DHX9-dependent recruitment of BRCA1 to RNA promotes DNA end resection in homologous recombination

Double stranded DNA Breaks (DSB) that occur in highly transcribed regions of the genome are preferentially repaired by homologous recombination repair (HR). However, the mechanisms that link transcription with HR are unknown. Here we identify a critical role for DHX9, a RNA helicase involved in the processing of pre-mRNA during transcription, in the initiation of HR. Cells that are deficient in DHX9 are impaired in the recruitment of RPA and RAD51 to sites of DNA damage and fail to repair DSB by HR. Consequently, these cells are hypersensitive to treatment with agents such as camptothecin and Olaparib that block transcription and generate DSB that specifically require HR for their repair. We show that DHX9 plays a critical role in HR by promoting the recruitment of BRCA1 to RNA as part of the RNA Polymerase II transcription complex, where it facilitates the resection of DSB. Moreover, defects in DHX9 also lead to impaired ATR-mediated damage signalling and an inability to restart DNA replication at camptothecin-induced DSB. Together, our data reveal a previously unknown role for DHX9 in the DNA Damage Response that provides a critical link between RNA, RNA Pol II and the repair of DNA damage by homologous recombination

Design and Development of Different Applications of PATB (Porous Aerostatic Thrust Bearing): A Review

In several applications demanding precise and ultra-precision movements, porous aerostatic thrust bearings had been employed as a crucial precision engineering component and enabling technology. By acting as a lubricant between the moving part and the stationary part in aerostatic bearings, pressurized air almost completely eliminates friction. Since air acts as the lubricant, oil-based lubricants leave no debris behind. The air prolongs the life of the substances by preventing them from slipping and wearing. The aerostatic type uses graphite as a porous film to disrupt the air uniformly over the surface, or a tiny hole is drilled through the centre of the bearing to let the air circulate and produce a thin layer between the components. With an increased reliance on computational and mathematical methodologies for design and bearing performance optimization, this review paper aims to present the state-of-the-art in aerostatic bearings advancement and research. It also conducts a critical analysis of their future research directions and development trends in the next ten years and beyond. Air bearings are utilized in the production of tools like lathes, CMM, and grinders because they are highly precise in their operation and decrease mistakes and production time. Air bearings are available in a variety of forms and sizes. The assessment of future trends and obstacles in aerostatic bearings investigation, as well as their prospective applications in the precision engineering sectors, concludes the study

Notes on the discovery and ecology of the invasive armoured catfish Pterygoplichthys disjunctivus (Weber, 1991) and the exotic cichlid Amphilophus trimaculatus (Gunther, 1867) from Southern West Bengal, India

This paper documents the first occurrence of the exotic, highly invasive, South American armoured sucker mouth catfish Pterygoplichthys disjunctivus (Weber, 1991) from the brackish waters of the Sundarban Tiger Reserve, West Bengal, India and the Central American cichlid Amphilophus trimaculatus (Gunther, 1867) from Southern Bengal, India. Notes on the possible threats due to invasion, sources of introduction, extent of spread and management of these and other invasive species are discussed in the paper

Prevalence Of Work-Related Musculoskeletal Disorders Among Construction Workers

Construction workers frequently have work-related musculoskeletal disorders (WRMSDs) with significant adverse health and financial effects. The aim of this study is to look at the reasons, effects, and prevention measures for WRMSDs among construction workers.Methods: In the study, one hundred thirty-six male construction workers between the ages of 30 and 56 participated. The postural stress experienced by the construction workers was assessed using a modified Nordic musculoskeletal questionnaire. The Body Part Discomfort (BPD) scale was used to assess the severity of the discomfort/pain in various body areas.Results: Discomfort or pain in neck portion was found to be maximum percentage of workers. BPD scaling revealed that neck, lower back and shoulder are among three most susceptible body parts in relation to pain sensation.Conclusion: Manual construction workers in the construction industry are particularly vulnerable to developing work-related musculoskeletal disorders (WRMSDs), working hours and MSD symptoms, particularly in the lower limb, are significantly correlated

Work-Related Musculoskeletal Disorder an Increasing Concern in Garment Industry

  Background:  Musculoskeletal Disorders (MSDs)-related occupational health concerns are becoming a growing problem for the clothing industry, which is influenced by the repetitive tasks, prolonged static postures and poor ergonomic conditions that characterise the nature of work in this industry. This study aims to provide a thorough assessment of the numerous musculoskeletal problems that are prevalent in the garment industry and to recommend useful intervention strategies to mitigate their consequences. Methods:  One hundred thirty textile workers aged between 25 to 45 years were taken randomly from five different textile manufacturing sites of Baranagar, West Bengal. A modified Nordic musculoskeletal questionnaire was applied to evaluate the postural stress of the garment’s workers. The discomfort/pain intensity in different body parts were evaluated by Body Part Discomfort (BPD) scale . Appropriate statistical tests were applied. Results: Discomfort or pain in hip and lower back were found to be maximum among workers. Conclusion: Pain, discomfort and postural stress among various body parts like upper back, lower back and hip are verry much common for the workers. Despite efforts to deal with these problems, more thorough research and efficient intervention strategies are required to reduce musculoskeletal ailments in the garment industry.

BRCA1 is required for maintenance of phospho-Chk1 and G₂/M arrest during DNA cross-link repair in DT40 cells

The Fanconi anemia DNA repair pathway is pivotal for the efficient repair of DNA interstrand cross-links. Here, we show that FA-defective (Fancc(-)) DT40 cells arrest in G(2) phase following cross-link damage and trigger apoptosis. Strikingly, cell death was reduced in Fancc(-) cells by additional deletion of the BRCA1 tumor suppressor, resulting in elevated clonogenic survival. Increased resistance to cross-link damage was not due to loss of toxic BRCA1-mediated homologous recombination but rather through the loss of a G(2) checkpoint. This proapoptotic role also required the BRCA1-A complex member ABRAXAS (FAM175A). Finally, we show that BRCA1 promotes G(2) arrest and cell death by prolonging phosphorylation of Chk1 on serine 345 after DNA damage to sustain arrest. Our data imply that DNA-induced cross-link death in cells defective in the FA pathway is dependent on the ability of BRCA1 to prolong cell cycle arrest in G(2) phase

Detailed study of the ELAIS N1 field with the uGMRT - I. Characterizing the 325 MHz foreground for redshifted 21 cm observations

In this first paper of the series, we present initial results of newly upgraded Giant Meterwave Radio Telescope (uGMRT) observation of European Large-Area ISO Survey-North 1 (ELAIS-N1) at 325 MHz with 32 MHz bandwidth. Precise measurement of fluctuations in Galactic and extragalactic foreground emission as a function of frequency as well as angular scale is necessary for detecting redshifted 21-cm signal of neutral hydrogen from Cosmic Dawn, Epoch of Reionization (EoR) and post-reionization epoch. Here, for the first time we have statistically quantified the Galactic and extragalactic foreground sources in the ELAIS-N1 field in the form of angular power spectrum using the newly developed Tapered Gridded Estimator (TGE). We have calibrated the data with and without direction-dependent calibration techniques. We have demonstrated the effectiveness of TGE against the direction dependent effects by using higher tapering of field of view (FoV). We have found that diffuse Galactic synchrotron emission (DGSE) dominates the sky, after point source subtraction, across the angular multipole range $1115 \leqslant \mathcal{\ell} \leqslant 5083$ and $1565 \leqslant \mathcal{\ell} \leqslant 4754$ for direction-dependent and -independent calibrated visibilities respectively. The statistical fluctuations in DGSE has been quantified as a power law of the form $\mathcal{C}_{\mathcal{\ell}}= A \mathcal{\ell}^{-\beta}$. The best fitted values of (A, $\beta$) are ($62 \pm 6$ $mK^{2}$, $2.55 \pm 0.3$) and ($48 \pm 4$ $mK^{2}$, $2.28 \pm 0.4$ ) for the two different calibration approaches. For both the cases, the power law index is consistent with the previous measurements of DGSE in other parts of sky.Comment: 13 pages, 5figures, 4 tables; accepted for publication in MNRA