A Hybrid Geostatistical Method for Estimating Citywide Traffic Volumes – A Case Study of Edmonton, Canada

Traffic volume information has long played an important role in many transportation related works, such as traffic operations, roadway design, air quality control, and policy making. However, monitoring traffic volumes over a large spatial area is not an easy task due to the significant amount of time and manpower required to collect such large-scale datasets. In this study, a hybrid geostatistical approach, named Network Regression Kriging,has been developed to estimate urban traffic volumes by incorporating auxiliary variables such as road type, speed limit, and network accessibility.Since standard kriging is based on Euclidean distances, this study implements road network distances to improve traffic volumes estimations.A case study using 10-year of traffic volume data collected within the city of Edmonton was conducted to demonstrate the robustness of the model developed herein. Results suggest that the proposed hybrid model significantly outperforms the standard kriging method in terms of accuracy by 4.0% overall, especially for a large-scale network. It was also found that the necessary stationarity assumption for kriging did not hold true for a large network whereby separate estimations for each road type performed significantly better than a general estimation for the overall network by 4.12%

In situ ultrafine force measurement with nanowire based cantilevers in SEM

In nanomechanics the measurement of ultrafine forces becomes increasingly important for unravelling subtle details of elastic and plastic deformation processes. In particular, achieving high force resolution in combination with in situ imaging is a major challenge which is becoming exceedingly difficult with conventional methods. In this work, we introduce a novel systematic method to measure ultrafine forces using well-defined nanowires as cantilever beams in situ in the Scanning Electron Microscope (SEM). Forces can be measured variably in the range from micro-newtons (mN) down to femto-newtons (fN), depending on the chosen reference nanowire. The reference wires are picked with a manipulator tip without the use of FIB (see Figure 1 a). Please click Additional Files below to see the full abstract

Intrinsic nano-diffusion-couple for studying high temperature diffusion in multi-component superalloys

We present a new approach for the quantitative study of high-temperature diffusion in compositionally complex superalloys on the nano-scale. As key element, the approach utilizes the γ/γ\u27-microstructure itself as intrinsic nano-diffusion-couple (NDC). By establishing equilibrium at one temperature followed by annealing at a different temperature, well-defined transient states are generated which are studied using STEM-EDXS. We demonstrate this approach for a multi-component superalloy of CMSX-4 type. The temporal evolution of element concentrations is consistently revealed for γ- and γ\u27-forming elements and is compared to diffusion simulations based on DICTRA. Excellent agreement is obtained for Ni, Co, and Cr whereas diffusion of Al and, in particular, Re lacks behind in experiment. Finally, it is demonstrated that transient states can also be captured by in situ TEM using chip-based heating devices. The NDC approach offers great opportunities for diffusion studies in compositionally complex superalloys and might be extended to other two-phase multi-component systems

Genetic Fingerprint Concerned with Lymphatic Metastasis of Human Lung Squamous Cancer

Background and objective With the most recent introduction of microarray technology to biology, it becomes possible to perform comprehensive analysis of gene expression in cancer cell. In this study the laser microdissection technique and cDNA microarray analysis were combined to obtain accurate molecular profiles of lymphatic metastasis in patients with lung squamous cell carcinoma. Methods Primary lung squamous cancer tissues and regional lymph nodes were obtained from 10 patients who underwent complete resection of lung cancer. According to the source of lung cancer cells, the samples were classified into three groups: the primary tumor with lymphatic metastasis (TxN+, n=5), the primary tumor without lymphatic metastasis (TxN-, n=5) and matched tumor cells from metastatic lymph nodes (N+, n=5). Total RNA was extracted from laser microdissected tumor samples. Adequate RNA starting material of mRNA from primary tumor or metastatic nodes were labeled and then hybridized into the same microarray containing 6 000 known, named human genes/ESTs. After scanning, data analysis was performed using GeneSpringTM6.2. Results A total of 37 genes were found to be able to separate TxN+ from TxN-. TxN+ have higher levels of genes concerned with structural protein, signal transducer, chaperone and enzyme. TxN- have higher levels of genes coding for cell cycle regulator, transporter, signal transducer and apoptosis regulator. Interestingly, there were no differentially expressed genes between N+ and TxN+. Conclusion The acquisition of the metastatic phenotype might occur early in the development of lung squamous cancer. We raise the hypothesis that the gene-expression signature described herein is valuable to elucidate the molecular mechanisms regarding lymphatic metastasis and to look for novel therapeutic targets

Nanoscale distribution of Bi atoms in InP1-xBix

The nanoscale distribution of Bi in InPBi is determined by atom probe tomography and transmission electron microscopy. The distribution of Bi atoms is not uniform both along the growth direction and within the film plane. A statistically high Bi-content region is observed at the bottom of the InPBi layer close to the InPBi/InP interface. Bi-rich V-shaped walls on the (−111) and (1–11) planes close to the InPBi/InP interface and quasi-periodic Bi-rich nanowalls in the (1–10) plane with a periodicity of about 100 nm are observed. A growth model is proposed to explain the formation of these unique Bi-related nanoscale features. These features can significantly affect the deep levels of the InPBi epilayer. The regions in the InPBi layer with or without these Bi-related nanostructures exhibit different optical properties

Fluctuation of circulating tumor cells in patients with lung cancer by real-time fluorescent quantitative-PCR approach before and after radiotherapy

Background and Aims: The failure to reduce the mortality of patients with solid tumours is mainly a result of the early dissemination of cancer cells to secondary site, which is usually missed by conventional diagnostic procedures used for tumour staging. The possibility to use easily accessible body fluids as a source for circulating tumour cells (CTCs) detection enables longitudinal observations of the disease. In the study, we evaluated the CTCs in lung cancer following locoregional radiation therapy. Methods: Samples of 5ml peripheral blood was taken from each lung cancer patients (n=15) both before and after the radiotherapy course. Meanwhile tumour size was determined by chest X-ray or computed tomography. Using cytokeratin 19(CK19) as marker,the blood samples were subjected to real time RT-PCR assay. All patients with lung cancer were treated with primary definitive and mediastinal radiotherapy. Results Compare to that of pre-treatment, the value of CK19 mRNA in peripheral blood after therapy decreased dramatically(5.0932\ub11.0628 vs. 4.2493\ub10.8323,t=3.192,P=0.007). The change of CK19 mRNA level before and after radiotherapy was closely related to the type (NSCLC vs. SCLC, 0.5389\ub10.9030 vs. 1.6826\ub10.9467,t=2.1465,P=0.051). Meanwhile, there appeared to be a close link between the grade (Well/Mod vs. Poor) and the change of CK19 mRNA (0.5024 vs. 1.5271,t=2.017,P=0.065). The change of CK19 mRNA level was related to variation of tumour burden during radiotherapy(r=0.0575,P=0.025). Of the 15 cases studied, 12 cases were positive before radiotherapy (12/15,80%). The positive rate was 53%(8/15) after radiotherapy, meaning that four patients converted into negative after radiotherapy. Conclusions: The disseminated circulating cancer cells can be affected by radiotherapy; meanwhile further more systemic adjuvant treatment should be conducted. Due to concordance between molecular response and radiological remission, assessment of the therapeutic response might be possible by serial quantitative of CTCs