Theoretical modeling of the terahertz spectrum of l-tyrosine leads to experimental verification of previously unobserved vibrational mode.

We have calculated the theoretical terahertz spectrum of the amino acid l-tyrosine using density functional theory (DFT). We tried two electron density functionals, Perdew-Burke-Ernzerhof (PBE) and PBE-d3. PBE-d3 includes dispersion corrections to build in van der Waals interactions, which play a role in intermolecular bonding. Both DFT models predicted a low-frequency mode that has not been previously reported. We designed an experiment to search for this mode. Using a deliberately thick sample, intense synchrotron radiation, low temperatures, and temperature variation has enabled us to observe a new resonance at 1.79 ±0.01 THz. While the PBE and PBE-d3 spectra are similar and both match the low-energy experimental data, overall the PBE-d3 appears to be slightly superior. Further refinement still of the functional may lead to even better agreement with experiment above 2.4 THz.

Determination of Vibrational Modes of l-Alanine Single Crystals by a Combination of Terahertz Spectroscopy Measurements and Density Functional Calculations.

Density-functional theory may be used to predict both the frequency and the dipole moment of the fundamental oscillations of molecular crystals. Suitably polarized photons at those frequencies excite such oscillations. Thus, in principle, terahertz spectroscopy may confirm the calculated fundamental modes of amino acids. However, reports to date have multiple shortcomings: (a) material of uncertain purity and morphology and diluted in a binder material is employed; (b) consequently, vibrations along all crystal axes are excited simultaneously; (c) data are restricted to room temperature, where resonances are broad and the background dominant; and (d) comparison with theory has been unsatisfactory (in part because the theory assumes zero temperature). Here, we overcome all four obstacles, in reporting detailed low-temperature polarized THz spectra of single-crystal l-alanine, assigning vibrational modes using density-functional theory, and comparing the calculated dipole moment vector direction to the electric field polarization of the measured spectra. Our direct and detailed comparison of theory with experiment corrects previous mode assignments for l-alanine, and reveals unreported modes, previously obscured by closely spaced spectral absorptions. The fundamental modes are thereby determined.

Terahertz tyrosine modes.

We have measured the terahertz spectrum of pure l-tyrosine at nineteen temperatures in the range 6K to 300K using a synchrotron as the source of radiation. By fitting the temperature dependence of the observed modes with a Bose-Einstein model, we determine unequivocal low-frequency modes of l-tyrosine at absolute zero temperature occur at 1.02 ± 0.01, 1.61 ± 0.01, 1.97 ± 0.01, and 2.19 ± 0.01THz. This determination is consistent with the more reliable of the earlier measurements. We conclude that many of the recently reported features in the terahertz spectrum of l-tyrosine are experimental artefacts.

Scale-up of the Internet-based Professional Learning to help teachers promote Activity in Youth (iPLAY) intervention: a hybrid type 3 implementation-effectiveness trial.

BACKGROUND: Whole-of-school programs have demonstrated success in improving student physical activity levels, but few have progressed beyond efficacy testing to implementation at-scale. The purpose of our study was to evaluate the scale-up of the 'Internet-based Professional Learning to help teachers promote Activity in Youth' (iPLAY) intervention in primary schools using the RE-AIM framework. METHODS: We conducted a type 3 hybrid implementation-effectiveness study and collected data between April 2016 and June 2021, in New South Wales (NSW), Australia. RE-AIM was operationalised as: (i) Reach: Number and representativeness of students exposed to iPLAY; (ii) Effectiveness: Impact of iPLAY in a sub-sample of students (n = 5,959); (iii) Adoption: Number and representativeness of schools that received iPLAY; (iv) Implementation: Extent to which the three curricular and three non-curricular components of iPLAY were delivered as intended; (v) Maintenance: Extent to which iPLAY was sustained in schools. We conducted 43 semi-structured interviews with teachers (n = 14), leaders (n = 19), and principals (n = 10) from 18 schools (11 from urban and 7 from rural locations) to determine program maintenance. RESULTS: Reach: iPLAY reached ~ 31,000 students from a variety of socio-economic strata (35% of students were in the bottom quartile, almost half in the middle two quartiles, and 20% in the top quartile). EFFECTIVENESS: We observed small positive intervention effects for enjoyment of PE/sport (0.12 units, 95% CI: 0.05 to 0.20, d = 0.17), perceptions of need support from teachers (0.26 units, 95% CI: 0.16 to 0.53, d = 0.40), physical activity participation (0.28 units, 95% CI: 0.10 to 0.47, d = 0.14), and subjective well-being (0.82 units, 95% CI: 0.32 to 1.32, d = 0.12) at 24-months. Adoption: 115 schools received iPLAY. IMPLEMENTATION: Most schools implemented the curricular (59%) and non-curricular (55%) strategies as intended. Maintenance: Based on our qualitative data, changes in teacher practices and school culture resulting from iPLAY were sustained. CONCLUSIONS: iPLAY had extensive reach and adoption in NSW primary schools. Most of the schools implemented iPLAY as intended and effectiveness data suggest the positive effects observed in our cluster RCT were sustained when the intervention was delivered at-scale. TRIAL REGISTRATION: ACTRN12621001132831.

Long-term forest monitoring reveals constant mortality rise in European forests.

European forests are an important source for timber production, human welfare, income, protection and biodiversity. During the last two decades, Europe has experienced a number of droughts which have been exceptional within the last 500 years, both in terms of duration and intensity. These droughts seem to leave remarkable imprints on the mortality dynamics of European forests. However, systematic observations on tree decline, with emphasis on a single species, has been scarce so far so that our understanding of mortality dynamics and drought occurrence is still limited at a continental scale. Here, we make use of the ICP Forest crown defoliation dataset, permitting us to retrospectively monitor tree mortality for all major conifers, major broadleaves, as well as a pooled dataset of minor tree species in Europe. In total, we analysed more than three million observations gathered during the last 25 years and employed a high-resolution drought index which can assess soil moisture anomaly based on a hydrological water-balance and runoff model. We found overall and species-specific increasing trends in mortality rates, accompanied by decreasing soil moisture. A generalized linear mixed model identified a previous-year soil moisture anomaly as the most important driver of mortality patterns in conifers, but the response was not uniform across the numerous analysed plots. We conclude that mortality patterns in European forests are currently reaching a concerning upward trend which could be further accelerated by global change-type droughts in the near future.

High-quality, temperature-dependent terahertz spectroscopy of single crystalline L-alanine: Experiment and density-functional theory.

For the first time, the terahertz transmittance spectra of l-alanine have been measured using a single crystal. Measurements were obtained over a large temperature range (12-300 K) and revealed 18 absorptions between 20 and 250 cm-1. These modes were sharp and symmetric, a feature of single crystals and low temperatures. The spectra were directly compared to those of a powdered pellet sample. Raman spectroscopy and x-ray diffraction were used to confirm the sample's structure and purity. With increasing temperature, all modes exhibit spectral redshift, well described by a Bose-Einstein model, indicating the phonon origin of the absorptions. The exceptions are the 91 and 128 cm-1 modes. The former blueshifts. The latter initially blueshifts but transitions to redshifting. Both behaviors are anomalous. Density-functional theory modeling helped assign all the observed modes.

Temperature-dependent terahertz spectroscopy of l-phenylalanine.

Undiluted l-phenylalanine has been cooled to 6K and its transmission spectrum obtained under terahertz radiation from a synchrotron source. Three distinct absorption bands are evident: at 1.37, 2.14, and 2.32THz. Each of these tracks to lower frequency ("redshifts") as the temperature is increased from 6 to 250K. The observed shifts are in the range of 0.1-0.2THz. The form of the temperature dependence is well accounted for by a Bose-Einstein model, from which the zero-temperature frequency of each mode and the characteristic temperature of the associated phonon bath may be estimated. At 6K a fourth band is evident, at 2.65THz. However, the depth of this, touching the noise floor, coupled with the increasing opacity of the sample with temperature for frequencies beyond 2.5THz, makes it difficult to track. The frequencies of all four modes are in good accord with and thus confirm a previous calculation.

The 3, 5, 6, and 7 THz resonances of α-glycine.

Using an optically thin single crystal sample, mounted in a cryostat permitting cooling to 6 K, and a synchrotron as a bright light source, exceptionally well defined absorption spectra of well-characterised α-glycine have been obtained in the spectral range 2.5-7.5 THz (approximately 80-240 cm-1). Four separate resonances have been observed, respectively at 93, 152, 188, and 223 cm-1 at the lowest temperature. Each reduces in frequency (redshifts) as temperature increases. The origin of this observed behaviour is attributed to a phonon-mediated anharmonicity in the crystal potential.

Terahertz response of DL-alanine: experiment and theory.

The terahertz (THz) spectrum of dl-alanine has been measured for the first time at cryogenic temperatures and with a pure sample. Several sharp absorptions are observed, over a wide frequency range (0.8-4.8 THz), at 8 K. The sample structure and purity were confirmed with both Raman spectroscopy and X-ray diffraction. Temperature dependent spectra revealed redshifting, with increasing temperature, for all modes except one at 2.70 THz. This mode exhibits blueshifting until ≈120 K, where it starts to redshift. A Bose-Einstein distribution has been used to model the frequency shift with temperature for the four lowest energy modes. Strong correlations between the fits and data indicate that these modes are caused by phonon excitation in an anharmonic potential. Density functional theory has also been used to identify the origin of these low frequency modes. They are attributed to large scale molecular vibrations.

Anharmonicity-driven redshift and broadening of sharp terahertz features of α-glycine single crystal from 20 K to 300 K: Theory and experiment.

For the first time, large single crystals of the simplest amino acid, glycine, have been used to determine the temperature dependence of its terahertz spectrum. High-quality spectra with very sharp absorption features are observed at cryogenic temperatures. The α-glycine structure and the purity of the crystals were verified via Raman spectroscopy and X-ray diffraction. Spectral redshift with increasing temperature was observed for all absorption bands in the terahertz region (10-250 cm-1, or 1-8 THz) over the temperature range of 20-300 K. X-ray diffraction revealed expansion in all planes of the crystal lattice over the same temperature range. A Bose-Einstein distribution was used to model the frequency position shift of the two lowest-energy fundamental modes at 50 cm-1 and 69 cm-1. On this basis, we attribute the observed redshift and broadening with increasing temperature to the anharmonic potential associated with the phonon bath.

Enablers and barriers to implementation of and compliance with school-based healthy food and beverage policies: a systematic literature review and meta-synthesis.

OBJECTIVE: Schools have been recognised as a potential setting for improving young peoples' food and beverage choices; however, many schools fail to adhere to healthy food and beverage policy standards. The current study aimed to explore the enablers and barriers to effective implementation of and compliance with school-based food and beverage policies. DESIGN: Systematic review and meta-synthesis. Eight electronic databases were searched for articles in June 2019. Studies were eligible for inclusion if they reported on implementation and/or compliance of school-based food and/or beverage policies with outcomes relating to enablers and/or barriers. This review had no restrictions on study design, year of publication or language. Seventy-two full-text articles were assessed for eligibility, of which twenty-eight were included in this review. SETTING: Studies conducted globally that focused on schools. PARTICIPANTS: School-based healthy food and beverage policies. RESULTS: Financial (cost of policy-compliant foods, decreased profit and revenue), physical (availability of policy-compliant foods, close geographical proximity to unhealthy food outlets) and social (poor knowledge, understanding, and negative stakeholders' attitudes towards policy) factors were the most frequently reported barriers for policy implementation. Sufficient funding, effective policy communication and management, and positive stakeholders' attitudes were the most frequently reported enablers for policy implementation. CONCLUSIONS: There is a need for better communication strategies, financial and social support prior to school-based food policy implementation. Findings of this review contribute to a thorough understanding of factors that underpin best practice recommendations for the implementation of school-based food policy, and inform those responsible for improving public health nutrition.

Working with Insulin, Carbohydrates, Ketones and Exercise to Manage Diabetes (WICKED): evaluation of a self-management course for young people with Type 1 diabetes.

AIMS: To evaluate a 5-day self-management education course for young people with Type 1 diabetes and assess its effects on knowledge, self-efficacy, beliefs, distress, self-management behaviours and HbA1c . METHODS: This is an evaluation of a structured education course. Young people (aged 16-24 years) with Type 1 diabetes were recruited from three diabetes centres. In the first centre, participants completed self-report measures of knowledge, self-efficacy, positive and negative outcome expectancies, and hypoglycaemic worries at baseline (n=47) and the end of the course (n=42). In two additional centres, participants completed these and other measures assessing self-management behaviours, cognitive adaptation to diabetes and diabetes distress at baseline (n=32), the end of the course (n=27) and 3-month follow-up (n = 27). HbA1c levels were recorded at baseline (n=79), 6 months (n=77) and 12 months (n=65). RESULTS: There were statistically significant increases in self-report knowledge, self-efficacy, positive outcome expectancies and self-management behaviours, and a statistically significant decrease in negative outcome expectances, between baseline and the end of the course. There were also statistically significant increases in self-report knowledge, self-efficacy, self-management behaviours and cognitive adaptation to diabetes between baseline and 3-month follow-up. Compared with baseline, HbA1c levels decreased by a mean (sd) of 5.44 (19.93) mmol/mol (0.48%) at 6 months (P=0.019), and by 5.98 (23.32) mmol/mol (0.54%) at 12 months (P =0.043). DISCUSSION: The results indicate the potential benefits of a self-management course designed to address the developmental needs and challenges faced by young people with Type 1 diabetes. Further studies with larger numbers and appropriate controls are required to confirm these initial findings.

Experiences of self-management among young adults with Type 1 diabetes in the context of a structured education programme: a qualitative study.

AIMS: To explore the experiences of young adults with regard to self-management of Type 1 diabetes in the context of a structured education programme. METHODS: Qualitative interviews and focus groups were conducted with young adults attending a structured education course promoting a flexible and self-directed format. Participants attending the structured education courses were recruited using purposive sampling to acquire a broad mix of participants based on age and equal numbers of young men and women. Fifteen interviews were conducted 12 weeks after each course, whilst seven focus groups and observations of the course delivery were conducted at two course sites and were led by nurse/dietitian educators representing two different diabetes centres (paediatric and adult). The interview and focus group data were audio recorded and transcribed, coded, and analysed thematically to identify similarities and differences. RESULTS: The analysis revealed three themes, 'we're in it together', 'tacit benefits' and 'transitions beyond the structured education programme'. The findings show that structured education programmes can facilitate reflective critical thinking and greater engagement with diabetes self-management if they: a) foster maximal learning from fellow participants to decrease feelings of isolation, b) maximize engagement during the course by delivering the content in a flexible manner, and c) recognize the social and emotional needs of young adults. CONCLUSION: Structured education courses can result in improved critical thinking and engagement with diabetes self-management by empowering young adults through a flexible and self-directed learning style that encourages peer group discussion.

Obesity during pregnancy in the mouse alters the Netrin-1 responsiveness of foetal arcuate nucleus neuropeptide Y neurones.

When individuals undergo gestation in an obese dam, they are at increased risk for impairments in the ability of the brain to regulate body weight. In rodents, gestation in an obese dam leads to a number of changes to the development of the hypothalamic neurones that regulate body weight, including reduced neuronal connectivity at birth. In the present study, we aimed to clarify how this neural circuitry develops normally, as well as to explore the mechanism underpinning the deficiency in connectivity seen in foetuses developing in obese dams. First, we developed an in vitro model for observing and manipulating the axonal growth of foetal arcuate nucleus (ARN) neuropeptide (NPY) neurones. We then used this model to test 2 hypotheses: (i) ARN NPY neurones respond to Netrin-1, one of a small number of axon growth and guidance factors that regulate neural circuit formation throughout the developing brain; and (ii) Netrin-1 responsiveness would be lost upon exposure to the inflammatory cytokine interleukin (IL)-6, which is elevated in foetuses developing in obese dams. We observed that ARN NPY neurones responded to Netrin-1 with a significant expansion of their growth cones, comprising the terminal apparatus that neurones use to navigate. Unexpectedly, we found further that NPY neurones from obese pregnancies had a reduced responsiveness to Netrin-1, raising the possibility that ARN NPY neurones from foetuses developing in obese dams were phenotypically different from normal NPY neurones. Finally, we observed that IL-6 treatment of normal NPY neurones in vitro led to a reduced growth cone responsiveness to Netrin-1, essentially causing them to behave similarly to NPY neurones from obese pregnancies. These results support the hypothesis that IL-6 can disrupt the normal process of axon growth from NPY neurones, and suggest one possible mechanism for how the body weight regulating circuitry fails to develop properly in the offspring of obese dams.

Incidence of symptomatic osteochondritis dissecans lesions of the knee: a population-based study in Olmsted County.

OBJECTIVE: To (1) define population-based incidence of knee Osteochondritis dissecans (OCD) lesions using the population of Olmsted County, (2) examine trends over time, and (3) evaluate rate of surgical management over time. METHOD: Study population included 302 individuals who were diagnosed with knee OCD lesions between January 1, 1976 and December 31, 2014. Complete medical records were reviewed to extract injury and treatment details. Age- and gender-specific incidence rates were calculated and adjusted to the 2010 US population. Poisson regression analyses were performed to examine incidence and surgery trends by age, gender, and calendar period. RESULTS: Overall age- and gender-adjusted incidence annual incidence of knee OCD lesions was 6.09 per 100,000 person-years. The incidence was significantly higher (P < 0.001) in males (8.82, 95% CI 7.63 to 10.00 per 100,000) compared to females (3.32, 95% CI 2.61 to 4.04 per 100,000). Age- and gender-specific incidence was highest in both males and females in the 11-15 years old at 39.06 and 16.15 per 100,000, respectively. In males aged 11-15 years, OCD incidence increased significantly over the study period from 20.68 in 1976-1985 to 48.16 in 2006-2014 (per 100,000). CONCLUSIONS: Overall age- and gender-adjusted annual incidence of knee OCD lesions in the Olmsted Country Population was 6.09 per 100,000 person-years with a significantly higher incidence in males compared to females. The highest incidence for both males and females occurred between the ages 11-15 years. Trends indicate increasing OCD incidence in younger males and decreasing surgical management in females over the last decade.

Regulation of human intestinal T-cell responses by type 1 interferon-STAT1 signaling is disrupted in inflammatory bowel disease.

Type 1 interferon (IFN-1) promotes regulatory T-cell function to suppress inflammation in the mouse intestine, but little is known about IFN-1 in the human gut. We therefore assessed the influence of IFN-1 on CD4+ T-cells isolated from human colon tissue obtained from healthy controls or patients with inflammatory bowel disease (IBD). Immunofluorescent imaging revealed constitutive expression of IFNß in human intestinal tissue, and colonic T-cells were responsive to exogenous IFN-1 as assessed by phosphorylation of signal transduction and activator of transcription 1 (pSTAT1) and induction of interferon stimulated genes (ISGs). Unlike their blood counterparts, intestinal T-cells from non-inflamed regions of IBD colon displayed enhanced responsiveness to IFN-1, increased frequency of pSTAT1+ cells, and greater induction of ISGs upon IFN-1 exposure in vitro. In healthy tissue, antibody neutralization of IFNß selectively reduced T-cell production of the pro-regulatory cytokine interleukin-10 (IL-10) and increased IFNγ synthesis. In contrast, neutralization of IFNß in IBD tissue cultures increased the frequency of T-cells producing inflammatory cytokines but did not alter IL-10 expression. These data support a role for endogenous IFN-1 as a context-dependent modulator of T-cell function that promotes regulatory activity in healthy human intestine, but indicate that the IFN-1/STAT1 pathway is dysregulated in inflammatory bowel disease.

Mytilus hybridisation and impact on aquaculture: A minireview.

The three species in the blue mussel complex (Mytilus edulis, Mytilus galloprovincialis and Mytilus trossulus) show varying levels of hybridisation wherever they occur sympatrically. The spatial variation in hybridisation patterns is potentially governed by environmental conditions, larval dispersal and aquaculture practices. Commercial mussel cultivation has been shown to increase hybridisation through introduction of non-native species or spat transfer. There is evidence that mussel cultivation may promote commercially less desirable phenotypes (e.g. fragile shells), however, to what extent hybridisation impacts aquaculture is currently not clear. The aim of this review is to summarize the available information on Mytilus hybridisation patterns in Europe and their promotion through aquaculture practices in order to shed light on the overall implications for the aquaculture industry.

Lack of effect of supplementation with EPA or DHA on platelet-monocyte aggregates and vascular function in healthy men.

BACKGROUND AND AIMS: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fish oil are postulated to have favourable effects on platelet, endothelial and vascular function. We investigated whether EPA has differential effects on in vivo platelet aggregation and other markers of cardiovascular risk compared to DHA. METHODS AND RESULTS: Following a 2 wk run-in taking encapsulated refined olive oil, 48 healthy young men were randomly allocated using a parallel design to receive EPA-rich (3.1 g EPA/d) or DHA-rich (2.9 g DHA/d) triglyceride concentrates or refined olive oil (placebo), for a total supplementary lipid intake of 5 g/d. The specified primary outcome was change in platelet monocyte aggregates (PMA); secondary outcomes were capillary density, augmentation index, digital pulse volume measurements, 24 h ambulatory BP, plasma 8-isoprostanes-F2α. Changes in the proportions of DHA and EPA in erythrocytes and non-esterified fatty acid composition indicated compliance to the intervention. There was no significant treatment effect on PMA (P = 0.382); mean changes (%) (95% CI) were placebo -0.5 (-2.0, 1.04), EPA 0.4 (-0.8, 1.6), DHA 0.3 (-1.5, 2.0). R-QUICKI, an index of insulin sensitivity, was greater following EPA compared to placebo (P < 0.05). No other significant differences were noted. CONCLUSION: Neither EPA- nor DHA-rich fish oil supplementation influence platelet-monocyte aggregation or several markers of vascular function after 6 wk in healthy young males. This trial was registered at clinicaltrials.gov as NCT01735357.

Greener neighbourhoods, slimmer children? Evidence from 4423 participants aged 6 to 13 years in the Longitudinal Study of Australian children.

OBJECTIVES: There is a growing belief that green space (for example, parks) help prevent obesity. There is evidence of an inverse association between green space and childhood body mass index (BMI); however, the majority of these studies are cross-sectional. Longitudinal studies that track change in BMI across childhood in relation to levels of green space proximity would improve the quality of evidence available for decision making. METHODS: Objectively measured BMI was obtained every 2 years between 2006 and 2012 for 4423 participants initially aged 6-7 years in the Longitudinal Study of Australian Children (LSAC). The LSAC is a nationally representative study on a range of health and socio-demographic measures. Using Australian Bureau of Statistics mesh block data, which classify small scale land areas based on the main usage, each participant was assigned an objective measure of green space availability within their Statistical Area (level 2) of residence. Gender-stratified multilevel linear regression was used to estimate BMI growth curves across childhood in relation to green space availability. Family income, Australian Indigenous status, mothers' education and language spoken were used to adjust for socio-economic confounding. RESULTS: Age was found to be an effect modifier of associations between green space and BMI for boys (P=0.005) and girls (P=0.048). As children grew older, an inverse patterning of BMI by green space availability emerged. These findings held after adjustment for socio-economic circumstances for boys (P=0.009), though were less robust for girls after this adjustment (P=0.056). CONCLUSION: A beneficial effect of green space on BMI emerges as children grow older. However, there was little additional benefit after a modest amount of green space was met. Further research is needed to understand whether the drivers of this effect are from age-specific mechanisms, or whether the benefit of living in a greener neighbourhood is accumulated through childhood.