Symmetry groupoids and admissible vector fields for coupled cell networks

The space of admissible vector fields, consistent with the structure of a network of coupled dynamical systems, can be specified in terms of the network's symmetry groupoid. The symmetry groupoid also determines the robust patterns of synchrony in the network – those that arise because of the network topology. In particular, synchronous cells can be identified in a canonical manner to yield a quotient network. Admissible vector fields on the original network induce admissible vector fields on the quotient, and any dynamical state of such an induced vector field can be lifted to the original network, yielding an analogous state in which certain sets of cells are synchronized. In the paper, necessary and sufficient conditions are specified for all admissible vector fields on the quotient to lift in this manner. These conditions are combinatorial in nature, and the proof uses invariant theory for the symmetric group. Also the symmetry groupoid of a quotient is related to that of the original network, and it is shown that there is a close analogy with the usual normalizer symmetry that arises in group-equivariant dynamics

GABA-B controls persistent Na+ current and coupled Na+-activated K+ current

AbstractThe GABA-B receptor is densely expressed throughout the brain and has been implicated in many CNS functions and disorders, including addiction, epilepsy, spasticity, schizophrenia, anxiety, cognitive deficits, and depression, as well as various aspects of nervous system development. How one GABA-B receptor is involved in so many aspects of CNS function remains unanswered. Activation of GABA-B receptors is normally thought to produce inhibitory responses in the nervous system, but puzzling contradictory responses exist. Here we report that in rat mitral cells of the olfactory bulb, GABA-B receptor activation inhibits both the persistent sodium current (INaP) and the sodium-activated potassium current (IKNa), which is coupled to it. We find that the primary effect of GABA-B activation is to inhibit INaP, which has the secondary effect of inhibiting IKNabecause of its dependence on persistent sodium entry for activation. This can have either a net excitatory or inhibitory effect depending on the balance of INaP/IKNacurrents in neurons. In the olfactory bulb, the cell bodies of mitral cells are densely packed with sodium-activated potassium channels. These channels produce a large IKNawhich, if constitutively active, would shunt any synaptic potentials traversing the soma before reaching the spike initiation zone. However, GABA-B receptor activation might have the net effect of reducing the IKNablocking effect, thus enhancing the effectiveness of synaptic potentials.</jats:p

Promoting Weight Loss Before Pregnancy: Feasible or Futile?

Pre-pregnancy obesity is a well-established risk factor for several adverse maternal and fetal outcomes, including gestational diabetes, hypertension, cesarean sections, and fetal macrosomia. Weight loss before pregnancy could help prevent such complications, but the feasibility of such an approach remains unknown. The current study examined the feasibility of a 3-month pre-pregnancy behavioral weight loss program in 12 overweight/obese women planning pregnancy. The 3 month program resulted in an average 5.4 ± 3.0 kg weight loss and significant improvements in self-monitoring, physical activity, eating and exercise self-efficacy, and healthy eating (p \u3c 0.04). By the end of the 9 month follow-up, half of sample (n = 6) had conceived. Women reported significant increases in weekly or more frequent self-weighing (p \u3c 0.0001), counting calories (p \u3c 0.001), consuming fruit and vegetables (p = 0.007), and cutting out fat (p = 0.0001) and junk foods (p = 0.002). A lifestyle modification program to promote weight loss before pregnancy promoted clinically significant weight loss and appeared feasible

Assessing, quantifying and valuing the ecosystem services of coastal lagoons

The natural conservation of coastal lagoons is important not only for their ecological importance, but also because of the valuable ecosystem services they provide for human welfare and wellbeing. Coastal lagoons are shallow semi-enclosed systems that support important habitats such as wetlands, mangroves, salt-marshes and seagrass meadows, as well as a rich biodiversity. Coastal lagoons are also complex social-ecological systems with ecosystem services that provide livelihoods, wellbeing and welfare to humans. This study assessed, quantified and valued the ecosystem services of 32 coastal lagoons. The main findings of the study are: (i) the definitions of ecosystem services are still not generally accepted; (ii) the quantification of ecosystem services is made in many different ways, using different units; (iii) the evaluation in monetary terms of some ecosystem service is problematic, often relying on non-monetary evaluation methods; (iv) when ecosystem services are valued in monetary terms, this may represent very different human benefits; and, (v) different aspects of climate change, including increasing temperature, sea-level rise and changes in rainfall patterns threaten the valuable ecosystem services of coastal lagoons.DEVOTES project, from the European Union's Seventh Framework Programme for research, technological development and demonstration [308392]; networks and communities of Eurolag; Future Earth Coasts; SCOR; Fundacao para a Ciencia e a Tecnologia (FCT) Investigador Programme [IF/00331/2013]; Fundacao para a Ciencia e a Tecnologia [UID/MAR/04292/2013]; CESAM by FCT/MEC national funds (PIDDAC) [UID/AMB/50017/2013 - POCI-01-0145-FEDER-007638]; FEDER; European Commission, under the 7th Framework Programme through the collaborative research project LAGOONS [283157]; FCT [SFRH/BPD/107823/2015, SFRH/BPD/91494/2012

The utility of wearable devices in assessing ambulatory impairments of people with multiple sclerosis in free-living conditions

Ambulatory impairments; Machine learning; Multiple sclerosisDeficiencias ambulatorias; Aprendizaje automático; Esclerosis múltipleDeficiències ambulatòries; Aprenentatge automàtic; Esclerosi múltipleAbstract Background and objectives Multiple sclerosis (MS) is a progressive inflammatory and neurodegenerative disease of the central nervous system affecting over 2.5 million people globally. In-clinic six-minute walk test (6MWT) is a widely used objective measure to evaluate the progression of MS. Yet, it has limitations such as the need for a clinical visit and a proper walkway. The widespread use of wearable devices capable of depicting patients’ activity profiles has the potential to assess the level of MS-induced disability in free-living conditions. Methods In this work, we extracted 96 features in different temporal granularities (from minute-level to day-level) from wearable data and explored their utility in estimating 6MWT scores in a European (Italy, Spain, and Denmark) MS cohort of 337 participants over an average of 10 months’ duration. We combined these features with participants’ demographics using three regression models including elastic net, gradient boosted trees and random forest. In addition, we quantified the individual feature's contribution using feature importance in these regression models, linear mixed-effects models, generalized estimating equations, and correlation-based feature selection (CFS). Results The results showed promising estimation performance with R2 of 0.30, which was derived using random forest after CFS. This model was able to distinguish the participants with low disability from those with high disability. Furthermore, we observed that the minute-level (≤ 8 minutes) step count, particularly those capturing the upper end of the step count distribution, had a stronger association with 6MWT. The use of a walking aid was indicative of ambulatory function measured through 6MWT. Conclusions This study demonstrates the utility of wearables devices in assessing ambulatory impairments in people with MS in free-living conditions and provides a basis for future investigation into the clinical relevance.The RADAR-CNS project has received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 115902. This Joint Undertaking receives support from the European Union's Horizon 2020 research and innovation programme and EFPIA, www.imi.europa.eu. This paper reflects the views of the RADAR-CNS consortium and neither IMI nor the European Union and EFPIA are liable for any use that may be made of the information contained herein. The funding body have not been involved in the design of the study, the collection or analysis of data, or the interpretation of data. RJBD is supported by the following: (1) NIHR Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London, London, UK; (2) Health Data Research UK, which is funded by the UK Medical Research Council, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Department of Health and Social Care (England), Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Health and Social Care Research and Development Division (Welsh Government), Public Health Agency (Northern Ireland), British Heart Foundation and Wellcome Trust; (3) The BigData@Heart Consortium, funded by the Innovative Medicines Initiative-2 Joint Undertaking under grant agreement No. 116074. This Joint Undertaking receives support from the European Union's Horizon 2020 research and innovation programme and EFPIA; it is chaired by DE Grobbee and SD Anker, partnering with 20 academic and industry partners and ESC; (4) the National Institute for Health Research University College London Hospitals Biomedical Research Centre; (5) the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London; (6) the UK Research and Innovation London Medical Imaging & Artificial Intelligence Centre for Value Based Healthcare; (7) the National Institute for Health Research (NIHR) Applied Research Collaboration South London (NIHR ARC South London) at King's College Hospital NHS Foundation Trust

Elevated blood pressure among adolescents in sub-Saharan Africa : A systematic review and meta-analysis

Background More people from sub-Saharan Africa aged between 20 years and 60 years are affected by end-organ damage due to underlying hypertension than people in high-income countries. However, there is a paucity of data on the pattern of elevated blood pressure among adolescents aged 10–19 years in sub-Saharan Africa. We aimed to provide pooled estimates of high blood pressure prevalence and mean levels in adolescents aged 10–19 years across sub-Saharan Africa. Methods In this systematic review and meta-analysis, we searched PubMed, Google Scholar, African Index Medicus, and Embase to identify studies published from Jan 1, 2010, to Dec 31, 2021. To be included, primary studies had to be observational studies of adolescents aged 10–19 years residing in sub-Saharan African countries reporting the pooled prevalence of elevated blood pressure or with enough data to compute these estimates. We excluded studies on non-systemic hypertension, in African people not living in sub-Saharan Africa, with participant selection based on the presence of hypertension, and with adult cohorts in which we could not disaggregate data for adolescents. We independently extracted relevant data from individual studies using a standard data extraction form. We used a random-effects model to estimate the pooled prevalence of elevated blood pressure and mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels overall and on a sex-specific basis. This study is registered with PROSPERO (CRD42022297948). Findings We identified 2559 studies, and assessed 81 full-text studies for eligibility, of which 36 studies comprising 37 926 participants aged 10–19 years from ten (20%) of 49 sub-Saharan African countries were eligible. A pooled sample of 29 696 adolescents informed meta-analyses of elevated blood pressure and 27 155 adolescents informed meta-analyses of mean blood pressure. Sex data were available from 26 818 adolescents (14 369 [53·6%] were female and 12 449 [46·4%] were male) for the prevalence of elevated blood pressure and 23 777 adolescents (12 864 [54·1%] were female and 10 913 [45·9%] were male) for mean blood pressure. Study quality was high, with no low-quality studies. The reported prevalence of elevated blood pressure ranged from 4 (0·2%) of 1727 to 1755 (25·1%) of 6980 (pooled prevalence 9·9%, 95% CI 7·3–12·5; I2=99·2%, pheterogeneity<0·0001). Mean SBP was 111 mm Hg (95% CI 108–114) and mean DBP was 68 mm Hg (66–70). 13·4% (95% CI 12·9–13·9; pheterogeneity<0·0001) of male participants had elevated blood pressure compared with 11·9% (11·3–12·4; pheterogeneity<0·0001) of female participants (odds ratio 1·04, 95% CI 0·81–1·34; pheterogeneity<0·0001). Interpretation To our knowledge, this systematic review and meta-analysis is the first systematic synthesis of blood pressure data specifically derived from adolescents in sub-Saharan Africa. Although many low-income countries were not represented in our study, our findings suggest that approximately one in ten adolescents have elevated blood pressure across sub-Saharan Africa. Accordingly, there is an urgent need to improve preventive heart-health programmes in the region. Funding None