Possible Ribose Synthesis in Carbonaceous Planetesimals.

The origin of life might be sparked by the polymerization of the first RNA molecules in Darwinian ponds during wet-dry cycles. The key life-building block ribose was found in carbonaceous chondrites. Its exogenous delivery onto the Hadean Earth could be a crucial step toward the emergence of the RNA world. Here, we investigate the formation of ribose through a simplified version of the formose reaction inside carbonaceous chondrite parent bodies. Following up on our previous studies regarding nucleobases with the same coupled physico-chemical model, we calculate the abundance of ribose within planetesimals of different sizes and heating histories. We perform laboratory experiments using catalysts present in carbonaceous chondrites to infer the yield of ribose among all pentoses (5Cs) forming during the formose reaction. These laboratory yields are used to tune our theoretical model that can only predict the total abundance of 5Cs. We found that the calculated abundances of ribose were similar to the ones measured in carbonaceous chondrites. We discuss the possibilities of chemical decomposition and preservation of ribose and derived constraints on time and location in planetesimals. In conclusion, the aqueous formose reaction might produce most of the ribose in carbonaceous chondrites. Together with our previous studies on nucleobases, we found that life-building blocks of the RNA world could be synthesized inside parent bodies and later delivered onto the early Earth.

Noise at sea: Characterization of extended shift noise exposures among U.S. Navy aircraft carrier support personnel.

The purpose of this investigation was to characterize 12-hr on-duty, 12-hr off-duty, and 24-hr noise exposures among U.S. Navy aircraft carrier support personnel. Noise dosimetry samples were collected for 47 aircraft carrier support personnel while at sea during airwing carrier qualifications. Leq measurements during 12-hr on-duty, 12-hr off-duty, and over 24-hr periods were compared to Threshold Limit Values. Four similar exposure groups (SEGs) were created based upon departmental assignment and similarity of work tasks: (1) Administration/Religious Ministries/Legal/Training, (2) Combat Systems/Operations, (3) Medical/Dental, and (4) Supply. Equivalent sound level (Leq) measurements in decibels "A" weighted (dBA) were compared to determine significant differences between each group according to 12-hr on-duty, 12-hr off-duty, and 24-hr periods. Mean 24-hr noise levels ranged from 69-88 dBA with 22% exceeding the 80 dBA Threshold Limit Value. Twelve-hr on-duty noise levels ranged from 71-90 dBA with 17% exceeding the 83 dBA 12-hr on-duty Threshold Limit Value. Twelve-hr off-duty noise exposure ranged from 68-84 dBA with 95% exceeding the 70 dBA American Conference of Governmental Industrial Hygienists threshold classified as effective quiet to allow for temporary threshold shift recovery. Welch Analysis of Variance and Dunnett T3 post hoc tests revealed SEG 2 had significantly higher 24-hr noise exposures than SEG 3 (p = 0.019) and SEG 4 (p = 0.045). SEG 2 had significantly higher 12-hr on-duty noise exposure than SEG 3 (p = 0.030). One Way Analysis of Variance revealed no significant differences between 12-hr off-duty noise exposures according to SEG (p = .096). Some aircraft carrier support personnel had 12-hr on-duty and 24-hr noise exposures exceeding Threshold Limit Values with a large proportion exceeding the 70 dBA effective quiet limit during 12-hr off-duty periods. Results suggest personnel that are typically considered low risk for hazardous noise exposure (<85 dBA) during 8-hr shifts may have a greater risk of noise exposure when considering full 12-hr and 24-hr shifts when working and living in close proximity.

Return-to-play after concussion: state of knowledge, frequency of use and application barriers of guidelines among decision-makers in rugby.

Validated strategies and guidelines for a safe and individualized diagnosis and return-to-play (RTP) after concussion in rugby are needed. Little is known about the state of knowledge, frequency of use and application barriers of state-of-the-art guidelines among decision-makers in professional or semi-professional rugby teams. Participants (n = 195) from the coaching team (head coach, assistance coach, athletic coach), the medical team (physiotherapist, physician, rehabilitation therapist, neuropsychologist), or from the officials of a professional or semi-professional rugby team (top three major leagues in Germany), filled in a questionnaire on their knowledge, frequency of use and application barriers of evidence-based guidelines (Graduated RTP protocol and The 5R). Depending on their function in the team and on the league of play, the state of knowledge and application of the diagnostic tools and the RTP guidelines differ. A considerable number are aware of one or both guidelines, but do not apply these guidelines (up to 27% of respondants). The main reasons for the non-usage were not my decision (59%), use of concurrent guidelines (54%), each player must decide by his own (36%), never experienced a concussion in my players (30%), other (19%), the guideline is useless (18%) and a player may play despite a concussion (14%). Raising awareness of the state-of-the-art guidelines is important to educate further the coaching, medical and official team members in identifying symptoms and executing the RTP-process in accordance with evidence-based strategies.

Protein arginine methylation of non-histone proteins and its role in diseases.

Protein arginine methyltransferases (PRMTs) are a family of enzymes that can methylate arginine residues on histones and other proteins. PRMTs play a crucial role in influencing various cellular functions, including cellular development and tumorigenesis. Arginine methylation by PRMTs is found on both nuclear and cytoplasmic proteins. Recently, there is increasing evidence regarding post-translational modifications of non-histone proteins by PRMTs, illustrating the previously unknown importance of PRMTs in the regulation of various cellular functions by post-translational modifications. In this review, we present the recent developments in the regulation of non-histone proteins by PRMTs.