Icing the Batter: The MYP Coordinator, Principal Leadership, and School Reform

The purpose of this study was to identify the educational leadership styles of one urban principal as he balanced the needs of a turnaround school with requirements of the International Baccalaureate’s Middle Years Programme. Further, this study sought to determine how principal leadership style impacted the role of the Middle Years Programme coordinator during turnaround. One principal and one coordinator contributed data via interviews, practice logs, emails, school newsletters, observations, and field notes. The researcher used constant comparative coding, open coding, and axial coding to analyze the data for emergent leadership themes and their impact. Findings include a determination that turning around a school on a strict timetable is not conducive to MYP programming

Set1 Targets Genes with Essential Identity and Tumor-Suppressing Functions in Planarian Stem Cells

Tumor suppressor genes (TSGs) are essential for normal cellular function in multicellular organisms, but many TSGs and tumor-suppressing mechanisms remain unknown. Planarian flatworms exhibit particularly robust tumor suppression, yet the specific mechanisms underlying this trait remain unclear. Here, we analyze histone H3 lysine 4 trimethylation (H3K4me3) signal across the planarian genome to determine if the broad H3K4me3 chromatin signature that marks essential cell identity genes and TSGs in mammalian cells is conserved in this valuable model of in vivo stem cell function. We find that this signature is indeed conserved on the planarian genome and that the lysine methyltransferase Set1 is largely responsible for creating it at both cell identity and putative TSG loci. In addition, we show that depletion of set1 in planarians induces stem cell phenotypes that suggest loss of TSG function, including hyperproliferation and an abnormal DNA damage response (DDR). Importantly, this work establishes that Set1 targets specific gene loci in planarian stem cells and marks them with a conserved chromatin signature. Moreover, our data strongly suggest that Set1 activity at these genes has important functional consequences both during normal homeostasis and in response to genotoxic stress

Activating and inhibiting connections in biological network dynamics

<p>Abstract</p> <p>Background</p> <p>Many studies of biochemical networks have analyzed network topology. Such work has suggested that specific types of network wiring may increase network robustness and therefore confer a selective advantage. However, knowledge of network topology does not allow one to predict network dynamical behavior – for example, whether deleting a protein from a signaling network would maintain the network's dynamical behavior, or induce oscillations or chaos.</p> <p>Results</p> <p>Here we report that the balance between activating and inhibiting connections is important in determining whether network dynamics reach steady state or oscillate. We use a simple dynamical model of a network of interacting genes or proteins. Using the model, we study random networks, networks selected for robust dynamics, and examples of biological network topologies. The fraction of activating connections influences whether the network dynamics reach steady state or oscillate.</p> <p>Conclusion</p> <p>The activating fraction may predispose a network to oscillate or reach steady state, and neutral evolution or selection of this parameter may affect the behavior of biological networks. This principle may unify the dynamics of a wide range of cellular networks.</p> <p>Reviewers</p> <p>Reviewed by Sergei Maslov, Eugene Koonin, and Yu (Brandon) Xia (nominated by Mark Gerstein). For the full reviews, please go to the Reviewers' comments section.</p

The collaborative improvement model: an interpretive study of revising a curriculum

Curriculum revisions in nursing programs are necessary to maintain currency and ensure that nursing students are prepared to competently practice nursing. Yet, the research for curriculum revisions in nursing education is sparse, leaving nursing educators with a thin evidence base upon which to revise curricula. The purpose of this phenomenological and hermeneutical study was to understand the experiences of faculty members and students who used the Collaborative Improvement Model (CIM) at a midwestern nursing department as an approach to revise their curriculum. The findings of this study demonstrate how the CIM (a) promoted student involvement in revising a curriculum, (b) facilitated faculty collaboration across two campuses with different campus cultures, (c) encouraged the Scholarship of Teaching and Learning, and (d) emphasized the need to use external facilitators when revising a curriculum. Faculty members in nursing programs can use this study when considering the CIM as a framework for revising their curricula

The Lamprey Genome: Illuminating Genomic Change across Eons and Embryogenesis

The lamprey genome provides unique insights into both the deep evolutionary history of vertebrate genomes and the maintenance of genome structure/integrity over development. The lamprey lineage diverged from all other vertebrates approximately 500 million years ago. As such, comparisons between lamprey and other vertebrates permit reconstruction of ancient duplication and rearrangement events that defined the fundamental architecture and gene content of all extant vertebrate genomes. Lamprey also undergoes programmatic changes genome structure that result in the physical elimination of ~20% of its genomic DNA (~0.5Gb from a ~2 Gb genome) from all somatic cell lineages during early embryonic development. Here, we outline recent progress in assembly and analysis of the lamprey germline genome, and progress in the development of methods for characterizing the cellular events that mediate DNA elimination. We have integrated information from several sampling approaches and sequencing technologies to achieve a highly contiguous assembly of lamprey genome (including: Illumina fragments/mate pairs, 20X coverage in Pacific Biosciences reads, dense meiotic maps and optical mapping data). This genome assembly has dramatically improved our ability to dissect the molecular basis and genetic outcomes of programmed genome rearrangements (PGRs), and has improved our understanding of the tempo and mode of large-­scale duplications and translocations within the ancestral vertebrate lineage. Analysis of the germline genome identifies several genes that are expressed in germline but physically eliminated from all somatic tissues. These eliminated genes correspond to several known oncogenes and appear to identify several other novel oncogene candidates. Complementing this assembly, the development of approaches to in situ analysis of 3D preserved cells has revealed that PGR unfolds through a series of dramatic cellular events that involve the programmatic alteration of several fundamental mechanisms of genome maintenance, including: alignment of chromosomes at metaphase, chromatid cohesion, separation and segregation, and nuclear envelope formation

Claimed Co-ethnics and Kin-State Citizenship in Southeastern Europe

The paper introduces the often neglected concept of 'claimed co-ethnics' in the analysis of citizenship policies. It argues that this is an interstitial category that further complicates the triadic nexus between national minorities, nationalising states and kin-states. The 'claimed co-ethnics' are defined as people who are recognised by the citizenship (or ethnizenship) conferring state as belonging to its main ethnic group, although they themselves do not embrace that definition. In addition to bringing the issue of claimed co-ethnics into focus, the paper elucidates how citizenship policies can affect groups that challenge the exact fit between ethnicity and nation, showing how national governments through particular citizenship policies and categorisation practices engage in the construction of these groups. The paper shows that the triadic nexus framework, which has had a strong influence on citizenship and minorities scholarship, needs to be revised to include unidirectional relations between the elements of the triadic nexus. The paper is based on the comparison between the cases of ethnic Vlachs (in the context of Albania and Greece) and Bunjevci (in the context of Serbia and Croatia).European Commission - Seventh Framework Programme (FP7

Iron conservation by reduction of metalloenzyme inventories in the marine diazotroph Crocosphaera watsonii

The marine nitrogen fixing microorganisms (diazotrophs) are a major source of nitrogen to open ocean ecosystems and are predicted to be limited by iron in most marine environments. Here we use global and targeted proteomic analyses on a key unicellular marine diazotroph Crocosphaera watsonii to reveal large scale diel changes in its proteome, including substantial variations in concentrations of iron metalloproteins involved in nitrogen fixation and photosynthesis, as well as nocturnal flavodoxin production. The daily synthesis and degradation of enzymes in coordination with their utilization results in a lowered cellular metalloenzyme inventory that requires ~40% less iron than if these enzymes were maintained throughout the diel cycle. This strategy is energetically expensive, but appears to serve as an important adaptation for confronting the iron scarcity of the open oceans. A global numerical model of ocean circulation, biogeochemistry and ecosystems suggests that Crocosphaera’s ability to reduce its iron-metalloenzyme inventory provides two advantages: It allows Crocosphaera to inhabit regions lower in iron and allows the same iron supply to support higher Crocosphaera biomass and nitrogen fixation than if they did not have this reduced iron requirement.National Science Foundation (U.S.). Chemical and Biological Oceanography Program (OCE-0452883)National Science Foundation (U.S.). Chemical and Biological Oceanography Program (OCE-0752291)National Science Foundation (U.S.). Chemical and Biological Oceanography Program (OCE-0723667)National Science Foundation (U.S.). Chemical and Biological Oceanography Program (OCE-0928414)National Science Foundation (U.S.). Polar Program (ANT-0732665)United States. Environmental Protection Agency (Star Fellowship)Woods Hole Oceanographic Institution. Ocean Life InstituteCenter for Microbial Oceanography: Research and EducationCenter for Environmental Bioinorganic Chemistr

Closely related phytoplankton species produce similar suites of dissolved organic matter

© The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Microbiology 5 (2014): 111, doi:10.3389/fmicb.2014.00111.Production of dissolved organic matter (DOM) by marine phytoplankton supplies the majority of organic substrate consumed by heterotrophic bacterioplankton in the sea. This production and subsequent consumption converts a vast quantity of carbon, nitrogen, and phosphorus between organic and inorganic forms, directly impacting global cycles of these biologically important elements. Details regarding the chemical composition of DOM produced by marine phytoplankton are sparse, and while often assumed, it is not currently known if phylogenetically distinct groups of marine phytoplankton release characteristic suites of DOM. To investigate the relationship between specific phytoplankton groups and the DOM they release, hydrophobic phytoplankton-derived dissolved organic matter (DOMP) from eight axenic strains was analyzed using high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Identification of DOM features derived from Prochlorococcus, Synechococcus, Thalassiosira, and Phaeodactylum revealed DOMP to be complex and highly strain dependent. Connections between DOMP features and the phylogenetic relatedness of these strains were identified on multiple levels of phylogenetic distance, suggesting that marine phytoplankton produce DOM that in part reflects its phylogenetic origin. Chemical information regarding the size and polarity ranges of features from defined biological sources was also obtained. Our findings reveal DOMP composition to be partially conserved among related phytoplankton species, and implicate marine DOM as a potential factor influencing microbial diversity in the sea by acting as a link between autotrophic and heterotrophic microbial community structures.This research was supported by grants to Daniel J. Repeta and Sallie W. Chisholm from the Gordon and Betty Moore Foundation and funding to Daniel J. Repeta, Edward F. DeLong, and Sallie W. Chisholm from the National Science Foundation Science and Technology Center Award 0424599