The State of Self-Organized Criticality of the Sun During the Last 3 Solar Cycles. I. Observations

We analyze the occurrence frequency distributions of peak fluxes $P$, total fluxes $E$, and durations $T$ of solar flares over the last three solar cycles (during 1980--2010) from hard X-ray data of HXRBS/SMM, BATSE/CGRO, and RHESSI. From the synthesized data we find powerlaw slopes with mean values of $\alpha_P=1.72\pm0.08$ for the peak flux, $\alpha_E=1.60\pm0.14$ for the total flux, and $\alpha_T=1.98\pm0.35$ for flare durations. We find a systematic anti-correlation of the powerlaw slope of peak fluxes as a function of the solar cycle, varying with an approximate sinusoidal variation $\alpha_P(t)=\alpha_0+\Delta \alpha \cos{[2\pi (t-t_0)/T_{cycle}]}$, with a mean of $\alpha_0=1.73$, a variation of $\Delta \alpha =0.14$, a solar cycle period $T_{cycle}=12.6$ yrs, and a cycle minimum time $t_0=1984.1$. The powerlaw slope is flattest during the maximum of a solar cycle, which indicates a higher magnetic complexity of the solar corona that leads to an overproportional rate of powerful flares.Comment: subm. to Solar Physic

School-based prevention for adolescent Internet addiction: prevention is the key. A systematic literature review

Adolescents’ media use represents a normative need for information, communication, recreation and functionality, yet problematic Internet use has increased. Given the arguably alarming prevalence rates worldwide and the increasingly problematic use of gaming and social media, the need for an integration of prevention efforts appears to be timely. The aim of this systematic literature review is (i) to identify school-based prevention programmes or protocols for Internet Addiction targeting adolescents within the school context and to examine the programmes’ effectiveness, and (ii) to highlight strengths, limitations, and best practices to inform the design of new initiatives, by capitalizing on these studies’ recommendations. The findings of the reviewed studies to date presented mixed outcomes and are in need of further empirical evidence. The current review identified the following needs to be addressed in future designs to: (i) define the clinical status of Internet Addiction more precisely, (ii) use more current psychometrically robust assessment tools for the measurement of effectiveness (based on the most recent empirical developments), (iii) reconsider the main outcome of Internet time reduction as it appears to be problematic, (iv) build methodologically sound evidence-based prevention programmes, (v) focus on skill enhancement and the use of protective and harm-reducing factors, and (vi) include IA as one of the risk behaviours in multi-risk behaviour interventions. These appear to be crucial factors in addressing future research designs and the formulation of new prevention initiatives. Validated findings could then inform promising strategies for IA and gaming prevention in public policy and education

Uncovering the heterogeneity and temporal complexity of neurodegenerative diseases with Subtype and Stage Inference

The heterogeneity of neurodegenerative diseases is a key confound to disease understanding and treatment development, as study cohorts typically include multiple phenotypes on distinct disease trajectories. Here we introduce a machine-learning technique\u2014Subtype and Stage Inference (SuStaIn)\u2014able to uncover data-driven disease phenotypes with distinct temporal progression patterns, from widely available cross-sectional patient studies. Results from imaging studies in two neurodegenerative diseases reveal subgroups and their distinct trajectories of regional neurodegeneration. In genetic frontotemporal dementia, SuStaIn identifies genotypes from imaging alone, validating its ability to identify subtypes; further the technique reveals within-genotype heterogeneity. In Alzheimer\u2019s disease, SuStaIn uncovers three subtypes, uniquely characterising their temporal complexity. SuStaIn provides fine-grained patient stratification, which substantially enhances the ability to predict conversion between diagnostic categories over standard models that ignore subtype (p = 7.18 7 10 124 ) or temporal stage (p = 3.96 7 10 125 ). SuStaIn offers new promise for enabling disease subtype discovery and precision medicine

Integrative science in practice : Process perspectives from ASB, the partnership for the tropical forest margins

ASB, the Partnership for the Tropical Forest Margins, is a decade-old, complex, multi-institutional, multi-disciplinary, multi-site research and development consortium. It has been recognized for its success in producing scientific outputs and real world impacts and as a pioneer in integrated natural resource management (iNRM). Until now, there has been little understanding of the reasons for its success in integrating different perspectives and ways of working. To fill this gap, an on-line consultation involving ASB researchers was structured following an analytical framework developed by the Initiative on Science and Technology for Sustainability. The structure of the presentation of major results presented in this article also follows that framework, which includes four dimensions of integration (disciplinary, functional, spatial/temporal, and knowledge) and linked challenges of institutional learning and adaptation, fostering appropriate participation, and managing resource and capacity constraints. To lay the foundations for interpreting these insights and to motivate the study, introductory sections present qualitative evidence regarding organizational learning within the consortium (using research hypotheses as indicators) and success in producing integrated results (using a selection of research results as evidence). This report on ASB's experience in integrative science and organizational learning is intended to advance understanding of the scope and limits of a complex international consortium to integrate activities across disciplines, organizations, scales and knowledge systems in order to produce knowledge and policy relevant outputs. ASB's processes and structures have weaknesses as well as strengths. And while there almost certainly are a range of effective alternative approaches to integrative science, the insights from ASB's experience documented in these online discussions could be of interest to other geographically dispersed teams, especially those working on environment and development issues. Moreover, from a methodological perspective, the use of information technology reported in this article proved to be an effective means of triangulating the perceptions of geographically dispersed researchers. In doing so, this web-based consultation provided a medium for reflection by a large ‘virtual team’ on whether words about integration are translated into practice, at least as perceived and self-reported by the scientists who participated. These techniques could be employed for process documentation by other dispersed teams, thereby adding to the stock of information on what works (and what does not) in efforts to put integrative science into practice on a significant scale

Concept and valuation of landscape functions at different scales

Natural, semi-natural and cultivated ecosystems and landscapes provide many goods and services to human society that are of great ecological, socio-cultural and economic value (Millennium Ecosystem Assessment 2005). In environmental planning and decision-making, however, these benefits are often not fully taken into account and productive, multifunctional landscapes continue to be converted into more simple, often single-function land use types (e.g. croplands) or turned into wastelands (e.g. eroded land after clear-cut logging or polluted and over-fished shelf-seas). Yet, increasingly studies are showing that the total value of multifunctional use of natural and semi-natural landscapes is often economically more beneficial than the value of the converted systems (Balmford et al. 2002). The question therefore is how to identify and quantify the many benefits of multi-functional landscapes in order to take more balanced decisions regarding trade-offs involved in land use planning in view of the increasing demands for space and resources