Category: Nevin Manimala

Environ Microbiol. 2023 Jun 16. doi: 10.1111/1462-2920.16444. Online ahead of print.

ABSTRACT

Microbial community assembly remains largely unexplored in marine mammals, despite its potential importance for conservation and management. Here, neonatal microbiota assembly was studied in harbour seals (Phoca vitulina richardii) at a rehabilitation facility soon after maternal separation, through weaning, to the time of release back to their native environment. We found that the gingival and rectal communities of rehabilitated harbour seals were distinct from the microbiotas of formula and pool water, and became increasingly diverse and dissimilar over time, ultimately resembling the gingival and rectal communities of local wild harbour seals. Harbour seal microbiota assembly was compared to that of human infants, revealing the rapid emergence of host specificity and evidence of phylosymbiosis even though these harbour seals had been raised by humans. Early life prophylactic antibiotics were associated with changes in the composition of the harbour seal gingival and rectal communities and surprisingly, with transient increases in alpha diversity, perhaps because of microbiota sharing during close cohabitation with other harbour seals. Antibiotic-associated effects dissipated over time. These results suggest that while early life maternal contact may provide seeding for microbial assembly, co-housing of conspecifics during rehabilitation may help neonatal mammals achieve a healthy host-specific microbiota with features of resilience.

PMID:37329141 | DOI:10.1111/1462-2920.16444

Sports Health. 2023 Jun 16:19417381231178822. doi: 10.1177/19417381231178822. Online ahead of print.

ABSTRACT

BACKGROUND: Fundamental movement skills (FMS) are critical components to lifelong participation in sports and physical activity. With the rise in early sports specialization, mastery of motor skills may be limited in youth athletes. The purpose of this study was to assess FMS proficiency in highly active middle school athletes and determine whether proficiency differed between specialization levels and sex.

HYPOTHESIS: (1) Most athletes would fail to achieve proficiency in all domains of the Test of Gross Motor Development (TGMD-2), (2) highly specialized athletes would demonstrate lower proficiency in all domains of the TGMD-2, and (3) male athletes would demonstrate higher proficiency than female athletes.

STUDY DESIGN: Cross-sectional.

LEVEL OF EVIDENCE: Level 4.

METHODS: A total of 91 athletes were recruited (44 male, 12.6 ± 0.9 years). Activity level was quantified using the Hospital for Special Surgery (HSS) Pediatric Functional Activity Brief Scale (Pedi-FABS), specialization level was determined using the Jayanthi Specialization Scale, and the TGMD-2 was used to assess FMS proficiency. Descriptive statistics were used to describe gross motor, locomotor, and object control percentile rank. A 1-way analysis of variance (ANOVA) was used to assess differences in percentile rank between low, moderate, and high specialization groups and independent samples t tests were used to compare sexes (α < 0.05).

RESULTS: Mean Pedi-FABS score was 23.6 ± 4.9. In total, 24.2%, 38.5%, and 37.4% of athletes classified as low, moderate, and highly specialized, respectively. Mean percentile ranks were 56.2%, 64.7%, and 62.6% for locomotor, object control, and gross motor domains, respectively. No athlete achieved a percentile rank >99% in any domain of the TGMD-2, and there was no significant difference between specialization groups or sex.

CONCLUSION: Despite high activity levels, no athlete demonstrated proficiency in any domain of the TGMD-2, and there was no difference in proficiency between specialization levels or by sex.

CLINICAL RELEVANCE: Sport participation, regardless of level, does not ensure adequate mastery of FMS.

PMID:37329118 | DOI:10.1177/19417381231178822

Anatol J Cardiol. 2023 Jun 15. doi: 10.14744/AnatolJCardiol.2023.2953. Online ahead of print.

ABSTRACT

BACKGROUND: This study aimed to systematically review the evidence of drug-coated balloon used in the treatment of acute myocardial infarction and compared with using drug-eluting stent in terms of clinical and angiographic outcomes for a relatively long follow-up period.

METHODS: Electronic databases including PubMed, Embase, and the Cochrane Library were used to search for the information of each study. A total of 8 studies involving 1310 patients were included in this meta-analysis.

RESULTS: During a median follow-up duration of 12 months (range 3-24 months), there were no statistical differences between the drug-coated balloon and drug-eluting stent group in terms of a major adverse cardiovascular event (odds ratio = 1.07; P =.75; 95% CI: 0.72-1.57), all-cause death (odds ratio = 1.01; P =.98; 95% CI = 0.56-1.82), cardiac death (odds ratio = 0.85, P =.65; 95% CI = 0.42-1.72), target lesion revascularization (odds ratio = 1.72; P =.09; 95% CI: 0.93-3.19), recurrent myocardial infarction (odds ratio = 0.89, P =.76; 95% CI: 0.44-1.83), and thrombotic event (odds ratio = 1.10; P =.90; 95% CI: 0.24-5.02). Drug-coated balloon was not linked with risk of late lumen loss compared with drug-eluting stent (mean difference = -0.06 mm; P =.42; 95% CI: -0.22-0.09 mm). However, there was a higher incidence of target vessel revascularization noted in the drug-coated balloon group compared with the drug-eluting stent group (odds ratio = 1.88; P =.02; 95% CI: 1.10-3.22). The subgroup analysis stratified by different study types and ethnicities showed there were no significant differences between the 2 groups.

CONCLUSIONS: Using drug-coated balloon might serve as a potential alternative strategy for patients with acute myocardial infarction because of the similar clinical and angiographic outcomes compared with using drug-eluting stent; nevertheless, the issue of target vessel revascularization should be more focused on. Larger and more representative studies are needed in the future.

PMID:37329115 | DOI:10.14744/AnatolJCardiol.2023.2953

Phys Rev E. 2023 May;107(5-1):054801. doi: 10.1103/PhysRevE.107.054801.

ABSTRACT

A simple two-dimensional statistical mechanical water model, called the rose model, was used in this work. We studied how a homogeneous constant electric field affects the properties of water. The rose model is a very simple model that helps explain the anomalous properties of water. Rose water molecules are represented as two-dimensional Lennard-Jones disks with potentials for orientation-dependent pairwise interactions mimicking formations of hydrogen bonds. The original model is modified by addition of charges for interaction with the electric field. We studied what kind of influence the electric field strength has on the model’s properties. To determine the structure and thermodynamics of the rose model under the influence of the electric field we used Monte Carlo simulations. Under the influence of a weak electric field the anomalous properties and phase transitions of the water do not change. On the other hand, the strong fields shift the phase transition points as well as the position of the density maximum.

PMID:37329104 | DOI:10.1103/PhysRevE.107.054801

Phys Rev E. 2023 May;107(5-2):055302. doi: 10.1103/PhysRevE.107.055302.

ABSTRACT

Many experimentally accessible, finite-sized interacting quantum systems are most appropriately described by the canonical ensemble of statistical mechanics. Conventional numerical simulation methods either approximate them as being coupled to a particle bath or use projective algorithms which may suffer from nonoptimal scaling with system size or large algorithmic prefactors. In this paper, we introduce a highly stable, recursive auxiliary field quantum Monte Carlo approach that can directly simulate systems in the canonical ensemble. We apply the method to the fermion Hubbard model in one and two spatial dimensions in a regime known to exhibit a significant “sign” problem and find improved performance over existing approaches including rapid convergence to ground-state expectation values. The effects of excitations above the ground state are quantified using an estimator-agnostic approach including studying the temperature dependence of the purity and overlap fidelity of the canonical and grand canonical density matrices. As an important application, we show that thermometry approaches often exploited in ultracold atoms that employ an analysis of the velocity distribution in the grand canonical ensemble may be subject to errors leading to an underestimation of extracted temperatures with respect to the Fermi temperature.

PMID:37329093 | DOI:10.1103/PhysRevE.107.055302

Phys Rev E. 2023 May;107(5-1):054135. doi: 10.1103/PhysRevE.107.054135.

ABSTRACT

Chromosomes are crumpled polymer chains further folded into a sequence of stochastic loops via loop extrusion. While extrusion has been verified experimentally, the particular means by which the extruding complexes bind DNA polymer remains controversial. Here we analyze the behavior of the contact probability function for a crumpled polymer with loops for the two possible modes of cohesin binding, topological and nontopological mechanisms. As we show, in the nontopological model the chain with loops resembles a comb-like polymer that can be solved analytically using the quenched disorder approach. In contrast, in the topological binding case the loop constraints are statistically coupled due to long-range correlations present in a nonideal chain, which can be described by the perturbation theory in the limit of small loop densities. As we show, the quantitative effect of loops on a crumpled chain in the case of topological binding should be stronger, which is translated into a larger amplitude of the log-derivative of the contact probability. Our results highlight a physically different organization of a crumpled chain with loops by the two mechanisms of loop formation.

PMID:37329090 | DOI:10.1103/PhysRevE.107.054135

Phys Rev E. 2023 May;107(5-1):054402. doi: 10.1103/PhysRevE.107.054402.

ABSTRACT

Purkinje cells exhibit a reduction of the mean firing rate at intermediate-noise intensities, which is somewhat reminiscent of the response enhancement known as “stochastic resonance” (SR). Although the comparison with the stochastic resonance ends here, the current phenomenon has been given the name “inverse stochastic resonance” (ISR). Recent research has demonstrated that the ISR effect, like its close relative “nonstandard SR” [or, more correctly, noise-induced activity amplification (NIAA)], has been shown to stem from the weak-noise quenching of the initial distribution, in bistable regimes where the metastable state has a larger attraction basin than the global minimum. To understand the underlying mechanism of the ISR and NIAA phenomena, we study the probability distribution function of a one-dimensional system subjected to a bistable potential that has the property of symmetry, i.e., if we change the sign of one of its parameters, we can obtain both phenomena with the same properties in the depth of the wells and the width of their basins of attraction subjected to Gaussian white noise with variable intensity. Previous work has shown that one can theoretically determine the probability distribution function using the convex sum between the behavior at small and high noise intensities. To determine the probability distribution function more precisely, we resort to the “weighted ensemble Brownian dynamics simulation” model, which provides an accurate estimate of the probability distribution function for both low and high noise intensities and, most importantly, for the transition of both behaviors. In this way, on the one hand, we show that both phenomena emerge from a metastable system where, in the case of ISR, the global minimum of the system is in a state of lower activity, while in the case of NIAA, the global minimum is in a state of increased activity, the importance of which does not depend on the width of the basins of attraction. On the other hand, we see that quantifiers such as Fisher information, statistical complexity, and especially Shannon entropy fail to distinguish them, but they show the existence of the mentioned phenomena. Thus, noise management may well be a mechanism by which Purkinje cells find an efficient way to transmit information in the cerebral cortex.

PMID:37329070 | DOI:10.1103/PhysRevE.107.054402

Phys Rev E. 2023 May;107(5):L053001. doi: 10.1103/PhysRevE.107.L053001.

ABSTRACT

The Poynting effect is a paragon of nonlinear soft matter mechanics. It is the tendency (found in all incompressible, isotropic, hyperelastic solids) exhibited by a soft block to expand vertically when sheared horizontally. It can be observed whenever the length of the cuboid is at least four times its thickness. Here we show that the Poynting effect can be easily reversed and the cuboid can shrink vertically, simply by reducing this aspect ratio. In principle, this discovery means that for a given solid, say one used as a seismic wave absorber under a building, an optimal ratio exists where vertical displacements and vibrations can be completely eliminated. Here we first recall the classical theoretical treatment of the positive Poynting effect, and then show experimentally how it can be reversed. Using finite-element simulations, we then investigate how the effect can be suppressed. We find that cubes always provide a reverse Poynting effect, irrespective of their material properties (in the third-order theory of weakly nonlinear elasticity).

PMID:37329069 | DOI:10.1103/PhysRevE.107.L053001

Phys Rev E. 2023 May;107(5-1):054128. doi: 10.1103/PhysRevE.107.054128.

ABSTRACT

Embedded random matrix ensembles with k-body interactions are well established to be appropriate for many quantum systems. For these ensembles the two point correlation function is not yet derived, though these ensembles are introduced 50 years back. Two-point correlation function in eigenvalues of a random matrix ensemble is the ensemble average of the product of the density of eigenvalues at two eigenvalues, say E and E^{‘}. Fluctuation measures such as the number variance and Dyson-Mehta Δ_{3} statistic are defined by the two-point function and so also the variance of the level motion in the ensemble. Recently, it is recognized that for the embedded ensembles with k-body interactions the one-point function (ensemble averaged density of eigenvalues) follows the so called q-normal distribution. With this, the eigenvalue density can be expanded by starting with the q-normal form and using the associated q-Hermite polynomials He_{ζ}(x|q). Covariances S_{ζ}S_{ζ^{‘}}[over ¯] (overline representing ensemble average) of the expansion coefficients S_{ζ} with ζ≥1 here determine the two-point function as they are a linear combination of the bivariate moments Σ_{PQ} of the two-point function. Besides describing all these, in this paper formulas are derived for the bivariate moments Σ_{PQ} with P+Q≤8, of the two-point correlation function, for the embedded Gaussian unitary ensembles with k-body interactions [EGUE(k)] as appropriate for systems with m fermions in N single particle states. Used for obtaining the formulas is the SU(N) Wigner-Racah algebra. These formulas with finite N corrections are used to derive formulas for the covariances S_{ζ}S_{ζ^{‘}}[over ¯] in the asymptotic limit. These show that the present work extends to all k values, the results known in the past in the two extreme limits with k/m→0 (same as q→1) and k=m (same as q=0).

PMID:37329068 | DOI:10.1103/PhysRevE.107.054128

Phys Rev E. 2023 May;107(5-2):055304. doi: 10.1103/PhysRevE.107.055304.

ABSTRACT

We present a general and numerically efficient method for calculation of collision integrals for interacting quantum gases on a discrete momentum lattice. Here we employ the original analytical approach based on Fourier transform covering a wide spectrum of solid-state problems with various particle statistics and arbitrary interaction models, including the case of momentum-dependent interaction. The comprehensive set of the transformation principles is given in detail and realized as a computer Fortran 90 library FLBE (Fast Library for Boltzmann Equation).

PMID:37329067 | DOI:10.1103/PhysRevE.107.055304