Symmetric expression of ohnologs encoding conserved antiviral responses in tetraploid common carp suggest absence of subgenome dominance after whole genome duplication.

Allopolyploids often experience subgenome dominance, with one subgenome showing higher levels of gene expression and greater gene retention. Here, we address the functionality of both subgenomes of allotetraploid common carp (Cyprinus carpio) by analysing a functional network of interferon-stimulated genes (ISGs) crucial in anti-viral immune defence. As an indicator of subgenome dominance we investigated retainment of a core set of ohnologous ISGs. To facilitate our functional genomic analysis a high quality genome was assembled (WagV4.0). Transcriptome data from an in vitro experiment mimicking a viral infection was used to infer ISG expression. Transcriptome analysis confirmed induction of 88 ISG ohnologs on both subgenomes. In both control and infected states, average expression of ISG ohnologs was comparable between the two subgenomes. Also, the highest expressing and most inducible gene copies of an ohnolog pair could be derived from either subgenome. We found no strong evidence of subgenome dominance for common carp.

Prevalence of chronic and multisite pain in adolescents and young adults with ADHD: a comparative study between clinical and general population samples (the HUNT study).

Attention-deficit/hyperactivity disorder (ADHD) and chronic pain are prevalent and associated. We examined the prevalence and distribution of chronic pain in adolescents and young adults with ADHD using 9-years longitudinal data (from T1:2009-2011 to T3:2018-2019) with three time points from a clinical health survey compared to two age-matched reference population-based samples. Mixed-effect logistic regression and binary linear regression were used to estimate the probability for chronic and multisite pain at each time point and to compare the prevalence of chronic pain with the reference populations. The prevalence of chronic and multisite pain was high in those with ADHD, especially in female young adults, with highly prevalent chronic pain at 9 years of follow-up (75.9%) compared to 45.7% in females in the reference population. The probability of having pain was only statistically significant for chronic pain in males at 3 years of follow-up (41.9%, p = 0.021). Those with ADHD were at higher risk of reporting single-site and multisite pain compared to the general population at all measurement points. Longitudinal studies should be tailored to further understand the complex sex differences of comorbid chronic pain and ADHD in adolescents, exploring predictive factors of pain assessing long-term associations with bodyweight, psychiatric comorbidities, and possible mechanisms of stimulant use effects on pain.

Artificial intelligence-based radiomics on computed tomography of lumbar spine in subjects with fragility vertebral fractures.

PURPOSE: There is emerging evidence that radiomics analyses can improve detection of skeletal fragility. In this cross-sectional study, we evaluated radiomics features (RFs) on computed tomography (CT) images of the lumbar spine in subjects with or without fragility vertebral fractures (VFs). METHODS: Two-hundred-forty consecutive individuals (mean age 60.4 ± 15.4, 130 males) were evaluated by radiomics analyses on opportunistic lumbar spine CT. VFs were diagnosed in 58 subjects by morphometric approach on CT or XR-ray spine (D4-L4) images. DXA measurement of bone mineral density (BMD) was performed on 17 subjects with VFs. RESULTS: Twenty RFs were used to develop the machine learning model reaching 0.839 and 0.789 of AUROC in the train and test datasets, respectively. After correction for age, VFs were significantly associated with RFs obtained from non-fractured vertebrae indicating altered trabecular microarchitecture, such as low-gray level zone emphasis (LGLZE) [odds ratio (OR) 1.675, 95% confidence interval (CI) 1.215-2.310], gray level non-uniformity (GLN) (OR 1.403, 95% CI 1.023-1.924) and neighboring gray-tone difference matrix (NGTDM) contrast (OR 0.692, 95% CI 0.493-0.971). Noteworthy, no significant differences in LGLZE (p = 0.94), GLN (p = 0.40) and NGDTM contrast (p = 0.54) were found between fractured subjects with BMD T score < - 2.5 SD and those in whom VFs developed in absence of densitometric diagnosis of osteoporosis. CONCLUSIONS: Artificial intelligence-based analyses on spine CT images identified RFs associated with fragility VFs. Future studies are needed to test the predictive value of RFs on opportunistic CT scans in identifying subjects with primary and secondary osteoporosis at high risk of fracture.

The Relationship Problem Solving (RePS) Model: How Partners Influence One Another to Resolve Relationship Problems.

In this article, we synthesize existing literatures across numerous domains to introduce a novel model-the Relationship Problem Solving (RePS) model-for understanding the process through which romantic partners influence one another to resolve relationship problems. The first section briefly describes the key constructs and stages of the model. The second section details the interpersonal behaviors that influence various intrapersonal factors (e.g., affect, self-efficacy) that ultimately influence partners' motivation and ability to progress through the stages of the model. The third section uses the model to generate novel predictions that suggest that the effectiveness of these interpersonal behaviors often depends on contextual factors. Finally, the fourth section discusses the implications of this model for understanding relationship problem solving, highlights the need to consider the role of context in the problem-solving process, and offers numerous specific predictions to be addressed by future research.

Neurocognitive functioning, clinical course and functional outcome in first-treatment bipolar I disorder patients with and without clinical relapse: A 1-year follow-up study.

OBJECTIVES: Due to limited research on the association between recurrence of mood episodes and the longitudinal course of neurocognitive functioning in early phase bipolar I disorder (BD I), the impact of recurrence on neurocognition remains unclear. Further, a strong correlation between neurocognitive impairment and functional impairment has been demonstrated. The longitudinal relationship between neurocognitive impairment and functional outcome in relation to recurrence is, however, not established. METHODS: The current study investigated the longitudinal relationship between neurocognition, recurrence of mood episodes and functional outcome in a sample of first-treatment (FT) BD I patients (N = 42), with and without relapse, during a 1-year follow-up period. The longitudinal course of neurocognitive functioning in the patients was also compared to that of a group of healthy controls (N = 143). RESULTS: Compared to both patients with relapse and healthy controls, no-relapse patients showed neurocognitive improvements. The polarity of the relapse episodes was mostly depressive, and for the no-relapse patients, reduction of symptoms was associated with neurocognitive improvement. No-relapse patients showed better global and occupational functioning. CONCLUSIONS: The current study found different neurocognitive and functional trajectories in FT BD I patients with and without relapse, with differences at follow-up to some degree being mediated by current symptoms. The current findings highlight the importance of treatment focusing on neurocognition and symptom states with the aim of improving functional recovery.

The association between discontinuing hormonal contraceptives and wives' marital satisfaction depends on husbands' facial attractiveness.

How are hormonal contraceptives (HCs) related to marital well-being? Some work suggests HCs suppress biological processes associated with women's preferences for partner qualities reflective of genetic fitness, qualities that may be summarized by facial attractiveness. Given that realizing such interpersonal preferences positively predicts relationship satisfaction, any changes in women's preferences associated with changes in their HC use may interact with partner facial attractiveness to predict women's relationship satisfaction. We tested this possibility using two longitudinal studies of 118 newlywed couples. Trained observers objectively rated husbands' facial attractiveness in both studies. In study 1, wives reported their marital satisfaction every 6 mo for 4 y and then reported the history of their HC use for their relationship. In study 2, wives reported whether they were using HCs when they met their husbands and then their marital satisfaction and HC use every 4 mo for up to three waves. In both studies, and in an analysis that combined the data from both studies, wives who were using HCs when they formed their relationship with their husband were less satisfied with their marriage when they discontinued HCs if their husband had a relatively less attractive face, but more satisfied if their husband had a relatively more attractive face. Beginning HCs demonstrated no consistent associations with marital satisfaction. Incongruency between HC use at relationship formation and current HC use was negatively associated with sexual satisfaction, regardless of husbands' facial attractiveness. These findings suggest that HC use may have unintended implications for women's close relationships.

History of psychosis and previous episodes as potential explanatory factors for neurocognitive impairment in first-treatment bipolar I disorder.

OBJECTIVES: Explanatory factors for the observed neurocognitive impairment in early-stage bipolar I disorder (BD-I) have received little attention. The current study investigated neurocognitive functioning in first-treatment (FT) BD-I compared to FT schizophrenia (SCZ), and healthy controls (HCs), and the effect of history of psychosis and previous episodes in the two clinical groups. METHODS: A total of 202 FT patients with BD-I (n = 101) and SCZ spectrum disorder (n = 101), in addition to HCs (n = 101), were included. A comprehensive neurocognitive test battery was used to assess verbal learning and memory, executive functioning, processing speed, and attention and working memory. Neurocognitive functioning and the effect of history of psychosis and number of previous episodes were analyzed using separate multivariate analyses of variance and correlation analysis. RESULTS: FT patients with BD-I performed intermediately between FT SCZ spectrum patients and HCs on all measures. Compared to HCs, FT BD-I showed impaired functioning across all neurocognitive domains. No differences in neurocognitive functioning were observed in psychotic versus nonpsychotic FT patients with BD-I. With the exception of an association between number of manic episodes and two measures of executive function in FT BD-I, no associations were found between number of episodes and neurocognitive performance. CONCLUSIONS: Neurocognitive impairments were present in FT BD-I, and were not explained by history of psychosis or number of previous psychotic or depressive episodes. There were indications that executive function could be associated with number of previous manic episodes.

Effects of temperature and salinity on the growth of Alexandrium (Dinophyceae) isolates from the Salish Sea.

Toxin-producing blooms of dinoflagellates in the genus Alexandrium have plagued the inhabitants of the Salish Sea for centuries. Yet the environmental conditions that promote accelerated growth of this organism, a producer of paralytic shellfish toxins, is lacking. This study quantitatively determined the growth response of two Alexandrium isolates to a range of temperatures and salinities, factors that will strongly respond to future climate change scenarios. An empirical equation, derived from observed growth rates describing the temperature and salinity dependence of growth, was used to hindcast bloom risk. Hindcasting was achieved by comparing predicted growth rates, calculated from in situ temperature and salinity data from Quartermaster Harbor, with corresponding Alexandrium cell counts and shellfish toxin data. The greatest bloom risk, defined at µ >0.25 d(-1) , generally occurred from April through November annually; however, growth rates rarely fell below 0.10 d(-1) . Except for a few occasions, Alexandrium cells were only observed during the periods of highest bloom risk and paralytic shellfish toxins above the regulatory limit always fell within the periods of predicted bloom occurrence. While acknowledging that Alexandrium growth rates are affected by other abiotic and biotic factors, such as grazing pressure and nutrient availability, the use of this empirical growth function to predict higher risk time frames for blooms and toxic shellfish within the Salish Sea provides the groundwork for a more comprehensive biological model of Alexandrium bloom dynamics in the region and will enhance our ability to forecast blooms in the Salish Sea under future climate change scenarios.

Factors regulating excystment of Alexandrium in Puget Sound, WA, USA.

Factors regulating excystment of a toxic dinoflagellate in the genus Alexandrium were investigated in cysts from Puget Sound, Washington State, USA. Experiments were carried out in the laboratory using cysts collected from benthic seedbeds to determine if excystment is controlled by internal or environmental factors. The results suggest that the timing of germination is not tightly controlled by an endogenous clock, though there is a suggestion of a cyclical pattern. This was explored using cysts that had been stored under cold (4 °C), anoxic conditions in the dark and then incubated for 6 weeks at constant favorable environmental conditions. Excystment occurred during all months of the year, with variable excystment success ranging from 31-90%. When cysts were isolated directly from freshly collected sediments every month and incubated at the in situ bottom water temperature, a seasonal pattern in excystment was observed that was independent of temperature. This pattern may be consistent with secondary dormancy, an externally modulated pattern that prevents excystment during periods that are not favorable for sustained vegetative growth. However, observation over more annual cycles is required and the duration of the mandatory dormancy period of these cysts must be determined before the seasonality of germination can be fully characterized in Alexandrium from Puget Sound. Both temperature and light were found to be important environmental factors regulating excystment, with the highest rates of excystment observed for the warmest temperature treatment (20 °C) and in the light.

Implicit self-evaluations predict changes in implicit partner evaluations.

Do people who feel good about themselves have better relations with others? Although the notion that they do is central to both classic and modern theories, there is little strong evidence to support it. We argue that one reason for the lack of evidence is that prior research has relied exclusively on explicit measures of self- and relationship evaluation. The current longitudinal study of newlywed couples used implicit measures of self- and partner evaluation, as well as explicit measures of self-, relationship, and partner evaluation, to examine the link between self-evaluations and changes in relationship evaluations over the first 3 years of marriage. Whereas explicit self-evaluations were unrelated to changes in all interpersonal measures, implicit self-evaluations positively predicted changes in implicit partner evaluations. This finding adds to previous research by highlighting the importance of automatic processes and implicit measures in the study of close interpersonal relationships.

Perceiving greater commitment increases selfishness among disagreeable people.

Perceiving that a partner is highly committed tends to benefit close relationships. However, there may be relational drawbacks to perceiving high commitment. In particular, given that high commitment may signal that a partner is unlikely to leave the relationship, perceiving that a partner is highly committed might lead people low in agreeableness to feel comfortable behaving more selfishly toward that partner. One correlational study consisting of a highly diverse sample of individuals (n = 307), one observational study of newlywed couples (n = 202), and one experiment with undergraduate couples (n = 252) examined whether the implications of perceived partner commitment for selfish behaviors depend on agreeableness. Results demonstrated that perceiving high commitment resulted in more selfish behavior among disagreeable participants (Studies 1-3), but less selfish behavior among agreeable participants (Studies 1 and 3). Together, these results suggest that signaling commitment to disagreeable partners may backfire in romantic relationships.

Shift schedule effects on firefighter health and fitness.

BACKGROUND: Firefighter health is of utmost importance both to first responders and the individuals they serve daily. The impact of shift schedule on firefighter health remains poorly understood. OBJECTIVE: The purpose of this study was to examine differences in health and performance outcomes in firefighters across two different shift schedules. METHODS: Firefighter (N = 1995) body composition, muscular strength, endurance, flexibility, and cardiorespiratory endurance were assessed and described. A Mann-Whitney U test was conducted to compare differences between shift schedules (48/96 and 4's and 6's). RESULTS: There was a statistically significant difference in BMI (U = 70115, z=-1.988, p = .047), BF% (U = 67341, z=-2.779, p = .005), and trunk flexion score (U = 81362, z = 1.979, p = .048) favoring the 48/96 shift schedule. CONCLUSION: Firefighters following a 48/96 shift schedule exhibited improved body composition and fitness performance in comparison to peers who followed a 4's and 6's shift schedule. Findings may guide regional firefighter scheduling to optimize health and performance.

Examining the social in the prosocial: Episode-level features of social interactions and kind acts predict social connection and well-being.

Experiments prompting people to engage in more prosocial behavior (e.g., acts of kindness) or simple social interactions (e.g., acting extraverted) have both shown promise in boosting well-being. However, little is known about how much the impact on well-being depends on the type of interpersonal interaction (i.e., social vs. prosocial) or on other proximal features (e.g., whether the interaction takes place online vs. in-person, the closeness of the relationship, or amount of social connection associated with a given interaction). We randomly assigned a sample of full-time employees recruited via a special employed mTurk sample (N = 754) to perform weekly acts of kindness online versus in-person, to engage in weekly social interactions online versus in-person, or to list their daily activities (control) over the course of 4 weeks. First, on average, all conditions reported improvements in well-being (i.e., increases in positive affect and life satisfaction, decreases in negative affect) across the 4-week intervention period. Second, relative to controls, the four experimental groups reported increases in general social connectedness over time. Finally, according to auxiliary analyses collapsed across the experimental condition, closer relationship with target and non-digital medium of delivery predicted episode-level social connection, which, in turn, was associated with general social connectedness and positive affect. We conclude that the "who" and the "how" of a behavior (i.e., its target, its delivery method, and the feelings of social connection generated) are important for well-being, but not the "what" (i.e., whether the behavior is social or prosocial). (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Treatment-resistant sensory motor symptoms in persons with SCI may be signs of restless legs syndrome.

STUDY DESIGN: Case report on the successful treatment with pramipexole in four men with chronic spinal cord injury (SCI) suffering from refractory symptoms that were previously considered to be manifestations of a post-traumatic spastic syndrome or neuropathic pain. OBJECTIVE: To raise awareness among health professionals regarding the diagnostic and therapeutic possibility of restless legs syndrome (RLS) and periodic limb movements (PLMs) in some patients with SCI responding poorly to conventional treatment for spasticity or neuropathic pain. SETTING: Neurorehabilitation department of the Rehabilitation Medicine Center of Northern University Hospital, Umeå, Sweden. METHODS: Medical records and clinical data were retrospectively reviewed. RESULTS: All cases obtained treatment with pramipexole, initially 0.09-0.72 mg day(-1). Two of the cases had RLS and PLMs, one RLS only and one PLMs only. All four reported symptoms in the lower extremities and one also in the upper extremities. Three patients with residual gait function reported RLS score with/without treatment as follows: 32/11, 37/12 and 33/12. One patient with complete paraplegia (with incomplete RLS score) reported 22/10. After a follow-up period of 16, 20, 43 and 49 months, respectively, all four still reported excellent outcomes. Two remained on initial dosage; one had increased dosage from 0.09 to 0.18 mg day(-1) and one from 0.27 to 0.80 mg day(-1) during the follow-up period. CONCLUSIONS: In persons with SCI suffering from infralesional involuntary movements and/or dysesthesia and with poor response to conventional antispastic or analgesic treatment, the possibility of RLS or PLMs should be considered, as these conditions seem eminently treatable.

Attachment anxiety and the curvilinear effects of expressive suppression on individuals' and partners' outcomes.

Suppressing the expression of negative emotions tends to undermine individuals' and their partners' wellbeing. However, sometimes expressive suppression may be relatively innocuous given that individuals commonly withhold negative emotions in order to maintain close relationships, and this may be especially the case when expressive suppression is enacted by people who exhibit amplified expressions of negative emotions, such as those high in attachment anxiety. The current research examined when and for whom expressive suppression may be more or less costly by testing whether the curvilinear effect of individuals' expressive suppression on individuals' and partners' outcomes is moderated by individuals' attachment anxiety. Our results across 3 dyadic studies revealed a linear effect of expressive suppression when predicting individuals' outcomes: greater expressive suppression had costs for individuals (lower relationship satisfaction, reported responsiveness and discussion success, and greater discussion threat). Furthermore, in 4 of the 5 models, a moderated curvilinear effect of expressive suppression emerged when predicting partners' outcomes. For individuals low in attachment anxiety, low levels of expressive suppression did not incur costs for their partners' relationship satisfaction, perceptions of individuals' responsiveness, discussion success, and discussion threat. Once expressive suppression surpassed moderate levels, however, greater expressive suppression had a detrimental effect on partners' outcomes. In contrast, for individuals high in attachment anxiety, the negative effect of moderate-to-high levels of expressive suppression on partners' outcomes was attenuated. These novel results demonstrate how considering curvilinear methods can uncover when and for whom expressive suppression may be more or less costly in intimate relationships. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Activated murine macrophages secrete a metabolite of arginine with the bioactivity of endothelium-derived relaxing factor and the chemical reactivity of nitric oxide.

L-arginine-dependent synthesis of nitrite (NO2-) and nitrate (NO3-) by macrophages correlates with and is required for their execution of nonspecific cytotoxicity toward some tumor cells and microbes. However, the bioactive L-arginine metabolites responsible for cytotoxicity are unknown. Mammalian endothelial cells have recently been shown to release nitric oxide (NO.); we therefore determined if this reactive metabolite was synthesized by activated murine macrophages. Macrophage-derived NO. was detected by two independent methods: a bioassay for NO.-mediated relaxation of preconstricted rings of rabbit aorta; and a spectroscopic measurement of the reaction of NO. with clostridial ferredoxin, an Fe-S protein. After activation with IFN-gamma and LPS, macrophages continuously secreted a substance that relaxed rabbit aortic rings denuded of endothelium. Production of the vasorelaxant was enhanced by 0.5 mM L-arginine and inhibited reversibly by NG-methylated L-arginine analogs that block macrophage NO2-/NO3- synthesis. The vasorelaxant was scavenged by ferrous myoglobin, was labile, and was neither NO2- nor a cyclooxygenase metabolite. Activated M phi also secreted a substance that bleached Fd, a reaction carried out by NO. and NO2, but not NO2-. Macrophage bleaching of Fd correlated directly with time, cell number, and concomitant NO2-/NO3- production, required L-arginine, and was independent of reactive oxygen intermediates. Thus, activated murine M phi release NO. and/or a closely related, highly reactive nitrogen oxide such as NO2, during their conversion of L-arginine to NO2-/NO3-. NO. and NO2 may mediate L-arginine-dependent pathologic effects of M phi, as well as physiologic effects not previously considered for this widely distributed cell type.

Medical conditions and outcomes at 1 year after acute traumatic spinal cord injury in a Greek and a Swedish region: a prospective, population-based study.

STUDY DESIGN: Prospective, population-based study. This paper is part of the Stockholm Thessaloniki Acute Traumatic Spinal Cord Injury Study (STATSCIS). OBJECTIVES: To evaluate and compare outcomes, length of stay (LOS), associated conditions and medical complications at 1-year post-trauma. SETTINGS: The Greater Thessaloniki region, Greece, and the Greater Stockholm region, Sweden. While Stockholm follows a SCI system of care, Thessaloniki follows a fragmented 'non-system' approach. SUBJECTS: Out of the 87 cases in Thessaloniki and the 49 cases in Stockholm who comprised the study population of STATSCIS, 75 and 42 cases respectively were successfully followed-up during the first year post-trauma. RESULTS: Significantly superior outcomes (that is, survival with neurological recovery, functional ability and discharge to home) and shorter LOS for initially motor complete cases occurred in Stockholm. Management routines known to increase long-term morbidity, for example, long-term tracheostomy and indwelling urethral catheters were significantly more common in Thessaloniki. Major medical complications, that is, multiple pressure ulcers, heterotopic ossification and bacteremia/sepsis were more frequent in Thessaloniki. CONCLUSIONS: Our findings show how two rather similar cohorts of TSCI manifest large discrepancies in terms of 1-year outcomes and complications, depending on the type of management they receive. As the major difference between regions was the presence or absence of a SCI system of care, rather than differences in availability of modern medicine, the mere presence of the latter does not seem to be sufficient to guarantee adequate outcomes. This study provides strong evidence as to the urgent need of implementing a SCI system of care in Greece.

Acute management of traumatic spinal cord injury in a Greek and a Swedish region: a prospective, population-based study.

STUDY DESIGN: Prospective, population-based study. This paper is part of the Stockholm Thessaloniki Acute Traumatic Spinal Cord Injury Study (STATSCIS). OBJECTIVES: To characterize patient populations and to compare acute management after traumatic spinal cord injury (TSCI). SETTINGS: The Greater Thessaloniki region in Greece and the Greater Stockholm region in Sweden. METHODS: Inception cohorts with acute TSCI that were hospitalized during the study period, that is September 2006 to October 2007, were identified. Overall, 81 out of 87 cases consented to inclusion in Thessaloniki and 47 out of 49 in Stockholm. Data from Thessaloniki were collected through physical examinations, medical record reviews and communication with TSCI cases and medical teams. Data from Stockholm were retrieved from the Nordic Spinal Cord Injury Registry. RESULTS: There were no significant differences between study groups with regard to core clinical characteristics. In contrast, there were significant differences in (1) transfer logistics from the scene of trauma to a tertiary-level hospital (number of intermediate admissions, modes of transportation and duration of transfer) and (2) acute key therapeutic interventions, that is, the use of mechanical ventilation (49% in Thessaloniki versus 20% in Stockholm), and performance of tracheostomy (36% in Thessaloniki versus 15% in Stockholm); spinal surgery was performed significantly more often and earlier in Stockholm than in Thessaloniki. CONCLUSIONS: Despite largely similar core clinical characteristics, Stockholm and Thessaloniki cases underwent significantly different acute management, most probably to be attributed to adaptations to the differing regional approaches of care one following a systematic approach of SCI care and the other not.

Look but don't touch?: Self-regulation determines whether noticing attractive alternatives increases infidelity.

People regularly encounter tempting alternatives to their relationship partners, and it has been argued that paying attention to desirable alternatives increases the risk of infidelity. However, whether the temptation of noticing attractive alternatives leads to actual infidelity should depend on the ability to resist such temptation. More specifically, taking heed of attractive others should increase the likelihood of infidelity only when people lack self-regulatory ability. One experiment and one longitudinal study of newlyweds both demonstrated that the implications of attending to attractive alternatives for infidelity depended on participants' self-regulatory ability to resist such temptations. Specifically, the tendency to notice attractive alternatives was associated with greater infidelity among those with poorer self-regulatory ability, but not among those with greater self-regulatory ability. These results further understanding about how people can maintain and protect their relationships in the face of temptation. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Assessing an Automatic Procedure of Extraction of Physiological Parameters from Skin using Video Photoplethysmography.

Video Photoplethysmography (vPPG) allows for estimation of blood volume pulse (BVP) from the skin by means of a video camera recording at high frequency rate. The estimation procedure presents several drawbacks in its application to real world conditions, such as light changes or movements that often generate artifacts in the extracted BVP waveform. In addition, the process requires a skin segmentation algorithm to distinguish skin pixels from the background. To date, even the most refined skin segmentation algorithms still need a manual definition that could lead to incorrect pixel classification, and consequently to a decrease in the signal-to-noise ratio (SNR). We here propose a fully autonomic procedure able to extract BVP from video recordings of the skin in real world conditions.The experimental protocol is designed to record the signals of interest and to evaluate changes in the Autonomic Nervous System modulation of the heart during a baseline condition and a controlled breathing phase. Video recordings are gathered from 4 young healthy subjects (age: 21±1 years). vPPG signals are processed in order to extract the BVP waveform, and a peak detection algorithm detects pulse wave peaks that are then used to compute specific measures of heart rate variability (HRV).The procedure is successfully validated by comparing the extracted HRV measures against those extracted using a finger photoplethysmograph (fPPG) using three different skin segmentation algorithms from BVP signals.