Predicting the Next Best View for 3D Mesh Refinement

3D reconstruction is a core task in many applications such as robot navigation or sites inspections. Finding the best poses to capture part of the scene is one of the most challenging topic that goes under the name of Next Best View. Recently, many volumetric methods have been proposed; they choose the Next Best View by reasoning over a 3D voxelized space and by finding which pose minimizes the uncertainty decoded into the voxels. Such methods are effective, but they do not scale well since the underlaying representation requires a huge amount of memory. In this paper we propose a novel mesh-based approach which focuses on the worst reconstructed region of the environment mesh. We define a photo-consistent index to evaluate the 3D mesh accuracy, and an energy function over the worst regions of the mesh which takes into account the mutual parallax with respect to the previous cameras, the angle of incidence of the viewing ray to the surface and the visibility of the region. We test our approach over a well known dataset and achieve state-of-the-art results.Comment: 13 pages, 5 figures, to be published in IAS-1

Introduction to statistical simulations in health research

In health research, statistical methods are frequently used to address a wide variety of research questions. For almost every analytical challenge, different methods are available. But how do we choose between different methods and how do we judge whether the chosen method is appropriate for our specific study? Like in any science, in statistics, experiments can be run to find out which methods should be used under which circumstances. The main objective of this paper is to demonstrate that simulation studies, that is, experiments investigating synthetic data with known properties, are an invaluable tool for addressing these questions. We aim to provide a first introduction to simulation studies for data analysts or, more generally, for researchers involved at different levels in the analyses of health data, who (1) may rely on simulation studies published in statistical literature to choose their statistical methods and who, thus, need to understand the criteria of assessing the validity and relevance of simulation results and their interpretation; and/or (2) need to understand the basic principles of designing statistical simulations in order to efficiently collaborate with more experienced colleagues or start learning to conduct their own simulations. We illustrate the implementation of a simulation study and the interpretation of its results through a simple example inspired by recent literature, which is completely reproducible using the R-script available from online supplemental file 1

Photodynamic therapy of DNA mismatch repair-deficient and -proficient tumour cells

Loss of DNA mismatch repair is a common finding in hereditary nonpolyposis colon cancer as well as in many types of sporadic human tumours. DNA mismatch repair-deficient cells have been reported to be resistant to many chemotherapeutic agents and to radiotherapy, and to have the potential of rapidly acquiring additional mutations leading to tumour progression. Photodynamic therapy is a new treatment modality using light to activate a photosensitiser that preferentially localises in tumour cells. An oxygen dependent photochemical reaction ensues, resulting in selective tumour necrosis. The effect of loss of DNA mismatch repair activity on the sensitivity to photodynamic therapy was tested using pairs of cell lines proficient or deficient in mismatch repair due to loss of either MLH1 or MSH2 protein function. Cells were incubated with the photosensitiser 5,10,15,20-meta-tetra(hydroxyphenyl)chlorin and exposed to laser light at 652 nm with various optical doses ranging from 0–1 J cm−2. Cell survival was assessed using the clonogenic assay. Loss of MLH1 or MSH2 function was not associated with resistance to photodynamic therapy. MCF-7 cells repeatedly treated with photodynamic therapy expressed parental levels of MLH1, MSH2, MSH6, and PMS2. DNA mismatch repair-deficient and -proficient cells showed similar subcellular distributions of meta-tetra(hydroxyphenyl)chlorin as analysed by laser scanning and fluorescence microscopy. Therefore, repeated exposure of tumour cells to photodynamic therapy does not seem to result in loss of DNA mismatch repair, and loss of mismatch repair, in turn, does not seem to contribute to resistance to photodynamic therapy. Our results suggest recommending photodynamic therapy as a strategy for circumventing resistance due to loss of DNA mismatch repair

Lung cancer risk among German male uranium miners: a cohort study, 1946–1998

From 1946 to 1990 extensive uranium mining was conducted in the southern parts of the former German Democratic Republic. The overall workforce included several 100 000 individuals. A cohort of 59 001 former male employees of the Wismut Company was established, forming a large retrospective uranium miners' cohort for the time period 1946–1998. Mean duration of follow-up was 30.5 years with a total of 1 801 630 person-years. Loss to follow-up was low at 5.3%. Of the workers, 16 598 (28.1%) died during the study period. Based on 2388 lung cancer deaths, the radon-related lung cancer risk is evaluated. The excess relative risk (ERR) per working level month (WLM) was estimated as 0.21% (95% CI: 0.18–0.24). It was dependent on time since exposure and on attained age. The highest ERR/WLM was observed 15–24 years after exposure and in the youngest age group (<55 years of age). While a strong inverse exposure-rate effect was detected for high exposures, no significant association was detected at exposures below 100 WLM. Excess relative risk /WLM was not modified by duration of exposure. The results would indicate the need to re-estimate the effects of risk modifying factors in current risk models as duration of exposure did not modify the ERR/WLM and there was only a modest decline of ERR/WLM with increasing time since exposure

Idiosyncratic deals for older workers: increased heterogeneity among older workers enhance the need for i-Deals

The rapid aging of the workforce throughout the Western world and parts of Asia, including Japan and China, poses many challenges on contemporary organizations (European Commission, 2010 ; Wang & Shultz, 2010 ). The Babyboom generation, consisting of workers born between 1945 and 1965, constitutes a large part of the current workforce. Due to decreased fertility rates, there are fewer younger workers entering the labor market, as a consequence of which the percentage of older workers is rapidly increasing (Truxillo & Fraccaroli, 2013 ). Consequently, organizations are increasingly aware that the employee population is changing, and that strategies to employ, motivate, and retain workers have to be adapted accordingly. It is no longer suffi cient for organizations to focus on employing younger workers (e.g., through designing traineeships for graduates), because the infl ux of younger workers in the labor market is stagnating, which is in particular present in certain sectors, such as technical occupations and health care (Polat, Bal, & Jansen, 2012 ). Hence, organizations increasingly will have to rely on older workers, and try to retain older workers, and motivate them to stay longer in the workforce. Similarly, governments across Europe are also increasing offi cial retirement ages, and making it fi nancially less attractive for older workers to retire early (European Commission)

TP53 regulates human AlkB homologue 2 expression in glioma resistance to Photofrin-mediated photodynamic therapy

2010-2011 > Academic research: refereed > Publication in refereed journa

Speed, Sensitivity, and Bistability in Auto-activating Signaling Circuits

Cells employ a myriad of signaling circuits to detect environmental signals and drive specific gene expression responses. A common motif in these circuits is inducible auto-activation: a transcription factor that activates its own transcription upon activation by a ligand or by post-transcriptional modification. Examples range from the two-component signaling systems in bacteria and plants to the genetic circuits of animal viruses such as HIV. We here present a theoretical study of such circuits, based on analytical calculations, numerical computations, and simulation. Our results reveal several surprising characteristics. They show that auto-activation can drastically enhance the sensitivity of the circuit's response to input signals: even without molecular cooperativity, an ultra-sensitive threshold response can be obtained. However, the increased sensitivity comes at a cost: auto-activation tends to severely slow down the speed of induction, a stochastic effect that was strongly underestimated by earlier deterministic models. This slow-induction effect again requires no molecular cooperativity and is intimately related to the bimodality recently observed in non-cooperative auto-activation circuits. These phenomena pose strong constraints on the use of auto-activation in signaling networks. To achieve both a high sensitivity and a rapid induction, an inducible auto-activation circuit is predicted to acquire low cooperativity and low fold-induction. Examples from Escherichia coli's two-component signaling systems support these predictions

Evaluation of Nod-Like Receptor (NLR) Effector Domain Interactions

Members of the Nod-like receptor (NLR) family recognize intracellular pathogens and recruit a variety of effector molecules, including pro-caspases and kinases, which in turn are implicated in cytokine processing and NF-κB activation

Characterisation and expression analysis of the Atlantic halibut (Hippoglossus hippoglossus L.) cytokines: IL-1β, IL-6, IL-11, IL-12β and IFNγ

Genes encoding the five Atlantic halibut (Hippoglossus hippoglossus L.) cytokines; interleukin (IL)-1β, IL-6, IL-11b, IL-12βc, and interferon (IFN) γ, were cloned and characterised at a molecular level. The genomic organisation of the halibut cytokine genes was similar to that seen in mammals and/or other fish species. Several mRNA instability motifs were found within the 3′-untranslated region (UTR) of all cytokine cDNA sequences. The putative cytokine protein sequences showed a low sequence identity with the corresponding homologues in mammals, avian and other fish species. Nevertheless, important structural features were presumably conserved such as the presence, or absence in the case of IL-1β, of a signal peptide, secondary structure and family signature motifs. The relative expression pattern of the cytokine genes was analyzed in several halibut organs, revealing a constitutive expression in both lymphoid and non-lymphoid organs. Interestingly, the gills showed a relatively high expression of IL-1β, IL-12βc and IFNγ. The real time RT-PCR data also showed that the mRNA level of IL-1β, IL-6, IL-12βc and IFNγ was high in the thymus, while IL-11b was relatively highly expressed in the posterior kidney and posterior gut. Moreover, the halibut brain showed a relatively high level of IL-6 transcripts. Anterior kidney leucocytes in vitro stimulated with imiquimod showed a significant increase in mRNA level of the five halibut cytokine genes. The sequence and characterisation data presented here will be useful for further investigation of both innate and adaptive immune responses in halibut, and be helpful in the design of vaccines for the control of various infectious diseases