Application of phenology to assist in hyperspectral species classification of a northern hardwood forest

Tree species have unique spectral reflectance patterns that allows them to be both compared to other objects and to other types of trees. Increasing the spectral separation of such images may assist with surveying and forestry inventories. In past studies, most classifications were done with summer leaves, which darken and become very similar shades of green. This study utilized the phenology of trees to investigate how the changing colors of young or senescing leaves may assist in species classification based on aerial images. Images were taken of the Hubbard Brook Experimental Forest, which is mainly dominated by sugar maple (Acer saccharum Marsh), beech (Fagus grandifolia Ehrh.), and yellow birch (Betula allegheniensism Britt). Classification of stands of same-species trees was attempted using spring hyperspectral images containing bands from fall RGB color photos. The combination of high-resolution RGB photos and lower-resolution hyperspectral data was found not to increase the spectral separation when combined

EMPLOYING WIKI AS A COLLABORATIVE INFORMATION REPOSITORY IN A MEDIA AND ENTERTAINMENT COMPANY: THE NBC UNIVERSAL CASE

Wiki has been widely accepted by educational institutions, homes, and corporations, and is expected to grow continuously. Business enterprises quickly recognize the value of shared content: Some of the largest corporations, such as Google and IBM use wikis to manage daily operations and to share information among employees. This case study presents how NBC Universal developed a wiki, and used it to enhance knowledge-sharing, thereby achieving significant costsavings, performance improvement and employee satisfactions. This case shows Wiki can bring greater value to an organization with a dynamically changing structure in which capturing and sharing of tacit knowledge is critical for its success. By clearly demonstrating benefits of collaborative information repositories in the widely-recognized media and entertainment firm, this case will provide valuable learning opportunities to both professional and academic audience

Jane Austen, marriage, and Emma

Call number: LD2668 .R4 ENGL 1987 S67Master of ArtsEnglis

Architecture of the trypanosome RNA editing accessory complex, MRB1

Trypanosoma brucei undergoes an essential process of mitochondrial uridine insertion and deletion RNA editing catalyzed by a 20S editosome. The multiprotein mitochondrial RNA-binding complex 1 (MRB1) is emerging as an equally essential component of the trypanosome RNA editing machinery, with additional functions in gRNA and mRNA stabilization. The distinct and overlapping protein compositions of reported MRB1 complexes and diverse MRB1 functions suggest that the complex is composed of subcomplexes with RNA-dependent and independent interactions. To determine the architecture of the MRB1 complex, we performed a comprehensive yeast two-hybrid analysis of 31 reported MRB1 proteins. We also used in vivo analyses of tagged MRB1 components to confirm direct and RNA-mediated interactions. Here, we show that MRB1 contains a core complex comprised of six proteins and maintained by numerous direct interactions. The MRB1 core associates with multiple subcomplexes and proteins through RNA-enhanced or RNA-dependent interactions. These findings provide a framework for interpretation of previous functional studies and suggest that MRB1 is a dynamic complex that coordinates various aspects of mitochondrial gene regulation

Association of UBP1 to ribonucleoprotein complexes is regulated by interaction with the trypanosome ortholog of the human multifunctional P32 protein

Regulation of gene expression in trypanosomatid parasitic protozoa is mainly achieved posttranscriptionally. RNA-binding proteins (RBPs) associate to 3′ untranslated regions in mRNAs through dedicated domains such as the RNA recognition motif (RRM). Trypanosoma cruziUBP1 (TcUBP1) is an RRM-type RBP involved in stabilization/degradation of mRNAs. TcUBP1 uses its RRM to associate with cytoplasmic mRNA and to mRNA granules under starvation stress. Here, we show that under starvation stress, TcUBP1 is tightly associated with condensed cytoplasmic mRNA granules. Conversely, under high nutrient/low density-growing conditions, TcUBP1 ribonucleoprotein (RNP) complexes are lax and permeable to mRNA degradation and disassembly. After dissociating from mRNA, TcUBP1 can be phosphorylated only in unstressed parasites. We have identified TcP22, the ortholog of mammalian P32/C1QBP, as an interactor of TcUBP1 RRM. Overexpression of TcP22 decreased the number of TcUBP1 granules in starved parasites in vivo. Endogenous TcUBP1 RNP complexes could be dissociated in vitro by addition of recombinant TcP22, a condition stimulating TcUBP1 phosphorylation. Biochemical and in silico analysis revealed that TcP22 interacts with the RNA-binding surface of TcUBP1 RRM. We propose a model for the decondensation of TcUBP1 RNP complexes in T.cruzi through direct interaction with TcP22 and phosphorylation.Fil: Cassola, Alejandro Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Romaniuk, María Albertina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Primrose, Debora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Cervini Bohm, Gabriela Marta . Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: D'Orso, Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Frasch, Alberto Carlos C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin

Mechanisms of carbon catabolite regulation in Bacilli

In Bacillus subtilis werden nahezu 10% aller Gene durch das Katabolit Kontroll Protein A (CcpA) reguliert. Im Zuge der Kohlenstoffkatabolitenregulation (KKR) dienen glykolytische Intermediate und die Phosphoproteine HPr-Ser46-P bzw. Crh-Ser46-P als Koeffektoren für CcpA. Die aus dieser Interaktion resultierenden allosterischen Veränderungen im Protein führen zur Bindung an sogenannte cre Elemente. Zu Beginn dieser Arbeit waren die CcpA-HPr-Ser46-P-cre bzw. CcpA-Crh-Ser46-P-cre Strukturen aus Bacillus megaterium noch unbekannt. Im ersten Teil dieser Arbeit wurden die Effekte von Punktmutationen in funktional unterschiedlichen Domänen von CcpA auf die Regulation von verschiedenen B. subtilis Promotoren untersucht. Für die Charakterisierung der Repression durch CcpA dienten PxynP und PgntR, welche in der Anzahl, Position und Sequenz der cre Elemente variieren. Für die mechanistisch unbekannte (in)direkte Aktivierung durch CcpA wurden PalsS ohne cre Element und PackA mit zwei stromaufwärts lokalisierten cre Motiven verwendet. Nach der Etablierung der in vivo Untersuchungssysteme ergaben sich CcpA Varianten mit differenziellen Aktivitäten. Erstens zeigen CcpA Mutanten (A300W, A302W, L306W, K308W) keine KKR aller Gene. Deren Aminosäurenreste befinden sich in der Korepressorbinderegion, sind aber nicht am allosterischen Schaltmechanismus beteiligt. Dieser Phänotyp resultiert daher aus dem Verlust der Koeffektorbindung. Andere CcpA Varianten (R54W, V301W, R304W) aktivieren ackA, sind aber zur KKR von gntR, xynP und alsS unbefähigt. Deren Aminosäurenreste sind in der Scharnierhelix und der Korepressorbinderegion lokalisiert und direkt in den allosterischen Schaltmechansimus involviert. Daher existieren als Folge unterschiedlicher Signaltransduktionswege multiple allosterische Mechanismen, welche durch eine veränderte Koeffektorbindung ausgelöst werden. CcpA Mutanten (+1W, I4W, M17R, M89W, N93W), deren Aminosäurenreste in der DBD oder Dimerisierungsebene lokalisiert sind, weisen KKR Defizienz von gntR, aber intakte KKR von ackA, alsS bzw. xynP auf. Dies könnte durch unterschiedliche Bindeaffinitäten von CcpA zu cre Elementen hervorgerufen werden. Zuletzt wurden CcpA Mutanten (T307W, D276A) mit Glukose unabhängiger Regulation erstmals auch von ackA identifiziert, deren Aminosäurenreste sich in der Korepressorbinderegion und im Effektorenbindespalt befinden. Dies ist auf eine verbesserte, vom Koeffektor unabhängige cre Bindung zurückzuführen, da diese Mutationen die DNA bindende Konformation von CcpA stabilisieren. Diese Mutationsanalysen bekräftigen die Strukturkomplexe aus B. megaterium, untermauern die Bedeutung vieler Aminosäuren für die KKR durch CcpA und liefern erste Ursachen für die differenziellen Aktivitäten der CcpA Mutanten. Die erhaltenen Daten unterstreichen daher die raffinierten multiplen Strategien eines einzigartigen LacI/GalR-Familien Mitglieds. Die Virulenzgenexpression wird in Listeria monocytogenes, einem zu B. subtilis hochverwandten Bakterium, auf komplexe Weise durch den Transkriptionsaktivator PrfA kontrolliert. Dieser bindet an sogenannte PrfA Boxen in Virulenzgenpromotoren, wodurch ein für Crp/FnR-Mitglieder typischer allosterischer Schaltmechanismus ausgelöst wird. Dabei kontaktiert PrfA die RNAP. Zu den am intrazellulären Infektionszyklus beteiligten Virulenzgenen zählen u. a. plcA, actA und hly. Im zweiten Teil dieser Arbeit wurde ein heterologes in vivo Expressionssystem zur Untersuchung der PrfA vermittelten Virulenzgenregulation aus L. monocytogenes in B. subtilis etabliert. In diesem liegen die Virulenzgenpromotor-lacZ Fusionen chromosomal vor, während die Transkription von prfA durch den Tet Repressor episomal gesteuert wird. Das führt zu unterschiedlich starker Aktivierung von actA, hly bzw. plcA in Abhängigkeit von der PrfA Box Konservierung. Die kontinuierliche Erhöhung der PrfA Dosis reguliert die Expression von actA bzw. hly in zwei Stufen. Während die erste Stufe auf die Aktivierung durch WT PrfA zurückzuführen ist, resultiert die maximale Virulenzgenexpression aus der verstärkten Bindung von allosterisch verändertem PrfA an die PrfA Box. In Anwesenheit von Glukose wurde eine Wuchsphasen unabhängige PrfA vermittelte Virulenzgenrepression in Abhängigkeit von der PrfA Konzentration erzielt. Durch ptsH1 und ptsG Mutanten, welche kein HPr-Ser46-P bzw. Enzym IIA des Phosphotransferasesystems (PTS) exprimieren, kommt es mit Glukose zur PrfA Dosis abhängigen Derepression von actA, hly und plcA. Dagegen weisen crh bzw. ccpA Deletionsmutanten den Phänotyp des WTs bzw. eine schwach eingeschränkte Virulenzgenrepression auf. Dadurch ist eindeutig demonstriert, dass KKR/PTS Komponenten (in)direkt mit der Allosterie von PrfA interferieren, indem sie lediglich WT PrfA beeinflussen. Da es durch ptsH Mutanten zu abgeschwächter Expression von hly, actA und plcA unabhängig von der Anwesenheit von Glukose kommt, bedingt die vollständige PrfA Aktivität zudem ein intaktes PTS. Die zweistufige PrfA vermittelte Aktivierung der Virulenzgenexpression ermöglicht Listerien die optimale Anpassung an die Situation innerhalb und außerhalb der Wirtszelle. Das erfordert komplexe Kontrollmechanismen, für welche die PrfA Boxen, die PrfA Konzentration, die PrfA Aktivität und die gezielte (in)direkte Steuerung durch Komponenten der KKR/PTS von Bedeutung sind.The catabolite control protein A (CcpA) regulates approximately 10% of the genes in Bacillus subtilis. Glycolytic intermediates and the phosphoproteins HPr-Ser46-P or Crh-Ser46-P serve as coeffectors for CcpA during carbon catabolite regulation (CCR). The interaction resulting in an allosteric switch of the protein leads to binding of so-called cre elements. At the beginning of this work the CcpA-HPr-Ser46-P-cre and CcpA-Crh-Ser46-P-cre structures of Bacillus megaterium were unknown. In the first part of this work the effects of point mutations in different functional domains of CcpA were analyzed on the regulation of various B. subtilis promoters. For the repression by CcpA, PxynP and PgntR were used, thereby varying in number, position and sequence of the cre elements. For the mechanistic unknown (in)direct activation by CcpA, PalsS without a cre element and PackA with two upstream localized cre motifs were used. After the establishment of the in vivo investigation systems, CcpA mutants with differential activities were identified. First, CcpA variants (A300W, A302W, L306W, K308W) mutated at residues in the corepressor binding region without allosteric functions are inactive which is due to the loss of coeffector binding. Other CcpA variants (R54W, V301W, R304W) with alterations in the hinge helix and the corepressor binding region which change their conformation upon coeffector binding regulate only ackA. Thus, multiple allosteric switch mechanisms may exist as a result of different signal transduction pathways caused by different coeffector binding. Furthermore, CcpA mutants (+1W, I4W, M17R, M89W, N93W) mutated at residues in the DBD and the dimerization interface exhibit CCR deficiency of gntR, but intact CCR of ackA, alsS and xynP. This might be due to different binding affinities of CcpA to cre. Last, the first CcpA mutants (T307W, D276A) with glucose independent regulation of ackA were identified, with their residues located in the corepressor binding region and the effector binding cleft. This is caused by altered coeffector independent cre binding, because these mutations stabilize the DNA binding conformation of CcpA. These mutation analyses confirm the structure complexes of B. megaterium, show the importance of several amino-acids for CcpA dependent CCR and provide first reasons for the different activities of CcpA mutants. Hence, the obtained data underline the sophisticated multiple strategies of a unique LacI/GalR-family member. The transcription activator PrfA controls virulence gene expression in Listeria monocytogenes, a near relative to B. subtilis, via complex mechanisms. PrfA binds to the so called PrfA boxes in virulence gene promoters leading to an allosteric change which is typical for Crp/FnR members thereby contacting the RNAP. The virulence genes involved in the intracellular infection cycle include among others actA, hly and plcA. In the second part of this work a heterologous in vivo expression system was established allowing investigation of PrfA mediated virulence gene expression of L. monocytogenes in B. subtilis. This system contains the virulence gene promoter-lacZ fusions chromosomally, while the transcription of prfA is episomally controlled via the Tet repressor. This leads to activation of actA, hly and plcA with different strength dependent on the PrfA box conservation. The continuous increase of the PrfA concentration regulates the expression of actA in two steps. The first step is due to the activation by WT PrfA, while the maximal virulence gene expression results of the altered binding of allosteric changed PrfA to the PrfA box. The presence of glucose leads to a growth phase independent PrfA mediated virulence gene repression dependent on the PrfA concentration. ptsH1 and ptsG mutants, lacking HPr-Ser46-P and EIIA of the phosphotransferasesystem (PTS), respectively, show PrfA dosis dependent derepression of actA, hly and plcA in the presence of glucose. crh and ccpA deletion mutants exhibit the phenotype of the WT or slightly decreased virulence gene repression. Hence, it is clearly demonstrated that components of the CCR/PTS interfere (in)directly with the allostery of PrfA by affecting only WT PrfA. Since a ptsH mutant decreases expression of actA, hly and plcA independently of the presence of glucose, the full PrfA activity seems to require also an intact PTS. The two step PrfA mediated activation of the virulence gene expression allows Listeria the optimal adaptation on the situation inside and outside the host cell. This requires a complex control via the PrfA box, PrfA concentration, PrfA activity and specific (in)direct regulation by components of the CCR/PTS