268 research outputs found

    Science and Heritage Language Integrated Learning (SHLIL):Evidence of the effectiveness of an innovative science outreach program for migrant students

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    Migrant students tend to underperform in Science, Technology, Engineering, and Mathematics (STEM) subjects and are less likely to pursue higher education in STEM when compared with their nonmigrant peers. Given the substantial increase in migration, this disparity has been a central concern in science education in many European countries. The purpose of this study was to investigate the effectiveness of an innovative science outreach program that brings together migrant students and STEM professionals with the same linguistic and cultural backgrounds. The program consists of one-off workshops that follow an inquiry-based approach and include hands-on activities and science communication in the students' heritage language. Using surveys with adapted scales and open-ended questions, we applied a randomized block design with waitlist control groups and repeated measures. Eighty-three Portuguese-speaking migrant students aged 6–17 years participated in the workshops in Germany and the United Kingdom. Results indicate that both the students and STEM professionals evaluated the program positively and that students who participated in the workshops tended to demonstrate an increase in their attainment value for science and an increase in their self-concept of ability for the heritage language 4 weeks after the intervention when compared with students in the control condition. These effects were particularly pronounced for students with low prior motivation to study science or speak the heritage language. Our results thus show that it is possible to foster migrant students' attainment value for science and increase their self-concept of ability regarding the heritage language through a brief science outreach intervention

    Checkpoints are blind to replication restart and recombination intermediates that result in gross chromosomal rearrangements

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    Replication fork inactivation can be overcome by homologous recombination, but this can cause gross chromosomal rearrangements that subsequently missegregate at mitosis, driving further chromosome instability. It is unclear when the chromosome rearrangements are generated and whether individual replication problems or the resulting recombination intermediates delay the cell cycle. Here we have investigated checkpoint activation during HR-dependent replication restart using a site-specific replication fork-arrest system. Analysis during a single cell cycle shows that HR-dependent replication intermediates arise in S phase, shortly after replication arrest, and are resolved into acentric and dicentric chromosomes in G2. Despite this, cells progress into mitosis without delay. Neither the DNA damage nor the intra-S phase checkpoints are activated in the first cell cycle, demonstrating that these checkpoints are blind to replication and recombination intermediates as well as to rearranged chromosomes. The dicentrics form anaphase bridges that subsequently break, inducing checkpoint activation in the second cell cycle

    SUMO chain formation is required for response to replication arrest in S. pombe

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    SUMO is a ubiquitin-like protein that is post-translationally attached to one or more lysine residues on target proteins. Despite having only 18% sequence identity with ubiquitin, SUMO contains the conserved betabetaalphabetabetaalphabeta fold present in ubiquitin. However, SUMO differs from ubiquitin in having an extended N-terminus. In S. pombe the N-terminus of SUMO/Pmt3 is significantly longer than those of SUMO in S. cerevisiae, human and Drosophila. Here we investigate the role of this N-terminal region. We have used two dimensional gel electrophoresis to demonstrate that S. pombe SUMO/Pmt3 is phosphorylated, and that this occurs on serine residues at the extreme N-terminus of the protein. Mutation of these residues (in pmt3-1) results in a dramatic reduction in both the levels of high Mr SUMO-containing species and of total SUMO/Pmt3, indicating that phosphorylation of SUMO/Pmt3 is required for its stability. Despite the significant reduction in high Mr SUMO-containing species, pmt3-1 cells do not display an aberrant cell morphology or sensitivity to genotoxins or stress. Additionally, we demonstrate that two lysine residues in the N-terminus of S. pombe SUMO/Pmt3 (K14 and K30) can act as acceptor sites for SUMO chain formation in vitro. Inability to form SUMO chains results in aberrant cell and nuclear morphologies, including stretched and fragmented chromatin. SUMO chain mutants are sensitive to the DNA synthesis inhibitor, hydroxyurea (HU), but not to other genotoxins, such as UV, MMS or CPT. This implies a role for SUMO chains in the response to replication arrest in S. pomb

    An annotated checklist of bryophytes of Europe, Macaronesia and Cyprus

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    Introduction. Following on from work on the European bryophyte Red List, the taxonomically and nomenclaturally updated spreadsheets used for that project have been expanded into a new checklist for the bryophytes of Europe. Methods. A steering group of ten European bryologists was convened, and over the course of a year, the spreadsheets were compared with previous European checklists, and all changes noted. Recent literature was searched extensively. A taxonomic system was agreed, and the advice and expertise of many European bryologists sought. Key results. A new European checklist of bryophytes, comprising hornworts, liverworts and mosses, is presented. Fifteen new combinations are proposed. Conclusions. This checklist provides a snapshot of the current European bryophyte flora in 2019. It will already be out-of-date on publication, and further research, particularly molecular work, can be expected to result in many more changes over the next few years.Peer reviewe

    Die EuropΓ€isierung der ΓΆffentlichen Aufgaben

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    Die zunehmende EuropΓ€isierung der ΓΆffentlichen Aufgaben ist einer der wichtigsten Trends im Wandel der StaatstΓ€tigkeit in der Bundesrepublik Deutschland und in anderen Mitgliedstaaten der EuropΓ€ischen Union. In diesem Essay werden die Stufen der EuropΓ€isierung der StaatstΓ€tigkeit nachgezeichnet, in WeiterfΓΌhrung von Lindberg/Scheingold (1970) und Schmitter (1996) quantifiziert und hinsichtlich ihrer Kosten und ihres Nutzen erΓΆrtert. Inhalt: Stufen der EuropΓ€isierung der ΓΆffentlichen Aufgaben Der EuropΓ€isierungsgrad der ΓΆffentlichen Aufgaben von 1950 bis zum Ende des 20. Jahrhunderts Vom Nutzen und von den Kosten der EuropΓ€isierung der ΓΆffentlichen Angelegenheiten Verzeichnis der zitierten Literatu

    Behavior and Impact of Zirconium in the Soil–Plant System: Plant Uptake and Phytotoxicity

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    Because of the large number of sites they pollute, toxic metals that contaminate terrestrial ecosystems are increasingly of environmental and sanitary concern (Uzu et al. 2010, 2011; Shahid et al. 2011a, b, 2012a). Among such metals is zirconium (Zr), which has the atomic number 40 and is a transition metal that resembles titanium in physical and chemical properties (Zaccone et al. 2008). Zr is widely used in many chemical industry processes and in nuclear reactors (Sandoval et al. 2011; Kamal et al. 2011), owing to its useful properties like hardness, corrosion-resistance and permeable to neutrons (Mushtaq 2012). Hence, the recent increased use of Zr by industry, and the occurrence of the Chernobyl and Fukashima catastrophe have enhanced environmental levels in soil and waters (Yirchenko and Agapkina 1993; Mosulishvili et al. 1994 ; Kruglov et al. 1996)

    ONYX-015: mechanisms of action and clinical potential of a replication-selective adenovirus

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    Accumulated knowledge in the molecular processes of tumour development combined with the availability of genetically modified viruses resemble the basis for new promising cancer therapeutics. The main advantages of employing replication-competent viruses are achievement of tumour selective killing and amplification of their oncolytic potential within the tumour mass. In this review, we describe the development of ONYX-015, one of the first and most advanced replication-competent viruses for cancer therapy. We discuss the molecular biology of this therapeutic approach and the interesting results obtained with this virus in clinical trials

    The Nuclear Protein Sge1 of Fusarium oxysporum Is Required for Parasitic Growth

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    Dimorphism or morphogenic conversion is exploited by several pathogenic fungi and is required for tissue invasion and/or survival in the host. We have identified a homolog of a master regulator of this morphological switch in the plant pathogenic fungus Fusarium oxysporum f. sp. lycopersici. This non-dimorphic fungus causes vascular wilt disease in tomato by penetrating the plant roots and colonizing the vascular tissue. Gene knock-out and complementation studies established that the gene for this putative regulator, SGE1 (SIX Gene Expression 1), is essential for pathogenicity. In addition, microscopic analysis using fluorescent proteins revealed that Sge1 is localized in the nucleus, is not required for root colonization and penetration, but is required for parasitic growth. Furthermore, Sge1 is required for expression of genes encoding effectors that are secreted during infection. We propose that Sge1 is required in F. oxysporum and other non-dimorphic (plant) pathogenic fungi for parasitic growth

    The CDK-Activating Kinase (CAK) Csk1 Is Required for Normal Levels of Homologous Recombination and Resistance to DNA Damage in Fission Yeast

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    BACKGROUND: Cyclin-dependent kinases (CDKs) perform essential roles in cell division and gene expression in all eukaryotes. The requirement for an upstream CDK-activating kinase (CAK) is also universally conserved, but the fission yeast Schizosaccharomyces pombe appears to be unique in having two CAKs with both overlapping and specialized functions that can be dissected genetically. The Mcs6 complex--orthologous to metazoan Cdk7/cyclin H/Mat1--activates the cell-cycle CDK, Cdk1, but its non-redundant essential function appears to be in regulation of gene expression, as part of transcription factor TFIIH. The other CAK is Csk1, an ortholog of budding yeast Cak1, which activates all three essential CDKs in S. pombe--Cdk1, Mcs6 and Cdk9, the catalytic subunit of positive transcription elongation factor b (P-TEFb)--but is not itself essential. METHODOLOGY/PRINCIPAL FINDINGS: Cells lacking csk1(+) are viable but hypersensitive to agents that damage DNA or block replication. Csk1 is required for normal levels of homologous recombination (HR), and interacts genetically with components of the HR pathway. Tests of damage sensitivity in csk1, mcs6 and cdk9 mutants indicate that Csk1 acts pleiotropically, through Cdk9 and at least one other target (but not through Mcs6) to preserve genomic integrity. CONCLUSIONS/SIGNIFICANCE: The two CAKs in fission yeast, which differ with respect to their substrate range and preferences for monomeric CDKs versus CDK/cyclin complexes as substrates, also support different functions of the CDK network in vivo. Csk1 plays a non-redundant role in safeguarding genomic integrity. We propose that specialized activation pathways dependent on different CAKs might insulate CDK functions important in DNA damage responses from those capable of triggering mitosis
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