Cor-Split: Defending Privacy in Data Re-Publication from Historical Correlations and Compromised Tuples

Abstract. Several approaches have been proposed for privacy preserving data publication. In this paper we consider the important case in which a certain view over a dynamic dataset has to be released a number of times during its history. The insufficiency of techniques used for one-shot publication in the case of subsequent releases has been previously recognized, and some new approaches have been proposed. Our research shows that relevant privacy threats, not recognized by previous proposals, can occur in practice. In particular, we show the cascading effects that a single (or a few) compromised tuples can have in data re-publication when coupled with the ability of an adversary to recognize historical correlations among released tuples. A theoretical study of the threats leads us to a defense algorithm, implemented as a significant extension of the m-invariance technique. Extensive experiments using publicly available datasets show that the proposed technique preserves the utility of published data and effectively protects from the identified privacy threats.

Dimension-specific search for multimedia retrieval.

Observing that current Global Similarity Measures (GSM) which average the effect of few significant differences on all dimensions may cause possible performance limitation, we propose the first Dimension-specific Similarity Measure (DSM) to take local dimensionspecific constraints into consideration. The rationale for DSM is that significant differences on some individual dimensions may lead to different semantics. An efficient search algorithm is proposed to achieve fast Dimension-specific KNN (DKNN) retrieval. Experiment results show that our methods outperform traditional methods by large gaps

TRY plant trait database – enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Accelerometer Measured Levels of Moderate-to-Vigorous Intensity Physical Activity and Sedentary Time in Children and Adolescents with Chronic Disease: a Systematic Review and Meta-Analysis

Context: Moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) are important for child and adolescent health. Objective: To examine habitual levels of accelerometer measured MVPA and ST in children and adolescents with chronic disease, and how these levels compare with healthy peers. Methods: Data sources: An extensive search was carried out in Medline, Cochrane library, EMBASE, SPORTDiscus and CINAHL from 2000–2017. Study selection: Studies with accelerometer-measured MVPA and/or ST (at least 3 days and 6 hours/day to provide estimates of habitual levels) in children 0–19 years of age with chronic diseases but without co-morbidities that would present major impediments to physical activity. In all cases patients were studied while well and clinically stable. Results: Out of 1592 records, 25 studies were eligible, in four chronic disease categories: cardiovascular disease (7 studies), respiratory disease (7 studies), diabetes (8 studies), and malignancy (3 studies). Patient MVPA was generally below the recommended 60 min/day and ST generally high regardless of the disease condition. Comparison with healthy controls suggested no marked differences in MVPA between controls and patients with cardiovascular disease (1 study, n = 42) and type 1 diabetes (5 studies, n = 400; SMD -0.70, 95% CI -1.89 to 0.48, p = 0.25). In patients with respiratory disease, MVPA was lower in patients than controls (4 studies, n = 470; SMD -0.39, 95% CI -0.80, 0.02, p = 0.06). Meta-analysis indicated significantly lower MVPA in patients with malignancies than in the controls (2 studies, n = 90; SMD -2.2, 95% CI -4.08 to -0.26, p = 0.03). Time spent sedentary was significantly higher in patients in 4/10 studies compared with healthy control groups, significantly lower in 1 study, while 5 studies showed no significant group difference. Conclusions: MVPA in children/adolescents with chronic disease appear to be well below guideline recommendations, although comparable with activity levels of their healthy peers except for children with malignancies. Tailored and disease appropriate intervention strategies may be needed to increase MVPA and reduce ST in children and adolescents with chronic disease

The use of three-dimensional models as a pedagogycal tool in teaching biology for students with visual impairment

A escola à um lugar de formaÃÃo da cidadania e deve preparar os jovens sem as barreiras de separaÃÃo de classes, gÃnero ou de pessoas com deficiÃncia. A riqueza da vida na natureza nÃo està na homogeneidade, mas na diversidade de espÃcies e formas de interaÃÃo. Nos meios social e educacional tambÃm deve ser assim. A escola pode entÃo contribuir com as mudanÃas estruturais necessÃrias à construÃÃo de uma sociedade orientada por relaÃÃes pacÃficas e respeitosas no acolhimento à diversidade humana. Diante deste cenÃrio de busca pela cidadania e de aceitaÃÃo das diferenÃas individuais, propÃs-se nesta dissertaÃÃo o uso de modelos tridimensionais como ferramenta pedagÃgica no ensino de Biologia para estudantes com deficiÃncia visual. Estes modelos foram produzidos a partir de desenhos e esquemas do conteÃdo de citologia, para promover maior aprendizagem, tanto pelo educando cego como o de baixa visÃo, no conhecimento de Biologia. A pesquisa foi desenvolvida numa escola pÃblica de Ensino MÃdio da cidade de Fortaleza, com alunos do 1 ano do turno manhÃ, por serem turma e turno que comporta maior quantidade de jovens com o perfil necessÃrio. Ao final do trabalho foi realizada uma exposiÃÃo com os modelos construÃdos pelos prÃprios estudantes, os estudantes com deficiÃncia visual e os que tÃm boa visÃo, com o intuito de garantir a interaÃÃo entre os alunos. Os modelos foram entÃo doados à Sala de Recursos Multifuncionais da escola. Concluiu-se que a implementaÃÃo de metodologias que favorecem a interaÃÃo entre videntes e estudantes com deficiÃncia visual, em sala de aula, bem como a viabilidade da utilizaÃÃo dos modelos confeccionados pelos prÃprios estudantes, os de visÃo normal e os estudantes com deficiÃncia visual, à de efetiva importÃncia no desenvolvimento da aprendizagem desses alunos, num trabalho cooperativo e interativo.The school is a place for citizenship development and it must prepare the youth without the barriers of classes division, genre, or people with impairments. The wealth of life in nature is not in the homogeneity, but in the diversity of species and forms of interaction. In social and educational environments it must also be this way. The school can then contribute with the structural changings which are necessary to the development of a society oriented by pacific relationships, respectful in the welcome of human diversity. In face of this scenery of citizenship searching, of the acceptance of individual differences, it was proposed in this dissertation the usage of tridimensional models as a pedagogical tool in the teaching of Biology for visually impaired students. These models were produced from drawings and schemes of the Cytology content, to promote better learning for blind and low vision students in the Biology knowledge. The research was developed in Escola de Ensino MÃdio Governador Adauto Bezerra, with students from the 1 grade of High School who have classes in the morning, because this is the group and turn that comprise the greatest number of students in the profile required. At the end of this work, it was performed an exposition of the models built by the students themselves, both the visual impaired and the ones with good vision, in order to guarantee the interaction between the students. The models were donated to the room of multifunctional resources of the school, so that other teachers can also use them. It was concluded that the implementation of methodologies that favor the interaction between the visual impaired and the seers, inside the classroom, as well as the viability of the usage of the models made by the students themselves, both the impaired and the visual ones, is of effective importance in these students learning development, in a cooperative and interactive work

Cryptanalysis of a provably secure Cross-Realm Client-to-Client Password-Authenticated Key Agreement protocol of CANS ’09

In this paper, we cryptanalyze the recent smart card based client-to-client password-authenticated key agreement (C2C-PAKA-SC) protocol for cross-realm settings proposed at CANS ’09. While client-to-client password-authenticated key exchange (C2C-PAKE) protocols exist in literature, what is interesting about this one is that it is the only such protocol claimed to offer security against password compromise impersonation without depending on public-key cryptography, and is one of the few C2C-PAKE protocols with provable security that has not been cryptanalyzed. We present three impersonation attacks on this protocol; the first two are easier to mount than the designer-considered password compromise impersonation. Our results are the first known cryptanalysis results on C2C-PAKA-SC

Secure Password-Based Authenticated Group Key Agreement for Data-Sharing Peer-to-Peer Networks

We explore authenticated group key agreement in data-sharing Peer-to-Peer networks. We first propose a novel password-based authenticated group key agreement protocol with key confirmation. We present a formal statement of its security in a variant of the Bresson et al. security model adapted for the password-based setting. A discussion of the limitations of our protocol in the case where the group size becomes large is then presented. We conclude the paper with an enhanced version of the protocol, using a CAPTCHA technique, designed to make it more robust against online password guessing attacks