106 research outputs found

    Engaging Rural Nevadans in Participatory Research to Explore and Explain the Community Food and Physical Activity Context

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    The purpose of this study was to engage residents of four rural Nevada communities to explain local resources and readiness to address environmental challenges to weight healthy lifestyles. Residents engaged in HEAL MAPPS™, a participatory research approach using photomapping and community conversations to document lived experiences of place-based resources as supports or barriers. Data were triangulated to scale community readiness-to-change. This study focuses on a description of methods and qualitative findings. Healthy food unavailability emerged consistently among communities as a barrier; produce options were limited and many residents relied on convenience foods. Physical activity opportunities were available, yet access was a barrier. Transportation-related issues emerged as barriers to healthy eating and physical activity. Communities ranged between “vague awareness” and “preplanning” on readiness-to-change. Local data and shared knowledge of the obesogenic context can inform community policy and environmental improvements that promote health and enhance quality of life for rural populations

    Cardiovascular drugs attenuated myocardial resistance against ischaemia-induced and reperfusion-induced injury in a rat model of repetitive occlusion

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    We investigated the impact of cardioprotective drugs on ST-elevation, arrhythmias and infarct size in a rat model of repetitive coronary artery occlusion

    Wave Packet Echoes in the Motion of Trapped Atoms

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    We experimentally demonstrate and systematically study the stimulated revival (echo) of motional wave packet oscillations. For this purpose, we prepare wave packets in an optical lattice by non-adiabatically shifting the potential and stimulate their reoccurence by a second shift after a variable time delay. This technique, analogous to spin echoes, enables one even in the presence of strong dephasing to determine the coherence time of the wave packets. We find that for strongly bound atoms it is comparable to the cooling time and much longer than the inverse of the photon scattering rate

    Polarization-dependent frequency shifts from Rb-3He collisions

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    We present measurements of the frequency shift of the Rb electron-paramagnetic-resonance (EPR) line in the presence of nuclear-polarized 3He gas for the temperature range of 30 to 85 °C. The frequency shift is due to the Fermi-contact interaction between the Rb valence electron and the polarized 3He nucleus. Expressions for both the frequency shift and the spin-exchange cross section are derived in terms of the strength of this contact interaction. From these expressions and the measured frequency shift, we estimate the Rb-3He spin-exchange cross section. The Rb EPR frequency shift, which is 53 kHz for a 100% polarized 10-amagat 3He sample at 50 °C, can be used to determine the absolute polarization of nuclear polarized 3He targets. From these measurements, one can also predict the shift of the 3He NMR line due to a polarized Rb vapor

    Synchronization of Hamiltonian motion and dissipative effects in optical lattices: Evidence for a stochastic resonance

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    We theoretically study the influence of the noise strength on the excitation of the Brillouin propagation modes in a dissipative optical lattice. We show that the excitation has a resonant behavior for a specific amount of noise corresponding to the precise synchronization of the Hamiltonian motion on the optical potential surfaces and the dissipative effects associated with optical pumping in the lattice. This corresponds to the phenomenon of stochastic resonance. Our results are obtained by numerical simulations and correspond to the analysis of microscopic quantities (atomic spatial distributions) as well as macroscopic quantities (enhancement of spatial diffusion and pump-probe spectra). We also present a simple analytical model in excellent agreement with the simulations

    Antenatal glucocorticoid treatment induces adaptations in adult midbrain dopamine neurons, which underpin sexually dimorphic behavioral resilience

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    We demonstrated previously that antenatal glucocorticoid treatment (AGT, gestational days 16-19) altered the size and organization of the adult rat midbrain dopaminergic (DA) populations. Here we investigated the consequences of these AGT-induced cytoarchitectural disturbances on indices of DA function in adult rats. We show that in adulthood, enrichment of striatal DA fiber density paralleled AGT-induced increases in the numbers of midbrain DA neurons, which retained normal basal electrophysiological properties. This was co-incident with changes in (i) striatal D2-type receptor levels (increased, both sexes); (ii) D1-type receptor levels (males decreased; females increased); (iii) DA transporter levels (males increased; females decreased) in striatal regions; and (iv) amphetamine-induced mesolimbic DA release (males increased; females decreased). However, despite these profound, sexually dimorphic changes in markers of DA neurotransmission, in-utero glucocorticoid overexposure had a modest or no effect on a range of conditioned and unconditioned appetitive behaviors known to depend on mesolimbic DA activity. These findings provide empirical evidence for enduring AGT-induced adaptive mechanisms within the midbrain DA circuitry, which preserve some, but not all, functions, thereby casting further light on the vulnerability of these systems to environmental perturbations. Furthermore, they demonstrate these effects are achieved by different, often opponent, adaptive mechanisms in males and females, with translational implications for sex biases commonly found in midbrain DA-associated disorders

    Detection and elimination of cellular bottlenecks in protein-producing yeasts

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    Yeasts are efficient cell factories and are commonly used for the production of recombinant proteins for biopharmaceutical and industrial purposes. For such products high levels of correctly folded proteins are needed, which sometimes requires improvement and engineering of the expression system. The article summarizes major breakthroughs that led to the efficient use of yeasts as production platforms and reviews bottlenecks occurring during protein production. Special focus is given to the metabolic impact of protein production. Furthermore, strategies that were shown to enhance secretion of recombinant proteins in different yeast species are presented

    Sex-specific disruption of murine midbrain astrocytic and dopaminergic developmental trajectories following antenatal GC treatment

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    The mammalian midbrain dopaminergic systems arising in the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) are critical for coping behaviours and are implicated in neuropsychiatric disorders where early life challenges comprise significant risk factors. Here, we aimed to advance our hypothesis that glucocorticoids (GCs), recognised key players in neurobiological programming, target development within these systems, with a novel focus on the astrocytic population. Mice received antenatal GC treatment (AGT) by including the synthetic GC, dexamethasone, in the mothers' drinking water on gestational days 16-19; controls received normal drinking water. Analyses of regional shapes and volumes of the adult SNc and VTA demonstrated that AGT induced long-term, dose-dependent, structural changes that were accompanied by profound effects on astrocytes (doubling/tripling of numbers and/or density). Additionally, AGT induced long-term changes in the population size and distribution of SNc/VTA dopaminergic neurons, confirming and extending our previous observations made in rats. Furthermore, glial/neuronal structural remodelling was sexually dimorphic and depended on the AGT dose and sub-region of the SNc/VTA. Investigations within the neonatal brain revealed that these long-term organisational effects of AGT depend, at least in part, on targeting perinatal processes that determine astrocyte density and programmed cell death in dopaminergic neurons. Collectively, our characterisation of enduring, AGT-induced, sex-specific cytoarchitectural disturbances suggests novel mechanistic links for the strong association between early environmental challenge (inappropriate exposure to excess GCs) and vulnerability to developing aberrant behaviours in later life, with translational implications for dopamine-associated disorders (such as schizophrenia, ADHD, autism, depression), which typically show a sex bia
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