237 research outputs found
NPM1/B23: A Multifunctional Chaperone in Ribosome Biogenesis and Chromatin Remodeling
At a first glance, ribosome biogenesis and chromatin remodeling are quite different processes, but they share a common problem involving interactions between charged nucleic acids and small basic proteins that may result in unwanted intracellular aggregations. The multifunctional nuclear acidic chaperone NPM1 (B23/nucleophosmin) is active in several stages of ribosome biogenesis, chromatin remodeling, and mitosis as well as in DNA repair, replication and transcription. In addition, NPM1 plays an important role in the Myc-ARF-p53 pathway as well as in SUMO regulation. However, the relative importance of NPM1 in these processes remains unclear. Provided herein is an update on the expanding list of the diverse activities and interacting partners of NPM1. Mechanisms of NPM1 nuclear export functions of NPM1 in the nucleolus and at the mitotic spindle are discussed in relation to tumor development. It is argued that the suggested function of NPM1 as a histone chaperone could explain several, but not all, of the effects observed in cells following changes in NPM1 expression. A future challenge is to understand how NPM1 is activated, recruited, and controlled to carry out its functions
Design and Development of a Multifunctional Test Rig
In this project, the several steps in a product development process can be followed, from the first brainstorming of basic concepts to the final implementation of the manufactured product in the factory. The project was assigned by Faiveley Transport Nordic AB and its aim was to design a well functioning test rig for testing of their train brake units. The new rig’s advantages compared to old existing test rigs at Faiveley, is that it should be compact, flexible and able to test multiple train brake units at the same time. Throughout the project the methodology of Ullrich and Eppinger’s “Product Design and Development” was used at a large extent. As a first step in this methodology, target specifications were set and thereafter the concept generation could start. The designing of the test rig was divided into sub problems to be solved separately and after several iterations a final design was found. To make sure the test rig was dimensioned in a satisfying way comprehensive calculations were carried out, e.g. ANSYS calculations. After the supervisors at Faiveley approved the design it was manufactured by the company Ingenjörsfirma Jeppsson AB. When the test rig was delivered careful testing took place. The results were very positive, all components functioned as wished and the test rig responded well when applied to forces. As Faiveley wanted a new pneumatic system to drive the train brakes, this was ordered by Festo. It consisted of one control unit and ten valve units in a terminal making the device very compact. A casing was designed and manufactured to protect the sensitive equipment. Finally the target specifications were compared to those of the actual test rig. All specifications were found satisfactory and the project was considered successful
Functional characterization of the alternative reading frame protein p14ARF
A deeper understanding of the molecular events underlying tumor
development is a prerequisite for the design of novel and efficient
therapies. Inactivation of the p53 and retinoblastoma (Rb) tumor
suppressor pathways appears as a common theme in most malignant human
tumors. Most intriguingly, both p53 and Rb proteins are in part regulated
through the CDKN2A (INK4a/ARF) locus on human chromosome 9p21, a region
frequently lost in tumors. This region encodes two structurally and
functionally distinct tumor suppressor proteins known as ARF (human
p14ARF, mouse p19ARF), and p16INK4a. Exons 1 alpha, 2 and 3 encode
p16INK4a, while exon 1 beta, spliced to exon 2 in an alternative reading
frame encodes ARF. p16INK4a induces cell cycle arrest by inhibiting
CDK4/6 whereas expression of ARF induces cell cycle arrest in part
through inhibition of MDM2, a negative regulator of p53. This thesis is
focused on the expression, localization and function of human p14ARF.
We discovered that p14ARF was overexpressed and localized to nucleoli, in
human tumor cell lines deficient for p53 function as described in paper
I. p14ARF had a similar intracellular localization as the major nucleolar
phosphoprotein B23 (also known as nucleophosmin or NPM) during
interphase, mitosis and in response to RNA polymerase I transcriptional
inhibition that causes nucleolar dysfunction. B23 was identified as a
bona fide p14ARF associated protein (paper II). The results indicated
that B23 could be involved in efficient nucleolar localization and
possibly stability of p14ARF protein. In paper III, the status of the
p14ARF-MDM2-p53 pathway was investigated in a panel of Burkitt´s lymphoma
(BL) cell lines. Loss of p14ARF (and p16INK4a) occurred in wildtype (wt)
p53 containing BL lines only, whereas other BLs with wt p53 contained
abundant levels of MDM2. Thus, inactivation of the p53 pathway was
frequent in BL cell lines, presumably as a mechanism to escape or
attenuate Myc induced p53-dependent apoptosis. Next, we were interested
in the role of p14ARF as a regulator of p53 activity in human fibroblasts
after the activation of Myc or E2F-1 oncogenes (paper IV). Both Myc and
E2F1 stabilized p53, along with phosphorylation on serine-15, induction
of p21 and MDM2. Only E2F-1 markedly induced p14ARF. Both Myc and E2F-1
stabilized p53 in primary fibroblasts also after depletion of ARF.
Caffeine blocked p53 accumulation after Myc or E2F-1 activation. Thus,
the p53 response to activated oncogenes in normal human fibroblasts was
not critically dependent on p14ARF. Interestingly, activation of Myc led
to a strong accumulation of p16INK4a protein in primary human fibroblasts
(paper V).
In summary, ARF is a nucleolar protein having some properties in common
with previously characterized nucleolar proteins. But ARF is also a
peculiar protein. Being both an inhibitor of MDM2 and of the ribosomal
RNA processing machinery, ARF represents an interesting and almost unique
link between p53 on one side, and the nucleolus on the other. The
relative roles of ARF and p16INK4a in human tumor development remain
enigmatic, but recent advances in the field indicate a predominant role
of p16INK4a in protecting human cells from oncogenic transformation
Characterization Methods for Elastic Properties of Wood Fibers from Mats for Composite Materials
Wood fibers offer excellent specific properties at low cost and are of interest as reinforcement in composites. This work compares two alternative test methods to determine the stiffness of wood fibers from simple macroscopic tests on fiber mats. One method is compression of the fiber mat in the thickness direction, which uses a statistical micromechanical model based on first-order beam theory to describe the deformation. The other method is tensile testing of fiber mats and back calculation of the fiber stiffness with a laminate model. Experiments include compression tests and tensile stiffness index tests as well as determination of fiber content, orientation, and dimensional distribution. For mats with unbleached softwood kraft fibers, an effective value of the Young's modulus of 20.1 GPa determined by the compression method can be compared with values of 17.4-19.0 GPa obtained from tensile tests. These are in agreement with values for similar cellulosic fibers found in literature. The compression method is more appropriate for low-density fiber mats, while the tensile test works better for well-consolidated high-density fiber mats. The two methods have different ranges of applicability and are complementary to one another. Limitations of the methods are also discussed. The main advantage of the methods is that they are quantitative. The potential as stiffening reinforcement of various types of fibers can be systematically investigated, even if the fiber mat microstructures are different
Screening of the two-component-system histidine kinases of Listeria monocytogenes EGD-e. LiaS is needed for growth under heat, acid, alkali, osmotic, ethanol and oxidative stresses
To study the role of each two-component system (TCS) histidine kinase (HK) in stress tolerance of Listeria monocytogenes EGD-e, we monitored the growth of individual HIC deletion mutant strains under heat (42.5 degrees C), acid (pH 5.6), alkali (pH 9.4), osmotic (6% NaCl), ethanol (3.5 vol%), and oxidative (5 mM H2O2) stresses. The growth of Delta liaS (Delta lmo1021) strain was impaired under each stress, with the most notable decrease under heat and osmotic stresses. The Delta ivirS (Delta lmo1741) strain showed nearly completely restricted growth at high temperature and impaired growth in ethanol. The growth of Delta agrC (Delta lmo0050) strain was impaired under osmotic stress and slightly under oxidative stress. We successfully complemented the HIC mutations using a novel allelic exchange based approach. This approach avoided the copy-number problems associated with in trans complementation from a plasmid. The mutant phenotypes were restored to the wild-type level in the complemented strains. This study reveals novel knowledge on the HKs needed for growth of L monocytogenes EGD-e under abovementioned stress conditions, with LiaS playing multiple roles in stress tolerance of L monocytogenes EGD-e. (C) 2017 Elsevier Ltd. All rights reserved.Peer reviewe
Standardized Collection of Production Data in Factory Environment
Tiedonkeruujärjestelmiä ollaan hyödynnetty tuotantoprosessien tuottaman datan keräämisessä jo pitkään. Nämä järjestelmät ovat kuitenkin tyypillisesti olleet erillisiä järjestelmiä, eikä dataa ole voitu kuljettaa hyödynnettäväksi muihin tietojärjestelmiin. Tiedonkeruun standardoinnin ja järjestelmäintegraation tavoitteena on, että tehtaan lattiatason järjestelmistä kerätty data saadaan kuljetettua aina liiketoimintatasolle asti, jolloin sitä on mahdollista hyödyntää useissa eri sovelluksissa. Tässä työssä perehdytään järjestelmäintegraatioon liittyviin standardeihin ja parhaisiin käytäntöihin, OPC-integraatiotekniikkaan sekä tietoturvamalleihin automaatioverkon suojaamiseksi.
Työ koostuu kirjallisuustutkimusosasta sekä osasta, joka käsittelee työn tilannutta yritystä ja sen lähtötietojen kartoittamista integraatiohanketta varten. Kirjallisuustutkimusosassa paneudutaan aluksi alan standardeihin ja tietomalleihin, joissa kuvataan teollisen tuotantoympäristön toimijoita sekä tieto- ja datavirtoja. Seuraavaksi käsitellään työn kannalta oleellisia automaatiojärjestelmiin liittyviä tiedonsiirtotekniikoita sekä Microsoftin kehittämää COM/DCOM-tekniikkaa, johon perinteinen OPC perustuu. Tämän jälkeen tutustutaan edellä mainittuun integraatiotekniikkaan eli OPC:iin, sen seuraajaan OPC UA:iin sekä tiedonkeruun tietoturvallisuusmenettelyihin.
Kohdeyritystä käsittelevässä osuudessa kerrotaan kohdeyrityksen lähtötilanteesta ja millaisia ongelmia ja tarpeita tiedonkeruuhankkeella tulisi pystyä ratkaisemaan. Osiossa käsitellään myös kohdeyritykselle suunniteltua tietomallia ja tuotantolinjoista tehtyä dokumentaatiota. Työn aikana tehdyt havainnot ja havaintojen pohjalta tehdyt suositukset jatkotoimenpiteistä on esitetty osion loppupuolella.
Työn tuloksena saatiin kartoitettua kohdeyrityksen lähtötilanne tiedonkeruuhankkeen tarpeiden ja tuotantolinjojen osalta. Havaintojen perusteella pystyttiin muodostamaan kokonaiskuva jatkotoimenpiteistä, joiden avulla tiedonkeruuhanketta voidaan viedä eteenpäin. Ohessa laadittiin tiedonkeruuhankkeen kannalta ohjeistus automaatiojärjestelmien hankintaa varten, jotta jatkossa oleelliset asiat osataan ottaa huomioon. Tällöin järjestelmien käyttöönotto nopeutuu ja järjestelmät ovat yhtenäisempiä
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