On the use of the group SO(4,2) in atomic and molecular physics

In this paper the dynamical noninvariance group SO(4,2) for a hydrogen-like atom is derived through two different approaches. The first one is by an established traditional ascent process starting from the symmetry group SO(3). This approach is presented in a mathematically oriented original way with a special emphasis on maximally superintegrable systems, N-dimensional extension and little groups. The second approach is by a new symmetry descent process starting from the noninvariance dynamical group Sp(8,R) for a four-dimensional harmonic oscillator. It is based on the little known concept of a Lie algebra under constraints and corresponds in some sense to a symmetry breaking mechanism. This paper ends with a brief discussion of the interest of SO(4,2) for a new group-theoretical approach to the periodic table of chemical elements. In this connection, a general ongoing programme based on the use of a complete set of commuting operators is briefly described. It is believed that the present paper could be useful not only to the atomic and molecular community but also to people working in theoretical and mathematical physics.Comment: 31 page

The increase of the functional entropy of the human brain with age

We use entropy to characterize intrinsic ageing properties of the human brain. Analysis of fMRI data from a large dataset of individuals, using resting state BOLD signals, demonstrated that a functional entropy associated with brain activity increases with age. During an average lifespan, the entropy, which was calculated from a population of individuals, increased by approximately 0.1 bits, due to correlations in BOLD activity becoming more widely distributed. We attribute this to the number of excitatory neurons and the excitatory conductance decreasing with age. Incorporating these properties into a computational model leads to quantitatively similar results to the fMRI data. Our dataset involved males and females and we found significant differences between them. The entropy of males at birth was lower than that of females. However, the entropies of the two sexes increase at different rates, and intersect at approximately 50 years; after this age, males have a larger entropy

Repetitive arm functional tasks after stroke (RAFTAS): a pilot randomised controlled trial

Background Repetitive functional task practise (RFTP) is a promising treatment to improve upper limb recovery following stroke. We report the findings of a study to determine the feasibility of a multi-centre randomised controlled trial to evaluate this intervention. Methods A pilot randomised controlled trial was conducted. Patients with new reduced upper limb function were recruited within 14 days of acute stroke from three stroke units in North East England. Participants were randomised to receive a four week upper limb RFTP therapy programme consisting of goal setting, independent activity practise, and twice weekly therapy reviews in addition to usual post stroke rehabilitation, or usual post stroke rehabilitation. The recruitment rate; adherence to the RFTP therapy programme; usual post stroke rehabilitation received; attrition rate; data quality; success of outcome assessor blinding; adverse events; and the views of study participants and therapists about the intervention were recorded. Results Fifty five eligible patients were identified, 4-6% of patients screened at each site. Twenty four patients participated in the pilot study. Two of the three study sites met the recruitment target of 1-2 participants per month. The median number of face to face therapy sessions received was 6 [IQR 3-8]. The median number of daily repetitions of activities recorded was 80 [IQR 39-80]. Data about usual post stroke rehabilitation were available for 18/24 (75%). Outcome data were available for 22/24 (92%) at one month and 20/24 (83%) at three months. Outcome assessors were unblinded to participant group allocation for 11/22 (50%) at one month and 6/20 (30%) at three months. Four adverse events were considered serious as they resulted in hospitalisation. None were related to study treatment. Feedback from patients and local NHS therapists about the RFTP programme was mainly positive. Conclusions A multi-centre randomised controlled trial to evaluate an upper limb RFTP therapy programme provided early after stroke is feasible and acceptable to patients and therapists, but there are issues which needed to be addressed when designing a Phase III study. A Phase III study will need to monitor and report not only recruitment and attrition but also adherence to the intervention, usual post stroke rehabilitation received, and outcome assessor blinding

Automated tuning of an eight-channel cardiac transceive array at 7 tesla using piezoelectric actuators.

Ultra-high field (UHF) MR scanning in the body requires novel coil designs due to B1 field inhomogeneities. In the transverse electromagnetic field (TEM) design, maximum B1 transmit power can only be achieved if each individual transmit element is tuned and matched for different coil loads, which requires a considerable amount of valuable scanner time.An integrated system for autotuning a multichannel parallel transmit (pTx) cardiac TEM array was devised, using piezoelectric actuators, power monitoring equipment and control software. The reproducibility and performance of the system were tested and the power responses of the coil elements were profiled. An automated optimization method was devised and evaluated.The time required to tune an eight-element pTx cardiac RF array was reduced from a mean of 30 min to less than 10 min with the use of this system.Piezoelectric actuators are an attractive means of tuning RF coil arrays to yield more efficient B1 transmission into the subject. An automated mechanism for tuning these elements provides a practical solution for cardiac imaging at UHF, bringing this technology closer to clinical use

The differential effects of ecstasy/polydrug use on executive components: shifting, inhibition, updating and access to semantic memory

Rationale/Objectives Recent theoretical models suggest that the central executive may not be a unified structure. The present study explored the nature of central executive deficits in ecstasy users. Methods In study 1, 27 ecstasy users and 34 non-users were assessed using tasks to tap memory updating (computation span; letter updating) and access to long-term memory (a semantic fluency test and the Chicago Word Fluency Test). In study 2, 51 ecstasy users and 42 non-users completed tasks that assess mental set switching (number/letter and plus/minus) and inhibition (random letter generation). Results MANOVA revealed that ecstasy users performed worse on both tasks used to assess memory updating and on tasks to assess access to long-term memory (C- and S-letter fluency). However, notwithstanding the significant ecstasy group-related effects, indices of cocaine and cannabis use were also significantly correlated with most of the executive measures. Unexpectedly, in study 2, ecstasy users performed significantly better on the inhibition task, producing more letters than non-users. No group differences were observed on the switching tasks. Correlations between indices of ecstasy use and number of letters produced were significant. Conclusions The present study provides further support for ecstasy/polydrug-related deficits in memory updating and in access to long-term memory. The surplus evident on the inhibition task should be treated with some caution, as this was limited to a single measure and has not been supported by our previous work

Strengthening seasonal marine CO2 variations due to increasing atmospheric CO2

The increase of atmospheric CO2 (ref. 1) has been predicted to impact the seasonal cycle of inorganic carbon in the global ocean2,3, yet the observational evidence to verify this prediction has been missing. Here, using an observation-based product of the oceanic partial pressure of CO2 (pCO2) covering the past 34 years, we find that the winter-to-summer difference of the pCO2 has increased on average by 2.2 ± 0.4 μatm per decade from 1982 to 2015 poleward of 10° latitude. This is largely in agreement with the trend expected from thermodynamic considerations. Most of the increase stems from the seasonality of the drivers acting on an increasing oceanic pCO2 caused by the uptake of anthropogenic CO2 from the atmosphere. In the high latitudes, the concurrent ocean-acidification-induced changes in the buffer capacity of the ocean enhance this effect. This strengthening of the seasonal winter-to-summer difference pushes the global ocean towards critical thresholds earlier, inducing stress to ocean ecosystems and fisheries4. Our study provides observational evidence for this strengthening seasonal difference in the oceanic carbon cycle on a global scale, illustrating the inevitable consequences of anthropogenic CO2 emissions

Stability mechanisms of a thermophilic laccase probed by molecular dynamics.

Laccases are highly stable, industrially important enzymes capable of oxidizing a large range of substrates. Causes for their stability are, as for other proteins, poorly understood. In this work, multiple-seed molecular dynamics (MD) was applied to a Trametes versicolor laccase in response to variable ionic strengths, temperatures, and glycosylation status. Near-physiological conditions provided excellent agreement with the crystal structure (average RMSD ∼0.92 Å) and residual agreement with experimental B-factors. The persistence of backbone hydrogen bonds was identified as a key descriptor of structural response to environment, whereas solvent-accessibility, radius of gyration, and fluctuations were only locally relevant. Backbone hydrogen bonds decreased systematically with temperature in all simulations (∼9 per 50 K), probing structural changes associated with enthalpy-entropy compensation. Approaching T opt (∼350 K) from 300 K, this change correlated with a beginning "unzipping" of critical β-sheets. 0 M ionic strength triggered partial denucleation of the C-terminal (known experimentally to be sensitive) at 400 K, suggesting a general salt stabilization effect. In contrast, F(-) (but not Cl(-)) specifically impaired secondary structure by formation of strong hydrogen bonds with backbone NH, providing a mechanism for experimentally observed small anion destabilization, potentially remedied by site-directed mutagenesis at critical intrusion sites. N-glycosylation was found to support structural integrity by increasing persistent backbone hydrogen bonds by ∼4 across simulations, mainly via prevention of F(-) intrusion. Hydrogen-bond loss in distinct loop regions and ends of critical β-sheets suggest potential strategies for laboratory optimization of these industrially important enzymes

Comparative fitness analysis of D-cycloserine resistant mutants reveals both fitness-neutral and high-fitness cost genotypes

Drug resistant infections represent one of the most challenging medical problems of our time. D-cycloserine is an antibiotic used for six decades without significant appearance and dissemination of antibiotic resistant strains, making it an ideal model compound to understand what drives resistance evasion. We therefore investigated why Mycobacterium tuberculosis fails to become resistant to D-cycloserine. To address this question, we employed a combination of bacterial genetics, genomics, biochemistry and fitness analysis in vitro, in macrophages and in mice. Altogether, our results suggest that the ultra-low rate of emergence of D-cycloserine resistance mutations is the dominant biological factor delaying the appearance of clinical resistance to this antibiotic. Furthermore, we also identified potential compensatory mechanisms able to minimize the severe fitness costs of primary D-cycloserine resistance conferring mutations

Targeting intolerance of uncertainty in young children diagnosed with autism: A randomized controlled trial of a parent-mediated group intervention

\ua9 2025 The Author(s). JCPP Advances published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health. Background: Young children diagnosed with autism experience high rates of co-occurring anxiety, with uncertainty-related concerns commonly reported. This randomized controlled trial investigated an 8-week parent-mediated group anxiety intervention, “Coping with Uncertainty in Everyday Situations” (CUES-Junior\ua9). Methods: Parents of 4–7-year-old children diagnosed with autism and experiencing uncertainty-related anxiety were recruited. The primary outcome was change from baseline in blinded assessor ratings of child responses to uncertainty and impact on family, measured post-intervention and 2-month follow-up. Secondary outcomes were parent-reported child anxiety and intolerance of uncertainty (IU), parental IU and mental health, parenting sense of competence, along with intervention feasibility and acceptability. Results: Sixty-four children were randomized to CUES-Junior\ua9 (n = 33) or waitlist (n = 31); five families withdrew post-randomization. Immediately post-intervention, significantly more CUES-Junior\ua9 participants were rated as clinically improved from baseline in child responses to uncertainty (OR = 34.48; 95% CI = 1.72–690.04, p = 0.02) and in family impact (OR = 8.99; 95% CI = 1.52–53.05, p = 0.02) compared to waitlist. Significant improvements were also observed in parent-reported child IU and parenting satisfaction, favoring CUES-Junior\ua9. At subsequent 2-month follow-up, CUES-Junior\ua9 participants showed sustained improvements in the impact of uncertainty on children, and parental ratings of child IU and anxiety, parenting sense of competence, and parental stress, compared to baseline. The program was feasible to administer and acceptable to parents. Conclusions: CUES-Junior\ua9 had an immediate treatment effect on child responses to uncertain situations and impact on families, with maintained improvements observed at follow-up. This novel mechanism-targeted and autism-informed program holds promise for addressing early uncertainty-related anxiety in young children diagnosed with autism

Cost-effectiveness of ultra-low-dose quadruple combination therapy for high blood pressure

Objective: To determine the cost-effectiveness and cost-utility of a quadpill containing irbesartan 37.5 mg, amlodipine 1.25 mg, indapamide 0.625 mg and bisoprolol 2.5 mg in comparison with irbesartan 150 mg for people with hypertension who are either untreated or receiving monotherapy. Methods: We conducted a within-trial and modelled economic evaluation of the Quadruple UltrA-low-dose tReaTment for hypErTension trial. The analysis was preplanned, and medications and health service use captured during the trial. The main outcomes were incremental cost-effectiveness ratios (ICERs) for cost per mm Hg systolic blood pressure (BP) reduction at 3 months, and modelled cost per quality-adjusted life year (QALY) over a lifetime. Results: The within-trial analysis showed no clear difference in cost per mm Hg BP lowering between randomised treatments at 3 months ($A10 (95$A -18 to $A37) per mm Hg per person) for quadpill versus monotherapy. The modelled cost-utility over a lifetime projected a mean incremental cost of$A265 (95% UI $A166 to$A357) and a mean 0.02 QALYs gained (95% UI 0.01 to 0.03) per person with quadpill therapy compared with monotherapy. Quadpill therapy was cost-effective in the base case (ICER of $A14 006 per QALY), and the result was sensitive to the quadpill cost in one-way sensitivity analysis. Conclusion(s): Quadpill in comparison with monotherapy is comparably cost-effective for short-term BP lowering. In the long-term, quadpill therapy is likely to be cost-effective. Trial registration number: ANZCTRN12616001144404