Orbitally excited D and B mesons in the approach of the QCD string with quarks at the ends

In this letter we discuss the masses and the splittings of 1(2S+1)P_J states in the spectrum of D and B mesons, as they appear in the approach of the QCD string with quarks at the ends. We find good agreement of our predictions with those of other QCD-motivated models as well as with the lattice and experimental data, including recent experimental results. We discuss the ordering pattern for P levels in D- and B-mesonic spectrum.Comment: 7 pages, LaTeX2e, 2 EPS figures, added comments, to appear in Phys.Lett.

Manners and method in classical criticism of the early eighteenth century

This article explores a neglected period in the history of classical scholarship: the first decades of the eighteenth century. It focuses on the tension between an evolving idea of method, and the tradition of personal polemic which had been an important part of the culture of scholarship since the Renaissance. There are two case studies: the conflict between Jean Le Clerc and Pieter Burman, and the controversy that followed Richard Bentley's edition of Horace's Odes. Both demonstrate the need to revise current paradigms for writing the history of scholarship, and invite us to reconsider the role of methodology in producing of scholarly authority

Geometry and subsidence history of the Dead Sea basin : a case for fluid-induced mid-crustal shear zone?

This paper is not subject to U.S. copyright. The definitive version was published in Journal of Geophysical Research 117 (2012): B01406, doi:10.1029/2011JB008711.Pull-apart basins are narrow zones of crustal extension bounded by strike-slip faults that can serve as analogs to the early stages of crustal rifting. We use seismic tomography, 2-D ray tracing, gravity modeling, and subsidence analysis to study crustal extension of the Dead Sea basin (DSB), a large and long-lived pull-apart basin along the Dead Sea transform (DST). The basin gradually shallows southward for 50 km from the only significant transverse normal fault. Stratigraphic relationships there indicate basin elongation with time. The basin is deepest (8–8.5 km) and widest (~15 km) under the Lisan about 40 km north of the transverse fault. Farther north, basin depth is ambiguous, but is 3 km deep immediately north of the lake. The underlying pre-basin sedimentary layer thickens gradually from 2 to 3 km under the southern edge of the DSB to 3–4 km under the northern end of the lake and 5–6 km farther north. Crystalline basement is ~11 km deep under the deepest part of the basin. The upper crust under the basin has lower P wave velocity than in the surrounding regions, which is interpreted to reflect elevated pore fluids there. Within data resolution, the lower crust below ~18 km and the Moho are not affected by basin development. The subsidence rate was several hundreds of m/m.y. since the development of the DST ~17 Ma, similar to other basins along the DST, but subsidence rate has accelerated by an order of magnitude during the Pleistocene, which allowed the accumulation of 4 km of sediment. We propose that the rapid subsidence and perhaps elongation of the DSB are due to the development of inter-connected mid-crustal ductile shear zones caused by alteration of feldspar to muscovite in the presence of pore fluids. This alteration resulted in a significant strength decrease and viscous creep. We propose a similar cause to the enigmatic rapid subsidence of the North Sea at the onset the North Atlantic mantle plume. Thus, we propose that aqueous fluid flux into a slowly extending continental crust can cause rapid basin subsidence that may be erroneously interpreted as an increased rate of tectonic activity.Fieldwork was funded by U.S. AID Middle Eastern Regional Cooperation Program grant M21–012, with in-kind contributions by Al-Balqa’ Applied University (Jordan), the Geophysical Institute of Israel, and the U.S. Geological Survey

Energy and symmetry of dddd excitations in undoped layered cuprates measured by Cu L3L_3 resonant inelastic x-ray scattering

We measured high resolution Cu $L_3$ edge resonant inelastic x-ray scattering (RIXS) of the undoped cuprates La$_2$CuO$_4$, Sr$_2$CuO$_2$Cl$_2$, CaCuO$_2$ and NdBa$_2$Cu$_3$O$_6$. The dominant spectral features were assigned to $dd$ excitations and we extensively studied their polarization and scattering geometry dependence. In a pure ionic picture, we calculated the theoretical cross sections for those excitations and used them to fit the experimental data with excellent agreement. By doing so, we were able to determine the energy and symmetry of Cu-3$d$ states for the four systems with unprecedented accuracy and confidence. The values of the effective parameters could be obtained for the single ion crystal field model but not for a simple two-dimensional cluster model. The firm experimental assessment of $dd$ excitation energies carries important consequences for the physics of high $T_c$ superconductors. On one hand, having found that the minimum energy of orbital excitation is always $\geq 1.4$ eV, i.e., well above the mid-infrared spectral range, leaves to magnetic excitations (up to 300 meV) a major role in Cooper pairing in cuprates. On the other hand, it has become possible to study quantitatively the effective influence of $dd$ excitations on the superconducting gap in cuprates.Comment: 22 pages, 11 figures, 1 tabl

Cost-effectiveness of classroom-based cognitive behaviour therapy in reducing symptoms of depression in adolescents: a trial-based analysis

Background A substantial minority of adolescents suffer from depression and it is associated with increased risk of suicide, social and educational impairment, and mental health problems in adulthood. A recently conducted randomized controlled trial in England evaluated the effectiveness of a manualized universally delivered age-appropriate CBT programme in school classrooms. The cost-effectiveness of the programme for preventing low mood and depression for all participants from a health and social care sector perspective needs to be determined. Methods A trial-based cost-effectiveness analysis based on a cluster-randomized controlled trial (trial registration – ISRCTN 19083628) comparing classroom-based CBT with usual school provision of Personal Social and Health Education. Per-student cost of intervention was estimated from programme records. The study was undertaken in eight mixed-sex UK secondary schools, and included 3,357 school children aged 12 to 16 years (in the two trial arms evaluated in the cost-effectiveness analysis). The main outcome measures were individual self-reported data on care costs, Quality-Adjusted Life-Years (QALYs, based on the EQ-5D health-related quality-of-life instrument) and symptoms of depression (Short Mood and Feelings Questionnaire) at baseline, 6 and 12 months. Results Although there was lower quality-adjusted life-years over 12 months (−.05 QALYs per person, 95% confidence interval −.09 to −.005, p = .03) with CBT, this is a ‘clinically’ negligible difference, which was not found in the complete case analyses. There was little evidence of any between-arm differences in SMFQ scores (0.19, 95% CI −0.57 to 0.95, p = .62), or costs (£142, 95% CI −£132 to £415, p = .31) per person for CBT versus usual school provision. Conclusions Our analysis suggests that the universal provision of classroom-based CBT is unlikely to be either more effective or less costly than usual school provision

High nitrogen rates do not increase canola yield and may affect soil bacterial functioning

Nitrogen fertilization has a fundamental role in agricultural productivity. However, injudicious N applications to crops are common. It is important to ensure the minimum N required for satisfactory crop growth is applied but that excess amounts are avoided due to potential impacts on agroecosystem functioning. Nitrogen at 0, 60, and 150 kg ha-1 was applied as limestone ammonium nitrate to plots arranged in a randomized complete block design, on three farms to determine the impact of rate and temporal distribution of fertilizer on canola (Brassica napus L.) production in South Africa, and the effect of N fertilizer application on the composition and diversity of soil bacterial communities. The amount and distribution of N had only minor effects on canola growth (P < 0.05) and no effects on yield or harvest index. Splitting fertilizer into two or three applications throughout the season resulted in more mineral N available in the soil later in the season. Increasing the N rate from 60 to 150 kg ha-1 had a significant impact on bacterial community composition. The lower rate favored bacteria that are more able to break down N-containing carbon sources. No effects of fertilizer amount or distribution were observed on either N fixation potential (number of nifH gene copies) or bacterial community diversity. Overall, a low rate of N fertilizer split into multiple applications is recommended for canola production, as higher rates do not increase yield and may have a detrimental impact on soil carbon and nitrogen cycling

3D dSTORM imaging reveals novel detail of ryanodine receptor localization in rat cardiac myocytes

Cardiomyocyte contraction is dependent on Ca2+ release from ryanodine receptors (RyRs). However, the precise localization of RyRs remains unknown, due to shortcomings of imaging techniques which are diffraction limited or restricted to 2D. We aimed to determine the 3D nanoscale organization of RyRs in rat cardiomyocytes by employing direct stochastic optical reconstruction microscopy (dSTORM) with phase ramp technology. Initial observations at the cell surface showed an undulating organization of RyR clusters, resulting in their frequent overlap in the z‐axis and obscured detection by 2D techniques. Non‐overlapping clusters were imaged to create a calibration curve for estimating RyR number based on recorded fluorescence blinks. Employing this method at the cell surface and interior revealed smaller RyR clusters than 2D estimates, as erroneous merging of axially aligned RyRs was circumvented. Functional groupings of RyR clusters (Ca2+ release units, CRUs), contained an average of 18 and 23 RyRs at the surface and interior, respectively, although half of all CRUs contained only a single ‘rogue’ RyR. Internal CRUs were more tightly packed along z‐lines than surface CRUs, contained larger and more numerous RyR clusters, and constituted ∼75% of the roughly 1 million RyRs present in an average cardiomyocyte. This complex internal 3D geometry was underscored by correlative imaging of RyRs and t‐tubules, which enabled quantification of dyadic and non‐dyadic RyR populations. Mirroring differences in CRU size and complexity, Ca2+ sparks originating from internal CRUs were of longer duration than those at the surface. These data provide novel, nanoscale insight into RyR organization and function across cardiomyocytes

Spatial and temporal modulation of cell instructive cues in a filamentous supramolecular biomaterial

Supramolecular materials provide unique opportunities to mimic both the structure and mechanics of the biopolymer networks that compose the extracellular matrix. However, strategies to modify their filamentous structures in space and time in 3D cell culture to study cell behavior as encountered in development and disease are lacking. We herein disclose a multicomponent squaramide-based supramolecular material whose mechanics and bioactivity can be controlled by light through co-assembly of a 1,2-dithiolane (DT) monomer that forms disulfide cross-links. Remarkably, increases in storage modulus from ∼200 Pa to >10 kPa after stepwise photo-cross-linking can be realized without an initiator while retaining colorlessness and clarity. Moreover, viscoelasticity and plasticity of the supramolecular networks decrease upon photo-irradiation, reducing cellular protrusion formation and motility when performed at the onset of cell culture. When applied during 3D cell culture, force-mediated manipulation is impeded and cells move primarily along earlier formed channels in the materials. Additionally, we show photopatterning of peptide cues in 3D using either a photomask or direct laser writing. We demonstrate that these squaramide-based filamentous materials can be applied to the development of synthetic and biomimetic 3D in vitro cell and disease models, where their secondary cross-linking enables mechanical heterogeneity and shaping at multiple length scales