Adaptive non-parametric estimation in the presence of dependence

We consider non-parametric estimation problems in the presence of dependent data, notably non-parametric regression with random design and non-parametric density estimation. The proposed estimation procedure is based on a dimension reduction. The minimax optimal rate of convergence of the estimator is derived assuming a sufficiently weak dependence characterized by fast decreasing mixing coefficients. We illustrate these results by considering classical smoothness assumptions. However, the proposed estimator requires an optimal choice of a dimension parameter depending on certain characteristics of the function of interest, which are not known in practice. The main issue addressed in our work is an adaptive choice of this dimension parameter combining model selection and Lepski's method. It is inspired by the recent work of Goldenshluger and Lepski (2011). We show that this data-driven estimator can attain the lower risk bound up to a constant provided a fast decay of the mixing coefficients.Comment: 39 pages, 4 figure

A Monomer-to-Trimer Transition of the Human Mitochondrial Transcription Termination Factor (mTERF) Is Associated with a Loss of in Vitro Activity

The human mitochondrial transcription termination factor (mTERF) is a nuclear-encoded 39-kDa protein that recognizes a mtDNA segment within the mitochondrial tRNALeu(UUR) gene immediately adjacent to and downstream of the 16 S rRNA gene. Binding of mTERF to this site promotes termination of rDNA transcription. Despite the fact that mTERF binds DNA as a monomer, the presence in its sequence of three leucine-zipper motifs suggested the possibility of mTERF establishing intermolecular interactions with proteins of the same or different type. When a mitochondrial lysate from HeLa cells was submitted to gel filtration chromatography, mTERF was eluted in two peaks, as detected by immunoblotting. The first peak, which varied in proportion between 30 and 50%, appeared at the position expected from the molecular mass of the monomer (41 ± 2 kDa), and the gel filtration fractions that contained it exhibited DNA binding activity. Most interestingly, the material in this peak had a strong stimulating activity on in vitro transcription of the mitochondrial rDNA. The second peak eluted at a position corresponding to an estimated molecular mass of 111 ± 5 kDa. No mTERF DNA binding activity could be detected in the corresponding gel filtration fractions. Therefore, we propose that mTERF exists in mitochondria in two forms, an active monomer and an inactive large size complex. The estimated molecular weight of this complex and the fact that purified mTERF can be eluted from a gel filtration column as a complex of the same molecular weight strongly suggest that this inactive complex is a homotrimer of mTERF

The ‘Great Escape’: In Pursuit of President Al Bashir in South Africa

In 2008 the first Chief Prosecutor of the International Criminal Court (‘the Court’ or ‘ICC’) Luis Moreno Ocampo, had shifted his prosecutorial strategy with regard to the situation in Sudan by deciding to pursue the serving President of Sudan, Omar al Bashir, whereas before, his strategy had been to request the Pre-Trial Chamber to issue summons for persons deemed to be mid-level individuals in the Khartoum government. Acting on that referral, the Prosecutor initiated investigations into the situation in Darfur beginning June 2005. On 14 July 2008, the Prosecutor filed an application requesting the Pre-Trial Chamber to issue a warrant of arrest against President Bashir, which was granted on 4 March 2009. Subsequently, warrants of arrest were issued for Al Bashir on 4 March 2009 and on 12 July 2010, with the second warrant being issued to reflect the inclusion of the charge of genocide in the indictment. This article examines how this "Great Escape", on the light of the last events.

'South Africa is Not an Accused': State (non) Co-operation with the ICC and the Case of the Arrest Warrants for President Omar al-Bashir

There is a confrontation between the International Criminal Court (ICC) and state parties, and at this particular point in time, the Republic of South Africa, in connection with the arrest warrants issued by the Court for the President of Sudan in 2009 and 2010. Between 13 and 15 June 2015, President Omar al-Bashir was present on the territory of South Africa for purposes of attending the 25th Ordinary Session of the Assembly of the African Union. Despite judgments from both the ICC upholding the obligation of South African authorities to arrest and surrender President Bashir and parallel domestic proceedings at the South African High Court in which authorities were ordered to prevent the departure of President Bashir from South African territory pending final judicial decision on whether the Government was required to execute the ICC arrest warrants, President Bashir nevertheless departed from the Waterkloof military air base on 15 June 2015, even as Government lawyers assured the High Court in a hearing on the same date that he was still in the country. Only after his plane had safely landed in Khartoum did the same lawyers then notify the High Court that he had left South Africa. This article will analyze this case in the following lines

A qualitative approach to assessing the pedestrian environment

European cities have always been attentive to the needs of pedestrians, and walking has traditionally been the prevailing means of transport. However, during the last century, car driving has been granted increasing priority in investment programs, and the rising urban car dependency has negatively affected pedestrians quality needs (PQN). Because of these problems, European cities will have to differently approach car-oriented policies, aiming at a more sustainable design and transport planning, as well as an effective mobility management. Generally, countries appear to be on the right path, and there are several examples of pedestrian-friendly cities. However, more needs to be done and in the European context there are too many disparities between countries performing at different levels. This article presents the PQN matrix, a qualitative approach to assessing pedestrian environment, which translated pedestrians’ quality needs into five basic requirements: connectivity, conspicuity 1 , comfort, convenience and conviviality. This framework only takes into account the connection between pedestrians’ needs and the environment, whilst neglecting the other three components of the system, i.e. person, vehicle and organisation. A practical application is also provided, through the analysis of twenty pedestrian-friendly cities in the countries taking part in COST Action 358. This analysis aims at developing a comprehensive comparison among these cities, stressing their differences and similarities. This article is based on the key findings achieved by the Short-Term Scientific Mission (STSM) that took place in February and March 2008 at AVV Transport Research Centre DVS in Rotterdam (The Netherlands

Cell bystander effect induced by radiofrequency electromagnetic fields and magnetic nanoparticles

Induced effects by direct exposure to ionizing radiation (IR) are a central issue in many fields like radiation protection, clinic diagnosis and oncological therapies. Direct irradiation at certain doses induce cell death, but similar effects can also occur in cells no directly exposed to IR, a mechanism known as bystander effect. Non-IR (radiofrequency waves) can induce the death of cells loaded with MNPs in a focused oncological therapy known as magnetic hyperthermia. Indirect mechanisms are also able to induce the death of unloaded MNPs cells. Using in vitro cell models, we found that colocalization of the MNPs at the lysosomes and the non-increase of the temperature induces bystander effect under non-IR. Our results provide a landscape in which bystander effects are a more general mechanism, up to now only observed and clinically used in the field of radiotherapy.Comment: 16 pages, 4 figures, submitted to International Journal of Radiation Biolog

Unaccompanied immigrant minors in the canary islands : a legal approach

The Canary Islands have received significant numbers of unaccompanied minors, especially during 2006. This phenomenon has resulted in the need to develop an appropriate policy response across the Spanish State and the European Union. The proposals to establish special protected status for unaccompanied migrant children have generated considerable controversy within the Autonomous Community of the Canary Islands, since it has assumed competence for taking the necessary measures for the protection of minors within its territory. This article provides an overview of the relevant legislation and policies on reception, return and integration applicable to unaccompanied minors, analysing the difficulties that policymakers must take into account as they address the phenomenon of child migration.peer-reviewe

The role of groups as local context in large Enterprise Social Networks: A Case Study of Yammer at Deloitte Australia

Enterprise Social Networking, the application of popular social networking techniques to the workplaces of organisations, is an increasingly common phenomenon. But its nature, benefits and proliferation are not yet fully understood. In this study we investigate ESN communication at the micro-level. We focus on the role of the group feature in structuring and providing context for communication in large ESNs. Our case study is Yammer at Deloitte. In contrast to previous studies we carry out an analysis of communication at the thread (conversation) level, rather than at the level of single messages. This allows us to provide a more contextual understanding of the group aspects of communication. We find that information sharing underpins the majority of communication threads, which speaks to the usefulness of ESN, in particular in the context of knowledge-intensive work. We further uncover differences between network-wide and group-centred communication and derive a framework of four group archetypes, based on different group communication patterns. Our findings are useful for decision-makers in providing a better understanding of the role of groups in providing local contexts for users in large ESNs

When Routine Work Becomes Social: How Virtual Social Facilitation Increases Performance on Simple IT-Based Tasks

With the advent of social applications, the question arises of how organizations can utilize such technology for improving task performance. While social applications certainly bear the potential to trigger the development of radically new business models and business processes, we seek to study how the enrichment of IT-based routine work (simple tasks) by complementing social features (audience condition) may advance performance. In 280 experiments with altogether 40 participants, we investigate the impact of a) monitoring, b) measurement, and c) feedback dialogs on performance of simple IT-based tasks. We compare the effects of these three treatments in a setting of physical presence and in a setting of virtual presence. The results show that monitoring has the strongest effect in the physical presence setting while, in the virtual presence setting, both monitoring and feedback dialogs can improve task performance significantly. Theory-wise, we draw on social psychology and develop a (design) theory of virtual social facilitation that bears major implications for designing routine work information systems and technology