Programmed –1 frameshifting by kinetic partitioning during impeded translocation.

Programmed –1 ribosomal frameshifting (−1PRF) is an mRNA recoding event utilized by cells to enhance the information content of the genome and to regulate gene expression. The mechanism of –1PRF and its timing during translation elongation are unclear. Here, we identified the steps that govern –1PRF by following the stepwise movement of the ribosome through the frameshifting site of a model mRNA derived from the IBV 1a/1b gene in a reconstituted in vitro translation system from Escherichia coli. Frameshifting occurs at a late stage of translocation when the two tRNAs are bound to adjacent slippery sequence codons of the mRNA. The downstream pseudoknot in the mRNA impairs the closing movement of the 30S subunit head, the dissociation of EF-G, and the release of tRNA from the ribosome. The slippage of the ribosome into the –1 frame accelerates the completion of translocation, thereby further favoring translation in the new reading frame

Mitigating Gender Bias in Machine Learning Data Sets

Artificial Intelligence has the capacity to amplify and perpetuate societal biases and presents profound ethical implications for society. Gender bias has been identified in the context of employment advertising and recruitment tools, due to their reliance on underlying language processing and recommendation algorithms. Attempts to address such issues have involved testing learned associations, integrating concepts of fairness to machine learning and performing more rigorous analysis of training data. Mitigating bias when algorithms are trained on textual data is particularly challenging given the complex way gender ideology is embedded in language. This paper proposes a framework for the identification of gender bias in training data for machine learning.The work draws upon gender theory and sociolinguistics to systematically indicate levels of bias in textual training data and associated neural word embedding models, thus highlighting pathways for both removing bias from training data and critically assessing its impact.Comment: 10 pages, 5 figures, 5 Tables, Presented as Bias2020 workshop (as part of the ECIR Conference) - http://bias.disim.univaq.i

Coeliac trunk and common hepatic artery variations in children: an analysis with computed tomography angiography

Background: Understanding the coeliac trunk (CeT) and hepatic artery anatomy is important not only in preventing iatrogenic injuries but also in planning surgical procedures in children. Therefore, the aim of this study is to analyse the prevalence of CeT and common hepatic artery (CHA) variations in the paediatric population.   Materials and methods: One hundred and seventy-four children who underwent abdominal multidetector computed tomography (MDCT) angiography, either because of trauma or liver transplantation, were analysed retrospectively. The patterns of CeT, CHA and their variant branches were revealed and compared with previous studies involving adults.   Results: A total of 157 (90.2%) of the 174 patients had normal CeT anatomy, whereas 17 (9.8%) had variations. Five types of CeT variations were identified according to Song’s classification in which ‘hepatosplenic trunk + left gastric artery + superior mesenteric artery’ was the most prevalent. One hundred-twelve (64.4%) of the 174 patients had normal CHA anatomy; however, 62 (35.6%) had variations. Six types of CHA variations were identified according to Michel’s and Hiatt’s classification. The most common was ‘replaced left hepatic artery originating from left gastric artery’.   Conclusions: The prevalences of CeT and hepatic artery variations are high in children, as they are in older patients. Awareness of these variations is important in terms of avoiding iatrogenic injury and in promoting surgical procedure planning for liver transplantation or abdominal tumour surgery

Diabetic Foot Due to Anaphylactic Shock: A Case Report

Introduction: Diabetic foot is a clinical disorder, which is commonly seen in patients with diabetes mellitus. It is also the major cause of below knee amputation in the world. There are many underlying causes such as neuropathic, ischemic, and infectious causes for diabetic foot. Local or systemic complications may develop after snake bite. Case Presentation: We reported a very rare case, involving a 78-year-old male admitted to the Emergency Department, who developed anaphylactic shock and diabetic foot after the snake bite. Conclusions: Reviewing the literature, this is the second reported case of snake bite associated with diabetic foot

Physiological, Biochemical, and Transcriptional Responses to Single and Combined Abiotic Stress in Stress-Tolerant and Stress-Sensitive Potato Genotypes

Potato production is often constrained by abiotic stresses such as drought and high temperatures which are often present in combination. In the present work, we aimed to identify key mechanisms and processes underlying single and combined abiotic stress tolerance by comparative analysis of tolerant and susceptible cultivars. Physiological data indicated that the cultivars Desiree and Unica were stress tolerant while Agria and Russett Burbank were stress susceptible. Abiotic stress caused a greater reduction of photosynthetic carbon assimilation in the susceptible cultivars which was associated with a lower leaf transpiration rate. Oxidative stress, as estimated by the accumulation of malondialdehyde was not induced by stress treatments in any of the genotypes with the exception of drought stress in Russett Burbank. Stress treatment resulted in increases in ascorbate peroxidase activity in all cultivars except Agria which increased catalase activity in response to stress. Transcript profiling highlighted a decrease in the abundance of transcripts encoding proteins associated with PSII light harvesting complex in stress tolerant cultivars. Furthermore, stress tolerant cultivars accumulated fewer transcripts encoding a type-1 metacaspase implicated in programmed cell death. Stress tolerant cultivars exhibited stronger expression of genes associated with plant growth and development, hormone metabolism and primary and secondary metabolism than stress susceptible cultivars. Metabolite profiling revealed accumulation of proline in all genotypes following drought stress that was partially suppressed in combined heat and drought. On the contrary, the sugar alcohols inositol and mannitol were strongly accumulated under heat and combined heat and drought stress while galactinol was most strongly accumulated under drought. Combined heat and drought also resulted in the accumulation of Valine, isoleucine, and lysine in all genotypes. These data indicate that single and multiple abiotic stress tolerance in potato is associated with a maintenance of CO2 assimilation and protection of PSII by a reduction of light harvesting capacity. The data further suggests that stress tolerant cultivars suppress cell death and maintain growth and development via fine tuning of hormone signaling, and primary and secondary metabolism. This study highlights potential targets for the development of stress tolerant potato cultivars

Dynamical transition, hydrophobic interface, and the temperature dependence of electrostatic fluctuations in proteins

Molecular dynamics simulations have revealed a dramatic increase, with increasing temperature, of the amplitude of electrostatic fluctuations caused by water at the active site of metalloprotein plastocyanin. The increased breadth of electrostatic fluctuations, expressed in terms of the reorganization energy of changing the redox state of the protein, is related to the formation of the hydrophobic protein/water interface allowing large-amplitude collective fluctuations of the water density in the protein's first solvation shell. On the top of the monotonic increase of the reorganization energy with increasing temperature, we have observed a spike at 220 K also accompanied by a significant slowing of the exponential collective Stokes shift dynamics. In contrast to the local density fluctuations of the hydration-shell waters, these spikes might be related to the global property of the water solvent crossing the Widom line.Comment: 9 pages, 8 figure