158 research outputs found
The Ribosome Cooperates with the Assembly Chaperone pICln to Initiate Formation of snRNPs
No full textSummaryThe formation of macromolecular complexes within the crowded environment of cells often requires aid from assembly chaperones. PRMT5 and SMN complexes mediate this task for the assembly of the common core of pre-mRNA processing small nuclear ribonucleoprotein particles (snRNPs). Core formation is initiated by the PRMT5-complex subunit pICln, which pre-arranges the core proteins into spatial positions occupied in the assembled snRNP. The SMN complex then accepts these pICln-bound proteins and unites them with small nuclear RNA (snRNA). Here, we have analyzed how newly synthesized snRNP proteins are channeled into the assembly pathway to evade mis-assembly. We show that they initially remain bound to the ribosome near the polypeptide exit tunnel and dissociate upon association with pICln. Coincident with its release activity, pICln ensures the formation of cognate heterooligomers and their chaperoned guidance into the assembly pathway. Our study identifies the ribosomal quality control hub as a site where chaperone-mediated assembly of macromolecular complexes can be initiated
Genèse et évolution de l'habitat rural dans le Bas-Chari tchadien
No full textGenesis and Evolution of the Rural Dwelling in Bas-Chari, Chad.
Four main types of villages are to be found among the Choa Arabs of Bas-Chari in Chad. It is suggested in the article that they correspond to four historical stages in the process of transition from nomadism to sedentarity. Thus, the author does not properly go on an assumption, but on a line of research in which historians as well as ethnologists and linguists might be interested. This is proof that the contribution of geographers to a pluridisciplinary investigation may assume many aspects, and be determinant of the general trend of collective work.II y a quatre grands types de villages chez les Arabes Choa du Bas-Chari tchadien. Nous proposons d'y voir l'illustration de quatre phases historiques marquant le passage du nomadisme à la sédentarité. Moins qu'une hypothèse, il s'agit là d'une direction de recherche que pourraient reprendre l'historien, l'ethnologue et le linguiste. C'est aussi la preuve que la contribution du géographe à une investigation pluridisciplinaire peut revêtir de multiples aspects et être déterminante quant à l'orientation générale du travail collectif.Bouquet Christian. Genèse et évolution de l'habitat rural dans le Bas-Chari tchadien. In: Études rurales, n°70, 1978. pp. 51-64
Distinctive Pulmonary Histopathology With Increased IgG4-positive Plasma Cells in Patients With Autoimmune Pancreatitis Report of 6 and 12 Cases With Similar Histopathology
No full textAutoimmune pancreatitis (AP) is one manifestation of a systemic, steroid-responsive disease with elevated serum IgG4 and characteristic histopathology, including increased IgG4-positive (+) plasma cells in the tissue. The histopathology of pulmonary IgG4 disease has not been well established. Six lung biopsies from patients with documented AP were studied, along with 12 additional cases showing similar pulmonary histopathology. For comparison, we examined Erdheim-Chester disease (n = 3), pulmonary Sjogren syndrome (n = 19), inflammatory myofibroblastic tumor (n = 10), various inflammatory and interstitial lung disease (n = 61), and nodal or extranodal Rosai-Dorfman disease (RD) in adults (n = 8). All cases were stained for IgG4 and scored as 1, 2, and 3 as described in AP according to the following criteria: 0, < 5 (per high power field); 1, 5 to 10; 2, 11 to 30; and 3, > 30. Five lung biopsies from AP patients showed IgG4 score of 3, and I had a score of 2. Consistent findings in lung biopsies of AP patients included endothelialitis of pulmonary vessels, active fibrosis, lymphangitic inflammatory infiltrates rich in plasma cells and histiocytes with or Without nodule formation, and fibrinous pleuriti's. Prominent lymphatic dilatation with histiocytes showing emperipolesis of lymphocytes was also seen. All 12 additional cases showing these histologic features also had the IgG4 score of 2 or 3. Among other conditions, an IgG4 score of 2 or 3 was seen in 6 of 8 RD, 4 of 10 inflammatory myofibroblastic tumors, and 8 of 61 inflammatory and interstitial lung disease, but in none of the rest. In conclusion, distinctive pulmonary histopathology was associated with increased IgG4+ cells in both AP patients and those unknown for AP status. The significance of increased IgG4 + cells in high proportion of RD cases merits further study as does overlap of RD and IgG4 disease
From definitional interpreter to symbolic executor
No full textSymbolic execution is a technique for automatic software validation and verification. New symbolic executors regularly appear for both existing and new languages and such symbolic executors are generally manually (re)implemented each time we want to support a new language. We propose to automatically generate symbolic executors from language definitions, and present a technique for mechanically (but as yet, manually) deriving a symbolic executor from a definitional interpreter. The idea is that language designers define their language as a monadic definitional interpreter, where the monad of the interpreter defines the meaning of branch points. Developing a symbolic executor for a language is a matter of changing the monadic interpretation of branch points. In this paper, we illustrate the technique on a language with recursive functions and pattern matching, and use the derived symbolic executor to automatically generate test cases for definitional interpreters implemented in our defined language.Programming Language
Parallel-plate capacitance sensor for nondestructive measurement of moisture content of different types of wheat
No full textA simple, low cost instrument that measures impedance and phase angle was used along with a parallel-plate capacitance system to estimate the moisture content (MC) of six types of wheat. Moisture content of grain is important and is measured at various stages of their processing and storage. A sample of about 150 g of wheat was placed separately between a set of parallel plate electrodes and the impedance and phase angle of the system were measured at frequencies 1 and 5 MHz. A semi-empirical equation was developed using the measured impedance and phase angle values, and the computed capacitance, and the MC values obtained by standard air-oven method. Multi Linear Regression (MLR) method was used for the empirical equation development using statistical software. In the present work, a low-cost impedance analyzer designed and assembled in our laboratory was used to measure the impedance and phase angles. MC values of wheat samples in the moisture range of 9% to 25%, not used in the calibration, were predicted by the equations and compared with their standard air-oven values. For over 97% of the samples tested from the six varieties of wheat, the predicted MC values were within 1% of the air-oven values. This method, being nondestructive and rapid, will have considerable application in the drying and storage processes of wheat and similar field crops
Robust Autopilot Design by Structured H∞ Loop Shaping: An Agile Aerospace Vehicle Application
No full textThis study demonstrates an effective systematic control design procedure by applying H∞ Loop-Shaping with a structured controller on an agile aerospace vehicle with a focus on automation. The gain-scheduled implementation is additionally described and tested with non-linear simulations, including a realistic moving point-hit scenario with guidance. The imposed robustness and performance requirements are met for most linear design points and for the non-linear simulations. The resulting autopilot design procedure is deemed effective in both the design procedure and implementation. It is subject to certain recommendations for improvement and extension.Aerospace Engineerin
Disc Large Homolog 1 Is Critical for Early T Cell Receptor Micro Cluster Formation and Activation in Human T Cells
No full textT cell activation by antigen involves multiple sequential steps, including T cell receptor-microcluster TCR-(MC) formation, immunological synapse formation, and phosphorylation of mediators downstream of the TCR. The adaptor protein, Disc Large Homolog 1 (DLG1), is known to regulate proximal TCR signaling and, in turn, T cell activation, acting as a molecular chaperone that organizes specific kinases downstream of antigen recognition. In this study, we used knockdown and knockout technologies in human primary T cells and a human T cell line to demonstrate the role of DLG1 in proximal T cell signaling. High-end confocal microscopy was used for pictorial representation of T cell micro-clusters and colocalization studies. From all these studies, we could demonstrate that DLG1 functions even earlier than immunological synapse formation, to regulate T cell activation by promoting TCR-MC formation. Moreover, we found that DLG1 can act as a bridge between the TCR-ζ chain and ZAP70 while inhibiting binding of the phosphatase SHP1 to TCR-ζ. Together, these effects drive dysregulation of T cell activation in DLG1-deficient T cells. Overall, the activation and survival status of T cell is a critical determinant of effective vaccine response, and DLG1-mediated T cell signaling events can be a driving factor for improving vaccine-designing strategies
Didi-Huberman and art history's amicable incursions
No full textThis paper takes as its departure point French philosopher and art historian Georges Didi-Huberman’s recent text Aperçues (2018). Clearly forsaking art-historical literary conventions, Aperçues is composed completely of fragments. Dated, but not organised chronologically, Didi-Huberman is drawing on a long literary history of essayistic writing that reaches back to Michel de Montaigne. With this history of experimental forms of writing in mind, this essay will argue that Didi-Huberman’s decision to write in fragmentary form signals a broader shift in art-historical writing: the turn to the ‘I’, or loosely demarcated autobiographical practices. This is not, however, a simplistic or uncomplicated return to the humanist subject. Instead, drawing from Roland Barthes’ 1971 exhumation of the author in Sade, Fourier, Loyola, the author is amicable. To be amicable is to demonstrate goodwill and a sense of intimacy with the reader. It also suggests the traditional neutral and rational subject is bracketed in favor of a friendly conviviality. Examining recent forms of art writing by Michael Ann Holly, T.J. Clark, and Didi-Huberman, this essay discusses the notion of the amical author as a possible trope for experimental art writing practices, where the subject returns, albeit in a fragmented and split condition.Full Tex
Covid-19 and the GDP fall in Germany: a business cycle accounting approach
No full textThe Business Cycle Accounting method by Chari, Kehoe, and Mc Grattan (2007) helps identify theories that have quantitative promise in explaining economic fluctuations. In this work project, it will be applied to Germany to study the impact of the COVID-19 pandemic. The efficiency wedge primarily drove Germany’s recession. The extensive lockdowns that prevented existing production factors such as labor and capital from producing at their full potential can explain the productivity loss. This suggests that the lock downs are well identified as significant drivers of the reduction in economic activity and that their end would predict a sharp recovery in Germany
Détermination calorimétrique du coefficient d'absorption du son dans les composés organiques liquides
No full textL'absorption d'ondes ultrasonores de fréquence 5 Mc/s dans divers composés organiques liquides est étudiée en mesurant le dégagement de chaleur produit à différentes distances de la source par le passage des ondes. On compare les résultats avec ceux obtenus par la méthode de la pression de radiation. La concordance est bonne
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