A quantum dynamical comparison of the electronic couplings derived from quantum electrodynamics and Förster theory:Application to 2D molecular aggregates

The objective of this study is to investigate under what circumstances Förster theory of electronic (resonance) energy transfer breaks down in molecular aggregates. This is achieved by simulating the dynamics of exciton diffusion, on the femtosecond timescale, in molecular aggregates using the Liouville–von Neumann equation of motion. Specifically the focus of this work is the investigation of both spatial and temporal deviations between exciton dynamics driven by electronic couplings calculated from Förster theory and those calculated from quantum electrodynamics. The quantum electrodynamics (QED) derived couplings contain medium- and far-zone terms that do not exist in Förster theory. The results of the simulations indicate that Förster coupling is valid when the dipole centres are within a few nanometres of one another. However, as the distance between the dipole centres increases from 2 nm to 10 nm, the intermediate- and far-zone coupling terms play non-negligible roles and Förster theory begins to break down. Interestingly, the simulations illustrate how contributions to the exciton dynamics from the intermediate- and far-zone coupling terms of QED are quickly washed-out by the near-zone mechanism of Förster theory for lattices comprising closely packed molecules. On the other hand, in the case of sparsely packed arrays, the exciton dynamics resulting from the different theories diverge within the 100 fs lifetime of the trajectories. These results could have implications for the application of spectroscopic ruler techniques as well as design principles relating to energy harvesting materials

Nitrogen Phosphorus, and Potassium Effects on Seeded Buffalograss Establishment

Field studies were conducted in Kansas, Nebraska, and Oklahoma in 1996 tp evaluate the influence of nitrogen (N), phosphorus (P), and potassium (K) applied alone or in combination on the establishment rate of buffalograss [Buchloe dactyloides (Nutt.) Engelm.] from seed. \u27Cody\u27 buffalograss burrs were planted at 98 kg∙ha-1 at planting and at 49 kg∙ha-1 weekly or every other week for 5 weeks after seeding (WAS). The total N amounts applied were 0, 49, 147, 294 kg∙ha-1. Phosphorus and K were applied at rates of 0 or 49 kg∙ha-1 at planting only. Percent buffalograss coverage ratings were taken weekly for up to 11 WAS. Buffalograss coverage was enhanced by N rates up to 147 kg∙ha-1. Application of P improved buffalograss establishment at the Nebraska and Oklahoma sites but had no effect on the Kansas site. Potassium application had no influence on establishment at any site. Chemical names used: methyl 2- [[[[(4-methoxy-6-methyl-1,3,5- triazin- 2- yl)- amino] carbonyl] amino] sulfonyl] benzoate (metsulfuron methyl); 6-chloro-N,N\u27-diethyl-1,3,5-triazine-2,4-diamine(simazine

Perfectionism And Eating Disorders: Current Status And Future Directions

The literature examining the relation between perfectionism and eating disorders was reviewed and content and methodological comparisons were made with the perfectionism literature in anxiety disorders and depressive disorders. A PsychInfo search using the key words perfectionism/ perfect/ perfectionistic, anorexia, bulimia, and eating disorders was performed and the generated list of papers was supplemented based on a review of reference lists in the papers. A total of 55 papers published between 1990 and 2005 were identified that assessed perfectionism among individuals with diagnosed eating disorders. The key research questions were distilled from these publications and empirical findings were summarized for each question, followed by a comparison with perfectionism papers in the anxiety and depressive disorder literatures. Also, key research design methodological parameters were identified and comparisons made across the three literatures: eating disorders, anxiety disorders, depressive disorders. The current review concludes with conceptual and methodological recommendations for researchers interested in perfectionism and eating disorders

Enantioselective Synthesis of Sealutomicin C

The sealutomicins are a family of anthraquinone antibiotics featuring an enediyne (sealutomicin A) or Bergman-cyclized aromatic ring (sealutomicins B–D). Herein we report the development of an enantioselective organocatalytic method for the synthesis of dihydroquinolines and the use of the developed method in the total synthesis of sealutomicin C which features a transannular cyclization of an aryllithium onto a γ-lactone as a second key step

Explicitly correlated trial wave functions in Quantum Monte Carlo calculations of excited states of Be and Be-

We present a new form of explicitly correlated wave function whose parameters are mainly linear, to circumvent the problem of the optimization of a large number of non-linear parameters usually encountered with basis sets of explicitly correlated wave functions. With this trial wave function we succeeded in minimizing the energy instead of the variance of the local energy, as is more common in quantum Monte Carlo methods. We applied this wave function to the calculation of the energies of Be 3P (1s22p2) and Be- 4So (1s22p3) by variational and diffusion Monte Carlo methods. The results compare favorably with those obtained by different types of explicitly correlated trial wave functions already described in the literature. The energies obtained are improved with respect to the best variational ones found in literature, and within one standard deviation from the estimated non-relativistic limitsComment: 19 pages, no figures, submitted to J. Phys.

Recent Advances in Geotechnical Post-earthquake Reconnaissance

Field observations are particularly important in geotechnical engineering, because it is difficult to replicate in the laboratory the response of soil deposits built by nature over thousands of years. Detailed mapping of damaged and undamaged areas provides the data for the well-documented case histories that drive the development of many current design procedures. Thus, documenting key insights from earthquakes advance research and practice. This has been a primary goal of the National Science Foundation-sponsored Geotechnical Extreme Events Reconnaissance (GEER) Association since its inception almost 20 years ago. New technologies are continually employed by GEER teams to capture ground deformation and its effects. These technologies include Light Imaging Detection and Ranging (LIDAR) and Structure-from-Motion (SfM) image processing techniques for generating and visualizing three-dimensional point cloud data sets. New sensor deployment platforms such as Unmanned Aerial Vehicles (UAVs) are playing an integral role in the data collection process. Unanticipated observations from major events often catalyze new research directions. An overview of some of these recent integrated technology deployments and their role at the core of earthquake disaster analysis is presented. Important advancements are possible through post-event research if their effects are captured and shared effectively

Effects of seed lots and seed production time on growth, flowering and cut flower quality in Bupleurum rotundifolium L.

Effects of three planting patterns; two-row-planting high density (25 plants·m(-2)), two-row-planting low density (12.5 plants·m(-2)), and four-row-planting (25 plants·m(-2)) on the cut flower number and quality of spray carnation (Dianthus caryophyllus L.) cv. ‘Barbara’ and ‘Cherry Tessino’ grown by fertigation cultivation were investigated. In ‘Barbara’, there was no difference in total cut flower number between two-row-planting high density and four-row-planting. Total cut flower number of two-row-planting low density decreased to 60% of two-row-planting high density or four-row-planting. In ‘Cherry Tessino’, the total cut flower number of two-row-planting high density was 15% more than that of four-row-planting. The total cut flower number of two-row-planting low density decreased to 60~70% of two-row-planting high density or four-row-planting. There was no difference in cut flower quality between two-row-planting high density and four-row-planting in both cultivars. Cut flower weight and stem diameter of two-row-planting low density increased compared to those of two-row-planting high density or four-row-planting. Thus, the result indicates that two-row-planting high density may be suitable for fertigation cultivation in carnation

Evaluation of multi-modal, multi-site neuroimaging measures in Huntington's disease: Baseline results from the PADDINGTON study.

BACKGROUND: Macro- and micro-structural neuroimaging measures provide valuable information on the pathophysiology of Huntington's disease (HD) and are proposed as biomarkers. Despite theoretical advantages of microstructural measures in terms of sensitivity to pathology, there is little evidence directly comparing the two. METHODS: 40 controls and 61 early HD subjects underwent 3 T MRI (T1- and diffusion-weighted), as part of the PADDINGTON study. Macrostructural volumetrics were obtained for the whole brain, caudate, putamen, corpus callosum (CC) and ventricles. Microstructural diffusion metrics of fractional anisotropy (FA), mean-, radial- and axial-diffusivity (MD, RD, AD) were computed for white matter (WM), CC, caudate and putamen. Group differences were examined adjusting for age, gender and site. A formal comparison of effect sizes determined which modality and metrics provided a statistically significant advantage over others. RESULTS: Macrostructural measures showed decreased regional and global volume in HD (p < 0.001); except the ventricles which were enlarged (p < 0.01). In HD, FA was increased in the deep grey-matter structures (p < 0.001), and decreased in the WM (CC, p = 0.035; WM, p = 0.053); diffusivity metrics (MD, RD, AD) were increased for all brain regions (p < 0.001). The largest effect sizes were for putamen volume, caudate volume and putamen diffusivity (AD, RD and MD); each was significantly larger than those for all other metrics (p < 0.05). CONCLUSION: The highest performing macro- and micro-structural metrics had similar sensitivity to HD pathology quantified via effect sizes. Region-of-interest may be more important than imaging modality, with deep grey-matter regions outperforming the CC and global measures, for both volume and diffusivity. FA appears to be relatively insensitive to disease effects

Clinical outcomes stratified by baseline functional class after initial combination therapy for pulmonary arterial hypertension

Background: Initial combination therapy with ambrisentan and tadalafil reduced the risk of clinical failure events for treatment-naïve participants with pulmonary arterial hypertension (PAH) as compared to monotherapy. Previous studies in PAH have demonstrated greater treatment benefits in more symptomatic participants. Methods: AMBITION was an event-driven, double-blind study in which participants were randomized 2:1:1 to oncedaily initial combination therapy with ambrisentan 10 mg plus tadalafil 40 mg, ambrisentan 10 mg plus placebo, or tadalafil 40 mg plus placebo. In this pre-specified subgroup analysis, we compared the efficacy data between those with functional class (FC) II vs. FC III symptoms at baseline. Results: This analysis included 500 participants in the previously defined primary analysis set (n = 155 FC II, n = 345 FC III). Comparing combination therapy to pooled monotherapy, the risk of clinical failure events was reduced by 79% (hazard ratio, 0.21 [95% confidence interval: 0.071, 0.63]) for FC II patients and 42 (hazard ratio, 0.58 [95% confidence interval: 0.39, 0.86]) for FC III patients. In a post-hoc analysis, the risk of first hospitalization for worsening PAH was also reduced by combination therapy, particularly for FC II patients (0 combination vs. 11 [14%] pooled monotherapy). Adverse events were frequent but comparable between the subgroups. Conclusions: Treatment benefit from initial combination therapy appeared at least as great for FC II as for FC III participants. Hospitalizations for worsening PAH were not observed in FC II participants assigned to combination. The present data support an initial combination strategy for newly diagnosed patients even when symptoms are less severe

Test-Retest Reliability of Diffusion Tensor Imaging in Huntington's Disease.

Diffusion tensor imaging (DTI) has shown microstructural abnormalities in patients with Huntington's Disease (HD) and work is underway to characterise how these abnormalities change with disease progression. Using methods that will be applied in longitudinal research, we sought to establish the reliability of DTI in early HD patients and controls. Test-retest reliability, quantified using the intraclass correlation coefficient (ICC), was assessed using region-of-interest (ROI)-based white matter atlas and voxelwise approaches on repeat scan data from 22 participants (10 early HD, 12 controls). T1 data was used to generate further ROIs for analysis in a reduced sample of 18 participants. The results suggest that fractional anisotropy (FA) and other diffusivity metrics are generally highly reliable, with ICCs indicating considerably lower within-subject compared to between-subject variability in both HD patients and controls. Where ICC was low, particularly for the diffusivity measures in the caudate and putamen, this was partly influenced by outliers. The analysis suggests that the specific DTI methods used here are appropriate for cross-sectional research in HD, and give confidence that they can also be applied longitudinally, although this requires further investigation. An important caveat for DTI studies is that test-retest reliability may not be evenly distributed throughout the brain whereby highly anisotropic white matter regions tended to show lower relative within-subject variability than other white or grey matter regions