Dear Editor,N6-methyladenosine (m6A) has been demonstrated to play important roles in various biological processes including nuclear RNA export, mRNA splicing, miRNA processing, mRNA degradation and translation -domain containing proteins are members of the conserved maa 230−383) forms liquid droplets , which are sensitive to 1,6-hexanediol  . Other members of this family, YTHDF1 and YTHDF3, also contain glutamine (Q) rich domain , and also have phase separation ability . As YTHDF2 glutamine compositional bias is conserved among vertebrates, to determine whether glutamine richness within the LC domain is important for LLPS of YTHDF2, we changed all glutamine to alanine in YTHDF2aa 230−383 , and the mutated protein essentially failed to form as many and large LLPS under the same assay condition . Similarly, another phase separation protein MED1 contains conserved serine (S) rich region, and this serine bias is necessary for MED1 phase separation , which includes both the LC and the YTH domains . Importantly, however, under the same assay condition, RNA oligos containing one m6A modification induced liquid like droplet formation . In addition, we found this phase separation enhancement appears to be dependent on the number of m6A in the RNA. As shown in Fig. 6A sites in the RNA oligos . These results are consistent with the recent reports that RNA oligos containing multiple m6A methylation sites robustly induce droplet formation by YTHDF2  ) in mouse ES cells. While wildtype YTHDF2 formed droplets in cell, YTH mutated YTHDF2 did not . We detected no YTHDF2 droplets in these cells Supplementary material 2 (MP4 3014 kb)Supplementary material 3 (DOCX 47 kb)Supplementary material 4 (PPTX 2065 kb)Below is the link to the electronic supplementary material.


Corynebacterium species poses a challenge due to the low genetic variation within the genus.Pulmonary infections caused by non-diphtheriae corynebacteria are increasing. However, rapid identification of ssrA was performed to simultaneously identify C. striatum, C. propinquum and C. simulans. To further evaluate this assay’s performance, 88 clinical sputum samples were tested by HRM and the detection results were compared with those of the traditional culture method and multiple cross-displacement amplification (MCDA) assay.Three reference strains and 99 clinical isolates were used in this study. A qPCR followed by high-resolution melting (HRM) targeting Corynebacterium species was 100 fg. Compared with the culture method, HRM detected 22 additional positive specimens, representing a 23.9% relative increase in detection rate. The HRM assay had 98.4%  sensitivity and 100%  specificity. Additionally, 95.5% concordance between HRM and MCDA  was noted.The melting curve produced by a pair of universal primers generated species-specific HRM curve profiles and could distinguish the three target species from other related bacteria. The limit of detection of HRM assay for DNA from the three purified C. striatum, C. propinquum, and C. simulans, with the potential to contribute to early diagnosis, epidemiological surveillance, and rapid response to outbreak.The HRM assay was a simple, rapid, sensitive, and specific diagnostic tool for detecting The online version contains supplementary material available at 10.1186/s12879-020-05633-z. Corynebacterium is composed of aerobic, non–spore-forming, pleomorphic, Gram-positive bacilli with worldwide distribution. The most well-established and well-described pathogen in this genus, C. diphtheria, is the main causative agent of diphtheria, the incidence of which has dropped due to effective vaccination programs [Corynebacterium species, which have been linked to multiple hospital outbreaks and nosocomial infections [C. striatum are emerging rapidly [Corynebacterium species are essential to intervention and infection treatment efforts.The genus programs . Howeverfections –4. Althofections . Of note rapidly –10. EarlC. simulans, due to its similarities with C. striatum [rpoB gene sequencing produces more reliable results, but is slow and cost prohibitive in developing countries [Corynebacterium spp. clinical isolates, but this technology is not yet fully accessible to clinical microbiology laboratories in resource-limited settings [Corynebacterium species.Traditionally, these microorganisms have been routinely identified by biochemical tests using the API Coryne system  or the RapID CB PLUS system  in clinical microbiology laboratories , 12. Howstriatum , 14. Ideountries , 16. Matsettings . Also, MThe high-resolution melting (HRM) assay, a recently developed technique based on quantitative real-time polymerase chain reaction (qPCR) that detects genetic variation in deoxyribonucleic acid (DNA) sequences, provides a good alternative for molecular diagnosis . Before C. striatum, C. propinquum, and C. simulans, as well as distinguishing between them in pure cultures and clinical specimens with increased specificity and sensitivity.In this study, we report the development of a qPCR–based HRM assay capable of detecting C. striatum ATCC 6940, C. propinquum DSM 44285, and C. simulans DSM 44415) and 99 clinical isolates were used in this study  in accordance with the manufacturer’s instructions. DNA concentration and purity were measured using a spectrophotometer  at A260/280. Purified DNA were kept at − 20 °C for subsequent experiments.ssrA gene, which encodes a transfer-messenger RNA (tmRNA), is highly conserved and phylogenetically informative [ssrA loci for three reference strains were obtained from published genomes in GenBank  and aligned using SeqMan software . C. striatum, C. propinquum, and C. simulans were tested by PCR using 20 primer sets. The primers ssrA-Fwd (5′-TCAGCGTGACTACGCCCTC-3′) and ssrA-Rev (5′-RCYTCGCCAGGGCTTCTC-3′) displayed positive amplification and were selected for qPCR and HRM assays (data not shown).As the ormative , it was A qPCR assay was set up containing the following components per reaction:15 μl 2× Taqman PCR Master Mix (Thermo Fisher); 0.9 μl Primer F (10 μΜ); 0.9 μl Primer R (10 μΜ); 0.3 μl Rox Reference Dye II (100×); 1.5 μl EvaGreen, 20× in water ; 1 ng DNA sample; and nuclease-free water to a total reaction volume of 30 μl. The qPCR assay was performed and validated using the ABI QuantStudio 6 Flex system  with the following run conditions: 1 cycle of 95 °C for 10 min, followed by 35 cycles of 95 °C for 15 s and 63 °C for 45 s. Next, HRM analysis was initiated by raising the temperature to 95 °C for 15 s and decreasing it to 60 °C for 1 min. Then, the melting curves were generated by increasing the temperature from 60 °C to 95 °C in increments of 0.025 °C/s. All of the amplicons were tested in triplicate to detect technical errors. The HRM data were analyzed using QuantStudio™ Real-Time PCR Software version 1.3. All of the experiments were performed in triplicate.Corynebacterium species, the genomic DNA templates of three reference strains were serially diluted with distilled water  to define the limit of detection. DNA templates of Nocardia farcinica were used as the negative control, and distilled water was the blank control. Each DNA concentration was assayed in duplicate by HRM.To assess the sensitivity of the HRM assay for identification of C. striatum, 3 C. propinquum, 6 C. simulans, and 30 non-target clinical samples  from 60 In total, 88 human sputum samples were recovered from hospitalized patients with pulmonary infections. These samples were previously identified using the culture method and stored at − 70 °C until use in the HRM assay. To evaluate the practical application of the novel HRM method, we employed this assay in routine detection for 88 clinical sputum samples, and compared the results with those of the traditional culture method and the multiple cross displacement amplification (MCDA) assay developed in a previous study . The DNAssrA were purified with a QIAquick PCR purification kit  and subjected to sequencing using the primers ssrA-Fwd and ssrA-Rev on the ABI PRISM 7500 Sequence Detection System . The sequencing results were analyzed using SeqMan software, and were further compared with the reference samples using the Basic Local Alignment Search Tool .To further confirm the reliability of the HRM assay, all of the HRM-positive/culture-negative amplicons from qPCR-HRM were sent to Sangon Biotech  to undergo direct sequencing in both strands. In brief, the PCR amplicons produced from To analyze assay sensitivity and specificity, we used the conventional culture method as the gold standard for the culture-positive specimens, while using consensus results from both the HRM and MCDA assays as a reference standard for the remaining specimens. The sensitivities of the HRM and MCDA assays were determined by the following equation:Specificity was determined by the following equation :\documeP < 0.05 was considered to indicate statistical significance. The agreement levels between HRM and MCDA results were measured using Cohen’s kappa test, which was calculated as described previously [Additionally, 95% confidence intervals (CIs) were calculated for sensitivity and specificity using the Wilson score method. We used McNemar’s chi-square test to assess whether the performances of these tests were different. A eviously .C. striatum, C. propinquum, and C. simulans in HRM analysis, amplified fragments of 233, 240, and 233 bp, respectively, for these species. In the HRM analysis, C. striatum and C. propinquum each had a single peak, while C. simulans produced two melting peaks , designed to detect C. striatum, C. propinquum, and C. simulans.To assess the sensitivity of the HRM assay, serial dilutions (10 ng–10 fg) of total genomic DNA extracted from the three reference strains were subjected to a HRM assay. The decreasing concentrations of genomic DNA are presented from left to right in Fig. C. striatum, 3 C. propinquum, 6 C. simulans, and 30 non-target strains were tested using the HRM assay under the standard conditions described above. As expected, all 69 cultured samples belonging to C. striatum, C. propinquum, and C. simulans were amplified and formed unique and reproducible melting curves  both MCDA and HRM results were positive for a culture-negative specimen [Specimens were defined as true positives if: (i) specimen –30. AmonP > 0.5). However, the HRM assay was more sensitive than the culture method (P < 0.001), and 95.5% concordance between the MCDA assay and our HRM assay  was noted.Ultimately, 22 culture-negative specimens were found to be positive by the MCDA and HRM assays, results that were further confirmed by nucleic acid sequencing. These 22 specimens were considered true positives. Sensitivity was calculated to be 65.6%  for the culture method, 92.2%  for the MCDA assay, and 98.4%  for the HRM assay; specificities were 100%  for all three assays Table . No signCorynebacterium species are usually thought of as colonizers or contaminants [C. striatum are resistant to multiple antimicrobials.Due to being common components of the skin microbiota, non-diphtheriae aminants , 32. Becaminants . In receaminants , 34, 35.C. striatum, C. propinquum, and C. simulans have similar colony morphologies and cultural characteristics. C. simulans and C. striatum share high genetic homology, and their biochemical reactions are very similar [C. simulans or C. propinquum as C. striatum by VITEK MS MALDI-TOF MS was observed in our investigation (data not shown), and this has also been reported previously [However, differentiation between these species remains difficult due to the low genetic variation between them.  similar . Misideneviously . CurrentC. striatum, C. propinquum, and C. simulans in cultured samples and clinical specimens within approximately 2 h after DNA extraction. Analysis of the normalized melt curve produced with the universal primers generated species-specific HRM curve profiles. The three species were clearly differentiated by the melting temperature of the dissociation curves, with melting peaks at 88.91 °C for C. striatum, 88.44 °C for C. propinquum, and 87.86 °C for C. simulans. Furthermore, these three strains were successfully identified based on their different plots, which were mutually distinct.In this study, we developed a HRM assay that could differentiate between C. striatum, C. propinquum, and C. simulans also gave it the ability to specifically distinguish these three species from other related bacteria.We also evaluated the limit of detection of the newly established HRM assay. This assay could detect quantities as low as 100 fg using DNA from pure cultures as templates. Assay specificity was further evaluated by testing the genomic DNA of 69 corynebacteria clinical isolates and 30 non-target strains. Results showed that the high discriminatory power of the HRM assay developed for Furthermore, we showed that HRM could be applied to direct tests of clinical sputum samples. Among the 42 culture-positive samples, all were identified by HRM, while one false negative result occurred. This one sample was also found to be negative by the MCDA assay. This result suggested that DNA might have been lost or degraded during the preparation, processing, and storage of the sputum samples.Corynebacterium spp.-positive samples. Putative sensitivity increased from 65.6% using the culture method to 98.4% using the HRM assay. Compared with the culture method, the use of the HRM assay to detect the three Corynebacterium spp. could potentially improve overall sensitivity and reduce turnaround times.Furthermore, 22 samples were identified as negative by the culture method, but identified as positive by HRM and MCDA assays. In our study, the culture method was likely to miss one quarter (22/88) of Corynebacterium species, C. striatum. In addition, this method requires the use of five pairs of primers, which can generate a complex mixture of various DNA products, and it can be difficult to distinguish between specific and non-specific products [Corynebacterium spp. in only one test.Our HRM assay was also comparable to the MCDA method, showing a high concordance rate (95.5%) . MCDA teproducts . CompareC. striatum, 3.1% by C. propinquum, and 1.6% by C. simulans, as identified by HRM. Among members of Corynebacterium spp., C. striatum and C. propinquum have been recognized as pathogens of the respiratory tract, and have been found in cases of pneumonia and chronic obstructive pulmonary disease (COPD) in hospital settings [C. striatum was the most prevalent non-diphtheriae Corynebacterium found in sputum specimens, and found that it caused a large proportion of respiratory infections [C. striatum highlights the importance of routine species-level identification to avoid further spread and outbreaks [In the present study, 95.3% of pulmonary infections were caused by settings , 38–40. utbreaks .C. striatum and C. propinquum, C. simulans has not been described as a cause of respiratory infection. Only a few well-documented infections have been reported, including one case of acute pyogenic spondylitis, one prosthetic joint infection, and one case of endocarditis [C. simulans from a respiratory specimen here appears to be novel and has clinical relevance, emphasizing its potential role as a causative pathogen of respiratory tract infections.Unlike carditis –44. The C. propinquum and C. simulans clinical isolates were small. This was because, despite our efforts, we could not find additional isolates. ii) C. pseudodiphtheriticum and C. amycolatum, which other reports have shown to be common non-diphtheriae corynebacteria [There were several limitations in our study. i) Sample sizes of bacteria , were noC. striatum, C. propinquum, and C. simulans directly from clinical sputum samples without isolating and culturing the pathogens. This meets the need for rapid diagnosis and, more importantly, yields high diagnostic accuracy in culture-negative samples. Second, this assay could potentially be applied to recognize novel or unusual Corynebacterium spp. in clinical specimens by targeting single loci, with no need to design new assays; this is supported by previous research [Despite these limitations, our study has some strengths. First, the HRM method can identify and differentiate between research . Third, C. striatum, C. propinquum, and C. simulans from pure cultures and clinical specimens. It outperformed the culture method, proving to be capable of detecting many samples the culture method missed. The present study demonstrated this HRM assay to be a simple, rapid, accurate, sensitive, specific, and cost-effective diagnostic approach. The HRM assay is a promising alternative for identifying Corynebacterium spp., effectively complementing current methods used in clinical microbiology laboratories, and has the potential to contribute to early diagnosis and epidemiological surveillance.In conclusion, the HRM assay described in this study is the first developed for the detection and identification of Additional file 1. Bacterial strains used in this study.Additional file 2. Representative results of clinical isolates tested by high-resolution melting graphs


This study presents preliminary results from a sewage-based surveillance to monitor the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the municipality of Niterói, State of Rio de Janeiro, Brazil. By using ultracentrifugation method associated to quantitative reverse transcription polymerase chain reaction (RT-qPCR) we detected SARS-CoV-2 in 41.6% (5/12) of raw sewage samples obtained from sewage treatment plants and sewers network in the city. This pioneer study carried out in Brazil aims to subsidise information for health surveillance concerning the viral circulation in different areas of the city and, revealed the insertion and importance of environmental virology in health public policies. Niterói notified the first Coronavirus Disease 2019 (COVID-19) case on 12th March 2020, and by now (April 24), seventeen fatal cases associated with COVID-19 were reported.® Viral RNA Mini kit  and a QIAcube® automated system (QIAGEN) and coronavirus RNA was detected by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Primers and probe previously published by the Centres for Disease Control and Prevention (CDC) 2020On April 15th, raw sewage samples were obtained at 12 different sampling points in the city of Niteroi, including sewage treatment plants (STPs), hospital wastewater and sewers network . Ten-hour composite sewage samples were collected in sterile polypropylene bottles and pasteurised at 60ºC for 90 min to inactivate the virus.We detected SARS-CoV-2 RNA in five of 12 (41.6%) samples that presented mean Ct values ranging from 36.3 to 39.8 . All posTo the best of our knowledge, there is no direct evidence to prove that the SARS-CoV-2 detected in the sewage system is infectious and contagious. Therefore, it is early to state that wastewater could be considered an important route of transmission. However, with the increase circulation of the virus in the population, the concentration of coronavirus particles in sewage waters could reach significant levels. Thus, it is important to monitor the occurrence and dissemination of SARS-CoV-2 in the sewerage system, identifying COVID-19 hotspots areas, as well as those areas with underreported cases in the health system. Through assessment of viral load and its distribution in sewers network in different areas of the city, the monitoring of the coronavirus circulation during the epidemic will subsidize information for health surveillance, allowing optimising the use of available resources and strengthening measures for prophylaxis in the area. This study confirms wastewater-based surveillance as a promising approach to understand the prevalence of the virus in a given community and the insertion of environmental virology in health public policies.


Nuclear bodies are membraneless, phase-separated compartments that concentrate specific proteins and RNAs in the nucleus. They are believed to serve as sites for the modification, sequestration, and storage of specific factors, and to act as organizational hubs of chromatin structure to control gene expression and cellular function. Architectural (arc) RNA, a class of long noncoding RNA (lncRNA), plays essential roles in the formation of nuclear bodies. Herein, we focus on specific arcRNAs containing short tandem repeat-enriched sequences and introduce their biological functions and recently elucidated underlying molecular mechanism. In various neurodegenerative diseases, abnormal nuclear and cytoplasmic bodies are built on disease-causing RNAs or toxic RNAs with aberrantly expanded short tandem repeat-enriched sequences. We discuss the possible analogous functions of natural arcRNAs and toxic RNAs with short tandem repeat-enriched sequences. Finally, we describe the technical utility of short tandem repeat-enriched arcRNAs as a model for exploring the structures and functions of nuclear bodies, as well as the pathogenic mechanisms of neurodegenerative diseases. Nuclear bodies are membraneless compartments in the nucleus, ~0.2 to 3 μm in diameter, which usually exhibit phase-separated features and liquid-like properties. In mammalian cells, there is a wide variety of nuclear bodies, including the nucleolus, Cajal bodies, histone locus bodies (HLBs), nuclear speckles, nuclear stress bodies (nSBs), paraspeckles, the perinucleolar compartment (PNC), polycomb bodies, and promyelocytic leukemia bodies. Nuclear bodies are defined by enrichment of specific marker proteins and RNA molecules, and some are conditionally formed upon experiencing certain stresses ,2,3,4. AADARB2 and IL8 is downregulated [The biological roles of nuclear bodies remain poorly understood, but it has been proposed to be classified them into three functional categories ,17. Firsegulated . Thirdlyegulated . Thus, Segulated ,23, raisTo implement these functions, especially the reaction crucible and molecular sponge functions, a subset of arcRNAs possess repeat sequences to accumulate multiple copies of specific proteins and/or RNAs. For example, the cytoplasmic noncoding RNA activated by DNA damage (NORAD) lncRNA sequestrates PUMILIO via at least 17 binding sites with an eight nucleotide (nt) unit (UGUAUAUA) to repress its function, which is essential for maintenance of genomic stability and mitochondrial function ,25,26. XSince most canonical RNA-binding domains of RBPs recognize five to six nt motifs for specific binding ,33, arcRHSATIII is an additional example of a short tandem repeat-enriched arcRNA that forms nuclear stress bodies (nSBs), consisting mainly of highly-repetitive (GGAAU)n sequences . The priAmong nSB-localized SRSFs and SR-related proteins, SRSF1 and SRSF9 are particularly highly enriched in nSBs, and share the common GGARG binding motif (R is A or G) , which iHSATIII arcRNAs also serve as a scaffold for a minor subclass of nSBs (named nSB-M) including HNRNPM, which is distinct from the major population of HSATIII-dependent bodies characterized by SAFB enrichment (named nSB-S) . This suSpinocerebellar ataxia type 31 (SCA31) is a neurological disease caused by insertion of a 2.5 to 3.8 kb repeat that includes the long TGGAA stretch present in a common intronic region of BEAN1 (brain expressed associated with NEDD4-1) and thymidine kinase 2 (TK2) genes ,40,45. BIn addition to SCA31 RNA described above, recent studies have demonstrated that several kinds of short-tandem repeat-enriched arcRNAs are also synthesized from specific gene loci containing pathogenic expansion of three to six nt repeats, which are believed to cause various neurological and neuromuscular disorders such as myotonic dystrophy 1 and 2, fragile X tremor ataxia syndrome (FXTAS), SCA8, SCA10, and SCA36 ,47,48. HFunctional analysis of short tandem repeat-enriched arcRNAs has provided important insight into the structures and functions of membraneless nuclear bodies formed on specific arcRNAs. Additionally, this class of arcRNAs can serve as models for structural and functional analysis of arcRNAs that are difficult to investigate directly due to technical reasons. Firstly, short tandem repeat-enriched arcRNAs are highly specific for particular nuclear bodies, hence they are the most reliable markers of nuclear bodies, whereas most associated proteins are typically located in the nucleoplasm outside nuclear bodies. In most cases, these arcRNAs are efficiently knocked down by nucleofection of a single antisense oligonucleotide (ASO) that hybridizes with multiple sites of the tandem repeat stretch, which enables the specific disruption of nuclear bodies and the ability to investigate their functions. Hybridization-based techniques for RNP precipitation, such as ChIRP, capture hybridization analysis of RNA targets (CHART), and RNA antisense purification (RAP) , have beTherefore, this approach is applicable for unveiling the structures and functions of novel arcRNA-dependent cellular bodies and disease-related RNA foci. Currently, small compounds that specifically bind to disease-related repeat RNAs have been explored as candidate therapeutic drugs ,53,54. F


We hypothesize prebiotic evolution of self-replicating macro-molecules  favoured the constituent nucleotides and biophysical properties observed in the RNA and DNA of modern organisms. Assumed initial conditions are a shallow tide pool, containing a racemic mix of diverse nucleotide monomers , subject to day/night thermal fluctuations . Self-replication, like Polymerase Chain Reactions, followed as higher daytime thermal energy “melted” inter-strand hydrogen bonds causing strand separation while solar UV radiation increased prebiotic nucleobase formation . Lower night energies allowed free monomers to form hydrogen bonds with their template counterparts leading to daughter strand synthesis .Evolutionary selection favoured increasing strand length to maximize auto-catalytic function in RNA and polymer stability in double stranded DNA . However, synthesis of the full daughter strand before daytime temperatures produced strand separation, longer polymer length required increased speed of self-replication. Computer simulations demonstrate optimal polynucleotide autocatalytic speed is achieved when the constituent nucleotides possess a left-right asymmetry that decreases the hydrogen bond kinetic barrier for the free nucleotide attachment to the template on one side and increases bond barrier on the other side preventing it from releasing prior to covalent bond formation. This phenomenon is similar to asymmetric kinetics observed during polymerization of the front and the back ends of linear cytoskeletal proteins such as actin and microtubules . Since rotation of the nucleotide would disrupt the asymmetry, the optimal nucleotides must form two or more hydrogen bonds with their counterpart on the template strand. All nucleotides in modern RNA and DNA have these predicted properties. Our models demonstrate these constraints on the properties of constituent monomers result in biophysical properties found in modern DNA and RNA including strand directionality, anti-parallel strand orientation, homochirality, quadruplet alphabet, and complementary base pairing. Furthermore, competition between RNA and DNA auto-replicators for 3 nucleotides in common permit states coexistence and possible cooperative interactions that could be incorporated into nascent living systems.Our findings demonstrate the molecular properties of DNA/RNA could have emerged from Darwinian competition among macromolecular replicators that selected nucleotide monomers that maximized the speed of autocatalysis. Living systems, uniquely in nature, acquire, store and use information to maintain a highly ordered state while remaining far from thermal equilibrium. The molecular carriers of heritable information, RNA in virtually all living systems consist of the same four nucleotides. The properties of DNA are similarly universal among cells. Thymine substitutes for uracil and deoxyribose for ribose in going from RNA to DNA . MultiplIf the constituent nucleotides of living systems do, in fact, represent one of many possible combinations, the universal properties of RNA and later DNA may simply represent the heritage (i.e. “frozen in time” ) of the will result from would permit prebiotic Darwinian dynamics among self-replicating polynucleotides. Central to our hypothesis is simply the day/nigh cycle which causes an external, diurnal energy fluctuations sufficient [We assume that early earth had widespread biophysical characteristics that fficient , 22 to pfficient  and hydrfficient , we favofficient  which wofficient .Schrödinger first noted self–replicating polymers capable of information storage , requiriand monomer retention. However, monomer acquisition is favoured by lowering the hydrogen bond kinetic barrier, which maximizes the probability that a monomer in solution will attach to the template. However, monomer retention is favoured by increasing the kinetic barrier which decreases the probability of monomer separation from the template strand. This is similar to the dynamical models of cytoskeletal filament polymerization [The technical details of our computer simulations have been published . The evorization –30, althAs Anderson observed , 32, a pIf the ribozyme properties of RNA evolution preceded the development of full living systems, we anticipate the “fittest” and most abundant extant RNA species would likely have been integrated into primordial life forms. This is supported by the following observations:The most obvious prediction of our hypothesis is that all nucleotides in modern RNA should show right-left directional asymmetry. It lowers the free nucleotide binding energy on one side and increases it on the other. Note that rotation of a nucleotide along its strand would reverse this effect and prevent the sequential addition of nucleotides on the growing strand. To prevent this rotational disruption, nucleotides must bind with their counterpart on the template strand with two or more hydrogen bonds Fig. . In factAs shown in Fig. As noted above, self-replicating polynucleotides in a constrained environment such as a tide pool would have competed for monomers. In addition, cycling temperatures which promoted the sequence of strand separation and replication also imposed selection for replicative speed and accuracy. That is, complete autocatalysis required the new strand to fully replicate each nucleotide on the template prior to the onset of warmer daytime temperatures, which would produce strand separation. Furthermore, erroneous integration of a nucleotide without asymmetric properties would reduce the replicative speed of the daughter strand reducing the probability it will subsequently replicate removing it from the lineage. Note, however, there is no restriction on mixing nucleotides that possess the necessary asymmetric effects during replication. In total, these dynamics produce both environmental selection forces, a mechanism of inheritance that is imperfect thus introducing heritable variation into the replicating population.In the Darwinian competition among autocatalytic replicators, mathematical models find that directional strand replication will be faster than will any other method of replication. For example, while simultaneous binding of nucleotides to all sites on the empty strand would intuitively seem to allow faster strand synthesis, the dwell time of each nucleotide on the template would be too low to allow covalent bonds to form consistently.Curiously, double-stranded RNA today only exists in the form of viruses indicating it can store information in a manner that we propose for the first replicators. The absence of double stranded RNA in prokaryotic and eukaryotic life probably reflects subsequent evolutionary optimization in which DNA evolved to provide a more biochemically stable molecule for storing information while RNA became specialized to translate this information into specific sequences of amino acids in a polypeptide. As described below, the proposed evolutionary dynamics would include competition between autocatalytic RNA and DNA for 3 of the 5 nucleotides. This would allow scenarios of stable co-existence so that both “species” of polynucleotides would have been available to be incorporated in early living systems.A simple prediction of the proposed right-left asymmetric influence on adjacent monomer bond energy is corresponding asymmetry in bond breaking. Experimental observations –37 demonAs strand length increases, the time for unidirectional replication will similarly increase thus imposing additional selection pressures. We propose, as with prior adaptive strategies, autocatalytic nucleotides “solved” the trade-off of polymer length and replication time through symmetry breaking. As shown in Fig. The unzipping of strands of a duplex heteropolymer will be faster if strands are populated predominantly by one type of nucleotide as shown in Fig. Here we speculate that the primary selection force is thermal energy needed for melting of the double strand in a changing environment. The regular diurnal cycles importantly allowed a predictable temporal variation in temperatures that likely represented an initial information source for the replicators. However, while the frequency of the cycle remained relatively constant, the amplitude would change frequently due to weather conditions and seasonal effects. It seems reasonable to expect changes in the minimum and maximum temperatures during cycles would alter the separation and replication kinetics of DNA and RNA.sequence of monomers such as 3-dimensional folding to perform enzymatic function in response to environmental changes.In considering the possible benefit of polymers formed of different nucleotides, it is notable that the energy needed to separate Adenine and Uracil (and later Thymine) with two hydrogen bonds is less than that for Cytosine and Guanine with 3 hydrogen bonds. This leads to the hypothesis that mixtures of these two types of nucleotides permitted heritable phenotypic plasticity that allowed the polynucleotides to undergo autocatalysis despite seasonal and regional variations in day and night temperatures. Furthermore, these variations allow replicators with a quadruplet alphabet to adapt to depth-dependent variations in temperature fluctuations in pools of water and perhaps variations in pH and concentrations of ions and minerals within the tidal pools. Note that this primitive information storage could lead to other phenotypic properties of single strands determined by the While this hypothesis is speculative, it does make experimentally testable predictions about the evolutionary roles of multiple nucleotides in self-replicators.Homochirality is one of the most intriguing properties of RNA/DNA molecules. We propose  chiralitThe proposed evolutionary dynamics allows formation of both DNA and RNA replicators. As noted above, each “species” will have different biophysical properties. Nevertheless, they will need to compete for 3 of the 5 constituent nucleotides while being subjected to identical environmental conditions and selection forces. We note that, under some scenarios, these pre-biotic evolutionary dynamics would permit equilibrium states in which both species co-existed. Furthermore, under some conditions of changing environmental conditions, they may have co-evolved mutually beneficial interactions that promoted cooperative dynamics that optimized survival for both species. These could have served as the precursors for the information dynamics of DNA and RNA in fully living systems. We anticipate this will be a subject of future investigations.There is extensive interest in the dynamics that led to the development of living systems on earth. There is a general consensus that RNA provided heritable information for early living systems . Here weHere we begin by assuming that prebiotic chemistry produced mixtures of monomers leading to random polymerization. However, only 5 are present in modern organisms. Here we propose that UCGA and later TCGA were integrated by legacy into early living systems due to prebiotic evolutionary dynamics among self-replicating polymers that initially formed stochastically. Thus, many of the properties of RNA/DNA are not novel adaptations meant to optimally serve cell-based life, but rather properties that served as adaptations for the first replicators. Those with these properties outcompeted all others and became the de facto ancestors of us. Subsequent living systems had to use and build upon the properties of DNA and RNA made available to them by prebiotic evolution.We propose a plausible spatially constrained environment such as a tide pool that is subject to cyclical fluctuations in thermal energy due to the day/night temperature variations. Similar to Polymerase Chain Reactions, this allows strand separation in warm temperatures and replication in cooler conditions. In these conditions, self-replicators will compete for nucleotides. They would be simultaneously subjected to selection for longer strand length and shorter replication time. We propose, as with any physical system subject to opposing forces, this selects for symmetry breaking. Specifically, it selects for monomers that asymmetrically alter the hydrogen bond kinetic barrier for adjacent nucleotide bonding with their partner on the template strand – properties found in all 5 nucleotides in modern living systems. Interestingly, the substitution of uracil in RNA for thymidine in DNA suggests that they were subject to slightly different selection forces – possibly because flexibility for autocatalysis was a critical selection factor for RNA while polymer stability was more critical for DNA , 41. TheWe demonstrate, similar to prior studies , that thprior to the presence of fully living systems.We conclude that the properties found in the DNA and RNA of all living organisms are not the result of chance inclusion in the Last Universal Common Ancestor. Rather, the specific nucleotides and replicative dynamics of the DNA/RNA available to early cells arose through Darwinian competition of polynucleotide self-replicators in environmental conditions likely present in the primordial earth. Thus, the DNA and RNA in modern living systems via evolutionary dynamics that occurred Examine evolution of self-replicating DNA and RNA molecules under conditions likely present in primordial earth.Our proposed evolutionary dynamics occur in tide pools, likely common in primordial earth. Tide pools provide weakly dispersive, spatially constrained liquid environment containing multiple monomer species generated by prebiotic chemistry , 42–44. We then subject the pool to regular, diurnal cycles near the melting temperatures of polynucleotides. The average Archean ocean temperature is estimated to be 26-35 °C but may have reached 70 °C in some locations , 45 and Within these conditions, the diurnal thermal cycle applied regular and predictable perturbations to the environment. The critical role of cyclical thermodynamic fluctuations  in developing information and converting energy to order (decreased entropy) has been widely recognized .We hypothesize higher daytime temperatures, similar to Polymerase Chain Reactions (PCR), provided sufficient thermal energy to melt hydrogen bonds causing the separation of polymer strands. Simultaneously, daytime UV-irradiation from sunlight could promote nucleobase formation . As therEvolution by natural selection requires heritable phenotypic variation and environmental constraints that limit proliferation such that the replicative success of an organism is governed by its properties and those of competing organisms. We propose these conditions are met as self-replicating RNA or its ancestral macromolecules, within the physical constraint of a tide pool, compete for available monomers. In addition, we note the diurnal cycle also imposes constraints on replicative speed. That is, successful completion of each daughter strand synthesis must occur prior to onset of daytime temperatures and strand separation. Thus, these prebiotic evolutionary dynamics would impose selection for fidelity and speed of replication, efficiency of substrate utilization, and stability (persistence) under local environmental conditions.Finally, fluctuating water levels in tidal pools permitted influx of new monomers and efflux of replicators. This latter resulted in dispersal of replicators so that successful variants could colonize new pools that lack self-replicating species or were populated by replicators with inferior properties. This weak coupling of subpopulations could accelerate and promote natural selection similar to Wright’s shifting balance theory .The mathematical models and details of computer simulations are discussed in detail in references . All cod


Situation selection is an emotion regulation strategy consisting in choosing a future emotional situation. Past research showed that Situation selection triggers a decrease in negative experience, exocrine reactions and respiratory activity, while maintaining stable positive experience. In this study, we wanted to replicate these observations and test emotional responses that follow an Illusory choice, i.e., when the chosen situation is not available and replaced by another. Sixty-eight participants watched emotional pictures, either in a condition in which the images were imposed, or in a condition in which they could perform a choice. In these latter trials, participants saw either the chosen option (Situation selection) or the non-selected option (Illusory choice). Continuous recordings of experience and physiological arousal showed that, unlike Situation selection, Illusory choice decreased positive experience but not negative experience. Strikingly, however, we showed that having the choice decreased skin conductance and respiratory arousal, regardless of whether the choice was respected or not. These results have important implications regarding emotion regulation through Situation selection, since having the choice about the upcoming emotional situation, no matter if we really end up in this situation, gives a sense of control that may be sufficient to alleviate physiological responses to stressors. Situation selection. Situation selection “involves taking actions that make it more (or less) likely that we will end up in a situation we expect will give rise to desirable (or undesirable) emotions.” , which in turn generates changes in three major emotional response systems: experience, expressivity, and physiological arousal . Results of these studies suggest that Reappraisal is more adaptive than Suppression  when a stimulation is chosen and then presented, and (b) when the same stimulation is presented without any prior choice procedure , we may end up not receiving what we choose. We call this Illusory choice. Concepts related to Illusory choice have already been used in the field of economics in relation to decision making and, closer to psychology, while testing sustained attention or motivational processes. For example, it has been shown that choosing a task increases the effort an individual is willing to invest , but in which the choice is ultimately not respected. In such cases, does choice retain its regulatory effect? Or, on the other hand, does non-respected choice provoke counteracting effects and reinforce the negative emotions into play? To test this question, we used a within-subject design and induced emotions by presenting emotional pictures, as already used in numerous studies . There are two possible outcomes: (1) the impact of the Illusory choice condition on emotional responses remains similar to that of the Situation selection condition. In this case, we could assume that choice alone is already regulatory, regardless of the situation it leads to; or (2) the two conditions give different outcomes, for example by inducing increased arousal for people who did not obtain what they asked for. This would mean that proposing Situation selection as a way to regulate emotions would have a beneficial effect only if we are able to offer the chosen option. Given the positive impact of Illusory choice on cognitive behaviours and beliefs (see previous paragraph), we expect to find the first option, i.e., there should be no significant interaction between choice (given or not) and respect of this choice (respected or not), replicating the previously found effects . Participants pressed a key to choose a picture category and a corresponding picture was almost immediately presented. In addition to the Situation selection condition, we implemented an Illusory choice condition, in which a choice was given, but the picture that was not chosen was subsequently presented. These two Choice conditions were contrasted to a condition in which participants were not given the opportunity to choose (Imposed condition).In the present study, we used a similar within-subject paradigm as in Thuillard and Dan-Glauser . SituatiChoice conditions (either in the Situation selection or in the Illusory choice condition), and once in the Imposed condition. To assess the respective impact of Situation selection and of Illusory choice, the recorded trials in each of these two categories were compared to a matching set of trials recorded under the Imposed condition, as illustrated in Fig. Situation selection, trials recorded under the Situation selection condition  were compared to trials with the same stimuli  recorded under the Imposed condition  were compared to trials with the same stimuli recorded under the Imposed condition , and sport  pictures. Since examples of the latter content type are rare in the GAPED, we added nine pictures of sport pictures from the International Affective Picture System  throughout the picture presentation. The slider was unipolar with negative reports on the left side and positive reports on the right side. Output voltage (0–9 V) was extracted and converted into a negative and a positive scale (see the Data Extraction section for further details).Corrugator Supercilii . Electrodes were standard 4 mm Ag–AgCl sensors. Three EMG sites were recorded. Because of its reliable link with negative expressivity, left Cacioppo . Skin waElectrocardiography (ECG): Three standard disposable pre-gelled Ag/AgCl electrodes were used for ECG recordings. One was placed approximately 5 cm below the lower rib on the left side of the abdomen. A second electrode was placed just below the right clavicle, along the mid-clavicular line. A third electrode, which functioned as a ground, was placed at the level of the C7 cervical vertebrae.Electrodermal activity: Skin conductance level was recorded with two pre-gelled disposable Ag/AgCl sensors. They were placed on the thenar and hypothenar eminences of the non-dominant hand palm.Respiration: Thoracic and abdominal respiration recordings were gathered with two respiration belts. The abdominal belt was placed around the waist, whereas the thoracic belt was placed high on the chest.In order to examine different systems involved in autonomic reactivity, we measured cardiovascular, exocrine, and respiratory activities.All parameters were recorded and amplified with MP150 compatible modules from Biopac Systems . All sensors were from the same company. All acquired channels were sampled at 1000 Hz.Participants were tested in two sessions: first a questionnaire session, and then the main testing phase including the emotion regulation task. All participants gave informed consent to participate in the study. The procedure was reviewed and authorized by our regional ethical committee , in accordance with the current national legal requirements (Ordinance on Human Research) and the latest version of the Declaration of Helsinki.Participant section). They also completed other emotion-related questionnaires that served as pilot data for another project (unpublished data). After checking right-handedness and absence of health-related issues, participants were invited to register for the second session.In the first session, participants came into the lab and completed the SF12 and the Edinburgh Handedness Inventory , you will have the opportunity to choose yourself, among two options, what image you wish to see. Using the arrows, select the image topics, then return to the slider and concentrate on your feelings to report them.”. Participants again performed a few training trials. Since some trials were illusory choices, we were concerned that participants may believe that the program was malfunctioning and stop the experiment. To avoid this, we informed the participants that sometimes it was not possible for us to give them their choice.Imposed and six under the Choice conditions. Blocks were presented in a semi-randomized order with no more than two consecutive blocks of the same condition. At first, we had set the same number of trials in the Imposed blocks and Chosen blocks but while testing our experiment we realized that since choosing a picture takes more time than when a picture is imposed, the Chosen blocks were much longer than the Imposed blocks. Since we did not want differences between our conditions to be attributed to fatigue or boredom in longer blocks, we chose to reduce as much as possible the duration differences between block types. To do this, we attributed a different number of trials to different blocks, while maintaining an equal number of picture categories within each block. There were thus 24 trials in the Imposed condition blocks and 16 in the Choice condition blocks. The 24 trials of the Imposed blocks consisted of 12 positive and 12 negative pictures, each with three images of each content category. Choice condition blocks were composed of eight positive and eight negative pictures, each with two images of each content category. Of these 16 trials, six were non-respected choices (Illusory Choice) and ten were respected choices (Situation selection). The last Choice block differed in the number of trials. This was due to the pairing procedure: the program exiting the last Choice condition block once no more option for pairing was available .All pictures were presented in a fully randomized order to control for habituation. All participants saw 10 blocks of pictures, four under the Imposed condition, the choice screen was replaced by the display of the category of picture about to be presented (for 1 s). Only the images of the Imposed condition that were also seen in the Choice condition were retained for analysis in order to have a perfect match of intrinsic emotional and perceptive content in both conditions , the choice screen, a blank screen again 1.5 s), a fixation cross (1.5 s), a blank screen again (0.5 s) and the picture presentation (8 s). In the .5 s, a fAll data were processed with Acknowledge 4.4 . Some channels were bandpass filtered to increase the signal-to-noise ratio . The channels were then manually scanned for movements or electric interferences, which were corrected by signal interpolation. To assess the temporal dynamics of emotional responses, the continuous parameters were segmented into 16 epochs of 0.5 s each. This segmentation was performed after the parameter extraction on the total duration of the recordings, which prevent signal distortion at the epoch boundaries. In addition to the 8 s picture presentation period, a baseline of 3.5 s was calculated for each trial and each parameter, spanning from 3.5 s before the picture presentation to the time of the picture onset. Thus, each trial had a baseline period that was used to normalize the response for some parameters (see below).Ratings were exported to obtain mean values for each epoch. The recorded baseline served as the 0 point to calculate emotion intensity. Any value below the baseline was considered as a negative feeling and any value above as a positive feeling. Values were extracted as percentages, representing how far the slider was pushed between its 0 point (baseline) and its extreme values on either side. The data for each of the valence sides go from 0 = absence of emotional feeling to 100 = extreme emotion intensity.Corrugator site. To parallel this negative expressivity with a single measure of positive expressivity, and given the high correlation found between the Zygomaticus and Orbicularis sites , positive expressivity was measured with an average of the Zygomaticus and Orbicularis signal.The EMG signal was rectified and smoothed (5 Hz) before being averaged for each epoch. Given the high variability in the contraction capacity of each individual, EMG values were expressed as the percentage of contraction with respect to the corresponding trial baseline (voltage recorded for a given time-frame / voltage recorded during baseline * 100) , these parameters were averaged. Similarly, thoracic and abdominal respiratory amplitudes were averaged for analyses. All these response channel data were calculated as the change in activity with respect to each trial baseline.Heart rate was calculated from the ECG channel by transforming the inter-beat interval (duration between successive R waves). The skin conductance level was exported as mean values for each epoch. Respiratory rate and amplitude were calculated for each epoch. Respiratory rate was obtained by converting the duration of the cycle intervals into a number of cycles per minute (c/min). Respiratory amplitude was the difference in volts between the point of maximum inspiration and the point of maximum expiration. Given the high correlations between thoracic and abdominal respiratory rates  and Time (16 epochs). Separate ANOVAs were performed for negative and positive trials for the following two reasons. First, contrasting positive and negative trials was not part of our research question. Second, previous research has shown different emotion  differentially impacted emotion responses, we conducted repeated-measure ANOVAs on each valence and parameter, investigating the effect of Regulation (Imposed vs. Choice conditions), the effect of Choice outcome (Illusory choice or regular Situation selection), and the effect of Time (16 time-frames). We were not interested in the reaction differences between avoided or chosen pictures (main effect of Choice outcome). Indeed, when given a choice, we already know that people tend to avoid negative pictures and choose pictures that are more positive. We did not focus either on Time main effect or on Time × Choice outcome interaction. Four effects were therefore of interest here: Regulation main effect, Time × Regulation interaction, Regulation × Choice outcome interaction (with simple effects focused on the regulation rather than on the choice contrasts), as well as the three-way interaction Regulation × Choice outcome × Time.To investigate how the type of choice  and confidence intervals were reported where appropriate. P-values for interaction effects were all corrected for multiple comparisons with the Holm-Bonferroni criterion. Threshold for significance for all effects was set to 0.05 (two-tailed).Greenhouse–Geisser corrections were applied where the assumption of sphericity was violated, and corrected degrees of freedom were reported in these cases. Effect sizes were reported using partial eta squares  that compared the experience mean to a 0-centered distribution. Both tests yielded significant results, t(63) = 22.43, p < 0.001 for negative and t(63) = 17.06, p < 0.001 for positive, confirming a successful emotional induction in the expected direction.We conducted two F = 21.92, p < 0.001, ηp2 = 0.26, and a Regulation x Time interaction, F = 3.97, p = 0.01, ηp2 = 0.06. When participants chose the image they wanted to see, this image triggered a negative experience (37.29) that was significantly lower than the reaction to the same image viewed without being chosen  = 0.62, p = 0.44. We also found no interaction Regulation x Time, F = 1.47, p = 0.23. For the sake of comparison, we have nevertheless included this measure in Fig. During positive picture viewing, the effect of Regulation was not significant, F1,6 = 0.62, F = 0.49, p = 0.49, nor a significant Regulation × Time interaction, F = 0.59, p = 0.71.The analyses performed on the negative trials did not show a significant effect of Regulation, F = 1.43, p = 0.24, and no significant Regulation x Time interaction, F = 1.2, p = 0.31.The analyses on the positive trials gave similar results, with no main effect of Regulation, F = 1.88, p = 0.18 but the interaction Regulation x Time was significant, F = 4.82, p = 0.001, ηp2 = 0.07  = 5.14, p = 0.027, ηp2 = 0.08, and a Regulation x Time interaction, F = 9.60, p < 0.001, ηp2 = 0.13. When participants chose the image they wanted to see, this image triggered a decrease in heart rate (− 1.29 bpm) that was significantly stronger than that recorded during imposed pictures viewing (− 0.81 bpm)  = 0.04, p = 0.85, but showed a significant Regulation × Time interaction, F = 6.73, p < 0.001, ηp2 = 0.12  = 0.005, p = 0.94, but a significant Regulation × Time interaction, F = 14.84, p < 0.001, ηp2 = 0.23  have been inserted in Fig. F = 0.06, p = 0.80, interaction: F = 1.81, p = 0.15), as well as for positive viewing  = 0.01, p = 0.98, interaction: F = 0.43, p = 0.72).The analyses on the respiratory rate showed no effect of the Regulation condition nor an interaction effect Regulation x Time. This was the case for negative viewing  = 6.38, p = 0.014, ηp2 = 0.09, and a Regulation × Time interaction, F = 5.34, p < 0.001, ηp2 = 0.08. When participants chose the image they wanted to see, this image triggered a slight increase in the respiratory amplitude signal (0.003 mV) that was significantly different from the decrease noted for imposed pictures  = 12.98, p = 0.001, ηp2 = 0.17, and a Regulation × Time interaction, F = 5.46, p = 0.001, ηp2 = 0.08. When participants chose the image they wanted to see, this image triggered virtually no change in the respiratory amplitude signal (− 0.001 mV) and this was significantly different from the decrease seen during imposed pictures viewing  = 18.43, p < 0.001, ηp2 = 0.23. The targeted two-way interactions were both significant  = 18.43, p < 0.001, ηp2 = 0.10, Regulation × Choice outcome: F = 5.19, p = 0.03, ηp2 = 0.08). Finally, the three-way interaction Time × Regulation × Choice outcome was also significant, F = 3.03, p = 0.03, ηp2 = 0.05. Interpreting these results requires focusing on the three-way interaction. In order to address the impact of Illusory choice, the most meaningful way to conduct this analysis is to look for the Time x Regulation interaction at the two different levels of the Choice outcome factor, taking into account the mean square of the residual for the full model. The resulting statistics for these interaction effects were F = 5.24, p = 0.002, ηp2 = 0.07 for the Situation selection condition (respected choice) and F = 11.2, p < 0.001, ηp2 = 0.14 for the Illusory choice condition (non-respected choice). Figure Situation selection versus Illusory choice , the image still triggered a less negative experience but the reduction was only transient, occurring only within the first two seconds of the presentation (from 0.5 s to 2 s after the image onset).For negative picture viewing, we observed a significant main effect of Regulation, F = 14.48, p < 0.001, ηp2 = 0.19, a Time × Regulation interaction, F = 5.55, p = 0.002, ηp2 = 0.08, a Regulation × Choice outcome interaction, F = 9.52, p = 0.003, ηp2 = 0.13, and a three-way interaction Time × Regulation × Choice outcome, F = 3.55, p = 0.017, ηp2 = 0.05. Like for negative pictures, we explored the three-way interaction by examining the Time × Regulation interaction at the two different levels of the Choice outcome factor, with full model residual correction. For Situation selection, the interaction effect was not significant, F = 1.35, p = 0.26. For Illusory choice, the interaction effect was significant, F = 11.53, p < 0.001, ηp2 = 0.16. Figure Situation selection had no impact on the positive experience felt during positive situations  than when the exact same image was seen in the Imposed condition  = 1.03, p = 0.32 (main effect of Regulation), F = 0.28, p = 0.87 (Time × Regulation), F = 0.05, p = 0.83 (Regulation × Choice outcome), and F = 0.67, p = 0.62 (three-way interaction Regulation × Choice outcome × Time); and for positive viewing: F = 1.39, p = 0.24 (main effect of Regulation), F = 0.96, p = 0.43 (Time × Regulation), F = 0.11, p = 0.74 (Regulation × Choice outcome), and F = 0.67, p = 0.61 (three-way interaction Regulation x Choice outcome × Time).Expressivity was not significantly affected by the tested factors. This was the case for negative viewing: F = 4.45, p = 0.04, ηp2 = 0.06, and a significant Time × Regulation interaction, F = 5.86, p < 0.001, ηp2 = 0.09  = 0.27, p = 0.60 and F = 1.47, p = 0.22, respectively.For negative trials, analyses showed a significant main effect of Regulation, F = 8.73, p = 0.004, ηp2 = 0.12, and a significant interaction Time × Regulation, F = 18.76, p < 0.001, ηp2 = 0.23  = 0.74, p = 0.39 and F = 0.81, p = 0.51, respectively.The same pattern of results was found for positive trials with a significant main effect of Regulation, Collectively, these results suggest that heart rate responses shared commonalities, whether the choice was respected or illusory. Globally, we see that, when people could choose the situation, their orienting response to the stimulation was subsequently stronger  than when this task was not given . Importantly, this was true regardless of whether choice was respected or not. Detailed dissection of the response time course with Holm-Bonferroni corrected contrasts Fig.  showed tF = 0.05, p = 0.83 (main effect of Regulation), F = 1.50, p = 0.23 (Time x Regulation), F = 0.00, p = 0.95 (Regulation × Choice outcome), and F = 2.14, p = 0.14 (three-way interaction). For the sake of comparison with Fig. None of the analyses conducted on the negative trials gave significant results, on), F2,7 = 1.50, F = 14.56, p < 0.001, ηp2 = 0.23. This interaction effect shows that, toward the end of the viewing period, the skin conductance measured in the Choice condition was lower than in the Imposed condition  = 0.89, p = 0.43). The other relevant effects were not significant, F = 0.41, p = 0.53 (main effect of Regulation), F = 0.42, p = 0.52 (Regulation x Choice outcome).For positive trials, we found a significant Time x Regulation interaction, F2,8 = 14.56,F = 4.47, p = 0.006, ηp2 = 0.07. Contrast analyses for this effect , as compared to the same pictures viewed under the Imposed conditions. All other relevant effects were not significant, F = 0.02, p = 0.89 (main effect of Regulation), F = 0.04, p = 0.84 (Regulation × Choice outcome), and F = 0.81, p = 0.47 (three-way interaction).For negative trials, we found a significant Time x Regulation interaction, F = 2.77, p = 0.05, ηp2 = 0.05  = 0.00, p = 0.94 (main effect of Regulation), F = 0.01, p = 0.91 (Regulation × Choice outcome), and F = 1.58, p = 0.20 (three-way interaction).For positive trials, the Time × Regulation interaction was only marginally significant F = 4.47, p = 0.006, ηp2 = 0.07. Contrast analyses for this effect . The main effect of Regulation was only marginally significant, F = 3.73, p = 0.06, ηp2 = 0.06. All other relevant effects were not significant, F = 1.25, p = 0.27 (Regulation x Choice outcome), and F = 0.89, p = 0.43 (three-way interaction).For negative trials, we found a significant Time × Regulation interaction, F = 6.53, p = 0.01, ηp2 = 0.09, and a significant interaction Time × Regulation, F = 8.59, p < 0.001, ηp2 = 0.12. Contrast analyses for this latter interaction . The Regulation × Choice outcome interaction and the three-way interaction were not significant, F = 1.53, p = 0.22 and F = 1.14, p = 0.33, respectively.Analyses on positive trials showed a significant main effect of Regulation, Situation selection an efficient emotion regulation strategy. Indeed, if we plan to promote the implementation of Situation selection in everyday situations for particular populations, we must gain a deeper understanding of how choice regulates emotions. More particularly, it is crucial to know whether choice has to be respected in order for it to be efficient. If this is the case, implementation of Situation selection should occur only if we can follow the proposed choice. On the contrary, if choice only has much more importance than the resulting situation, following up on the choice is not mandatory for Situation selection to successfully regulate emotions. To answer to this point, we have adapted a previous protocol to carefully examine Choice conditions in which we can distinguish between respected and non-respected choices. More importantly, and in order to eliminate differences between chosen and avoided options in terms of content, we designed an analysis procedure that allowed us to compare the responses to an identical picture in a Choice condition (whether respected or not) and in an Imposed condition. Finally, given the importance of response dynamics in emotion processes, we included time as a factor to be able to discuss even transient effects.With the present research, our aim was twofold. First, we wanted to replicate the results of a previous study , the only difference between the conditions lying in the fact of having the choice or not.With respect to our first aim, and as expected, we found that Situation selection impact for positive situation, but did not find the previously reported expressivity enhancement in negative viewing. The absence of positive correlation between experience and expressivity in both studies contradicts the supposed coupling and coherence between experiential and expressive emotional reactions , coupled with a decrease in skin conductance level at the end of the recording period. Regarding respiration, we found a reduction in respiratory amplitude in the Imposed condition, whereas in the Situation selection condition participants showed a rather stable amplitude throughout the viewing. We thus confirm a more aroused respiratory pattern in the Imposed condition than in the Situation selection condition. Overall, it appears that the choice mechanism involved in Situation selection helps regulating emotions by decreasing negative experience and sympathetic excretive function, and slightly enhancing cardiovascular reactivity.With respect to physiological arousal, we found results that are similar to the previous study. Indeed, our present results confirm a stronger orienting response in the Situation selection lost its regulatory function on negative emotional experience. Hence, if we focus on subjective emotional experience as felt by the participants, offering a choice that cannot be followed has deleterious consequences on the experiential outcome, cancelling the benefit induced by giving the choice. However, and contrary to what could have been further expected, a non-respected choice does not trigger additional negative feelings. Thus, on average, giving a choice will trigger less negative experience than imposing a negative situation. However, a non-respected choice in positive situations will trigger less positive experience than when it is imposed. Extrapolating this idea to a daily life example we can for instance argue that when we choose a meal in a restaurant that turns out to be unavailable, we would appreciate the replacement dish less than if this dish was the only available option in the first place.With respect to the second aim, there are two main results to discuss. First, and contrary to what we expected, three-way interactions between our factors of interest are present only in the experiential domain. Further analyses showed that when choice was not respected, Choice conditions triggered less physiological arousal than the exact same stimuli seen in an Imposed condition, regardless of whether the choice was respected or not. This is especially true for skin conductance and respiratory activity results. While we cannot equate absence of interaction with evidence of no effect, and that habituation effect may have blunted existing differences, the fact that both respected and non-respected choices converged to decrease arousal is in contradiction with our second proposed option that not getting what we choose could have triggered a strong increase in emotional arousal instead of the expected regulation-induced decrease. An absence of major emotional rebound effect  is in itself an important finding in the light of offering emotional choices in daily life. Having the choice may thus lower body reactivity, at least in the short term, and counteract emotional arousal in people facing emotional stimulations. At the time the present study was completed, a study by Vujovic and colleague  being already regulatory on some emotional responses .A second important result regards the physiological parameters. We observed that none of the parameters showed a three-way Time × Regulation × Choice outcome interaction, which is congruent with our expectations. Instead, most of the results showed that stimuli seen in the Situation selection as an efficient emotion regulation strategy, we confirm that some emotional responses may be down-regulated when choosing an emotional situation. However, this is not the case with heart functioning, which shows a stronger orienting effect in the Choice condition, regardless of whether choice is respected or not. This may indicate that Choice condition is sufficiently challenging to trigger an orienting response , while other differences seem to emerge rather late in the process . For this latter case, it remains open whether these differences persist beyond these 8 s post-stimulation threshold. It will therefore be crucial in future studies to specifically address the significance of this dynamic differences and uncover the biological mechanism and relevance the switch (if any) between transient and prolonged effects of emotion regulation.Several limitations can be highlighted regarding this study. First of all, choice is limited to two options, which is very particular as we cannot really disentangle whether the choice is made according to preference for the chosen option, or avoidance of the alternative. The choice given to participants would deserve to be extended to a less limited and more ecologically valid set of options. A second limitation is the unbalance between respected vs. non-respected trials in order to reduce expectations regarding the image that was going to be presented. This is associated with the more general limitation that we do not know how the participants’ expectations vary with these instructions. Indeed, they know in advance that sometimes there will be non-respected trials. The first impulse to address this limitation would be to think that between-subject design would be more appropriate, with one group having respected choice and the other non-respected choice. We believe that this is not the case. Indeed, in addition to the limitation of comparing different physiologies of different people, we would face the reaction of participants always placed in the non-respected condition. In such a setting, they would quickly turn to selecting the option they want to avoid in order to get their choice. Future studies could also consider creating designs combining within and between subject analyses in order to deal with these important intertwined concepts. In particular, between-subject testing of several combination of respected and non-respected trials would permit to eliminate the expectations regarding the upcoming trials and would permit to lessen the habituation necessarily induced by the high number of trials necessary in within-subject designs. Third, we considered here broad valence affects (positive and negative) as raised by dimensional theorists of affect (Posner et al. Situation selection goes beyond the choice we make and occurs irrespectively of the success of the selection. We confirmed that the choice process is determinant in the regulation effect for some physiological measures of emotion such as skin conductance and respiration. However, we did not find a regulatory effect for negative emotional experience when Situation selection is not followed by the chosen situation. Nevertheless, even though Illusory choice loses the positive effect of choice and does not reduce negative experience, it does not increase it either. This point is essential when reflecting upon implementing a decision or an action in order to regulate emotion in daily life situations or for advising it in case of patient emotion regulation coaching. For this latter case, particular attention should be given to the concept of uncontrollability, which could be especially triggered by Situation selection not being followed by the chosen option, and could lead the patient to abandon this strategy altogether. Particular attention on this matter should be given to patients with depressive pathology and low psychological flexibility (Trindade et al. Situation selection efficiency. In particular, what seems to be an important aspect is to feel in control of our emotional future…no matter if this is the case, or not.This study investigated whether the effect of


C. elegans . Consistent with the role of a terminal selector, unc-42(e419) loss-of-function mutants were shown to lack the expression of the putative chemoreceptor genes sra-6 and srb-6 specifically in the ASHs, while, for example, srb-6 expression in the ADL and ADF sensory neurons was unaffected . unc-42(e419) mutants also lack ASH expression of several other terminal identity markers: three Gα encoding genes , the neuropeptide encoded by flp-21, and the eat-4 vesicular glutamate transporter . Furthermore, loss of UNC-42 function disrupted behavioral responses to high osmolarity and nose touch , which are both detected primarily by the ASHs . However, the severity of the nose touch defect was likely due to developmental defects in both the ASH sensory neurons as well as some downstream interneurons, where altered glutamate receptor expression accompanies loss of UNC-42 .The genes encoding transcription factors that initiate the terminal differentiation programs within individual neurons have been termed “terminal selectors” (Hobert 2008). They are considered master regulators of neuronal identity because they integrate upstream lineage inputs to ultimately drive (directly and/or indirectly) the expression of all terminal differentiation features of a neuron . The paired-like homeodomain transcription factor UNC-42 has been proposed to function as the terminal selector in the developmental specification of the ASH polymodal nociceptors in Table 1: Summary of the effect of unc-42(gk598) on ASH terminal marker gene expression*sra-6 expression in ASH was previously reported to be affected by unc-42(e419) .unc-42(gk598) allele, we confirmed the role of UNC-42 in regulating ASH terminal markers, and identified seven additional genes whose ASH expression strongly depends upon UNC-42  mutants, with only ~20% of animals losing expression in one ASH (image not shown). In addition, ASH expression of some genes  was found to be unaffected in unc-42(gk598) animals (Table 1). We note that several of these are either expressed broadly throughout the nervous system, or function in several sensory neurons. As such, they may not necessarily be constituents of the terminally differentiated gene battery of the ASHs. Combined, UNC-42 broadly regulates the expression of ASH identity markers, although additional transcription factors are likely to also contribute.Using the DiD was purchased from Molecular Probes (Invitrogen).unc-42(gk598) strain was generated by the C. elegans Reverse Genetics Core Facility at the University of British Columbia, which is part of the International C. elegans Gene Knockout Consortium. The gk598 allele contains a 1430 basepair deletion . VC1444 was outcrossed 6x to N2 to generate FG498 for use in this study. Some of the strains used in this study were obtained from the Caenorhabditis Genetics Center, which is funded in part by the National Institutes of Health – National Center for Research Resources.The VC1444 unc-42(gk598), CX3465 kyIs39 [sra-6::gfp + lin-15(+)], HA1695 rtIs27 [osm-10p::gfp], PY5163  line 1, NK885 unc-119(ed4);qyIs174 [hlh-2p::gfp::hlh-2 + unc-119(+)], CX2565 kyIs4 lin-15A(n765) [ceh-23p::unc-76::gfp + lin-15(+)], RW10748 unc-119(ed3); zuIs178; stIs10024; stIs10549 [stIs10549 = nhr-79::H1-wCherry + unc-119(+)], HA357 rtEx251 [nlp-15p::gfp + lin-15(+)]; lin-15B lin-15A(n765), AL132 icIs132 [unc-40::gfp], HA341 lin-15; rtEx235 [nlp-3::gfp], LX990 lin-15B lin-15A(n765); vsEx494 [ocr-2p::gfp::ocr-2 3’utr + lin-15(+)], CX3716lin-15B lin-15A(n765) kyIs141 [osm-9::gfp5 + lin-15(+)], IC692 quEx162 [sax-3p::gfp + (pRF4) rol-6]. Transgenes were examined in the wild-type andunc-42(gk598) background. For the generation of extrachromosomal arrays, germline transformations were performed as previously described . Plasmids injected for analysis include: sri-14p::venus, pFG258 srd-33p::gfp and pFG233 srd-10p::gfp. Transgenic lines were examined in the N2 wild-type background, and at least one array was chosen to be crossed into the unc-42(gk598) background for comparison. Strains generated in our lab for this study have not been sent to the CGC.Strains used in this study include: N2 Bristol wild-type, FG498


The study of HRM and Performance of public service is an extremely relevant theme. Although studies on the HRM-performance link have been well documented, the results were inconclusive. Besides, previous studies have paid little attention to the public service from developing country's context. Drawing on the AMO Model and SET, the present study examined the effect of HRM System on Employee Engagement and Organizational Performance. Likewise, this study tested the intervening effect of Employee Engagement in the HRM-performance link. Using a sample of federal employees (n Organization Performance; Public Service Organizations.; employee engagement; Human Resource Management; HRM-performance nexus, Management; Business Management; Business In connection with this, Knies and colleagues (2018) argued that basically, the welfare of the country depends on the performance of the public service organizations. To realize an eloquent service delivery in the public service, proper management of the Human Resource (hereinafter: HR) should materialize .Noticeably, the public service sector remains overlooked in HRM-Performance research , indicatCombs et al., 2006;Ethiopia is a very good context to study the HRM-Performance linkage for some reasons. First, it is located in a strategic area in East Africa, owning one of the largest economies in the continent . It is wTessema and Soeters, 2006This study contributes to the HRM-performance debate by providing empirical evidence from developing country's context in the public service through a mediation model. Regarding the organization of the article, the report is divided into five sections. The first section reviews the background of the study. Next, the literature review and Hypothesis formulation were described. Third, we then presented the methodological perspectives employed followed by the analysis and discussion section. Lastly, the implications, limitations and future research directions are included in this study.2The concept of HRM is one of the fields of management that gained popularity in the last 30 years or so. Although HRM is the most popular research area, there is no universally accepted and generally acknowledged single definition . For exa;In the HRM-performance debate, the conceptualization of the term HRM, and set of practices used are the most basic part . The terBoselie et al., 2005;Huselid, 1995;Boselie et al., 2005;Jiang et al., 2012;While review of the empirical studies, it was realized that there are various phrases given for HRM System such as a High-Performance Work System  or High ;Subramony, 2009;Regarding the HR practices employed, different researchers applied different sets of practices in their study. According to Boselie et al., 2005;Despite the varying number of HRM practices, Vermeeren, 2014;Following prior studies, the present study comprised of six utmost widely used HR practices in the service settings . These HR practices are selected using AMO theory  rather tBoxall et al., 2007;Theoretically, the HRM-Performance relationship is upheld by several theories such as the resource-based approach, AMO framework, Social Exchange theory, behavioral theory, and others . NeverthSun et al., 2007Boseile and colleagues argued that HR practices affect HR, internal, and financial performance respectively. Similarly, In the theory of performance, Considering the above arguments, the present study build a conceptual model which includes mediation effect in the HRM-performance debate see . As it i2.1Understanding the nexus between the HRM system and organizational performance has been considered the essential and central research question in strategic HRM . Previou;Hypothesis 1There is a positive and significant relationship between HRM system and organizational performanceHypothesis 1AThere is a positive and a significant relationship between the individual HR practices  and organizational performancePrevious studies  found a Darwish, 2013Hypothesis 2There is a positive and significant relationship between HRM and employee engagement.Hypothesis 2AThere is a positive and a significant relationship between the individual HR practices  and employee engagement.Employee engagement is a crucial construct in today's ever-changing and dynamic business environment . The theHypothesis 3There is a positive and significant relationship between employee engagement and organizational performance.The ultimate essence of an employee being engaged in the workplace is to enhance Organizational Performance . Recentl2.2;Wright and Gardner, 2003;Kehoe and Wright, 2013;Paauwe, 2009;Boselie et al., 2005;Guest, 2011;Ko and Smith-Walter, 2013;Vermeeren, 2014;Guest et al., 2003;Wright and Gardner, 2003;Wall and Wood, 2005;Combs et al., 2006;Guest, 2011;Riaz, 2015;” in the linkage  noted that the HR practices do indirectly result in performance through changes in the attitudes and behaviors of the workforce. Following this suggestion, the present study takes the Savaneviciene and Stankeviciute, 2012;Patterson et al., 2010;Sundaray, 2011;Ahmed et al., 2016;Muduli et al., 2016). In 2006, Saks confirmed the role played by employee engagement as a mediating variable in the bond between antecedents and its consequences. Hypothesis 4Employee engagement can mediate the relationship between HRM and organizational performance in Ethiopian public service.In the conceptual and empirical studies, employee engagement is considered as employee outcome  and then two organizations were randomly selected from each sector (8 organizations) and Ministry of Public Service and Human Resource Development, the governing body of the country's civil service administration is intentionally included in the sample. The random selection of the sample organizations were done through this process: first, the researcher numbered all the public service organizations in each category on paper slip then mixed these slips; second, the researcher chooses one slip at a time to reach a reasonable sample of nine federal public service organizations for this study. This study took 30% of the total organizations, showing a fair representation of the population organization as the previous studies in public service took 20% of population organizations see: . In the ; Sekaran and Bougie, 2013;Kline, 2011,In SEM analysis, sample size determination is critical and it is noted that large sample size is necessary to improve statistical power and trustworthiness of the results . And alsHair et al., 20103.2Sekaran, and Bougie (2013) argued that the constructs under study should be measured. The current study utilized a validated and developed standard questionnaire from previous studies conducted in the public sector was used to measure all the study variables. Responses to all questionnaire items were given on a five-point Likert scale in which 1 = “Strongly disagree” and 5 = “Strongly agree”. As the official language of Ethiopia is Amharic, the questionnaires were administered in Amharic which was originally designed in English, and then interpreted into Amharic through the help of university professors and professionals following the recommendation of research literature. The back-interpreted version was compared with the original to ensure accuracy and consistency of meaning and didn't see any validity problem. Objectively, a pilot test was conducted by randomly selecting employees To test the Hypothesis, 3.2.1This index is measured using 31 items, six High Commitment based HR Practices namely: Recruitment and Selection, Training and Development; Performance Appraisal; Compensation and Reward; Autonomy and Employee Participation based on the work developed by 3.2.22017, Kulikowski reviewed several studies and found that the short version of the Utrecht Work Engagement Scale is the most popular, reliable, and valid and have higher psychometric properties than the 17 item version. To test the applicability of the questionnaires in the Ethiopian contexts, the study employed factor analysis method using principal component extraction with varimax rotation for the short version of the Utrecht Work Engagement Scale and the EFA analysis using principal axis factoring method result discovered that the nine items are categorized into one factor, which is consistent with previous studies  and AMOS (version 23). Before going into further discussion, preliminary analysis to test for missing data, outliers, normality and multicollinearity concerns were performed to improve the accuracy of the data preparation and screening process which is critical stage in SEM analysis  technique was employed to analyze both the measurement and structural model respectively . The curSahin, 2010To test the CFA of each construct, item parcels were developed for HRM construct due to the presence of a large number of items (31 items). Some scholars  argued t, the present study employed internal consistency approach to form item parceling. To this end, HRM has six dimensions and items of each dimensions are parcel together. To enter the parcels into CFA, the present study follows the procedure identified by prior scholars . The acclaimed values for factor loading are supposed to be greater than 0.55, for AVE at least 0.5 and that of CR to be greater than 0.7  of the study variables . To asse. The accthan 0.7 . Thus, tAs it is shown in ;Kline, 2016). As shown in The second objective of measurement model is to test discriminant validity. Divergent validity is the degree to which a construct is strictly different from others . To test for common method bias, we followed the suggestion of . The pre4.5;Kline, 2011,The second stage of SEM analysis is evaluating the structural model . Interestingly, As it was hypothesized, it was found that HRM has a positive and significant effect on organizational performance. This result is consistent with the previous empirical findings  can mediate the mechanism through which HRM-related organizational performance. In the HRM literature, there are two paths (direct and indirect) of research to link the HRM and organizational performance . Recentl, the system's perspective is very critical to scrutinize the effect of HR practices on organizational benefits. The essence of the systems perspective is that if the critical elements of the HRM activities are well organized and coordinated, then the effect on the performance of an organization is more significant when the HR practices are implemented as a system/bundle rather than individual practices as in isolation. That means the effect of the system/bundles of HRM on both individual and organizational performance is much greater than the individual HR practices alone es alone .It also supports the AMO framework that HR practices can be classified into Ability, Motivation, and Opportunity so that they can contribute to performance. 8The study has practical implications. It was found that HRM is a strong predictor of both employee engagement and organizational performance. This implies that if there is sound HRM and there is proper implementation of the HR practices, then employees will have the appropriate skill and knowledge to perform their work; create proper motivation and have the opportunity to operate their work. This all will help them to be engaged in their work. If there is an engaged workforce in an organization, then, the performance of organizations will be improved. 9This study is subject to some limitations. The first limitation is related to the duration of the study. This study is cross-sectional in nature where data needed for all the study constructs were collected in one period in time. Cross-sectional studies didn't provide the opportunity to see the cause-effect between constructs. Thus, it is better to conduct longitudinal studies in the future to conclude sound and robust causality. Second, this study collects data from the same sources for all the constructs  which may lead to common method variance. However, the present study collected data from different types of employees from different public service organizations in various hierarchies. To minimize the common method variance, the study followed the suggestion of ). Fourth, the study was based on the individual level of analysis in examining the HRM-Performance equation. Although it is appropriate to evaluate the link in this way, recent researches calls are suggesting to conduct multi-level analysis in examining the HRM-Performance debate. So, future researchers are recommended to conduct both organizational and individual levels together in the HRM-Performance Linkage. Fifth, this study only considers HRM as an antecedent of employee engagement. Despite the fact that the major organizational factor that affects employee engagement is HRM practices, different factors, for example, leadership, and working climate can be considered in the future. This is because there are many factors that enhance employee engagement which in return affect organizational outcomes. Finally, to avoid the inter-industry effect, this study focused on one sector and it didn't take into account the cultural influence in the link between HRM and Organizational Performance. In any case, it is imperative to consider and comprehend the cross-cultural issues in measuring employee engagement (The third limitation of the study was measuring organizational performance subjectively. It can be measured through both objective as well as subjective measures. However, an objective measure of organizational performance was difficult to get in public government organizations. Other scholars have also relied on subjective evaluation of organizational performance . Fourth,gagement . In streAssefa Tsegay Tensay, Manjit Singh: Conceived and designed the experiments; Performed the experiments; Analyzed and interpreted the data; Wrote the paper.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.The authors declare no conflict of interest.No additional information is available for this paper.