocytes/sperm. Multiple sibling births (p < 0.001, 28.1% vs. 3.0%) and low birth weight (p = 0.008; OR = 2.659, 95% CI = 1.258-5.621) occurred significantly more often in offspring born to survivors who utilized ART than spontaneously conceived children, whereas similar percentages were born preterm or too small for their gestational age. ART did not increase the prevalence of childhood cancer or congenital malformations in offspring born to survivors. Conclusion: ART use by childhood cancer survivors was successful with both fresh and cryopreserved oocytes/sperm, and did not influence perinatal health or health outcomes when known confounders were taken into account. Implications for cancer survivors: Oncofertility is an important component of patient care. Our study implicates that the utilization of ART by adult survivors of childhood cancer does not put offspring at additional risk for adverse perinatal or health outcomes

    Evaluation of Three Automated Genome Annotations for Halorhabdus utahensis

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    Genome annotations are accumulating rapidly and depend heavily on automated annotation systems. Many genome centers offer annotation systems but no one has compared their output in a systematic way to determine accuracy and inherent errors. Errors in the annotations are routinely deposited in databases such as NCBI and used to validate subsequent annotation errors. We submitted the genome sequence of halophilic archaeon Halorhabdus utahensis to be analyzed by three genome annotation services. We have examined the output from each service in a variety of ways in order to compare the methodology and effectiveness of the annotations, as well as to explore the genes, pathways, and physiology of the previously unannotated genome. The annotation services differ considerably in gene calls, features, and ease of use. We had to manually identify the origin of replication and the species-specific consensus ribosome-binding site. Additionally, we conducted laboratory experiments to test H. utahensis growth and enzyme activity. Current annotation practices need to improve in order to more accurately reflect a genome's biological potential. We make specific recommendations that could improve the quality of microbial annotation projects

    The Use of Assisted Reproductive Technology by European Childhood Cancer Survivors

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    CCS often wish to have biological children yet harbour concerns about fertility impairment, pregnancy risks and the general health risks of prospective offspring. To clarify these concerns, health outcomes in survivor offspring born following ART (n = 74, 4.5%) or after spontaneous conception (n = 1585) were assessed in our European offspring study by descriptive and bivariate analysis. Outcomes were compared to a sibling offspring cohort (n = 387) in a 4:1 matched-pair analysis (n = 1681). (i) Survivors were more likely to employ ART than their siblings (4.5% vs. 3.7%, p = 0.501). Successful pregnancies were achieved after a median of one cycle with, most commonly, intracytoplasmic sperm injection (ICSI) using non-cryopreserved oocytes/sperm. (ii) Multiple-sibling births (p < 0.001, 29.7% vs. 2.5%), low birth weight (p < 0.001; OR = 3.035, 95%-CI = 1.615-5.706), and preterm birth (p < 0.001; OR = 2.499, 95%-CI = 1.401-4.459) occurred significantly more often in survivor offspring following ART utilisation than in spontaneously conceived children. ART did not increase the prevalence of childhood cancer, congenital malformations or heart defects. (iii) These outcomes had similar prevalences in the sibling population. In our explorative study, we could not detect an influence on health outcomes when known confounders, such as multiple births, were taken into account

    The ACS Fornax Cluster Survey. VI. The Nuclei of Early-Type Galaxies in the Fornax Cluster

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    The Advanced Camera for Surveys (ACS) Fornax Cluster Survey is a Hubble Space Telescope program to image 43 early-type galaxies in the Fornax cluster, using the F475W and F850LP bandpasses of the ACS. We employ both 1D and 2D techniques to characterize the properties of the stellar nuclei in these galaxies, defined as the central "luminosity excesses" relative to a Sersic model fitted to the underlying host. We find 72+/-13% of our sample (31 galaxies) to be nucleated, with only three of the nuclei offset by more than 0.5" from their galaxy photocenter, and with the majority of nuclei having colors bluer than their hosts. The nuclei are observed to be larger, and brighter, than typical Fornax globular clusters, and to follow different structural scaling relations. A comparison of our results to those from the ACS Virgo Cluster Survey reveals striking similarities in the properties of the nuclei belonging to these different environments. We briefly review a variety of proposed formation models and conclude that, for the low-mass galaxies in our sample, the most important mechanism for nucleus growth is probably infall of star clusters through dynamical friction, while for higher mass galaxies, gas accretion triggered by mergers, accretions and tidal torques is likely to dominate, with the relative importance of these two processes varying smoothly as a function of galaxy mass. Some intermediate-mass galaxies in our sample show a complexity in their inner structure that may be the signature of "hybrid nuclei" that arose through parallel formation channels.Comment: 34 pages, 27 figures, accepted for publication in ApJ

    MYC Overexpression Induces Prostatic Intraepithelial Neoplasia and Loss of Nkx3.1 in Mouse Luminal Epithelial Cells

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    Lo-MYC and Hi-MYC mice develop prostatic intraepithelial neoplasia (PIN) and prostatic adenocarcinoma as a result of MYC overexpression in the mouse prostate[1]. However, prior studies have not determined precisely when, and in which cell types, MYC is induced. Using immunohistochemistry (IHC) to localize MYC expression in Lo-MYC transgenic mice, we show that morphological and molecular alterations characteristic of high grade PIN arise in luminal epithelial cells as soon as MYC overexpression is detected. These changes include increased nuclear and nucleolar size and large scale chromatin remodeling. Mouse PIN cells retained a columnar architecture and abundant cytoplasm and appeared as either a single layer of neoplastic cells or as pseudo-stratified/multilayered structures with open glandular lumina—features highly analogous to human high grade PIN. Also using IHC, we show that the onset of MYC overexpression and PIN development coincided precisely with decreased expression of the homeodomain transcription factor and tumor suppressor, Nkx3.1. Virtually all normal appearing prostate luminal cells expressed high levels of Nkx3.1, but all cells expressing MYC in PIN lesions showed marked reductions in Nkx3.1, implicating MYC as a key factor that represses Nkx3.1 in PIN lesions. To determine the effects of less pronounced overexpression of MYC we generated a new line of mice expressing MYC in the prostate under the transcriptional control of the mouse Nkx3.1 control region. These “Super-Lo-MYC” mice also developed PIN, albeit a less aggressive form. We also identified a histologically defined intermediate step in the progression of mouse PIN into invasive adenocarcinoma. These lesions are characterized by a loss of cell polarity, multi-layering, and cribriform formation, and by a “paradoxical” increase in Nkx3.1 protein. Similar histopathological changes occurred in Hi-MYC mice, albeit with accelerated kinetics. Our results using IHC provide novel insights that support the contention that MYC overexpression is sufficient to transform prostate luminal epithelial cells into PIN cells in vivo. We also identified a novel histopathologically identifiable intermediate step prior to invasion that should facilitate studies of molecular pathway alterations occurring during early progression of prostatic adenocarcinomas

    CANDELS Visual Classifications: Scheme, Data Release, and First Results

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    We have undertaken an ambitious program to visually classify all galaxies in the five CANDELS fields down to H \u3c 24.5 involving the dedicated efforts of over 65 individual classifiers. Once completed, we expect to have detailed morphological classifications for over 50,000 galaxies spanning 0 \u3c z \u3c 4 over all the fields, with classifications from 3 to 5 independent classifiers for each galaxy. Here, we present our detailed visual classification scheme, which was designed to cover a wide range of CANDELS science goals. This scheme includes the basic Hubble sequence types, but also includes a detailed look at mergers and interactions, the clumpiness of galaxies, k-corrections, and a variety of other structural properties. In this paper, we focus on the first field to be completed—GOODS-S, which has been classified at various depths. The wide area coverage spanning the full field (wide+deep+ERS) includes 7634 galaxies that have been classified by at least three different people. In the deep area of the field, 2534 galaxies have been classified by at least five different people at three different depths. With this paper, we release to the public all of the visual classifications in GOODS-S along with the Perl/Tk GUI that we developed to classify galaxies. We present our initial results here, including an analysis of our internal consistency and comparisons among multiple classifiers as well as a comparison to the Sérsic index. We find that the level of agreement among classifiers is quite good (\u3e70% across the full magnitude range) and depends on both the galaxy magnitude and the galaxy type, with disks showing the highest level of agreement (\u3e50%) and irregulars the lowest (k-corrections between the V-band and H-band observations and find that a small fraction (84 galaxies in total) are classified as being very different between these two bands. These galaxies typically have very clumpy and extended morphology or are very faint in the V-band
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