Collaborative Localization in Wireless Sensor Networks via Pattern Recognition in Radio Irregularity Using Omnidirectional Antennas

In recent years, various received signal strength (RSS)-based localization estimation approaches for wireless sensor networks (WSNs) have been proposed. RSS-based localization is regarded as a low-cost solution for many location-aware applications in WSNs. In previous studies, the radiation patterns of all sensor nodes are assumed to be spherical, which is an oversimplification of the radio propagation model in practical applications. In this study, we present an RSS-based cooperative localization method that estimates unknown coordinates of sensor nodes in a network. Arrangement of two external low-cost omnidirectional dipole antennas is developed by using the distance-power gradient model. A modified robust regression is also proposed to determine the relative azimuth and distance between a sensor node and a fixed reference node. In addition, a cooperative localization scheme that incorporates estimations from multiple fixed reference nodes is presented to improve the accuracy of the localization. The proposed method is tested via computer-based analysis and field test. Experimental results demonstrate that the proposed low-cost method is a useful solution for localizing sensor nodes in unknown or changing environments

A High-Resolution Texture Mapping Technique for 3D Textured Model

We proposed a texture mapping technique that comprises mesh partitioning, mesh parameterization and packing, texture transferring, and texture correction and optimization for generating a high-quality texture map of a three-dimensional (3D) model for applications in e-commerce presentations. The main problems in texture mapping are that the texture resolution is generally worse than in the original images and considerable photo inconsistency exists at the transition of different image sources. To improve the texture resolution, we employed an oriented boundary box method for placing mesh islands on the parametric (UV) map. We also provided a texture size that can keep the texture resolution of the 3D textured model similar to that of the object images. To improve the photo inconsistency problem, we employed a method to detect and overcome the missing color that might exist on a texture map. We also proposed a blending process to minimize the transition error caused by different image sources. Thus, a high-quality 3D textured model can be obtained by applying this series of processes for presentations in e-commerce

Posterior Atrophy and Medial Temporal Atrophy Scores Are Associated with Different Symptoms in Patients with Alzheimer's Disease and Mild Cognitive Impairment.

Whether the occurrence of posterior atrophy (PA) and medial temporal lobe atrophy (MTA) was correlated with cognitive and non-cognitive symptoms in Alzheimer's disease (AD) and mild cognitive impairment (MCI) patients are unclear.Patients with probable AD and MCI from a medical center outpatient clinic received attention, memory, language, executive function evaluation and Mini-Mental Status Examination (MMSE). The severity of dementia was rated by the Clinical Dementia Rating (CDR) Sum of Box (CDR-SB). The neuropsychiatric inventory (NPI) subscale of agitation/aggression and mood symptoms was also applied. Magnetic resonance imaging (MRI) was scored visually for the MTA, PA and white matter hyperintensity (WMH) scores.We recruited 129 AD and 31 MCI (mean age 78.8 years, 48% female) patients. MMSE scores, memory, language and executive function were all significantly decreased in individuals with AD than those with MCI (p < 0.01). MTA and PA scores reflected significant atrophy in AD compared to MCI; however, the WMH scores did not differ. The MTA scores were significantly correlated with the frontal, parieto-occipital and global WMH scores (p < 0.01) while the PA scores showed a correlation with the parieto-occipital and temporal WMH scores (p < 0.01). After adjusting for age, education, APOE4 gene and diagnostic group covariates, the MTA scores showed a significant association with MMSE and CDR-SB, while the right side PA scores were significantly associated with NPI-agitation/aggression subscales (p < 0.01).Regional atrophy is related to different symptoms in patients with AD or MCI. PA score is useful as a complementary measure for non-cognitive symptom

Correlation analysis of brain MRI visual rating scores in AD and MCI patients.

<p>Values are Pearson correlation coefficients.</p><p>MRI, magnetic resonance imaging; AD, Alzheimer’s disease; MCI, mild cognitive impairment; MTA, medial temporal atrophy; PA, posterior atrophy; FWMH, frontal white matter hyperintensity; POWMH, parieto-occipital white matter hyperintensity; TWMH, temporal white matter hyperintensity; TOWMH, total white matter hyperintensity.</p><p>*p < 0.01.</p><p>Correlation analysis of brain MRI visual rating scores in AD and MCI patients.</p

Brain MRI visual rating scores of AD and MCI patients.

<p>Values are means with standard deviations. Values in boldface indicate statistically significant differences between groups.</p><p>MRI, magnetic resonance imaging; AD, Alzheimer’s disease; MCI, mild cognitive impairment; MTA, medial temporal atrophy; PA, posterior atrophy; WMH, white matter hyperintensity;</p><p>* Independent two sample t-test tests.</p><p>Brain MRI visual rating scores of AD and MCI patients.</p

Exploring Azobenzenethiol Adsorption on the Ag/Ge(111) Surface with Surface Raman Spectroscopy

Self-assembled monolayers (SAMs) formed with thiols on surfaces represent the most representative system of such kind. Their detailed adsorption orientation and kinetics are however rarely elucidated completely, making the development of the SAM systems mostly based on try-and-error approach. We have studied the adsorption of azobenzenethiol (azoSH) on the Ag/Ge(111)-(√3 × √3)<i>R</i>30° surface, as an archetype of SAMs on compound surfaces, with <i>in situ</i> surface Raman spectroscopy. Two different adsorbates have been identified with their vibrational signatures and orientations. They respectively correspond to the two adsorption sites of this compound surface system, owing to distinct molecule–surface interactions, and both exhibit Langmuir adsorption behavior. These traits are compared with that on the Ge(111) surface, bearing homogeneous adsorption propensity, where one precursor of adsorption has been identified. The revelation of the detailed adsorption traits of azoSH has demonstrated that surface Raman spectroscopy is expedient in revealing complex adsorption behaviors of the SAM systems

Correlation analysis of clinical data and brain MRI visual rating scores in AD and MCI patients.

<p>Values are Pearson correlation coefficients.</p><p>MRI, magnetic resonance imaging; AD, Alzheimer’s disease; MCI, mild cognitive impairment; MTA, medial temporal atrophy; PA, posterior atrophy; FWMH, frontal white matter hyperintensity; POWMH, parieto-occipital white matter hyperintensity; TWMH, temporal white matter hyperintensity; TOWMH, total white matter hyperintensity; MMSE, Mini-Mental State Examination; NPI, Neuropsychiatric Inventory; CDR-SB, clinical dementia rating sum of boxes.</p><p>*p < 0.01.</p><p>Correlation analysis of clinical data and brain MRI visual rating scores in AD and MCI patients.</p

A synthetic three-dimensional niche system facilitates generation of functional hematopoietic cells from human-induced pluripotent stem cells

Abstract Background The efficient generation of hematopoietic stem cells (HSCs) from human-induced pluripotent stem cells (iPSCs) holds great promise in personalized transplantation therapies. However, the derivation of functional and transplantable HSCs from iPSCs has had very limited success thus far. Methods We developed a synthetic 3D hematopoietic niche system comprising nanofibers seeded with bone marrow (BM)-derived stromal cells and growth factors to induce functional hematopoietic cells from human iPSCs in vitro. Results Approximately 70 % of human CD34+ hematopoietic cells accompanied with CD43+ progenitor cells could be derived from this 3D induction system. Colony-forming-unit (CFU) assay showed that iPSC-derived CD34+ cells formed all types of hematopoietic colonies including CFU-GEMM. TAL-1 and MIXL1, critical transcription factors associated with hematopoietic development, were expressed during the differentiation process. Furthermore, iPSC-derived hematopoietic cells gave rise to both lymphoid and myeloid lineages in the recipient NOD/SCID mice after transplantation. Conclusions Our study underscores the importance of a synthetic 3D niche system for the derivation of transplantable hematopoietic cells from human iPSCs in vitro thereby establishing a foundation towards utilization of human iPSC-derived HSCs for transplantation therapies in the clinic

Additional file 1: of A synthetic three-dimensional niche system facilitates generation of functional hematopoietic cells from human-induced pluripotent stem cells

Growth kinetics of iPSCs seeded in various 3D hematopoietic induction milieu from day 0 to day 10-14. iPSCs were digested with collagenase IV, pipetted gently into small cell aggregations, and then seeded in 3D induction culture. The morphology was captured at indicated time points post seeding. The morphology on day 0 was shown in fig A, D, G, J and M representative of different 3D hematopoietic induction milieu. After 3 days, the formation of a blast colony from iPSC mass was detected as shown in fig B, E, H, K, and N. During induction for 10–14 days, round grape-like cells appeared in 3D induction systems as shown in C, F, I, L, and O. There was no obvious disparity in morphology among various 3D induction systems. (JPG 522 kb

Development of Stem-Cell-Mobilizing Agents Targeting CXCR4 Receptor for Peripheral Blood Stem Cell Transplantation and Beyond

The function of the CXCR4/CXCL12 axis accounts for many disease indications, including tissue/nerve regeneration, cancer metastasis, and inflammation. Blocking CXCR4 signaling with its antagonists may lead to moving out CXCR4⁺ cell types from bone marrow to peripheral circulation. We have discovered a novel series of pyrimidine-based CXCR4 antagonists, a representative (i.e., <b>16</b>) of which was tolerated at a higher dose and showed better HSC-mobilizing ability at the maximal response dose relative to the approved drug <b>1</b> (AMD3100), and thus considered a potential drug candidate for PBSCT indication. Docking compound <b>16</b> into the X-ray crystal structure of CXCR4 receptor revealed that it adopted a spider-like conformation striding over both major and minor subpockets. This putative binding mode provides a new insight into CXCR4 receptor–ligand interactions for further structural modifications