Somno-Art Software identifies pathology-induced changes in sleep parameters similarly to polysomnography.

Polysomnographic sleep architecture parameters are commonly used to diagnose or evaluate treatment of sleep disorders. Polysomnography (PSG) having practical constraints, the development of wearable devices and algorithms to monitor and stage sleep is rising. Beside pure validation studies, it is necessary for a clinician to ensure that the conclusions drawn with a new generation wearable sleep scoring device are consistent to the ones of gold standard PSG, leading to similar interpretation and diagnosis. This paper reports on the performance of Somno-Art Software for the detection of differences in sleep parameters between patients suffering from obstructive sleep apnea (OSA), insomniac or major depressive disorder (MDD) compared to healthy subjects. On 244 subjects (n = 26 healthy, n = 28 OSA, n = 66 insomniacs, n = 124 MDD), sleep staging was obtained from PSG and Somno-Art analysis on synchronized electrocardiogram and actimetry signals. Mixed model analysis of variance was performed for each sleep parameter. Possible differences in sleep parameters were further assessed with Mann-Whitney U-test between the healthy subjects and each pathology group. All sleep parameters, except N1+N2, showed significant differences between the healthy and the pathology group. No significant differences were observed between Somno-Art Software and PSG, except a 3.6±2.2 min overestimation of REM sleep. No significant interaction 'group'*'technology' was observed, suggesting that the differences in pathologies are independent of the technology used. Overall, comparable differences between healthy subjects and pathology groups were observed when using Somno-Art Software or polysomnography. Somno-Art proposes an interesting valid tool as an aid for diagnosis and treatment follow-up in ambulatory settings.

Long-term effects of Roluperidone on negative symptoms of schizophrenia.

Roluperidone has antagonist properties for 5-HT2A, sigma2, α1A- and α1B-adrenergic receptors, but no dopaminergic binding affinities. In 2 randomized controlled trials (RCT), treatment improved negative symptoms of schizophrenia and social functioning among patients with moderate to severe negative symptoms. We report results of the protocol specified analysis of 2 open-label extension studies of 24 and 40 weeks investigating whether improvement of negative symptoms was sustained without significant adverse effects or worsening of psychosis. Following 12-week double-blind phase of both RCTs, patients were eligible to receive monotherapy roluperidone 32 mg/day or 64 mg/day for 24 weeks (trial 1) or 40 weeks (trial 2) in open-label extension study. Trial 1 included 244 patients of whom 142 entered 24-week open-label extension and trial 2 included 513 patients of whom 341 entered 40-week open-label extension. Trial 1 had PANSS negative factor score of Pentagonal Structure Model as primary outcome. Trial 2 had Marder Negative Symptoms Factor Score as primary outcome measure and Personal and Social Performance (PSP) Total score as secondary outcome. During open-label extensions, continued improvements in negative symptoms and on PSP were observed. Overall rate of symptomatic worsening requiring discontinuation of roluperidone and treatment with an antipsychotic was <10 %. Roluperidone was well tolerated with no meaningful changes in vital signs, laboratory values, weight gain, metabolic indices, or extrapyramidal symptoms. Results of 2 open-label extension trials support roluperidone as a treatment of negative symptoms and social functioning deficits in patients with moderate to severe negative symptoms of schizophrenia.

Performance of Somno-Art Software compared to polysomnography interscorer variability: A multi-center study.

The visual scoring of gold standard polysomnography (PSG) is known to present inter- and intra-scorer variability. Previously, Somno-Art Software, a cardiac based sleep scoring algorithm, has been validated in comparison to 2 expert visual PSG scorers. The goal of this research is to evaluate the performances of the algorithm against a pool of scorers. Sixty PSG and actimetry recording nights, representative of clinical practice (healthy subjects and patients suffering from obstructive sleep apnea [OSA], insomnia or major depressive disorder), were scored by 5 different sleep scoring centers and by the Somno-Art Software. Intra-class correlation coefficient (ICC) and Wilcoxon Signed-Rank Test were calculated between each scorer and the average value of the 6 scorers, including Somno-Art Software. In addition, epoch-by-epoch agreement between scorers were analyzed. Somno-Art Software estimation of sleep efficiency, wake, N1+N2, N3 and REM sleep fit within the interscorer range for the full dataset and the subgroups, except for underestimating N3 sleep in OSA patients. Additionally, Somno-Art Software overestimated sleep latency compared to the average scoring for insomniacs (+4.7 ± 1.6min). On the full dataset, Somno-Art Software had good (0.75 < ICC<0.90) or excellent (ICC>0.90) ICC scores for all sleep parameters except N3 sleep (moderate score, 0.50 < ICC<0.75). For the 4-stages epoch-by-epoch agreement, Somno-Art Software was slightly below that of the visual scorers except for the healthy sub-group where an overlap was demonstrated. Somno-Art Software sleep scoring shows a good interscorer reliability in the range of the 5 visual polysomnography scorers.

Efficacy and Safety of Roluperidone for the Treatment of Negative Symptoms of Schizophrenia.

BACKGROUND: This is a placebo-controlled multi-national trial of roluperidone, a compound with antagonist properties for 5-HT2A, sigma2, and α1A-adrenergic receptors, targeting negative symptoms in patients with schizophrenia. This trial follows a previous trial that demonstrated roluperidone superiority over placebo in a similar patient population. METHODS: Roluperidone 32 mg/day, roluperidone 64 mg/day, or placebo was administered for 12 weeks to 513 patients with schizophrenia with moderate to severe negative symptoms. The primary endpoint was the PANSS-derived Negative Symptom Factor Score (NSFS) and the key secondary endpoint was Personal and Social Performance scale (PSP) total score. RESULTS: NSFS scores were lower (improved) for roluperidone 64 mg compared to placebo and marginally missing statistical significance for the intent-to-treat (ITT) analysis data set (P ≤ .064), but reached nominal significance (P ≤ .044) for the modified-ITT (m-ITT) data set. Changes in PSP total score were statistically significantly better on roluperidone 64 mg compared to placebo for both ITT and m-ITT (P ≤ .021 and P ≤ .017, respectively). CONCLUSIONS: Results of this trial confirm the potential of roluperidone as a treatment of negative symptoms and improving everyday functioning in patients with schizophrenia. Study registration: Eudra-CT: 2017-003333-29; NCT03397134.

Validation of Somno-Art Software, a novel approach of sleep staging, compared with polysomnography in disturbed sleep profiles.

Study Objectives: Integrated analysis of heart rate (electrocardiogram [ECG]) and body movements (actimetry) during sleep in healthy subjects have previously been shown to generate similar evaluation of sleep architecture and continuity with Somno-Art Software compared to polysomnography (PSG), the gold standard. However, the performance of this new approach of sleep staging has not yet been evaluated on patients with disturbed sleep. Methods: Sleep staging from 458 sleep recordings from multiple studies comprising healthy and patient population (obstructive sleep apnea [OSA], insomnia, major depressive disorder [MDD]) was obtained from PSG visual scoring using the American Academy of Sleep Medicine rules and from Somno-Art Software analysis on synchronized ECG and actimetry. Results: Inter-rater reliability (IRR), evaluated with 95% absolute agreement intra-class correlation coefficient, was rated as "excellent" (ICCAAAvg95% ≥ 0.75) or "good" (ICCAAAvg95% ≥ 0.60) for all sleep parameters assessed, except non-REM (NREM) and N3 sleep in healthy participants (ICCAAAvg95% = 0.43, ICCAAAvg95% = 0.56) and N3 sleep in OSA patients (ICCAAAvg95% = 0.59) rated as "fair" IRR. Overall sensitivity, specificity, accuracy, and Cohen's kappa coefficient of agreement (κ) on the entire sample were respectively of 93.3%, 69.5%, 87.8%, and 0.65 for wake/sleep classification and accuracy and κ were of 68.5% and 0.55 for W/N1+N2/N3/rapid eye movement (REM) classification. These performances were similar in healthy and patient population. Conclusions: The present results suggest that Somno-Art can be a valid sleep-staging tool in both healthy subjects and patients with OSA, insomnia, or MDD. It could complement existing non-attended techniques measuring sleep-related breathing patterns or be a useful alternative to laboratory-based PSG when this latter is not available.

Do Patterns of Instability or Severity of Psychopathology During Screening Predict Relapse in Schizophrenic Outpatient Subjects with Moderate to Severe Negative Symptoms Assigned to Placebo?

Background: Patients with schizophrenia who, prior to inclusion in placebo-controlled trials, experience the most severe and/or unstable symptoms might be more likely to manifest symptomatic worsening upon antipsychotic discontinuation. Methods: This retrospective analysis included all randomized patients assigned to placebo (n=83) in a 12-week, double-blind, placebo-controlled outpatient trial of MIN-101 (roluperidone) for the treatment of negative symptoms in schizophrenia. The following risk factors were defined for exacerbation: instability between screening and baseline defined operationally as patients with the highest 10 percent of absolute change from the screening visit to baseline in the Positive and Negative Syndrome Scale (PANSS) total or one of the five PANSS Marder factors; screening or baseline severity in PANSS total or one of the five PANSS Marder factors; and gender and age. We used two operational criteria of relapse and the odds ratios of meeting the relapse criteria were calculated for each risk factor. Results: The odds of meeting one of the operational thresholds for relapse after antipsychotic discontinuation were not statistically significantly increased in the subjects who were unstable on the PANSS total or on one of the five PANSS Marder factors before antipsychotic discontinuation. Further, the severity of PANSS total and Marder factor scores at screening and baseline were not statistically significantly associated with odds of relapse. Neither age nor gender had any effect on relapse rates. Conclusion: Mild to moderate symptomatic variations in the severity of symptoms during screening and more severe symptomology at baseline as measured by the PANSS were not predictive of increased risk of subsequent relapse in schizophrenic patients.

Network Analysis Indicates That Avolition Is the Most Central Domain for the Successful Treatment of Negative Symptoms: Evidence From the Roluperidone Randomized Clinical Trial.

A recent conceptual development in schizophrenia is to view its manifestations as interactive networks rather than individual symptoms. Negative symptoms, which are associated with poor functional outcome and reduced rates of recovery, represent a critical need in schizophrenia therapeutics. MIN101 (roluperidone), a compound in development, demonstrated efficacy in the treatment of negative symptoms in schizophrenia. However, it is unclear how the drug achieved its effect from a network perspective. The current study evaluated the efficacy of roluperidone from a network perspective. In this randomized clinical trial, participants with schizophrenia and moderate to severe negative symptoms were randomly assigned to roluperidone 32 mg (n = 78), 64 mg (n = 83), or placebo (N = 83). Macroscopic network properties were evaluated to determine whether roluperidone altered the overall density of the interconnections among symptoms. Microscopic properties were evaluated to examine which individual symptoms were most influential (ie, interconnected) on other symptoms in the network and are responsible for successful treatment effects. Participants receiving roluperidone did not differ from those randomized to placebo on macroscopic properties. However, microscopic properties (degree and closeness centrality) indicated that avolition was highly central in patients receiving placebo and that roluperidone reduced this level of centrality. These findings suggest that decoupling the influence of motivational processes from other negative symptom domains is essential for producing global improvements. The search for pathophysiological mechanisms and targeted treatment development should be focused on avolition, with the expectation of improvement in the entire constellation of negative symptoms if avolition is effectively treated.

Effects of Roluperidone (MIN-101) on two dimensions of the negative symptoms factor score: Reduced emotional experience and reduced emotional expression.

BACKGROUND: Recent research has suggested that negative symptoms (NS) can be considered in terms of two different dimensions: reduced expression (expressive deficit) and reduced experience (experiential deficit). Roluperidone, a compound with high affinities for 5 HT2A and sigma2 receptors, has previously shown superiority over placebo on improving NS in a prospective study in patients with schizophrenia. The objective here is to explore the effect of roluperidone compared to placebo, on the 2 domains of the Negative Symptoms. METHODS: This was a multi-national Phase 2b trial that enrolled 244 symptomatically stable patients with schizophrenia who had baseline scores ≥20 on the NS subscale of the PANSS. Patients were randomized to daily monotherapy with roluperidone 32 mg, roluperidone 64 mg, or placebo in a 1:1:1 ratio. All enrolled patients were Caucasian, and 137 (56%) were male. The 3 treatment groups were balanced on all demographic and illness-related baseline characteristics. RESULTS: Both doses of roluperidone were superior to placebo on both domains: Reduced Experience (p ≤ .006 for the 32 mg; p ≤ .001 for the 64 mg) with persistent superiority from Week 2 for the 64 mg dose and Week 8 for the 32 mg dose; Reduced Expression (p ≤ .003 for 32 mg; p ≤ .001 for 64 mg) with similar persistence. IMPLICATIONS: Both doses of roluperidone previously improved PANSS negative symptoms in general and demonstrated tolerability in stable schizophrenia patients. The post hoc analysis reported here found the drug to work on both the reduced emotional experience and reduced emotional expression sub-scales empirically derived from the PANSS.

Cognitive Effects of MIN-101 in Patients With Schizophrenia and Negative Symptoms: Results From a Randomized Controlled Trial.

OBJECTIVE: Current dopamine-blocking antipsychotic drugs have little impact on the cognitive deficits associated with schizophrenia. We evaluated whether MIN-101, a molecule that combines sigma-2 antagonism and 5-HT2A antagonism, might improve cognitive deficits in individuals with moderate to severe negative symptoms in schizophrenia. METHODS: Individuals (N = 244) aged 18 to 60 years with stable symptoms of DSM-5-defined schizophrenia and moderate to severe negative symptoms were randomized to placebo (n = 83), MIN-101 32 mg (n = 78), or MIN-101 64 mg (n = 83) in a 12-week, phase 2b, prospective, double-blind, placebo-controlled, parallel-group trial between May 2015 and December 2015. In a post hoc analysis, mean z and T score changes from baseline at 12 weeks of treatment in the cognitive composite score and individual tests on the Brief Assessment of Cognition in Schizophrenia (BACS) Battery were compared between MIN-101 and placebo. RESULTS: A total of 79 patients (95.2%) from the placebo group, 76 (97.4%) from the MIN-101 32 mg group, and 79 (95.2%) from the MIN-101 64 mg group completed the BACS at baseline. The BACS token motor (P = .04), verbal fluency (P = .01), and composite z scores (P = .05) showed significant improvements in the MIN-101 32 mg group compared to the placebo group. At week 4, the clinical improvements from baseline in the Positive and Negative Syndrome Scale (PANSS) negative factor showed a significant correlation with improvements from baseline on the BACS composite in the 64 mg group (r = -0.292, P = .020). At week 12, improvement in the PANSS negative factor showed significant correlations with improvements in the BACS composite (r = -0.408, P = .002), Trail Making Test (r = -0.394, P = .003), and verbal memory (r = -0.322, P = .017) for the 64 mg group. CONCLUSIONS: Results suggest a possible benefit of MIN-101 on cognitive performance in individuals with schizophrenia with stable positive symptoms and concurrent clinically significant negative symptoms. TRIAL REGISTRATION: EU Clinical Trials Register identifier: 2014-004878-42​.

The brief negative symptom scale (BNSS): Sensitivity to treatment effects.

The Brief Negative Symptom Scale (BNSS) grew out of a recommendation by the NIMH-sponsored Consensus Development Conference on Negative Symptoms that a scale based on contemporary concepts be developed. We assessed sensitivity to change of the BNSS in a trial of MIN-101, which showed efficacy for negative symptoms (PANSS pentagonal model) at daily doses of 32 and 64mg/day. Using mixed-effects model for repeated measures, we examined change in BNSS total score and in the BNSS factors of anhedonia/avolition/asociality (AAA), and expressivity (EXP). Compared to placebo, the 64mg group (N=83) showed a significant decrease in BNSS total score (effect size d [ES] 0.56, p<0.01) and both factor scores (AAA ES=0.48, EXP ES=0.46, p<0.02 for both). Patients in the trial had minimal depression and positive symptom scores; covarying for disorganization, positive symptoms, or anxiety/depression did not cause a meaningful change in the significance of the BNSS total or factor scores in this group. The 32mg group (N=78) did not differ significantly from placebo (N=83) on BNSS total score (ES=0.33, p<0.09), AAA (ES=0.25, p<0.20) or EXP (ES=0.30, p<0.12) scores. These results demonstrate the BNSS is sensitive to change.

Efficacy and Safety of MIN-101: A 12-Week Randomized, Double-Blind, Placebo-Controlled Trial of a New Drug in Development for the Treatment of Negative Symptoms in Schizophrenia.

OBJECTIVE: The authors assessed the efficacy, safety, and tolerability of MIN-101, a compound with affinities for sigma-2 and 5-HT2A receptors and no direct dopamine affinities, in comparison with placebo in treating negative symptoms in stabilized patients with schizophrenia. METHOD: The trial enrolled 244 patients who had been symptomatically stable for at least 3 months and had scores of at least 20 on the negative subscale of the Positive and Negative Syndrome Scale (PANSS). After at least 5 days' withdrawal from all antipsychotic medication, patients were randomly assigned to receive placebo or 32 mg/day or 64 mg/day of MIN-101 for 12 weeks. The primary outcome measure was the PANSS negative factor score (pentagonal structure model). Secondary outcome measures were PANSS total score and scores on the Clinical Global Impressions Scale (CGI), the Brief Negative Symptom Scale, the Brief Assessment of Cognition in Schizophrenia, and the Calgary Depression Scale for Schizophrenia. RESULTS: A statistically significant difference in PANSS negative factor score was observed, with lower scores for the MIN-101 32 mg/day and 64 mg/day groups compared with the placebo group (effect sizes, d=0.45 and d=0.57, respectively). Supporting these findings were similar effects on several of the secondary outcome measures, such as the PANSS negative symptom, total, and activation factor scores, the CGI severity item, and the Brief Negative Symptom Scale. There were no statistically significant differences in PANSS positive scale score between the MIN-101 and placebo groups. No clinically significant changes were observed in vital signs, routine laboratory values, weight, metabolic indices, and Abnormal Involuntary Movement Scale score. CONCLUSIONS: MIN-101 demonstrated statistically significant efficacy in reducing negative symptoms and good tolerability in stable schizophrenia patients.

Assessing sleep architecture and continuity measures through the analysis of heart rate and wrist movement recordings in healthy subjects: comparison with results based on polysomnography.

OBJECTIVE: The objective of the study was to evaluate the reliability of a new methodology for assessing sleep architecture descriptors based on heart rate and body movement recordings. METHODS: Twelve healthy male and female subjects between 18 and 40 years of age, without sleep disorders and not taking any drug or medication that could affect sleep, were recorded continuously during five consecutive nights. Together with the standard polysomnography, heart rate was recorded with a Holter and wrist movements by actimetry. Of the 60 recorded nights, 48 artifact-free nights were analyzed by two independent and well-trained visual scorers according to the rules of the American Academy of Sleep Medicine. Sleep stages were assigned to every 30-s epoch. In parallel, the same nights were analyzed by the new methodology using only heart rate and actimetry data, allowing a 1-s epoch sleep stage classification. Sleep architecture was measured for 48 nights, independently for the two manual scorings and the automatic analysis. RESULTS: Over 42 nights, the intra-class correlation coefficient, used to assess the consistency or reproducibility of quantitative measurements made by different observers, was classified as excellent when all 12 descriptors were combined. Analyses of the individual descriptors showed excellent interclass correlation for eight and good for four of the 12. CONCLUSION: The automatic analysis of heart rate and body movement during sleep allows for the evaluation of sleep architecture and continuity that is equivalent to those obtained by manual scoring of polysomnography. The technique used here is simple and robust to allow for home sleep monitoring.

AVI-7288 for Marburg Virus in Nonhuman Primates and Humans.

BACKGROUND: AVI-7288 is a phosphorodiamidate morpholino oligomer with positive charges that targets the viral messenger RNA that encodes Marburg virus (MARV) nucleoprotein. Its safety in humans is undetermined. METHODS: We assessed the efficacy of AVI-7288 in a series of studies involving a lethal challenge with MARV in nonhuman primates. The safety of AVI-7288 was evaluated in a randomized, multiple-ascending-dose study in which 40 healthy humans (8 humans per dose group) received 14 once-daily infusions of AVI-7288 (1 mg, 4 mg, 8 mg, 12 mg, or 16 mg per kilogram of body weight) or placebo, in a 3:1 ratio. We estimated the protective dose in humans by comparing pharmacokinetic variables in infected nonhuman primates, uninfected nonhuman primates, and uninfected humans. RESULTS: Survival in infected nonhuman primates was dose-dependent, with survival rates of 0%, 30%, 59%, 87%, 100%, and 100% among monkeys treated with 0 mg, 3.75 mg, 7.5 mg, 15 mg, 20 mg, and 30 mg of AVI-7288 per kilogram, respectively (P<0.001 with the use of the log-rank test for the comparison of survival across groups). No safety concern was identified at doses up to 16 mg per kilogram per day in humans. No serious adverse events were reported. Drug exposure (the area under the curve) was dose-dependent in both nonhuman primates and humans; drug clearance was independent of dose but was higher in nonhuman primates than in humans. The protective dose in humans was initially estimated, on the basis of exposure, to be 9.6 mg per kilogram per day (95% confidence interval, 6.6 to 12.5) for 14 days. Monte Carlo simulations supported a dose of 11 mg per kilogram per day to match the geometric mean protective exposure in nonhuman primates. CONCLUSIONS: This study shows that, on the basis of efficacy in nonhuman primates and pharmacokinetic data in humans, AVI-7288 has potential as postexposure prophylaxis for MARV infection in humans. (Funded by the Department of Defense; ClinicalTrials.gov number, NCT01566877.).

Safety and pharmacokinetic profiles of phosphorodiamidate morpholino oligomers with activity against ebola virus and marburg virus: results of two single-ascending-dose studies.

Two identical single-ascending-dose studies evaluated the safety and pharmacokinetics (PK) of AVI-6002 and AVI-6003, two experimental combinations of phosphorodiamidate morpholino oligomers with positive charges (PMOplus) that target viral mRNA encoding Ebola virus and Marburg virus proteins, respectively. Both AVI-6002 and AVI-6003 were found to suppress disease in virus-infected nonhuman primates in previous studies. AVI-6002 (a combination of AVI-7537 and AVI-7539) or AVI-6003 (a combination of AVI-7287 and AVI-7288) were administered as sequential intravenous (i.v.) infusions of a 1:1 fixed dose ratio of the two subcomponents. In each study, 30 healthy male and female subjects between 18 and 50 years of age were enrolled in six-dose escalation cohorts of five subjects each and received a single i.v. infusion of active study drug (0.005, 0.05, 0.5, 1.5, 3, and 4.5 mg/kg per component) or placebo in a 4:1 ratio. Both AVI-6002 and AVI-6003 were safe and well tolerated at the doses studied. A maximum tolerated dose was not observed in either study. The four chemically similar PMOplus components exhibited generally similar PK profiles. The mean peak plasma concentration and area under the concentration-time curve values of the four components exhibited dose-proportional PK. The estimated plasma half-life of all four components was 2 to 5 h. The safety of the two combinations and the PK of the four components were similar, regardless of the target RNA sequence.

Eteplirsen for the treatment of Duchenne muscular dystrophy.

OBJECTIVE: In prior open-label studies, eteplirsen, a phosphorodiamidate morpholino oligomer, enabled dystrophin production in Duchenne muscular dystrophy (DMD) with genetic mutations amenable to skipping exon 51. The present study used a double-blind placebo-controlled protocol to test eteplirsen's ability to induce dystrophin production and improve distance walked on the 6-minute walk test (6MWT). METHODS: DMD boys aged 7 to 13 years, with confirmed deletions correctable by skipping exon 51 and ability to walk 200 to 400 m on 6 MWT, were randomized to weekly intravenous infusions of 30 or 50 mg/kg/wk eteplirsen or placebo for 24 weeks (n = 4/group). Placebo patients switched to 30 or 50 mg/kg eteplirsen (n=2/group) at week 25; treatment was open label thereafter. All patients had muscle biopsies at baseline and week 48. Efficacy included dystrophin-positive fibers and distance walked on the 6MWT. RESULTS: At week 24, the 30 mg/kg eteplirsen patients were biopsied, and percentage of dystrophin-positive fibers was increased to 23% of normal; no increases were detected in placebo-treated patients (p≤0.002). Even greater increases occurred at week 48 (52% and 43% in the 30 and 50 mg/kg cohorts, respectively), suggesting that dystrophin increases with longer treatment. Restoration of functional dystrophin was confirmed by detection of sarcoglycans and neuronal nitric oxide synthase at the sarcolemma. Ambulation-evaluable eteplirsen-treated patients experienced a 67.3 m benefit compared to placebo/delayed patients (p≤0.001). INTERPRETATION: Eteplirsen restored dystrophin in the 30 and 50 mg/kg/wk cohorts, and in subsequently treated, placebo-controlled subjects. Duration, more than dose, accounted for dystrophin production, also resulting in ambulation stability. No severe adverse events were encountered.