11 research outputs found
Detecting Data-Flow Errors in BPMN 2.0
Data-flow errors in BPMN 2.0 process models, such as missing or unused data, lead to undesired process executions. In particular, since BPMN 2.0 with a standardized execution semantics allows specifying alternatives for data as well as optional data, identifying missing or unused data systematically is difficult. In this paper, we propose an approach for detecting data-flow errors in BPMN 2.0 process models. We formalize BPMN process models by mapping them to Petri Nets and unfolding the execution semantics regarding data. We define a set of anti-patterns representing data-flow errors of BPMN 2.0 process models. By employing the anti-patterns, our tool performs model checking for the unfolded Petri Nets. The evaluation shows that it detects all data-flow errors identified by hand, and so improves process quality
Atomic force microscopy-based mechanobiology
Mechanobiology emerges at the crossroads of medicine, biology, biophysics and engineering and describes how the responses of proteins, cells, tissues and organs to mechanical cues contribute to development, differentiation, physiology and disease. The grand challenge in mechanobiology is to quantify how biological systems sense, transduce, respond and apply mechanical signals. Over the past three decades, atomic force microscopy (AFM) has emerged as a key platform enabling the simultaneous morphological and mechanical characterization of living biological systems. In this Review, we survey the basic principles, advantages and limitations of the most common AFM modalities used to map the dynamic mechanical properties of complex biological samples to their morphology. We discuss how mechanical properties can be directly linked to function, which has remained a poorly addressed issue. We outline the potential of combining AFM with complementary techniques, including optical microscopy and spectroscopy of mechanosensitive fluorescent constructs, super-resolution microscopy, the patch clamp technique and the use of microstructured and fluidic devices to characterize the 3D distribution of mechanical responses within biological systems and to track their morphology and functional state.Peer ReviewedPostprint (published version
Molecular Gas in the Disk of M 31
We present a study of the molecular gas throughout the disk of M 31. From observations with the IRAM 30-m telescope in the HCN and HCO^+ lines we have deduced the distribution of the dense gas in the disk of the galaxy and its variation as a function of the galactocentric radius. We have focused on a segment of a spiral arm to compare ISM tracers (CO, H I), star formation tracers (Hα, 24 μm) and the [C II] line emission from ISO observations. [C II] emission is an excellent tracer of star formation and by comparison with photodissociation region models we have estimated the quantity of H I that is the product of H_2 dissociation
Atomic force microscopy-based mechanobiology
Mechanobiology emerges at the crossroads of medicine, biology, biophysics and engineering and describes how the responses of proteins, cells, tissues and organs to mechanical cues contribute to development, differentiation, physiology and disease. The grand challenge in mechanobiology is to quantify how biological systems sense, transduce, respond and apply mechanical signals. Over the past three decades, atomic force microscopy (AFM) has emerged as a key platform enabling the simultaneous morphological and mechanical characterization of living biological systems. In this Review, we survey the basic principles, advantages and limitations of the most common AFM modalities used to map the dynamic mechanical properties of complex biological samples to their morphology. We discuss how mechanical properties can be directly linked to function, which has remained a poorly addressed issue. We outline the potential of combining AFM with complementary techniques, including optical microscopy and spectroscopy of mechanosensitive fluorescent constructs, super-resolution microscopy, the patch clamp technique and the use of microstructured and fluidic devices to characterize the 3D distribution of mechanical responses within biological systems and to track their morphology and functional state.Peer Reviewe
Dioxins, PCBs, chlorinated pesticides and brominated flame retardants in free-range chicken eggs from peri-urban areas in Arusha, Tanzania: Levels and implications for human health
The environment in the northern part of Tanzania is influenced by rapid population growth, and increased urbanization. Urban agriculture is common and of economic value for low income families. In Arusha, many households sell eggs from free-ranging backyard chicken. In 2011, 159 eggs from different households in five different locations in Arusha were collected, homogenized, pooled into 28 composite samples and analyzed for a wide selection of POPs. Levels of POPs varied widely within and between the locations. The levels of dieldrin and σDDT ranged between 2 and 98,791 and 2 and 324 ng/g lipid weight (lw), respectively. EU MRLs of 0.02 mg/kg dieldrin for eggs were exceeded in 4/28 samples. PCBs, HCHs, chlordanes, toxaphenes and endosulfanes were found at lower frequency and levels. Brominated flame retardants (BFRs), e.g polybrominated diphenylethers (PBDEs), hexabromocyclododecane (HBCD) and 1,2-bis(2,4,6-tribromphenoxy)ethane (BTBPE) were present in 100%, 60% and 46% of the composite samples, respectively. Octa-and deca-BDEs were the dominating PBDEs and BDE 209 levels ranged between <. LOQ (limit of quantification) - 312 ng/g lw. Dioxins were measured using the DR-LUC bio-assay and found in levels of <. LOQ - 20 pg bio-TEQs/g lw. Four samples (13%) exceeded the maximum level of 5 pg/g total WHO-TEQs for hen eggs set by the Commission Regulation (EU) No 1259/2011. The daily/weekly intake was calculated and risk was characterized for all compounds comparing with available toxicity reference values (TRVs) such as the provisional tolerable intake (PTDI) or Reference Doses (RfDs). In one sample dieldrin exceeded the PTDI (100 ng/kg bw/day). Correlation was found between bio-TEQs and lipid adjusted levels of σPBDEs, suggesting similar sources. Open fires in backyards may be one of the sources for contamination of eggs with BFRs and dioxins
An event/trigger mechanism to enforce complex consistency constraints in design databases
Multi-dimensional Model Driven Policy Generation
International audienceAs Cloud Computing provides agile and scalable IT infrastructure, QoS-assured services and customizable computing environment, it increases the call for agile and dynamic deployment and governance environments over mul-ti-cloud infrastructure. By now, governance and Non Functional Properties (such as security, QoS…) are managed in a static way, limiting the global bene-fits of deploying service-based information system over multi-cloud environments. To overcome this limit, we propose a contextualised policy generation process to allow both an agile management NFP in a multi-cloud context and a secured deployment of the service-based information system. The last step of this Model Driven Policy Engineering approach uses policies as Mod-el@runtime to select, compose, deploy and orchestrate NFP management func-tions depending on the exact execution context. Moreover, a dynamic govern-ance loop including autonomic KPI management is used to control continuously the governance results