Standard deviations

The show Standard Deviations is composed of fifty-six relief prints based off of the combination and reorganization of two hundred and fifty linocuts. Within my work I am attempting to create a narrative space that uses a combination of object representations to form a single environment. The images produced by these composites relay narratives through image and viewer relationships. Standard Deviations deals with the altered perception, degradation, and rehabilitation of human and material components. It notes narrative and ethnographical values through image distortion, resulting in an exploration of mankind’s self-integration with objects of pseudo-natural landscapes. The depictions used within the final compositions redefine and reshape the purposes and definitions behind the original human and inanimate objects for the sake of finding meaningful mythology within the everyday. Individual images of works included

Two-Loop Diagrammatics in a Self-Dual Background

Diagrammatic rules are developed for simplifying two-loop QED diagrams with propagators in a constant self-dual background field. This diagrammatic analysis, using dimensional regularization, is used to explain how the fully renormalized two-loop Euler-Heisenberg effective Lagrangian for QED in a self-dual background field is naturally expressed in terms of one-loop diagrams. The connection between the two-loop and one-loop vacuum diagrams in a background field parallels a corresponding connection for free vacuum diagrams, without a background field, which can be derived by simple algebraic manipulations. It also mirrors similar behavior recently found for two-loop amplitudes in N=4 SUSY Yang-Mills theory.Comment: 16 pp, Latex, Axodra

Compared to conventional, ecological intensive management promotes beneficial proteolytic soil microbial communities for agro-ecosystem functioning under climate change-induced rain regimes

Projected climate change and rainfall variability will affect soil microbial communities, biogeochemical cycling and agriculture. Nitrogen (N) is the most limiting nutrient in agroecosystems and its cycling and availability is highly dependent on microbial driven processes. In agroecosystems, hydrolysis of organic nitrogen (N) is an important step in controlling soil N availability. We analyzed the effect of management (ecological intensive vs. conventional intensive) on N-cycling processes and involved microbial communities under climate change-induced rain regimes. Terrestrial model ecosystems originating from agroecosystems across Europe were subjected to four different rain regimes for 263 days. Using structural equation modelling we identified direct impacts of rain regimes on N-cycling processes, whereas N-related microbial communities were more resistant. In addition to rain regimes, management indirectly affected N-cycling processes via modifications of N-related microbial community composition. Ecological intensive management promoted a beneficial N-related microbial community composition involved in N-cycling processes under climate change-induced rain regimes. Exploratory analyses identified phosphorus-associated litter properties as possible drivers for the observed management effects on N-related microbial community composition. This work provides novel insights into mechanisms controlling agro-ecosystem functioning under climate change

Small RNAs Prevent Transcription-Coupled Loss of Histone H3 Lysine 9 Methylation in Arabidopsis thaliana

In eukaryotes, histone H3 lysine 9 methylation (H3K9me) mediates silencing of invasive sequences to prevent deleterious consequences including the expression of aberrant gene products and mobilization of transposons. In Arabidopsis thaliana, H3K9me maintained by SUVH histone methyltransferases (MTases) is associated with cytosine methylation (5meC) maintained by the CMT3 cytosine MTase. The SUVHs contain a 5meC binding domain and CMT3 contains an H3K9me binding domain, suggesting that the SUVH/CMT3 pathway involves an amplification loop between H3K9me and 5meC. However, at loci subject to read-through transcription, the stability of the H3K9me/5meC loop requires a mechanism to counteract transcription-coupled loss of H3K9me. Here we use the duplicated PAI genes, which stably maintain SUVH-dependent H3K9me and CMT3-dependent 5meC despite read-through transcription, to show that when PAI sRNAs are depleted by dicer ribonuclease mutations, PAI H3K9me and 5meC levels are reduced and remaining PAI 5meC is destabilized upon inbreeding. The dicer mutations confer weaker reductions in PAI 5meC levels but similar or stronger reductions in PAI H3K9me levels compared to a cmt3 mutation. This comparison indicates a connection between sRNAs and maintenance of H3K9me independent of CMT3 function. The dicer mutations reduce PAI H3K9me and 5meC levels through a distinct mechanism from the known role of dicer-dependent sRNAs in guiding the DRM2 cytosine MTase because the PAI genes maintain H3K9me and 5meC at levels similar to wild type in a drm2 mutant. Our results support a new role for sRNAs in plants to prevent transcription-coupled loss of H3K9me

abd-A Regulation by the iab-8 Noncoding RNA

The homeotic genes in Drosophila melanogaster are aligned on the chromosome in the order of the body segments that they affect. The genes affecting the more posterior segments repress the more anterior genes. This posterior dominance rule must be qualified in the case of abdominal-A (abd-A) repression by Abdominal-B (Abd-B). Animals lacking Abd-B show ectopic expression of abd-A in the epidermis of the eighth abdominal segment, but not in the central nervous system. Repression in these neuronal cells is accomplished by a 92 kb noncoding RNA. This “iab-8 RNA” produces a micro RNA to repress abd-A, but also has a second, redundant repression mechanism that acts only “in cis.” Transcriptional interference with the abd-A promoter is the most likely mechanism

Outside-In Signalling Generated by a Constitutively Activated Integrin αIIbβ3 Impairs Proplatelet Formation in Human Megakaryocytes

BACKGROUND: The interaction of megakaryocytes with matrix proteins of the osteoblastic and vascular niche is essential for megakaryocyte maturation and proplatelet formation. Fibrinogen is present in the vascular niche and the fibrinogen receptor α(IIb)β(3) is abundantly expressed on megakaryocytes, however the role of the interaction between fibrinogen and α(IIb)β(3) in proplatelet formation in humans is not yet fully understood. We have recently reported a novel congenital macrothrombocytopenia associated with a heterozygous mutation of the β(3) subunit of α(IIb)β(3). The origin of thrombocytopenia in this condition remains unclear and this may represent an interesting natural model to get further insight into the role of the megakaryocyte fibrinogen receptor in megakaryopoiesis. METHODOLOGY/PRINCIPAL FINDINGS: Patients' peripheral blood CD45+ cells in culture were differentiated into primary megakaryocytes and their maturation, spreading on different extracellular matrix proteins, and proplatelet formation were analyzed. Megakaryocyte maturation was normal but proplatelet formation was severely impaired, with tips decreased in number and larger in size than those of controls. Moreover, megakaryocyte spreading on fibrinogen was abnormal, with 50% of spread cells showing disordered actin distribution and more evident focal adhesion points than stress fibres. Integrin α(IIb)β(3) expression was reduced but the receptor was constitutively activated and a sustained, and substrate-independent, activation of proteins of the outside-in signalling was observed. In addition, platelet maturation from preplatelets was impaired. CONCLUSIONS/SIGNIFICANCE: Our data show that constitutive activation of α(IIb)β(3)-mediated outside-in signalling in human megakaryocytes negatively influences proplatelet formation, leading to macrothombocytopenia

Current Issues in Environmental Law

Materials from the Current Issues in Environmental Law seminar held by UK/CLE in April 1995

“Genes”

In order to describe a cell at molecular level, a notion of a “gene” is neither necessary nor helpful. It is sufficient to consider the molecules (i.e., chromosomes, transcripts, proteins) and their interactions to describe cellular processes. The downside of the resulting high resolution is that it becomes very tedious to address features on the organismal and phenotypic levels with a language based on molecular terms. Looking for the missing link between biological disciplines dealing with different levels of biological organization, we suggest to return to the original intent behind the term “gene”. To this end, we propose to investigate whether a useful notion of “gene” can be constructed based on an underlying notion of function, and whether this can serve as the necessary link and embed the various distinct gene concepts of biological (sub)disciplines in a coherent theoretical framework. In reply to the Genon Theory recently put forward by Klaus Scherrer and Jürgen Jost in this journal, we shall discuss a general approach to assess a gene definition that should then be tested for its expressiveness and potential cross-disciplinary relevance