555 research outputs found
Notes on Factor Price Equality and Biased Technical Change in a Two-Cone Trade Model
We reconsider the effects of long-run economic growth on relative factor prices across cones of specialization. We model economic growth as exogenous technical change. Allowing for capital biased technical change with a sector bias and for endogenous commodity prices, we find that economic growth may increase or decrease factor price differences across cones. For a neutral demand side and capital biased growth in the most capital intensive sector, we find that eco-nomic growth encourages less factor price diversity across cones.Factor Price Equalization, Cones of Diversification, Trade, Technical Change, Growth
Targeted mutagenesis of the Sap47 gene of Drosophila: Flies lacking the synapse associated protein of 47 kDa are viable and fertile
BACKGROUND: Conserved proteins preferentially expressed in synaptic terminals of the nervous system are likely to play a significant role in brain function. We have previously identified and molecularly characterized the Sap47 gene which codes for a novel synapse associated protein of 47 kDa in Drosophila. Sequence comparison identifies homologous proteins in numerous species including C. elegans, fish, mouse and human. First hints as to the function of this novel protein family can be obtained by generating mutants for the Sap47 gene in Drosophila. RESULTS: Attempts to eliminate the Sap47 gene through targeted mutagenesis by homologous recombination were unsuccessful. However, several mutants were generated by transposon remobilization after an appropriate insertion line had become available from the Drosophila P-element screen of the Bellen/Hoskins/Rubin/Spradling labs. Characterization of various deletions in the Sap47 gene due to imprecise excision of the P-element identified three null mutants and three hypomorphic mutants. Null mutants are viable and fertile and show no gross structural or obvious behavioural deficits. For cell-specific over-expression and "rescue" of the knock-out flies a transgenic line was generated which expresses the most abundant transcript under the control of the yeast enhancer UAS. In addition, knock-down of the Sap47 gene was achieved by generating 31 transgenic lines expressing Sap47 RNAi constructs, again under UAS control. When driven by a ubiquitously expressed yeast transcription factor (GAL4), Sap47 gene suppression in several of these lines is highly efficient resulting in residual SAP47 protein concentrations in heads as low as 6% of wild type levels. CONCLUSION: The conserved synaptic protein SAP47 of Drosophila is not essential for basic synaptic function. The Sap47 gene region may be refractory to targeted mutagenesis by homologous recombination. RNAi using a construct linking genomic DNA to anti-sense cDNA in our hands is not more effective than using a cDNA-anti-sense cDNA construct. The tools developed in this study will now allow a detailed analysis of the molecular, cellular and systemic function of the SAP47 protein in Drosophila
Notes on factor price equality and biased technical change in a two-cone trade model
We reconsider the effects of long-run economic growth on relative factor prices across cones of specialization. We model economic growth as exogenous technical change. Allowing for capital biased technical change with a sector bias and for endogenous commodity prices, we find that economic growth may increase or decrease factor price differences across cones. For a neutral demand side and capital biased growth in the most capital intensive sector, we find that economic growth encourages less factor price diversity across cones
Notes on factor price equality and biased technical change in a two-cone trade model
We reconsider the effects of long-run economic growth on relative factor prices across cones of specialization. We model economic growth as exogenous technical change. Allowing for capital biased technical change with a sector bias and for endogenous commodity prices, we find that economic growth may increase or decrease factor price differences across cones. For a neutral demand side and capital biased growth in the most capital intensive sector, we find that economic growth encourages less factor price diversity across cones
Zur stratigraphischen Gliederung der jungpleistozänen Sedimente im nördlichen Oberrheintalgraben
Die quartäre Grabenfüllung des nördlichen Oberrheintales baut sich aus den petrographisch gut unterscheidbaren, fluviatilen Sedimenten von Rhein, Main und Neckar auf. An der Oberfläche dieser fluviatilen Ablagerungen kam es im Jungpleistozän und Holozän zur Bildung von Flugsanddecken verschiedener Mächtigkeit und Ausdehnung; auf größeren Flächen wurden die Flugsande zu Dünen unregelmäßiger Form und Anordnung aufgeweht. Die verschiedene petrographische Ausbildung dieser Flugsande machte eine Abgrenzung folgender Flugsand-Faziesräume notwendig: 1. Das Maingebiet mit seinen mittel-grobkörnigen und meist kalkfreien Flugsanden. 2. Die Bergsträßer Flugsandvorkommen, in denen feinkörnige, kalkhaltige äolische Sedimente überwiegen. 3. Das Lorsch-Viernheimer Dünengebiet, dessen Flugsande sich von denen des Bergsträßer Raumes nur wenig unterscheiden. 4. Der Sprendlinger Horst mit seinen, den Mainflugsanden petrographisch ähnlichen, äolischen Sedimenten. Die vollständigste Profilentwicklung war im Maingebiet zu beobachten. In diesem Raum überlagern die äolischen Deckschichten, wie die eingehende Untersuchung der fluviatilen Ablagerungen deutlich gezeigt hat, auf großen Flächen die Reste eines letztinterglazialen Bodens an der Oberfläche der alt- bis mittelpleistozänen Kelsterbacher Terrasse. Gelegentlich sind Flugsande und Dünen auch auf den geringmächtigen Ablagerungen einer vermutlich Oberen Niederterrasse verbreitet, besonders wo diese randlich auf die Kelsterbacher Terrasse übergreift. Aus dem Profilaufbau der Dünen im Maingebiet läßt sich, teilweise in Anlehnung an die Lößstratigraphie, folgender Geschehnisablauf rekonstruieren: Auf den, der fluviatilen Akkumulation entzogenen, älteren Terrassenflächen überwogen im Frühwürm intensive Abtragungs- und Verlagerungsvorgänge. Am Ende dieses durch kühlfeuchte Klimabedingungen gekennzeichneten Zeitabschnittes dürfte die Bildung der lehmstreifigen Basiswechselfolge der Dünen erfolgt sein. Über den, durch einen schwer einstufbaren (W I/II?), geringmächtigen Kryoturbationshorizont nach oben begrenzten Basisschichten folgt die Hauptmasse der, meist mehrere Meter mächtigen, Dünensande. Diese im tieferen Teil stellenweise durch einen schwach ausgeprägten Naßfleckenhorizont (W II/III?) gegliederte Flugsandabfolge dürfte stratigraphisch dem Würm III-Löß der hessischen Gliederung entsprechen. Die unter den besonderen Klimabedingungen des Spätglazials auf diesen Dünensanden einsetzende Bodenentwicklung führte bis zum Alleröd-Interstadial bereits zur Bildung von Sandparabraunerden (Bänderflugsande), während im Vergleich dazu auf den jüngsten Lößdecken stellenweise schwach ausgeprägte Parabraunerden entstanden. Durch die Einlagerung einer im Mittel-Alleröd (Laacher-See-Ausbruch) gebildeten Bims-Tuffschicht im Hangenden der Bänderflugsande ist eine absolute Zeitmarke gegeben. Die Verwitterung der mit Flugsanden vermischten Bims-Tuffe zu einem braunerdeartigen Boden begann vermutlich noch während des Alleröd-Interstadials. Aus den während des Kälterückschlages in der Jüngeren Tundrenzeit gebildeten Flugsanden entstanden unter dem Einfluß des postglazialen Klimaoptimums tiefgründige Braunerden, stratigraphisch vergleichbar den Steppenböden aus Löß im benachbarten Rheinhessen sowie den Lockerbraunerden der hessischen Mittelgebirge. Diese Bodenentwicklung wurde, wie durch paläolithische Funde und die C14-Bestimmung an Holzkohlen aus einer Brandschicht nachgewiesen werden konnte, im 6.—7. Jahrh. n. Chr. durch eine letztmalige stärkere Flugsandaufwehung beendet. Die jüngsten Flugsande sind auf den Dünen meist nur schwach verwittert. In einem besonderen Abschnitt wurden Fragen der Entstehung der für Sande charakteristischen Bänderung (Sandparabraunerde) erörtert. Bei diesen Bändern handelt es sich, wie aus den Befunden eingehender Untersuchungen hervorging, um meist dünne Ton-Eisenanreicherungshorizonte; das eingeschlämmte Material entstammt wahrscheinlich im wesentlichen nicht überlagernden Bv-Horizonten, sondern dem Sediment selbst. Die Verlagerung und Anreicherung der mobilisierbaren Substanzen dürfte sowohl mechanisch als auch durch die Einwirkung chemischer Prozesse erfolgt sein. Wie aus den stratigraphischen Untersuchungen hervorging, lag die Hauptbänderbildung bereits vor dem Alleröd-Interstadial; unter gegebenen Bedingungen kann es jedoch auch heute noch zur Bänderbildung kommen.researc
Folga orçamentária sob a percepção dos acadêmicos de ciências contábeis da Universidade Federal de Santa Catarina
TCC (Graduação) - Universidade Federal de Santa Catarina. Centro Socioeconômico. Curso de Ciências ContábeisEste estudo teve como objetivo avaliar a percepção dos alunos formandos de Ciências Contábeis em relação à criação de folga orçamentária nas empresas. A pesquisa caracteriza-se como descritiva. A pesquisa pode ser descrita como tipo survey. O instrumento de pesquisa utilizado foi a aplicação de questionário aos alunos das fases finais do curso de Ciências Contábeis da Universidade Federal de Santa Catarina, e a amostra obtida foi de 154 respondentes. Para análise dos resultados foi aplicada a técnica do ranking médio e analisadas as frequências. Os resultados mostram que embora os respondentes entendam que o orçamento é de grande importância para a gestão da organização, os mesmos possuem baixo contato com a ferramenta. Foi reconhecida a criação de folga orçamentária pelos respondentes.The objective of this study was to evaluate students' perceptions of accounting sciences in relation to the creation of budget slack in companies. The research is characterized as descriptive. The study can be described as survey type. The research instrument used was the application of a questionnaire to the students of the final stages of the Accounting Sciences course of the Federal University of Santa Catarina, and the sample obtained was of 154 respondents. For the analysis of the results the average ranking technique was applied and the frequencies were analyzed. The results show that although the respondents understand that the budget is of great importance for the management of the organization, they have low contact with the tool. The creation of budgetary gap was recognized by the respondents. Keywords: Business Budget; Budgetary Slack; Perception
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Seasonal variability of atmospheric tides in the mesosphere and lower thermosphere: Meteor radar data and simulations
Thermal tides play an important role in the global atmospheric dynamics and provide a key mechanism for the forcing of thermosphere–ionosphere dynamics from below. A method for extracting tidal contributions, based on the adaptive filtering, is applied to analyse multi-year observations of mesospheric winds from ground-based meteor radars located in northern Germany and Norway. The observed seasonal variability of tides is compared to simulations with the Kühlungsborn Mechanistic Circulation Model (KMCM). It is demonstrated that the model provides reasonable representation of the tidal amplitudes, though substantial differences from observations are also noticed. The limitations of applying a conventionally coarse-resolution model in combination with parametrisation of gravity waves are discussed. The work is aimed towards the development of an ionospheric model driven by the dynamics of the KMCM
The Role of Sphingolipids and Ceramide in Pulmonary Inflammation in Cystic Fibrosis
Sphingolipids and in particular ceramide have been shown to be critically involved in the response to many receptor-mediated, but also receptor-independent, mainly stress stimuli. Recent studies demonstrate that ceramide plays an important role in the pathogenesis of cystic fibrosis, a hereditary metabolic disorder caused by mutations of the Cystic Fibrosis Transmembrane Conductance Regulator. Patients with cystic fibrosis suffer from chronic pulmonary inflammation and microbial lung infections, in particular with Pseudomonas aeruginosa. Chronic pulmonary inflammation in these patients seems to be the initial pathophysiological event. Inflammation may finally result in the high infection susceptibility of these patients, fibrosis and loss of lung function. Recent studies demonstrated that ceramide accumulates in lungs of cystic fibrosis mice and causes age-dependent pulmonary inflammation as indicated by accumulation of neutrophils and macrophages in the lung and increased pulmonary concentrations of Interleukins 1 and 8, death of bronchial epithelial cells, deposition of DNA in bronchi and high susceptibility to Pseudomonas aeruginosa infections. Genetic or pharmacological inhibition of the acid sphingomyelinase blocks excessive ceramide production in lungs of cystic fibrosis mice and corrects pathological lung findings. First clinical studies confirm that inhibition of the acid sphingomyelinase with small molecules might be a novel strategy to treat patients with cystic fibrosis
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Characteristics of the Quiet-Time Hot Spot GravityWaves Observed by GOCE Over the Southern Andes on 5 July 2010
We analyze quiet-time data from the Gravity Field and Ocean Circulation Explorer satellite as it overpassed the Southern Andes at z≃275 km on 5 July 2010 at 23 UT. We extract the 20 largest traveling atmospheric disturbances from the density perturbations and cross-track winds using Fourier analysis. Using gravity wave (GW) dissipative theory that includes realistic molecular viscosity, we search parameter space to determine which hot spot traveling atmospheric disturbances are GWs. This results in the identification of 17 GWs having horizontal wavelengths λH = 170–1,850 km, intrinsic periods τIr = 11–54 min, intrinsic horizontal phase speeds cIH = 245–630 m/s, and density perturbations (Formula presented.) 0.03–7%. We unambiguously determine the propagation direction for 11 of these GWs and find that most had large meridional components to their propagation directions. Using reverse ray tracing, we find that 10 of these GWs must have been created in the mesosphere or thermosphere. We show that mountain waves (MWs) were observed in the stratosphere earlier that day and that these MWs saturated at z∼ 70–75 km from convective instability. We suggest that these 10 Gravity Field and Ocean Circulation Explorer hot spot GWs are likely tertiary (or higher-order) GWs created from the dissipation of secondary GWs excited by the local body forces created from MW breaking. We suggest that the other GW is likely a secondary or tertiary (or higher-order) GW. This study strongly suggests that the hot spot GWs over the Southern Andes in the quiet-time middle winter thermosphere cannot be successfully modeled by conventional global circulation models where GWs are parameterized and launched in the troposphere or stratosphere. ©2019. The Authors
Computer Aided Diagnosis of Clustered Microcalcifications Using Artificial Neural Nets
Objective: Development of a fully automated computer application for detection and classification of clustered microcalcifications using neural nets. Material and Methods: Mammographic films with clustered microcalcifications of known histology were digitized. All clusters were rated by two radiologists on a 3 point scale: benign, indeterminate and malignant. Automated detected clustered microcalcifications were clustered. Features derived from those clusters were used as input to 2 artificial neural nets: one was trained to identify the indeterminate clusters, whereas the second ANN classified the remaining clusters in benign or malignant ones. Performance evaluation followed the patient-based receiver operator characteristic analysis. Results: For identification of patients with indeterminate clusters a an Az-value of 0.8741 could be achieved. For the remaining patients their clusters could be classified as benign or malignant at an Az-value of 0.8749, a sensitivity of 0.977 and specificity of 0.471. Conclusions: A fully automated computer system for detection and classification of clustered microcalcifications was developed. The system is able to identify patients with indeterminate clusters, where additional investigations are recommended, and produces a reliable estimation of the biologic dignity for the remaining ones
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