1,970 research outputs found

    Study of resonance light scattering for remote optical probing

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    Enhanced scattering and fluorescence processes in the visible and UV were investigated which will enable improved remote measurements of gas properties. The theoretical relationship between scattering and fluorescence from an isolated molecule in the approach to resonance is examined through analysis of the time dependence of re-emitted light following excitation of pulsed incident light. Quantitative estimates are developed for the relative and absolute intensities of fluorescence and resonance scattering. New results are obtained for depolarization of scattering excited by light at wavelengths within a dissociative continuum. The experimental work was performed in two separate facilities. One of these utilizes argon and krypton lasers, single moded by a tilted etalon, and a 3/4 meter double monochromator. This facility was used to determine properties of the re-emission from NO2, I2 and O3 excited by visible light. The second facility involves a narrow-line dye laser, and a 3/4 meter single monochromator. The dye laser produces pulsed light with 5 nsec pulse duration and 0.005 nm spectral width

    Development of the CSOMIO Coupled Ocean-Oil-Sediment- Biology Model

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    The fate and dispersal of oil in the ocean is dependent upon ocean dynamics, as well as transformations resulting from the interaction with the microbial community and suspended particles. These interaction processes are parameterized in many models limiting their ability to accurately simulate the fate and dispersal of oil for subsurface oil spill events. This paper presents a coupled ocean-oil-biology-sediment modeling system developed by the Consortium for Simulation of Oil-Microbial Interactions in the Ocean (CSOMIO) project. A key objective of the CSOMIO project was to develop and evaluate a modeling framework for simulating oil in the marine environment, including its interaction with microbial food webs and sediments. The modeling system developed is based on the Coupled Ocean-Atmosphere-Wave-Sediment Transport model (COAWST). Central to CSOMIO’s coupled modeling system is an oil plume model coupled to the hydrodynamic model (Regional Ocean Modeling System, ROMS). The oil plume model is based on a Lagrangian approach that describes the oil plume dynamics including advection and diffusion of individual Lagrangian elements, each representing a cluster of oil droplets. The chemical composition of oil is described in terms of three classes of compounds: saturates, aromatics, and heavy oil (resins and asphaltenes). The oil plume model simulates the rise of oil droplets based on ambient ocean flow and density fields, as well as the density and size of the oil droplets. The oil model also includes surface evaporation and surface wind drift. A novel component of the CSOMIO model is two-way Lagrangian-Eulerian mapping of the oil characteristics. This mapping is necessary for implementing interactions between the ocean-oil module and the Eulerian sediment and biogeochemical modules. The sediment module is a modification of the Community Sediment Transport Modeling System. The module simulates formation of oil-particle aggregates in the water column. The biogeochemical module simulates microbial communities adapted to the local environment and to elevated concentrations of oil components in the water column. The sediment and biogeochemical modules both reduce water column oil components. This paper provides an overview of the CSOMIO coupled modeling system components and demonstrates the capabilities of the modeling system in the test experiments

    Incommensurate magnetism near quantum criticality in CeNiAsO

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    Two phase transitions in the tetragonal strongly correlated electron system CeNiAsO were probed by neutron scattering and zero field muon spin rotation. For T<TN1T <T_{N1} = 8.7(3) K, a second order phase transition yields an incommensurate spin density wave with wave vector k=(0.44(4),0,0)\textbf{k} = (0.44(4), 0, 0). For T<TN2T < T_{N2} = 7.6(3) K, we find co-planar commensurate order with a moment of 0.37(5) μB0.37(5)~\mu_B, reduced to 30%30 \% of the saturation moment of the ∣±12⟩|\pm\frac{1}{2}\rangle Kramers doublet ground state, which we establish by inelastic neutron scattering. Muon spin rotation in CeNiAs1−xPxO\rm CeNiAs_{1-x}P_xO shows the commensurate order only exists for x ≤\le 0.1 so the transition at xcx_c = 0.4(1) is from an incommensurate longitudinal spin density wave to a paramagnetic Fermi liquid

    Cyclin D1 repressor domain mediates proliferation and survival in prostate cancer.

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    Regulation of the androgen receptor (AR) is critical to prostate cancer (PCa) development; therefore, AR is the first line therapeutic target for disseminated tumors. Cell cycle-dependent accumulation of cyclin D1 negatively modulates the transcriptional regulation of AR through discrete, CDK4-independent mechanisms. The transcriptional corepressor function of cyclin D1 resides within a defined motif termed repressor domain (RD), and it was hypothesized that this motif could be utilized as a platform to develop new strategies for blocking AR function. Here, we demonstrate that expression of the RD peptide is sufficient to disrupt AR transcriptional activation of multiple, prostate-specific AR target genes. Importantly, these actions are sufficient to specifically inhibit S-phase progression in AR-positive PCa cells, but not in AR-negative cells or tested AR-positive cells of other lineages. As expected, impaired cell cycle progression resulted in a suppression of cell doubling. Additionally, cell death was observed in AR-positive cells that maintain androgen dependence and in a subset of castrate-resistant PCa cells, dependent on Akt activation status. Lastly, the ability of RD to cooperate with existing hormone therapies was examined, which revealed that RD enhanced the cellular response to an AR antagonist. Together, these data demonstrate that RD is sufficient to disrupt AR-dependent transcriptional and proliferative responses in PCa, and can enhance efficacy of AR antagonists, thus establishing the impetus for development of RD-based mimetics

    Demultiplexing of fibre Bragg grating temperature and strain sensors

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    We describe a demultiplexing scheme for fibre optic Brag grating sensors in which signal recovery is achieved by locking each sensor grating to a corresponding receiver grating. As a demonstration, the technique is applied to strain and temperature sensing, achieving a resolution of 3.0 µε and 0.2°C, respectively

    High-intensity interval training for reducing blood pressure: a randomized trial vs. moderate-intensity continuous training in males with overweight or obesity

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    The optimal exercise-training characteristics for reducing blood pressure (BP) are unclear. We investigated the effects of 6-weeks of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) on BP and aortic stiffness in males with overweight or obesity. Twenty-eight participants (18–45 years; BMI: 25–35 kg/m2) performed stationary cycling three times per week for 6 weeks. Participants were randomly allocated (unblinded) to work-matched HIIT (N = 16; 10 × 1-min intervals at 90–100% peak workload) or MICT (N = 12; 30 min at 65–75% peak heart rate). Central (aortic) and peripheral (brachial) BP and aortic stiffness was assessed before and after training. There were no significant group × time interactions for any BP measure (all p > 0.21). HIIT induced moderate reductions in central (systolic/diastolic ∆: −4.6/−3.5 mmHg, effect size d = −0.51/−0.40) and peripheral BP (−5.2/−4 mmHg, d = −0.45/−0.47). MICT induced moderate reductions in diastolic BP only (peripheral: −3.4 mmHg, d = −0.57; central: −3 mmHg, d = −0.50). The magnitude of improvement in BP was strongly negatively correlated with baseline BP (r = −0.66 to −0.78), with stronger correlations observed for HIIT (r = −0.73 to −0.88) compared with MICT (r = −0.43 to −0.61). HIIT was effective for reducing BP (~3–5 mmHg) in the overweight to obese cohort. Exercise training induced positive changes in central (aortic) BP. The BP-lowering effects of exercise training are more prominent in those with higher baseline BP, with stronger correlation in HIIT than MICT

    The effect of high-intensity interval training and moderate-intensity continuous training on aerobic fitness and body composition in males with overweight or obesity: A randomized trial

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    The optimal exercise training characteristics for improving body composition in individuals with obesity are not clear. This study assessed the effects of 6-weeks of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) on aerobic fitness and body composition in males with overweight or obesity. Twenty-eight participants (18–45 years; BMI: 25–35 kg/m2) performed stationary cycling 3 times per week for 6 weeks. Participants were randomly allocated to work-matched HIIT (N = 16) (10 × 1-min intervals at ~90% peak heart rate) or MICT (N = 12) (30 min at 65–75% peak heart rate). Maximal aerobic capacity (VO2peak) and body composition were assessed before and after 6-week training. Both HIIT and MICT induced moderate increases in aerobic fitness (Δ% VO2peak: HIIT 9 ± 8%, ES = 0.42; MICT: 7 ± 13%, ES = 0.32) and work capacity (Δ% peak workload: HIIT 13 ± 10%, ES = 0.69: MICT 17 ± 15%, ES = 0.76), but these changes did not differ significantly between the groups (all p > 0.16). The effects of HIIT or MICT on body composition outcomes were negligible to small across whole-body and all regional-specific sites (all effect sizes ES = −0.19 to 0.38) and did not differ significantly between the groups (all p > 0.21). Short-term (6-weeks) cycling training did not improve body composition in males with overweight or obesity. Improvements in aerobic fitness were comparable between work-matched HIIT and MICT
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