Phosphorylation of eIF4GII and 4E-BP1 in response to nocodazole treatment: a reappraisal of translation initiation during mitosis

Translation mechanisms at different stages of the cell cycle have been studied for many years, resulting in the dogma that translation rates are slowed during mitosis, with cap-independent translation mechanisms favored to give expression of key regulatory proteins. However, such cell culture studies involve synchronization using harsh methods, which may in themselves stress cells and affect protein synthesis rates. One such commonly used chemical is the microtubule de-polymerization agent, nocodazole, which arrests cells in mitosis and has been used to demonstrate that translation rates are strongly reduced (down to 30% of that of asynchronous cells). Using synchronized HeLa cells released from a double thymidine block (G 1/S boundary) or the Cdk1 inhibitor, RO3306 (G 2/M boundary), we have systematically re-addressed this dogma. Using FACS analysis and pulse labeling of proteins with labeled methionine, we now show that translation rates do not slow as cells enter mitosis. This study is complemented by studies employing confocal microscopy, which show enrichment of translation initiation factors at the microtubule organizing centers, mitotic spindle, and midbody structure during the final steps of cytokinesis, suggesting that translation is maintained during mitosis. Furthermore, we show that inhibition of translation in response to extended times of exposure to nocodazole reflects increased eIF2α phosphorylation, disaggregation of polysomes, and hyperphosphorylation of selected initiation factors, including novel Cdk1-dependent N-terminal phosphorylation of eIF4GII. Our work suggests that effects on translation in nocodazole-arrested cells might be related to those of the treatment used to synchronize cells rather than cell cycle status

Happy Rag / music by R. G. Gradi; words by R. G. Gradi

Cover: caricature of an African American male playing a five-string banjo; Publisher: Ajax Music Co. (Chicago)https://egrove.olemiss.edu/sharris_c/1052/thumbnail.jp

Noise Attenuation of a Duct-resonator System Using Coupled Helmholtz Resonator - Thin Flexible Structures

Several studies have been devoted to increasing the attenuation performance of the Helmholtz resonator (HR). One way is by periodic coupling of HRs in a ducting system. In this study, we propose a different approach, where a membrane (or a thin flexible structure in general) is added to the air cavity of a periodic HR array in order to further enhance the attenuation by utilizing the resonance effect of the membrane. It is expected that three attenuation mechanisms will exist in the system that can enhance the overall attenuation, i.e. the resonance mechanism of the HR, the Bragg reflection of the periodic system, and the resonance mechanism of the membrane or thin flexible structure. This study found that the proposed system yields two adjacent attenuation peaks, related to the HR and the membrane respectively. Moreover, extension of the attenuation bandwidth was also observed as a result of the periodic arrangement of HRs. With the same HR parameters, the peak attenuation by the membrane is tunable by changing its material properties. However, such a system does not always produce a wider attenuation bandwidth; the resonance bandwidths of both mechanisms must overlap

Noise Attenuation of a Duct-resonator System Using Coupled Helmholtz Resonator - Thin Flexible Structures

Several studies have been devoted to increasing the attenuation performance of the Helmholtz resonator (HR). One way is by periodic coupling of HRs in a ducting system. In this study, we propose a different approach, where a membrane (or a thin flexible structure in general) is added to the air cavity of a periodic HR array in order to further enhance the attenuation by utilizing the resonance effect of the membrane. It is expected that three attenuation mechanisms will exist in the system that can enhance the overall attenuation, i.e. the resonance mechanism of the HR, the Bragg reflection of the periodic system, and the resonance mechanism of the membrane or thin flexible structure. This study found that the proposed system yields two adjacent attenuation peaks, related to the HR and the membrane respectively. Moreover, extension of the attenuation bandwidth was also observed as a result of the periodic arrangement of HRs. With the same HR parameters, the peak attenuation by the membrane is tunable by changing its material properties. However, such a system does not always produce a wider attenuation bandwidth; the resonance bandwidths of both mechanisms must overlap

Christmas Chimes

Illustration of bell swinging/ringinghttps://scholarsjunction.msstate.edu/cht-sheet-music/6262/thumbnail.jp

Relações de gênero nas famílias agricultoras associadas a mini-usinas de leite no Estado de Santa Catarina

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências HumanasA divisão sexual do trabalho nas unidades de pequena produção agropecuárias é influenciada pelo sexo, idade e tamanho da família, uma vez que a mão-de-obra utilizada nas mesmas é preponderantemente familiar. Apesar de trabalhar cerca de 10/16 horas semanais a mais do que o homem, o trabalho da mulher é considerado atividade não econômica, não produtiva, além de ser não remunerado. Esta situação de desconsideração pelo trabalho feminino é verificado na família produtora, nos órgãos institucionais, e em algumas ONGs, muitas delas responsáveis por programas de desenvolvimento junto a essas famílias agricultoras, que não levam em consideração a participação real das mulheres nos mesmos. Na análise de duas agroindústrias de pequeno porte, duas mini-usinas de leite, verificamos que as mulheres participaram no processo de gestação e implementação das mini-usinas mas o mesmo não ocorria atualmente. Uma reestruturação dos projetos voltados para a agricultura familiar, no sentido de incentivar e valorizar uma maior participação das mulheres e jovens em todas as etapas do processo, se faz necessária para que haja um nível de aceitação maior por parte de toda a família

Analisis Kinerja Kuantifikasi Mikroplastik dari Total Suspended Particulate dengan Metode Berbasis Peralatan Laboratorium Dasar

Penelitian ini bertujuan untuk identifikasi dan kuantifikasi mikroplastik di udara kawasan Kampus ITB menggunakan metode dengan peralatan sederhana. Hasil ini kemudian dibandingkan dengan studi serupa di lokasi yang sama. Sampel partikel dari Total Suspended Particulate (TSP) dikumpulkan selama tujuh hari menggunakan High Volume Sampler (HVS), kemudian dilakukan ekstraksi dengan air ultrapure, dekomposisi organik menggunakan H?O?, dan pemisahan densitas dengan larutan NaI. Identifikasi visual dilakukan untuk mengetahui jumlah partikel, bentuk, dan warna. Hasil identifikasi menunjukkan dominasi fragmen (404,90 partikel/filter) dan fiber (137,99 partikel/filter), dengan konsentrasi 1,3–7,3 partikel/m³. Hasil menunjukkan estimasi jumlah partikel yang sebanding dengan kuantifikasi sampel yang menggunakan µFTIR dan metoda ekstraksi yang serupa. Pendekatan ini terbukti efektif untuk kuantifikasi mikroplastik dalam TSP dengan peralatan sederhana. Penelitian ini memberikan fondasi penting bagi pengembangan riset mikroplastik di Indonesia, khususnya di laboratorium dengan keterbatasan fasilitas analitik mutakhir

Modelling Sound Absorption Of Tunable Double Layer Woven Fabrics

The woven fabric is known to have micro structures inherently so that it can be employed as sound absorber with the same absorption mechanism as the micro-perforated panel (MPP) when it is backed up by an air cavity. In the context of multi-layer system, having high flow resistance at all layers do not guarantee high sound absorption coefficients are achieved apart from narrow absorption bandwidth issue in the MPP. These have been extensively discussed in fibrous porous materials, but it is lacking for the woven fabrics, particularly on the analysis of the relationship of flow resistance for each layer to the sound absorption bandwidth. In this paper, a double-layer system of woven fabric is considered. Two cases are studied: a system with identical flow resistance and one with non-identical flow resistance. The Johnson-Champoux-Allard (JCA) formulation and the transfer matrix method are used to develop the prediction model. It is revealed that for a system with identical flow resistances, high flow resistance produces low amplitude of absorption coefficient, but with relatively wide frequency bandwidth. Lower flow resistance can improve the absorption amplitude, but with a dip in between two absorption peaks which degrades the half absorption bandwidth. This can be solved by having the combination of non-identical resistance between the layers. The selection of flow resistances together with the ratio of the air cavity depths can be used in tuning the performance of the double-layer woven fabric absorber. The experimental data show good agreement with the predictions

Microstructural and microhardness variations of laser powder bed fusion (L-PBF) additively manufactured Inconel 718 due to machine variability and wall thickness for aerospace applications

This paper reports on a study investigating the microstructure and microhardness of thin walls fabricated by Laser Powder Bed Fusion (L-PBF) from sixteen geometric feature build plates. The study evaluated any variance in those properties with the variation in thickness by characterizing the XY and YZ planes of seven thin walls of different thicknesses and the base parts. Electron Backscatter Diffraction (EBSD) analysis with inverse pole figure (IPF) mapping was done for four samples from four different machine manufacturers. From the EBSD grain boundary map, the microstructure is composed of equiaxed grains with a lower threshold angle with smaller grains in the border area. Compositional analysis for both the powders and the resulting fully heat-treated LPBF manufactured material was analyzed for alloy element stability and contaminants using 10 mg samples. The paper concludes by showing the relationship between composition and microstructural properties.Mechanical Engineerin

Gemin5 proteolysis reveals a novel motif to identify L protease targets

Translation of picornavirus RNA is governed by the internal ribosome entry site (IRES) element, directing the synthesis of a single polyprotein. Processing of the polyprotein is performed by viral proteases that also recognize as substrates host factors. Among these substrates are translation initiation factors and RNA-binding proteins whose cleavage is responsible for inactivation of cellular gene expression. Foot-and-mouth disease virus (FMDV) encodes two proteases, Lpro and 3Cpro. Widespread definition of Lpro targets suffers from the lack of a sufficient number of characterized substrates. Here, we report the proteolysis of the IRES-binding protein Gemin5 in FMDV-infected cells, but not in cells infected by other picornaviruses. Proteolysis was specifically associated with expression of Lpro, yielding two stable products, p85 and p57. In silico search of putative L targets within Gemin5 identified two sequences whose potential recognition was in agreement with proteolysis products observed in infected cells. Mutational analysis revealed a novel Lpro target sequence that included the RKAR motif. Confirming this result, the Fas-ligand Daxx, was proteolysed in FMDV-infected and Lpro-expressing cells. This protein carries a RRLR motif whose substitution to EELR abrogated Lpro recognition. Thus, the sequence (R)(R/K)(L/A)(R) defines a novel motif to identify putative targets of Lpro in host factors