Nonlinear Schroedinger equation for a superfluid Bose gas from weak coupling to unitarity: Study of vortices

We introduce a nonlinear Schroedinger equation to describe the dynamics of a superfluid Bose gas in the crossover from the weak-coupling regime, where $a n^{1/3}\ll 1$ with $a$ the inter-atomic s-wave scattering length and $n$ the bosonic density, to the unitarity limit, where $a\to +\infty$. We call this equation the {unitarity Schroedinger equation} (USE). The zero-temperature bulk equation of state of this USE is parametrized by the Lee-Yang-Huang low-density expansion and Jastrow calculations at unitarity. With the help of the USE we study the profiles of quantized vortices and vortex-core radius in a uniform Bose gas. We also consider quantized vortices in a Bose gas under cylindrically-symmetric harmonic confinement and study their profile and chemical potential using the USE and compare the results with those obtained from the Gross-Pitaevskii-type equations valid in the weak-coupling limit. Finally, the USE is applied to calculate the breathing modes of the confined Bose gas as a function of the scattering length.Comment: 10 pages, 15 figure

Defining family business: a closer look at definitional heterogeneity

Researchers have used a myriad of different definitions in seeking to explain the heterogeneity of family firms and their unique behavior; however, no widely-accepted definition exists today. Definitional clarity in any field is essential to provide (a) the basis for the analysis of performance both spatially and temporally and (b) the foundation upon which theories, frameworks and models are developed. We provide a comprehensive analysis of prior research and identify and classify 82 definitions of family business. We then review and evaluate five key theoretical perspectives in family business to identify how these have shaped and informed the definitions employed in the field and duly explain family firm heterogeneity. Finally, we provide a conceptual diagram to inform the choice of definition in different research settings

Corrective effects on airway epithelial function by human amniotic epithelial cells (HAEC) when treating cystic fibrosis

Background: Cystic fibrosis (CF) remains the most common life-shortening genetic disease affecting children. The defective protein product of the affected gene, cystic fibrosis transmembrane conductance regulator (CFTR), blocks Cl - and water absorption into the airway epithelium resulting in a reduction of the air surface liquid (ASL). Reduced ASL impedes ciliary activity and reduces clearance of airway secretions contributing to an abnormal airway microenvironment that is pro-inflammatory and promotes infection. Thus, an intervention to address the basic CFTR defect has the potential to be disease modifying. One possibility may be via the utilization of stem cells. We have previously demonstrated the potential of stem cell based therapy using hAECs in lung fibrosis (Moodley Y, et al. Am J Respir Crit Care Med. 2010;182:643-51). Hence, the aim of this study was to assess the potential of hAECs to restore ion transport function to CF airway epithelial in vitro. Methods: Primary AECs were obtained from children with CF (homozygous for F508del) when attending the Princess Margaret Hospital for Children for their annual bronchoscopy and bronchoalveolar lavage and cultures established (Sutanto EN, et al. Am J Respir Cell Mol Biol. 2011;44:761-7). Co-cultures were established at ratios of 1:1, 1:10 and 1:100 of primary AEC and hAEC respectively (Cell Applications CA, USA). Air liquid interface (ALI) cultures were also set up with hAECs and primary AECs, differentiation confirmed and resulting ASL height determined. Finally, Ussing chamber and yellow fluorescent protein (YFP) halide reporter assays were used to measure resulting CFTR function. Results: Co-cultures were successfully established at ratios of 1:1, 1:10 and 1:100 of primary AEC and hAEC respectively. ALI cultures established with hAEC at a ratio of 1:1 had a significantly greater ASL height compared to matched primary AEC ALI cultures (9.5 ± 1.0μm vs 6.0 ± 0.5μm, n=6). Ussing chamber results identified that correction of ASL height was due to enhanced CFTR-induced efflux of Cl - . This was corroborated using the YFP halide reporter which illustrated an induction of normal Cl - function of CFTR at the 1:1 co-culture cell ratio. Conclusions: We provide for the first time in vitro “proof of concept” data indicating the feasibility of cell-based therapy using hAEC to treat CF. Supported by Telethon New Children’s Hospital Grant, WA

Towards human translation of lentiviral airway gene delivery for cystic fibrosis: A one-month CFTR and reporter gene study in marmosets

Gene therapy continues to be a promising contender for the treatment of cystic fibrosis (CF) airway disease. We have previously demonstrated that airway conditioning with lysophosphatidylcholine (LPC) followed by delivery of a HIV-1 based lentiviral vector (LV) functionally corrects the CF transmembrane conductance regulator (CFTR) defect in the nasal airways of CF mice. In our earlier pilot study we showed that our technique can transduce marmoset lungs acutely; this study extends that work to examine gene expression in this non-human primate (NHP) 1 month after gene vector treatment. A mixture of three separate HIV-1 VSV-G pseudotyped LV vectors containing the luciferase (Luc), LacZ and hCFTR transgenes was delivered into the trachea via a miniature bronchoscope. We examined whether a single-dose delivery of lentiviral vector after LPC conditioning could increase levels of transgene expression in the trachea and lungs compared to control (PBS) conditioning. At one month, bioluminescence was detected in vivo in the trachea of 3 of the 6 animals within the PBS control group, compared to 5 of the 6 LPC-treated animals. When examined ex vivo there was weak evidence that LPC improves tracheal Luc expression levels. In the lungs, bioluminescence was detected in vivo in 4 of the 6 PBS treated animals, compared to 5 of the 6 LPC treated animals; however, bioluminescence was present in all lungs when imaged ex vivo. LacZ expression was predominantly observed in the alveolar regions of the lung. hCFTR was detected by qPCR in the lungs of 5 of the 11 animals. Basal cells were successfully isolated and expanded from marmoset tracheas, but no LacZ positive colonies were detected. There was no evidence of an inflammatory response towards the LV vector at one month post-delivery, with cytokines remaining at baseline levels. In conclusion, we found weak evidence that LPC conditioning improved gene transduction in the trachea, but not in the marmoset lungs. We also highlight some of the challenges associated with translational lung gene therapy studies in NHPs.Nigel Farrow, Patricia Cmielewski, Juliette Delhove, Nathan Rout-Pitt, Lewis Vaughan, Tim Kuchel, Chris Christou, John Finnie, Matthew Smith, Emma Knight, Martin Donnelley and David Parson

Coaching and guidance with patient decision aids : A review of theoretical and empirical evidence

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedCoaching and guidance are structured approaches that can be used within or alongside patient decision aids (PtDAs) to facilitate the process of decision making. Coaching is provided by an individual, and guidance is embedded within the decision support materials. The purpose of this paper is to: a) present updated definitions of the concepts “coaching” and “guidance”; b) present an updated summary of current theoretical and empirical insights into the roles played by coaching/guidance in the context of PtDAs; and c) highlight emerging issues and research opportunities in this aspect of PtDA designPeer reviewedFinal Published versio