A geomorphological interpretation of saltmarsh channel network morphology and function

Although tidal channel networks are a near-ubiquitous feature of saltmarsh environments developed on the marine sedimentary shores of Britain, only limited progress has been made towards achieving a scientific understanding of their morphological characteristics and the physical functions that they perform. Based on data acquired from a combination of high resolution aerial photography and field survey, a range of descriptive indices and morphometric measures are used to characterise planimetric, longitudinal and cross-sectional adjustment in saltmarsh channel networks from 29 localities around England and Wales. In accordance with the extensive methodological approach employed during this exploratory phase of the study, regularities and distinguishing features of the selected formations are interpreted in terms of broad-scale environmental controls, which represent the relative intensity of erosional versus resistive forces. While statistical analyses suggest that creek morphology reflects a multiplicity of influences, the strongest bivariate associations, between tidal prism and cross-sectional geometry, are consistent with the finding of earlier process studies that creek morphology is principally adapted to perform a conveyance function. Theoretically-based mathematical models are employed to more fully elucidate relations of causality between creek morphology and function. This intensive investigation utilises Brancaster Marsh, Norfolk as an illustrative case study. The availability of airborne laser altimetry (lidar) for this site facilitates the evaluation of alternative models of channel function. Optimality models of angular geometry are implemented at a network-scale, and cross-sectional adjustments are modelled with reference to the concept of stability shear stress. While of interest from a geomorphological perspective, the insights offered into creek morphology and function are also relevant to the field of coastal engineering. Here, they provide an empirical basis for post-project appraisal, and may lead to theoretical guidelines for the design of tidal channel networks, as an integral component of saltmarsh restoration and flood defence realignment schemes

Disease management projects and the Chronic CareModel in action: Baseline qualitative research

Background: Disease management programs, especially those based on the Chronic Care Model (CCM),are increasingly common in the Netherlands. While disease management programs have beenwell-researched quantitatively and economically, less qualitative research has been done. Theoverall aim of the study is to explore how disease management programs are implementedwithin primary care settings in the Netherlands; this paper focuses on the early developmentand implementation stages of five disease management programs in the primary care setting,based on interviews with project leadership teams. Methods: At the five sites, eleven semi-structured interviews were conducted at the five selected siteswith sixteen professionals interviewed; all project leaders were interviewed. The interviewsfocused on each project's chosen chronic illness (diabetes, eating disorders, COPD, multimorbidity,CVRM) and project plan, barriers to development and implementation, the projectleaders' action and reactions, as well as their roles and responsibilities, and diseasemanagement strategies. Analysis was inductive and interpretive, based on the content of theinterviews. After analysis, the results of this research on disease management programs andthe Chronic Care Model are viewed from a traveling technology framework. Results: This analysis uncovered four themes that can be mapped to disease management and theChronic Care Model: (1) changing the health care system, (2) patient-centered care, (3)technological systems and barriers, and (4) integrating projects into the larger system. Projectleaders discussed the paths, both direct and indirect, for transforming the health care systemto one that addresses chronic illness. Patient-centered care was highlighted as needed and aparadigm shift for many. Challenges with technological systems were pervasive.

Schubert calculus of Richardson varieties stable under spherical Levi subgroups

We observe that the expansion in the basis of Schubert cycles for $H^*(G/B)$ of the class of a Richardson variety stable under a spherical Levi subgroup is described by a theorem of Brion. Using this observation, along with a combinatorial model of the poset of certain symmetric subgroup orbit closures, we give positive combinatorial descriptions of certain Schubert structure constants on the full flag variety in type $A$. Namely, we describe $c_{u,v}^w$ when $u$ and $v$ are inverse to Grassmannian permutations with unique descents at $p$ and $q$, respectively. We offer some conjectures for similar rules in types $B$ and $D$, associated to Richardson varieties stable under spherical Levi subgroups of SO(2n+1,\C) and SO(2n,\C), respectively.Comment: Section 4 significantly shortened, and other minor changes made as suggested by referees. Final version, to appear in Journal of Algebraic Combinatoric

Discovery and Observations of ASASSN-13db, an EX Lupi-Type Accretion Event on a Low-Mass T Tauri Star

We discuss ASASSN-13db, an EX Lupi-type ("EXor") accretion event on the young stellar object (YSO) SDSS J051011.01$-$032826.2 (hereafter SDSSJ0510) discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN). Using archival photometric data of SDSSJ0510 we construct a pre-outburst spectral energy distribution (SED) and find that it is consistent with a low-mass class II YSO near the Orion star forming region ($d \sim 420$ pc). We present follow-up photometric and spectroscopic observations of the source after the $\Delta V \sim-$5.4 magnitude outburst that began in September 2013 and ended in early 2014. These data indicate an increase in temperature and luminosity consistent with an accretion rate of $\sim10^{-7}$ $\rm{M}_\odot$ yr$^{-1}$, three or more orders of magnitude greater than in quiescence. Spectroscopic observations show a forest of narrow emission lines dominated by neutral metallic lines from Fe I and some low-ionization lines. The properties of ASASSN-13db are similar to those of the EXor prototype EX Lupi during its strongest observed outburst in late 2008.Comment: 14 pages, 4 figures, 1 table. Updated May 2014 to reflect changes in the final version published in ApJL. Photometric data presented in this submission are included as ancillary files. For a brief video explaining this paper, see http://youtu.be/yRCCrNJnvt

Enhanced stability of layered phases in parallel hard-spherocylinders due to the addition of hard spheres

There is increasing evidence that entropy can induce microphase separation in binary fluid mixtures interacting through hard particle potentials. One such phase consists of alternating two dimensional liquid-like layers of rods and spheres. We study the transition from a uniform miscible state to this ordered state using computer simulations and compare results to experiments and theory. We conclude that (1) there is stable entropy driven microphase separation in mixtures of parallel rods and spheres, (2) adding spheres smaller then the rod length decreases the total volume fraction needed for the formation of a layered phase, therefore small spheres effectively stabilize the layered phase; the opposite is true for large spheres and (3) the degree of this stabilization increases with increasing rod length.Comment: 11 pages, 9 figures. Submitted to Phys. Rev. E. See related website http://www.elsie.brandeis.ed

Evaluatie van disease management programma's in Nederland

In het ZonMw programma ‘Disease Management Chronische Ziekten’ (DMCZ) zijn 22 praktijkprojecten ontwikkeld, gevolgd en geëvalueerd. Deze ZonMw-praktijkprojecten hadden een looptijd van ongeveer drie jaar. Gedurende deze periode zijn de projecten systematisch gevolgd op een aantal proces- en effectmaten en kosten-effectiviteit. De verwachting is dat disease management programma's gebaseerd op Ed Wagner's chronische zorgmodel bijdragen aan betere kwaliteit van chronische zorgverlening. Inzicht in de korte en lange termijn effecten van implementatie van dit type programma's voor verschillende chronische aandoeningen is echter nog schaars. [...

The management of cardiovascular disease in the Netherlands: analysis of different programmes

Background: Disease management programmes are increasingly used to improve the efficacy and effectiveness of chronic care delivery. But, disease management programme development and implementation is a complex undertaking that requires effective decision-making. Choices made in the earliest phases of programme development are crucial, as they ultimately impact costs, outcomes and sustainability. Methods: To increase our understanding of the choices that primary healthcare practices face when implementing such programmes and to stimulate successful implementation and sustainability, we compared the early implementation of eight cardiovascular disease management programmes initiated and managed by healthcare practices in various regions of the Netherlands. Using a mixed-methods design, we identified differences in and challenges to programme implementation in terms of context, patient characteristics, disease management level, healthcare utilisation costs, development costs and health-related quality of life. Results: Shifting to a multidisciplinary, patient-centred care pathway approach to disease management is demanding for organisations, professionals and patients, and is especially vulnerable when sustainable change is the goal. Funding is an important barrier to sustainable implementation of cardiovascular disease management programmes, although development costs of the individual programmes varied considerably in relation to the length of the development period. The large number of professionals involved in combination with duration of programme development was the largest cost drivers. While Information and Communication Technology systems to support the new care pathways did not directly contribute to higher costs, delays in implementation indirectly did. Conclusions: Developing and implementing cardiovascular disease management programmes is time-consuming and challenging. Multidisciplinary, patient-centred care demands multifaceted changes in routine care. As care pathways become more complex, they also become more expensive. Better preparedness and training can prevent unnecessary delays during the implementation period and are crucial to reducing costs

Nonlinear atom optics and bright gap soliton generation in finite optical lattices

We theoretically investigate the transmission dynamics of coherent matter wave pulses across finite optical lattices in both the linear and the nonlinear regimes. The shape and the intensity of the transmitted pulse are found to strongly depend on the parameters of the incident pulse, in particular its velocity and density: a clear physical picture for the main features observed in the numerical simulations is given in terms of the atomic band dispersion in the periodic potential of the optical lattice. Signatures of nonlinear effects due the atom-atom interaction are discussed in detail, such as atom optical limiting and atom optical bistability. For positive scattering lengths, matter waves propagating close to the top of the valence band are shown to be subject to modulational instability. A new scheme for the experimental generation of narrow bright gap solitons from a wide Bose-Einstein condensate is proposed: the modulational instability is seeded in a controlled way starting from the strongly modulated density profile of a standing matter wave and the solitonic nature of the generated pulses is checked from their shape and their collisional properties