Transcriptional Regulation of N-Acetylglutamate Synthase and its Clinical Relevance

The urea cycle converts ammonia, the toxic byproduct of protein metabolism, to non-toxic urea utilizing six enzymes in mammalian liver hepatocytes. In the mitochondria, the enzyme N-acetylglutamate synthase (NAGS), produces the essential allosteric activator, N-acetylglutamate (NAG), for the first enzyme of the cycle, carbamylphosphate synthetase 1 (CPS1). Ammonia sequestered by CPS1 is condensed with bicarbonate and phosphate from ATP to produce to carbamylphosphate, which is then condensed with ornithine to produce citrulline by ornithine transcarbamylase (OTC). Citrulline is then transported to the cytoplasm where it is further converted by the distal urea cycle enzymes argininosuccinate synthetase, argininosuccinate lyase, and arginase 1 to the end product, urea. Prior to sequestration of ammonia, signaling pathways sense dietary protein load. Analysis was conducted to determine the effect of protein composition on metabolic signaling and nutrient sensing pathways AMPK, mTOR, and eIF2, promote transcriptional activation of urea cycle genes and translation of urea cycle proteins. Future studies will determine the importance of these pathways on the urea cycle and whether post-translational control mechanisms, such as phosphorylation, also respond to protein in the diet. Since NAGS plays an important role in controlling the rate of urea production by activating the rate limiting CPS1, its regulatory mechanisms control ureagenesis flux. This project elucidated the regulatory domains of NAGS including a promoter which contains multiple tissue- and species- specific transcription initiation sites and binding sites for transcription factors CREB and Sp1. It also found and characterized an enhancer 3kb upstream of the translational start site which confers liver specificity and has binding sites for NF-Y and HNF-1. These transcription factors are regulated by glucocorticoid and glucagon hormone signaling pathways and are also regulated in a tissue selective manner. A deficiency of NAGS in humans and mice leads to high ammonia, low urea, and high glutamine levels in the plasma, and can be overcome by treatment with N-carbamylglutamate (NCG). This project identified a patient with NAGS deficiency and hyperammonemia caused by a deleterious mutation in the HNF-1 binding site within the enhancer of the NAGS gene, which was identified and characterized by this research. This mutation caused decreased transcription of NAGS due to reduced HNF-1 binding. Subsequently, this work found disease-causing mutations in the promoter region of OTC which have been shown to interfere with HNF-4 binding. The knowledge garnered by this project significantly increases our understanding of the regulation of urea cycle RNA and protein expression and their role in disease pathophysiology. Understanding of these mechanisms will lead to improved diagnoses and continued development of effective treatments for people with urea cycle disorders and hyperammonemia

Managing the Unmanageable: How IS Research Can Contribute to the Scholarship of Cyber Projects

Cyber projects are large-scale efforts to implement computer, information, and communication technologies in scientific communities. These projects seek to build scientific cyberinfrastructure that will promote new scientific collaborations and transform science in novel and unimagined ways. Their scope and complexity, the number and diversity of stakeholders, and their transformational goals make cyber projects extremely challenging to understand and manage. Consequently, scholars from multiple disciplines, including computer science, information science, sociology, and information systems, have begun to study cyber projects and their impacts. As IS scholars, our goal is to contribute to this growing body of inter-disciplinary knowledge by considering three areas of IS research that are particularly germane to this class of project, given their characteristics: development approaches, conflict, and success factors. After describing cyber projects, we explore how IS research findings in these three areas are relevant for cyber projects, and suggest promising avenues of future research. We conclude by discussing the importance and unique challenges of cyber projects and propose that, given our expertise and knowledge of project management, IS researchers are particularly well suited to contribute to the inter-disciplinary study of these projects

Lebenslänglich Emigrantin - die Flucht ins 'Anderssein': Selbststilisierung als Habitus der Krisenbewältigung

'Dieser Beitrag widmet sich anhand einer exemplarischen objektiv hermeneutischen Fallanalyse der Frage nach der Bedeutung von (erzwungener) Emigration im Kindes- und Jugendalter für die Identitätsentwicklung. Die Fallrekonstruktion geht hervor aus meinem Dissertationsprojekt, in dem narrative Interviews mit Frauen und Männern, die im Kindes- oder Jugendalter aus dem nationalsozialistischen Deutschland emigrieren mussten, mit dem Verfahren der objektiven Hermeneutik analysiert und hinsichtlich der Frage interpretiert wurden, welche Bedeutung das Erleben von Verfolgung und Emigration in Kindheit bzw. Jugend für die Identitätsbildung und somit für die Entwicklung von Selbst- und Weltbildern sowie insbesondere für die Entwicklung eines Habitus der Krisenbewältigung hat. Im folgenden Text soll besonders auf den letztgenannten Aspekt eingegangen werden.' (Autorenreferat)'Based on a case study conducted in terms of objective hermeneutics, the paper explores the question of how (forced) emigration in childhood and adolescence affects identity development. The case is being reconstructed as a sequel to the author's project for a doctoral thesis. For this project, narrative interviews with individuals, both female and male, who in their childhood or adolescence had to emigrate from Nazi Germany were analyzed using procedures of objective hermeneutics. Interpretation was concerned with the impact the experience of persecution and emigration in childhood or adolescence may have on identity formation and, thus, on the development of self-perception and world views as well as, more specifically, on the development of a habitus of coping with crisis. The following text is mainly dedicated to the latter aspect.' (author's abstract

Characterization of Chicken CAT-2 Isoforms

Lysine and arginine transport is primarily mediated by cationic amino acid transporters (CATs) in cells. The chicken CAT-2 (cCAT-2) transcript is alternatively spliced to three isoforms. Transcriptional and cellular localization experiments were utilized to study their regulation. The mRNA abundance of cCAT-2 isoforms was estimated in body tissues, and although differentially expressed, all tissues expressed each cCAT-2 isoform gene, indicating that alternative splicing was not tissue-specific. Both cCAT-2A and cCAT-2B proteins localized to the plasma membrane and cCAT-2C protein was retained in the cytosol. Chicken CAT-2A functions as a low affinity transporter with specificity for lysine and arginine. Chicken CAT-2B and cCAT-2C transporter functions were not detectable. Our data indicates that CAT-2 transporters are conserved in non-mammalian vertebrates, but cCAT-2 isoforms differ in their tissue distribution and transporter function from previously characterized CAT-2 transporters. These results also indicate a mechanism by which additional dietary lysine and arginine contribute to increased protein accretion in muscle tissue

Educação ambiental na escola: conscientização da necessidade de proteção contra a radiação ultravioleta

This paper refers to a field research on the subject: "Environmental Education in School:Awareness of the Need for Protection Against Ultraviolet Radiation," in which I proposed to"develop educational activities with students of second year and third year high school ElementarySchool of Basic Education Francisco Brochad da Rocha, issues and environmental problems,specifically problems related to overexposure to the sun, aiming to verify: the importance ofworking with students to preserve the environment, the need to protection against ultravioletradiation and the main diseases caused by excessive exposure to the Sun Data collection wasperformed with 12 (twelve) students of second year and twelve (12) third graders EducationFundamental through semi-structured interviews and questionnaires. It is necessary to becomeaware of what to avoid mistreating the environment is to preserve the future and, from that,knowing that everybody's duty, not only perform your part, but also to educate those who arearound you.Este trabalho se refere a uma pesquisa de campo acerca da temática: “Educação Ambiental Na Escola: Conscientização da Necessidade de Proteção Contra a Radiação Ultravioleta”, na qual me propus a “Desenvolver ações educativas junto aos alunos do segundo ano e terceira série do Ensino Fundamental da Escola de Educação Básica Francisco Brochado da Rocha, sobre questões e problemas ambientais, mais especificamente os problemas relacionados à exposição excessiva ao Sol, tendo como objetivos verificar: a importância de se trabalhar com os alunos a preservação do meio ambiente, da necessidade de proteção contra a radiação ultravioleta e as principais doenças causadas pela exposição excessiva ao Sol. A coleta de dados foi realizada com 12(doze) alunos do segundo ano e 12(doze) alunos da terceira série do Ensino Fundamental por meio de entrevistas semi-estruturadas e questionários. É necessário que se tome consciência de que evitar maltratar o meio ambiente é preservar o futuro e, a partir disso, saber que é dever de todos, não somente realizar sua parte, mas também conscientizar a quem esteja a sua volta

Radiometric Correction and 3D Integration of Long-Range Ground-Based Hyperspectral Imagery for Mineral Exploration of Vertical Outcrops

Recently, ground-based hyperspectral imaging has come to the fore, supporting the arduous task of mapping near-vertical, difficult-to-access geological outcrops. The application of outcrop sensing within a range of one to several hundred metres, including geometric corrections and integration with accurate terrestrial laser scanning models, is already developing rapidly. However, there are few studies dealing with ground-based imaging of distant targets (i.e., in the range of several kilometres) such as mountain ridges, cliffs, and pit walls. In particular, the extreme influence of atmospheric effects and topography-induced illumination differences have remained an unmet challenge on the spectral data. These effects cannot be corrected by means of common correction tools for nadir satellite or airborne data. Thus, this article presents an adapted workflow to overcome the challenges of long-range outcrop sensing, including straightforward atmospheric and topographic corrections. Using two datasets with different characteristics, we demonstrate the application of the workflow and highlight the importance of the presented corrections for a reliable geological interpretation. The achieved spectral mapping products are integrated with 3D photogrammetric data to create large-scale now-called “hyperclouds”, i.e., geometrically correct representations of the hyperspectral datacube. The presented workflow opens up a new range of application possibilities of hyperspectral imagery by significantly enlarging the scale of ground-based measurements

Characterizing the effect of glutamine supplementation on asparagine and glutamine metabolism using 13C metabolic flux analysis

Upstream development efforts often focus on improved productivity. Among those efforts, improvements in medium formulations have translated into greater titers. To continue this historical trend, a better understanding of the cell metabolism is warranted for guiding efficient utilization of medium components to improve titer while minimizing byproducts. 13C Metabolic Flux Analysis (13C MFA) offers opportunities to study metabolic phenotypes by applying isotope tracers to estimate the intracellular fluxes through metabolic pathways. In this work, 13C MFA was applied to study the effects of glutamine supplementation by 13C parallel labelling of cultures with [U-13C]asparagine, [U-13C]glutamine and an a mixture of [U-13C]glucose with [1,2-13C]glucose. The study was focused on two metabolic states characterized by glutamine consumption in the early exponential phase and glutamine production in the late exponential phase of a fed-batch culture. To quantify individual metabolic pathway activity, metabolic flux maps were generated for the glutamine supplemented feeds compared to a control case with glutamine in the initial medium. The glutamine supplementation condition resulted in redistribution of the fluxes in the TCA cycle. Furthermore, measurements of the enrichment of cell protein indicate different allocations of the fed nutrients into generated biomass for the glutamine supplemented condition. Comparison between the early and the late exponential phases provided novel insights on how glutamine modulates CHO central carbon metabolism and supports the important role of glutamine as a major source of energy for cell proliferation. These findings contribute towards an improved characterization of the metabolism of industrial cells with useful implications for optimizing medium and feed development

Intravenous Delayed Gadolinium-Enhanced MR Imaging of the Endolymphatic Space: A Methodological Comparative Study

In-vivo non-invasive verification of endolymphatic hydrops (ELH) by means of intravenous delayed gadolinium (Gd) enhanced magnetic resonance imaging of the inner ear (iMRI) is rapidly developing into a standard clinical tool to investigate peripheral vestibulo-cochlear syndromes. In this context, methodological comparative studies providing standardization and comparability between labs seem even more important, but so far very few are available. One hundred eight participants [75 patients with Meniere's disease (MD; 55.2 ± 14.9 years) and 33 vestibular healthy controls (HC; 46.4 ± 15.6 years)] were examined. The aim was to understand (i) how variations in acquisition protocols influence endolymphatic space (ELS) MR-signals; (ii) how ELS quantification methods correlate to each other or clinical data; and finally, (iii) how ELS extent influences MR-signals. Diagnostics included neuro-otological assessment, video-oculography during caloric stimulation, head-impulse test, audiometry, and iMRI. Data analysis provided semi-quantitative (SQ) visual grading and automatic algorithmic quantitative segmentation of ELS area [2D, mm2] and volume [3D, mm3] using deep learning-based segmentation and volumetric local thresholding. Within the range of 0.1–0.2 mmol/kg Gd dosage and a 4 h ± 30 min time delay, SQ grading and 2D- or 3D-quantifications were independent of signal intensity (SI) and signal-to-noise ratio (SNR; FWE corrected, p < 0.05). The ELS quantification methods used were highly reproducible across raters or thresholds and correlated strongly (0.3–0.8). However, 3D-quantifications showed the least variability. Asymmetry indices and normalized ELH proved the most useful for predicting quantitative clinical data. ELH size influenced SI (cochlear basal turn p < 0.001), but not SNR. SI could not predict the presence of ELH. In conclusion, (1) Gd dosage of 0.1–0.2 mmol/kg after 4 h ± 30 min time delay suffices for ELS quantification. (2) A consensus is needed on a clinical SQ grading classification including a standardized level of evaluation reconstructed to anatomical fixpoints. (3) 3D-quantification methods of the ELS are best suited for correlations with clinical variables and should include both ears and ELS values reported relative or normalized to size. (4) The presence of ELH increases signal intensity in the basal cochlear turn weakly, but cannot predict the presence of ELH

Integration of Vessel-Based Hyperspectral Scanning and 3D-Photogrammetry for Mobile Mapping of Steep Coastal Cliffs in the Arctic

Remote and extreme regions such as in the Arctic remain a challenging ground for geological mapping and mineral exploration. Coastal cliffs are often the only major well-exposed outcrops, but are mostly not observable by air/spaceborne nadir remote sensing sensors. Current outcrop mapping efforts rely on the interpretation of Terrestrial Laser Scanning and oblique photogrammetry, which have inadequate spectral resolution to allow for detection of subtle lithological differences. This study aims to integrate 3D-photogrammetry with vessel-based hyperspectral imaging to complement geological outcrop models with quantitative information regarding mineral variations and thus enables the differentiation of barren rocks from potential economic ore deposits. We propose an innovative workflow based on: (1) the correction of hyperspectral images by eliminating the distortion effects originating from the periodic movements of the vessel; (2) lithological mapping based on spectral information; and (3) accurate 3D integration of spectral products with photogrammetric terrain data. The method is tested using experimental data acquired from near-vertical cliff sections in two parts of Greenland, in Karrat (Central West) and Søndre Strømfjord (South West). Root-Mean-Square Error of (6.7, 8.4) pixels for Karrat and (3.9, 4.5) pixels for Søndre Strømfjord in X and Y directions demonstrate the geometric accuracy of final 3D products and allow a precise mapping of the targets identified using the hyperspectral data contents. This study highlights the potential of using other operational mobile platforms (e.g., unmanned systems) for regional mineral mapping based on horizontal viewing geometry and multi-source and multi-scale data fusion approaches

Tinto: Multisensor Benchmark for 3-D Hyperspectral Point Cloud Segmentation in the Geosciences

The increasing use of deep learning techniques has reduced interpretation time and, ideally, reduced interpreter bias by automatically deriving geological maps from digital outcrop models. However, accurate validation of these automated mapping approaches is a significant challenge due to the subjective nature of geological mapping and the difficulty in collecting quantitative validation data. Additionally, many state-of-the-art deep learning methods are limited to 2-D image data, which is insufficient for 3-D digital outcrops, such as hyperclouds. To address these challenges, we present Tinto, a multisensor benchmark digital outcrop dataset designed to facilitate the development and validation of deep learning approaches for geological mapping, especially for nonstructured 3-D data like point clouds. Tinto comprises two complementary sets: 1) a real digital outcrop model from Corta Atalaya (Spain), with spectral attributes and ground-truth data and 2) a synthetic twin that uses latent features in the original datasets to reconstruct realistic spectral data (including sensor noise and processing artifacts) from the ground truth. The point cloud is dense and contains 3242964 labeled points. We used these datasets to explore the abilities of different deep learning approaches for automated geological mapping. By making Tinto publicly available, we hope to foster the development and adaptation of new deep learning tools for 3-D applications in Earth sciences. The dataset can be accessed through this link: https://doi.org/10.14278/rodare.2256