Fast and Adaptive Sparse Precision Matrix Estimation in High Dimensions

This paper proposes a new method for estimating sparse precision matrices in the high dimensional setting. It has been popular to study fast computation and adaptive procedures for this problem. We propose a novel approach, called Sparse Column-wise Inverse Operator, to address these two issues. We analyze an adaptive procedure based on cross validation, and establish its convergence rate under the Frobenius norm. The convergence rates under other matrix norms are also established. This method also enjoys the advantage of fast computation for large-scale problems, via a coordinate descent algorithm. Numerical merits are illustrated using both simulated and real datasets. In particular, it performs favorably on an HIV brain tissue dataset and an ADHD resting-state fMRI dataset.Comment: Maintext: 24 pages. Supplement: 13 pages. R package scio implementing the proposed method is available on CRAN at https://cran.r-project.org/package=scio . Published in J of Multivariate Analysis at http://www.sciencedirect.com/science/article/pii/S0047259X1400260

Açai (Euterpe oleracea) in the Amazon: until when a non-timber forest product?

Until the 1990s the açai was a product basically of local consumption in the states or the Brazilian Amazon, being even known as "food of the poor". Since then, following the expansion of its market, the exploitation or this fruit has undergone numerous transformations. Nowadays. besides being nationally known, it also has its demand expanded in the international markets, being considered now as a superfood. Such increase in demand has consequently influenced an increase in consumer prices and in most cases in the remuneration of extractivists, originally the exclusive suppliers of the fruit. The increase in supply has been due to the multiplication and diversification or actors in the chain, as well as the diversification of management and production practices (native acai trees densification, increase or monoculture or consortium plantations), depending on the economic context of the producing region, proximity to the industry and time in the activity of the primary suppliers. These changes can also bring vulnerability to more traditional forms and with smaller scale of production. Considering the trajectory or other extractive products that had their demands increased and, in order to meet them, had to identify substitutes, or to change the type or production system, this paper discusses, from recent data, if the main form of açai offer in the future will still remain through extraction or through cultivation systems. The paper also discusses what forms of market regulation and maintenance of traditional practices could guarantee the permanence of diversified and more sustainable systems

Framing professional competencies for systems thinking in practice: final report of an action research eSTEeM inquiry

The Open University eSTEeM project (The OU Centre for STEM Pedagogy) was a 12-month inquiry beginning March 2017 building on an initial eSTEeM project (2014-2016) entitled ‘Enhancing Systems Thinking in Practice in the Workplace’ reported on in Reynolds et al (2016). The initial report highlighted the challenges of enacting systems thinking in practice (STiP) in the workplace after qualifying with STiP core modules at The OU. Expressions of interest were manifest amongst systems thinking practitioners and employers for having some kind of formalised externally validated ‘competency framework’ for professional recognition of systems thinking in practice. The primary aim of the inquiry was to provide STiP alumni with externally recognised institutionalised professional backing for their newly acquired skill-sets associated with systems thinking. The project aimed to design a learning system – through the idea of an action learning lab – for developing a competency framework associated with systems thinking in practice. The project was carried out by a core team of three academics – Reynolds, Shah, and van Ameijde, associated with the Applied Systems Thinking in Practice (ASTiP) Group in the School of Engineering and Innovation, along with advice and support from other ASTiP colleagues – most notably Ray Ison and Chris Blackmore. The inquiry comprised some desktop research on competency framings, a series of online interviews, the drafting of an interim report, a video recording of employee/ employer interaction regarding application of STiP competencies in the workplace, a workshop held in London Regional Office in June 2017, and follow-up reporting and conversations arising from the workshop. One significant outcome from this activity led to ideas and consultations with Employer representatives, professional bodies and the Institute for Apprenticeships to initiate a Trailblazing Committee for a new Systems Thinking Practitioner apprenticeship Standard

Framing systems thinking in practice competencies: report on systems thinking in practice competencies workshop 10 June 2017

On 10 June 2017, fourteen stakeholders from across the UK came together in Camden, London to engage in a collaborative inquiry on the framing of Systems Thinking in Practice (STiP) competencies as part of ongoing work that seeks to better support professional and institutional recognition of STiP skill-sets and capabilities. Phase 1 of this current inquiry comprised a series of online conversations with six prominent systems thinking practitioners. Phase 2 sought to extend the inquiry with a selective invitation to engage with a one-day workshop in London. Phase 3 will seek to deepen and widen the conversations on framing STiP competencies and capabilities with a view towards developing and enacting a platform for managing systems thinking in practice capabilities through ongoing development of competency frameworks associated with STiP. During the workshop reported on in this paper, stakeholders examined several existing and emerging competency frameworks in the systems thinking domain and explored issues of mutual interest and concern, whilst envisaging how to co-operate over the framing and enactment of competencies and capabilities in STiP