Chaos and Thermalization in the one-dimensional Bose-Hubbard model in the classical-field approximation

In this thesis, we present a comprehensive study of chaos and thermalization of the one-dimensional Bose-Hubbard Model (BHM) within the classical field approximation. Two quantitative measures are compared: the ensemble-averaged Finite-time Maximal Lyapunov exponent, a measures of chaos and the normalized spectral entropy, a measure of the distance between the numerical time-averaged momentum distribution and the one predicted by thermodynamics. A threshold for chaos is found, which depends on two parameters, the nonlinearity and the total energy-per-particle. Below the threshold, the dynamics are regular, while far above the threshold, complete thermalization is observed, as measured by the normalized spectral entropy. We study individual resonances in the Bose-Hubbard model to determine the criterion for chaos. The criterion based on Chirikov's method of overlapping resonances diverges in the thermodynamic limit, in contrast to the criterion parameters inferred from numerical calculations, signifying the failure of the standard Chirikov's approach. The Ablowitz-Ladik lattice is one of several integrable models that are close to the BHM. We outline the method of Inverse Scattering Transform and generate the integrals of motion of the Ablowitz-Ladik lattice. Furthermore, we discuss the possible role of these quantities in the relaxation dynamics of the BHM.Comment: PhD Thesis. 143 pages. Minor edits

Generalized Thermalization in an Integrable Lattice System

After a quench, observables in an integrable system may not relax to the standard thermal values, but can relax to the ones predicted by the generalized Gibbs ensemble (GGE) [M. Rigol et al., Phys. Rev. Lett. 98, 050405 (2007)]. The GGE has been shown to accurately describe observables in various one-dimensional integrable systems, but the origin of its success is not fully understood. Here we introduce a microcanonical version of the GGE and provide a justification of the GGE based on a generalized interpretation of the eigenstate thermalization hypothesis, which was previously introduced to explain thermalization of nonintegrable systems. We study relaxation after a quench of one-dimensional hard-core bosons in an optical lattice. Exact numerical calculations for up to 10 particles on 50 lattice sites (~10^10 eigenstates) validate our approach.Comment: 8 pages, 9 figures, as publishe

Higher dietary flavonoid intakes are associated with lower objectively measured body composition in women: evidence from discordant monozygotic twins

Background: Although dietary flavonoid intake has been associated with less weight gain there are limited data on its impact on fat mass and the contribution of genetic factors to this relationship has not previously been assessed. Objective: To examine associations between flavonoid intakes and fat mass. Design: In a study of 2734 healthy female twins aged 18-83 years from the TwinsUK registry intakes oftotalflavonoids and seven subclasses(flavanones, anthocyanins, flavan-3-ols, flavonols, flavones, polymers and proanthocyanidins) were calculated from food frequency questionnaires. Measures of DXA-derived fat mass included limb-to-trunk fat ratio (FMR), fat mass index and central fat mass index. Results: In cross-sectional multivariable analyses, higher intake of anthocyanins, flavonols and proanthocyanidins were associated with lower FMR, with differences between extreme quintiles of -0.03 (SE 0.02 P-trend = 0.02), -0.03 (SE 0.02 P-trend = 0.03) and -0.05 (SE 0.02 P-trend <0.01), respectively. These associationsremained significant even after further adjustment for fibre and total fruit and vegetable intakes. In monozygotic intake-discordant twin-pairs, those with higher intakes of flavan-3-ols (n= 154, P = 0.03), flavonols (n= 173, P = 0.03) and proanthocyanidins (n= 172, P < 0.01)had significantly lower FMR than their cotwins with within-pair differences of 3-4%. Furthermore, in confirmatory food-based analyses, twins with higher intake of flavonol- (onion, tea and pears, P = 0.01) and proanthocyanidin- (apples and cocoa drinks, P = 0.04) and, in younger participants (< 50 y) only, anthocyanin-rich foods (berries, pears, grapes and wine, P = 0.01) had 3-9% lower FMR than their co-twins. Conclusions: These data suggest that higher habitual intake of a number of flavonoids, including anthocyanins,flavan-3-ols,flavonols and proanthocyanidins, are associated with lower fat massindependent ofshared genetic and common environmental factors. Intervention trials are now needed to further examine the effect of flavonoid-rich foods on body composition

Epigenetics and social inequalities in asthma and allergy

Respiratory illnesses, such as asthma and allergy disorders, are disproportionately more common among minority racial/ethnic groups and those of low socioeconomic status. In the United States, asthma prevalence and severity are highest among Puerto Ricans (19.2%), American Indians/Alaska Natives (13%), and Black Americans (12.7%) and higher in families living below the poverty threshold than among those living above it (11% vs 8%–9%).1 Many studies of asthma/allergy inequalities assume that genetic differences underlie racial/ethnic differences in these disorders, pointing to genetic ancestry differences between races, but most genetic variants fail to explain racial/ethnic differences and are usually studied only in White populations.2 In reality, racial and ethnic groups—terms that are often used interchangeably and in overlapping ways—can exhibit varying levels of genetic ancestry, cultural traits, and environmental exposures that all may be entangled together. Thus, any genetic finding differing by race/ethnicity can be confounded by social and environmental factors that also track with different ancestries. However, epigenetic mechanisms (i.e., heritable and stable changes in gene expression) may prove important in explaining these inequalities, as they are influenced by a combination of environmental, social, and genetic factors

Young people’s recall and perceptions of gambling advertising and intentions to gamble on sport

Background There has been an increased international policy focus on the factors that may contribute to, and prevent, the normalization of gambling for young people. However, there is still limited research, which investigates the role of advertising in shaping young people’s gambling attitudes and consumption intentions. Methods Mixed methods study of 111 young people aged 11–16 years recruited from community basketball stadiums in Victoria, Australia, between May and July 2018. Interviewer-assisted surveys investigated recall and awareness of sports betting brands, perceptions of promotional strategies, intention to gamble, and reasons for betting on particular sports. Quantitative data were analyzed using descriptive statistics and χ2 tests. Thematic analyses were used to interpret qualitative responses. Results Young people had high recall and awareness of advertising, with most able to name at least one betting brand (n = 90, 81.1%), and many demonstrating a high awareness of the distinct characteristics (such as colors and appeal strategies) of different brands. A fifth of young people (n = 25, 22.5%) expressed intentions to gamble at 18 years, with boys significantly more likely than girls to state they would gamble (χ2 = 10.90, p = .001). Young people perceived that advertising strategies associated with inducement promotions would be the most influential in encouraging individuals to gamble. While many young people took promotions at face value, there was evidence that some were able to critically engage with and challenge the messages within marketing. Discussion and conclusions Current regulatory structures appear to be ineffective in limiting young people’s recall and awareness of gambling advertising. Lessons from tobacco control support the application of precautionary approaches as a more effective way to limit young people’s development of positive gambling attitudes and behaviors

Profiling lung adenocarcinoma by liquid biopsy: can one size fit all?

BACKGROUND: Cancer is first and foremost a disease of the genome. Specific genetic signatures within a tumour are prognostic of disease outcome, reflect subclonal architecture and intratumour heterogeneity, inform treatment choices and predict the emergence of resistance to targeted therapies. Minimally invasive liquid biopsies can give temporal resolution to a tumour's genetic profile and allow the monitoring of treatment response through levels of circulating tumour DNA (ctDNA). However, the detection of ctDNA in repeated liquid biopsies is currently limited by economic and time constraints associated with targeted sequencing. METHODS: Here we bioinformatically profile the mutational and copy number spectrum of The Cancer Genome Network's lung adenocarcinoma dataset to uncover recurrently mutated genomic loci. RESULTS: We build a panel of 400 hotspot mutations and show that the coverage extends to more than 80% of the dataset at a median depth of 8 mutations per patient. Additionally, we uncover several novel single-nucleotide variants present in more than 5% of patients, often in genes not commonly associated with lung adenocarcinoma. CONCLUSION: With further optimisation, this hotspot panel could allow molecular diagnostics laboratories to build curated primer banks for 'off-the-shelf' monitoring of ctDNA by droplet-based digital PCR or similar techniques, in a time- and cost-effective manner

The Effect Of High Intensity Interval Run Training On Cross Sectional Area Of The Vastus Lateralis In Untrained College Students

International Journal of Exercise Science 10(1): 137-145, 2017 Aerobic cycling has been repeatedly shown to induce hypertrophy in skeletal muscle across a variety of populations, while there has been a lack of investigation into the impact of running upon hypertrophy. An increasingly popular model of aerobic exercise is high-intensity interval training (HIIT); in addition to its positive impact upon cardiovascular health, HIIT may be sufficient for inducing significant muscular hypertrophy. Therefore, the purpose of this investigation was to examine the influence of a high-intensity interval running protocol upon hypertrophy of the vastus lateralis in an untrained, young population. Twelve recreationally active university students (Male: 2; Female: 10; 19.9±0.5 yr.; 169.8±1.9 cm; 63.8±2.3 kg; VO2max: 42.1±1.6 ml.kg-1min-1) completed 24.5±0.6 sessionsof high-intensity interval run training over 10 weeks. The protocol consisted of four sets of 4 minutes running at 90-95% HRmax followed by 3 minutes active rest at 70% HRmax. Relative and absolute aerobic capacity increased 5.2±2.2% and 6.0±2.3% respectively as a result of the intervention (p\u3c 0.05). Cross-sectional area (CSA) of the vastus lateralis was measured via panoramic ultrasound imaging pre- and post-intervention. Following the protocol, CSA of the intervention group was 10.6±2.7% greater (p\u3c 0.05), while that of the control group did not change. This is the first data to demonstrate hypertrophy of the vastus lateralis in a young population following a running protocol. These data support the existing body of evidence suggesting aerobic exercise to be an effective mode of improving cardiorespiratory fitness as well as increasing whole muscle size of the quadriceps

Phosphoregulation provides specificity to biomolecular condensates in the cell cycle and cell polarity

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gerbich, T. M., McLaughlin, G. A., Cassidy, K., Gerber, S., Adalsteinsson, D., & Gladfelter, A. S. Phosphoregulation provides specificity to biomolecular condensates in the cell cycle and cell polarity. Journal of Cell Biology, 219(7), (2020): e201910021, doi:10.1083/jcb.201910021.Biomolecular condensation is a way of organizing cytosol in which proteins and nucleic acids coassemble into compartments. In the multinucleate filamentous fungus Ashbya gossypii, the RNA-binding protein Whi3 regulates the cell cycle and cell polarity through forming macromolecular structures that behave like condensates. Whi3 has distinct spatial localizations and mRNA targets, making it a powerful model for how, when, and where specific identities are established for condensates. We identified residues on Whi3 that are differentially phosphorylated under specific conditions and generated mutants that ablate this regulation. This yielded separation of function alleles that were functional for either cell polarity or nuclear cycling but not both. This study shows that phosphorylation of individual residues on molecules in biomolecular condensates can provide specificity that gives rise to distinct functional identities in the same cell.The work was supported by National Institutes of Health grant R01-GM-081506

Leveraging Factors of Self-Efficacy and Motivation to Optimize Stroke Recovery

The International Classification of Functioning, Disability and Health framework recognizes that an individual's functioning post-stroke reflects an interaction between their health condition and contextual factors encompassing personal and environmental factors. Personal factors significantly impact rehabilitation outcomes as they determine how an individual evaluates their situation and copes with their condition in daily life. A key personal factor is self-efficacy—an individual's belief in their capacity to achieve certain outcomes. Self-efficacy influences an individual's motivational state to execute behaviors necessary for achieving desired rehabilitation outcomes. Stroke rehabilitation practice and research now acknowledge self-efficacy and motivation as critical elements in post-stroke recovery, and increasing evidence highlights their contributions to motor (re)learning. Given the informative value of neuroimaging-based biomarkers in stroke, elucidating the neurological underpinnings of self-efficacy and motivation may optimize post-stroke recovery. In this review, we examine the role of self-efficacy and motivation in stroke rehabilitation and recovery, identify potential neural substrates underlying these factors from current neuroimaging literature, and discuss how leveraging these factors and their associated neural substrates has the potential to advance the field of stroke rehabilitation