Modelling Fresh Strawberry Supply "From-Farm-to-Fork" as a Complex Adaptive Network

 The purpose of this study is to model and thereby enable simulation of the complete business entity of fresh food supply. A case narrative of fresh strawberry supply provides basis for this modelling. Lamming et al. (2000) point to the importance of discerning industry-specific product features (or particularities) regarding managing supply networks when discussing elements in "an initial classification of a supply network" while Fisher (1997) and Christopher et al. (2006, 2009) point to the lack of adopting SCM models to variations in products and market types as an important source of SCM failure. In this study we have chosen to move along a research path towards developing an adapted approach to model end-to-end fresh food supply influenced by a combination of SCM, system dynamics and complex adaptive network thinking...

The African hind's (Cephalopholis taeniops, serranidae) use of artificial reefs off Sal Island (Cape Verde): a preliminary study based on acoustic telemetry

The African hind Cephalopholis taeniops (Valenciennes, 1828) is one of the most important commercial demersal species caught in the Cape Verde archipelago. The species is closely associated with hard substrate and is one of the main attractions for SCUBA divers. In January 2006 a former Soviet fishing vessel - the Kwarcit - was sunk off Santa Maria Bay (Sal Island). Young C. taeniops are commonly observed in this artificial reef (AR). In order to investigate the species' use of the AR, 4 specimens were captured and surgically implanted underwater with Vemco brand acoustic transmitters. The fish were monitored daily with an active telemetry receiver for one week after release. Simultaneously, an array of 3 passive VR2 / VR2W receivers was set for 63 days, registering data that allowed an analysis of spatial, daily and short term temporal activity patterns. The results showed site fidelity to the AR, with no migrations to the nearby natural reef. The method used allowed to register a consistent higher activity during daytime and a preference for the area opposite the dominant current

A theory of L1L^1-dissipative solvers for scalar conservation laws with discontinuous flux

We propose a general framework for the study of $L^1$ contractive semigroups of solutions to conservation laws with discontinuous flux. Developing the ideas of a number of preceding works we claim that the whole admissibility issue is reduced to the selection of a family of "elementary solutions", which are certain piecewise constant stationary weak solutions. We refer to such a family as a "germ". It is well known that (CL) admits many different $L^1$ contractive semigroups, some of which reflects different physical applications. We revisit a number of the existing admissibility (or entropy) conditions and identify the germs that underly these conditions. We devote specific attention to the anishing viscosity" germ, which is a way to express the "$\Gamma$-condition" of Diehl. For any given germ, we formulate "germ-based" admissibility conditions in the form of a trace condition on the flux discontinuity line $x=0$ (in the spirit of Vol'pert) and in the form of a family of global entropy inequalities (following Kruzhkov and Carrillo). We characterize those germs that lead to the $L^1$-contraction property for the associated admissible solutions. Our approach offers a streamlined and unifying perspective on many of the known entropy conditions, making it possible to recover earlier uniqueness results under weaker conditions than before, and to provide new results for other less studied problems. Several strategies for proving the existence of admissible solutions are discussed, and existence results are given for fluxes satisfying some additional conditions. These are based on convergence results either for the vanishing viscosity method (with standard viscosity or with specific viscosities "adapted" to the choice of a germ), or for specific germ-adapted finite volume schemes

On the polarization properties of the charmed baryon Lambda^+_c in the Lambda^+_c -> p + K^- + pi^+ + pi^0 decay

The polarization properties of the charmed Lambda^+_c baryon are investigated in weak non-leptonic four-body Lambda^+_c -> p + K^- + pi^+ + pi^0 decay. The probability of this decay and the angular distribution of the probability are calculated in the effective quark model with chiral U(3)XU(3) symmetry incorporating Heavy Quark Effective theory (HQET) and the extended Nambu-Jona-Lasinio model with a linear realization of chiral U(3)XU(3) symmetry. The theoretical value of the probability of the decay Lambda^+_c -> p + K^- + pi^+ + pi^0 relative to the probability of the decay Lambda^+_c -> p + K^- + pi^+ does not contain free parameters and fits well experimental data. The application of the obtained results to the analysis of the polarization of the Lambda^+_c produced in the processes of photo and hadroproduction is discussed.Comment: 10 pages, no figures, Late

Resonant Two-body D Decays

The contribution of a $K^*(1430)$ $0^+$ resonance to $D^0\to K^-\pi^+$ is calculated by applying the soft pion theorem to $D^+ \to K^* \pi^+$, and is found to be about 30% of the measured amplitude and to be larger than the $\Delta I=3/2$ component of this amplitude. We estimate a 70% contribution to the total amplitude from a higher $K^*(1950)$ resonance. This implies large deviations from factorization in D decay amplitudes, a lifetime difference between D^0 and D^+, and an enhancement of $D^0-\bar D^0$ mixing due to SU(3) breaking.Comment: To be published in Physical Review Letters, some corrections, references update

Principles for research on ethnicity and health: the Leeds consensus statement

Background: There is substantial evidence that health and health-care experiences vary along ethnic lines and the need to understand and tackle ethnic health inequalities has repeatedly been highlighted. Research into ethnicity and health raises ethical, theoretical and methodological issues and, as the volume of research in this area grows, so too do concerns regarding its scientific rigour and reporting, and its contribution to reducing inequalities. Guidance may be helpful in encouraging researchers to adopt standard practices in the design, conduct and reporting of research. However, past efforts at introducing such guidance have had limited impact on research practice, and the diversity of disciplinary perspectives on the key challenges and solutions may undermine attempts to derive and promote guiding principles. Methods: A consensus building Delphi exercise—the first of its kind in this area of research practice—was undertaken with leading academics, practitioners and policymakers from a broad range of disciplinary backgrounds to assess whether consensus on key principles could be achieved. Results: Ten key principles for conducting research on ethnicity and health emerged, covering: the aims of research in this field; how such research should be framed and focused; key design-related considerations; and the direction of future research. Despite some areas of dispute, participants were united by a common concern that the generation and application of research evidence should contribute to better health-care experiences and health outcomes for minority ethnic people. Conclusion: The principles provide a strong foundation to guide future ethnicity-related research and build a broader international consensus

Evaluating the effectiveness and cost effectiveness of the ‘strengthening families, strengthening communities’ group-based parenting programme: study protocol and initial insights

Background: Up to 20% of UK children experience socio-emotional difficulties which can have serious implications for themselves, their families and society. Stark socioeconomic and ethnic inequalities in children’s well-being exist. Supporting parents to develop effective parenting skills is an important preventive strategy in reducing inequalities. Parenting interventions have been developed, which aim to reduce the severity and impact of these difficulties. However, most parenting interventions in the UK focus on early childhood (0–10 years) and often fail to engage families from ethnic minority groups and those living in poverty. Strengthening Families, Strengthening Communities (SFSC) is a parenting programme designed by the Race Equality Foundation, which aims to address this gap. Evidence from preliminary studies is encouraging, but no randomised controlled trials have been undertaken so far. Methods/design: The TOGETHER study is a multi-centre, waiting list controlled, randomised trial, which aims to test the effectiveness of SFSC in families with children aged 3–18 across seven urban areas in England with ethnically and socially diverse populations. The primary outcome is parental mental well-being (assessed by the Warwick-Edinburgh Mental Well-Being Scale). Secondary outcomes include child socio-emotional well-being, parenting practices, family relationships, self-efficacy, quality of life, and community engagement. Outcomes are assessed at baseline, post intervention, three- and six-months post intervention. Cost effectiveness will be estimated using a cost-utility analysis and cost-consequences analysis. The study is conducted in two stages. Stage 1 comprised a 6-month internal pilot to determine the feasibility of the trial. A set of progression criteria were developed to determine whether the stage 2 main trial should proceed. An embedded process evaluation will assess the fidelity and acceptability of the intervention. Discussion: In this paper we provide details of the study protocol for this trial. We also describe challenges to implementing the protocol and how these were addressed. Once completed, if beneficial effects on both parental and child outcomes are found, the impact, both immediate and longer term, are potentially significant. As the intervention focuses on supporting families living in poverty and those from minority ethnic communities, the intervention should also ultimately have a beneficial impact on reducing health inequalities. Trial registration: Prospectively registered Randomised Controlled Trial ISRCTN15194500

Cabibbo-allowed nonleptonic weak decays of charmed baryons

Cabibbo-allowed nonleptonic weak decays of charmed baryons \lamc,~\xin,~\xip and $\Omega_c^0$ into an octet baryon and a pseudoscalar meson are analyzed. The nonfactorizable contributions are evaluated under pole approximation, and it turns out that the $s$-wave amplitudes are dominated by the low-lying \halfm resonances, while $p$-wave ones governed by the ground-state \halfp poles. The MIT bag model is employed to calculate the coupling constants, form factors and baryon matrix elements. Our conclusions are: (i) $s$ waves are no longer dominated by commutator terms; the current-algebra method is certainly not applicable to parity-violating amplitudes, (ii) nonfactorizable $W$ exchange effects are generally important; they can be comparable to and somtimes even dominate over factorizable contributions, depending on the decay modes under consideration, (iii) large-$N_c$ approximation for factorizable amplitudes also works in the heavy baryon sector and it accounts for the color nonsuppression of \lamc\ri p\bar{K}^0 relative to \lamc\ri\Lambda\pi^+, (iv) a measurement of the decay rate and the sign of the $\alpha$ asymmetry parameter of certain proposed decay modes will help discern various models; especially the sign of $\alpha$ in \lamc\ri\Sigma\pi decays can be used to unambiguously differentiate recent theoretical schemes from current algebra, and (v) $p$ waves are the dominant contributions to the decays \lamc\ri\Xi^0 K^+ and \xin\ri\Sigma^+ K^-, but they are subject to a large cancellation; this renders present theoretical predictions on these two channels unreliable.Comment: PHYZZX, 31 pages, 3 tables, IP-ASTP-10-93, ITP-SB-93-2