bluuebunny/crossref_metadata_2025 huggingface dataset:
Aptamer-siRNA Chimeras: Discovery, Progress, and Future Prospects
Authors: Kruspe Sven , Giangrande Paloma
Published: August 2017

Synthetic nucleic acid ligands (aptamers) have emerged as effective delivery tools for many therapeutic oligonucleotide-based drugs, including small interfering RNAs (siRNAs). In this review, we summarize recent progress in the aptamer selection technology that has made possible the identification of cell-specific, cell-internalizing aptamers for the cell-targeted delivery of therapeutic oligonucleotides. In addition, we review the original, proof-of-concept aptamer-siRNA delivery studies and discuss recent advances in aptamer-siRNA conjugate designs for applications ranging from cancer therapy to the development of targeted antivirals. Challenges and prospects of aptamer-targeted siRNA drugs for clinical development are further highlighted.
Masonry’s Resistance to Driving Rain: Mortar Water Content and Impregnation
Authors: Slapø Fredrik , Kvande Tore , Bakken Noralf , Haugen Marit , Lohne Jardar
Published: August 2017

Alongside well-researched themes such as water and moisture, the service life and function of masonry veneers are often compromised by precipitation combined with poor design considerations, execution, and selection of materials. Little research has been carried out on the subject of the impact of mortar consistency on masonry’s resistance to driving rain. Water-repellent (WR) impregnation is typically considered a quick fix when problems occur. Wall-panels of 1 m2 built with different flow table values for the mortar have been tested in a driving rain chamber, where both time-lapse videos and the measuring of penetrated water are used to evaluate performance. Subsequently, the panels were impregnated with the most common types of WR products and re-tested. The analysis shows that changing the mortar mix from dry to wet can decrease the penetration of driving rain by a factor of ten. The test results presented in this article show that mortar with low water content gives a porous interfacial transition zone (ITZ), thereby increasing the rate of water penetration. The tested WRs are found to be ineffective in increasing masonry’s resistance to high pressure driving rain. The results, combined with what is already known about WR treatments on masonry, call for careful consideration before applying such treatment. This proves especially true in countries with much driving rain followed by frequent freeze-thaw cycles.
Precipitant-Free Crystallization of Protein Molecules Induced by Incision on Substrate
Authors: Ghatak Anindita , Rawal Gaurav , Ghatak Animangsu
Published: August 2017

Nucleation of protein crystals has been shown to be facilitated by substrates decorated with both nano- to micro-scale hierarchical undulations and spatially varying surface potential. In fact, on such surfaces, several proteins were found to crystallize without having to use any precipitant in contrast to all other homogeneous and heterogeneous systems in which precipitant is an essential ingredient for nucleation. While these surfaces were so patterned whole through the area that was brought in contact with the protein solution, it was not clear exactly to what extent the surfaces were required to be patterned to trigger nucleation without use of any precipitant. Here we show that a simple incision may be enough on an otherwise smooth surface for this purpose. In particular, the substrate used here is a smooth silicone film with its surface plasma oxidized to create a thin crust of silica. An incision is then generated on this surface using a sharp razor blade. The silica crust being brittle leads to random nano-microscopic undulations at the vicinity of the incision. These undulations along with surface charge can induce protein crystal nucleation without precipitant.
A View of Information-Estimation Relations in Gaussian Networks
Authors: Dytso Alex , Bustin Ronit , Poor H. , Shamai (Shitz) Shlomo
Published: August 2017

Relations between estimation and information measures have received considerable attention from the information theory community. One of the most notable such relationships is the I-MMSE identity of Guo, Shamai and Verdú that connects the mutual information and the minimum mean square error (MMSE). This paper reviews several applications of the I-MMSE relationship to information theoretic problems arising in connection with multi-user channel coding. The goal of this paper is to review the different techniques used on such problems, as well as to emphasize the added-value obtained from the information-estimation point of view.
Numerical Investigation of the Effect of Variable Baffle Spacing on the Thermal Performance of a Shell and Tube Heat Exchanger
Authors: Bayram Halil , Sevilgen Gökhan
Published: August 2017

In this present study, numerical and theoretical analysis were both used to investigate the effect of the variable baffle spacing on the thermal characteristics of a small shell and tube heat exchanger. The numerical study was performed by using a three dimensional computational fluid dynamics (CFD) method and the computations were performed under steady-state conditions. We employed five different cases where the first had equal baffle spacing and the others had variable ones considering different configurations for balancing the pressure drop on the shell side. Theoretical calculations were run using the Bell-Delaware and Kern methods which are the most commonly used methods in the available literature. We show that the thermal performance of a shell and tube heat exchanger can be improved by evaluating together the results of the CFD and Bell-Delaware methods. From the numerical results, we can say that variable spacing with centered baffle spacing scheme can be proposed as an alternative shell side construction layout compared to an equal baffle spacing scheme. The numerical results were in good agreement with the theoretical data in the available literature.
Analysis of Cooling Effectiveness and Temperature Uniformity in a Battery Pack for Cylindrical Batteries
Authors: Shahid Seham , Agelin-Chaab Martin
Published: August 2017

In this paper, techniques to improve cooling and temperature uniformity in a simple battery pack are examined. Four battery pack configurations are developed. In the first configuration, an inlet plenum is added to a simple battery pack. In the second configuration, jet inlets are incorporated along with the inlet plenum, and in the third configuration, multiple vortex generators are added in addition to the inlet plenum. Finally, in the fourth configuration, an inlet plenum, jet inlets, and multiple vortex generators are incorporated into the battery pack. The results conclude that by adding inlet plenum, multiple vortex generators, and jet inlets in the same configuration, significant improvements are observed. The results also show that the maximum temperature of the battery pack is reduced by ~5%, and the temperature difference between the maximum temperature and the minimum temperature exhibited by the battery pack is reduced by 21.5%. Moreover, there is a ~16% improvement in the temperature uniformity of a single cell.
Identification of Financing Barriers to Energy Efficiency in Small and Medium-Sized Enterprises by Integrating the Fuzzy Delphi and Fuzzy DEMATEL Approaches
Authors: Dong Jun , Huo Huijuan
Published: August 2017

Energy efficiency is one of the most practical ways for China to simultaneously tackle environmental issues and achieve sustainable development. However, the issue of inadequate capital inflows is a bottleneck in energy efficiency projects, especially for small and medium-sized enterprises (SMEs). This study focuses on the complicated financial barriers to effectively promoting such projects for SMEs. A hybrid framework was proposed to recognize the most obvious financing barriers under uncertain circumstances. Potential barriers were collected firstly to build an index system, including the five dimensions of “policy and regulation”, “economic market”, “financial institutions”, “behavior” and “economic non-market”. Then, this paper introduced a novel way to combine a fuzzy Delphi and a fuzzy decision making trial and evaluation laboratory (DEMATEL) method. The fuzzy Delphi method was applied to extract significant factors from potential barriers. To analyze a series of causal relationships, the fuzzy DEMATEL approach was employed. Moreover, triangular fuzzy numbers (TFNs) are used firstly to express vague linguistic ratings in the proposed framework. Based on the experts’ opinions, seventeen significant factors were chosen to assemble a final evaluation system. Eleven key barriers were identified by analyzing cause-effect relations, including “slight fiscal incentives”, “inadequate energy market trading mechanisms”, “a low priority of energy saving issues”, etc. The key barriers affiliated with “market” and “policy and regulation” are much more important than the others. Except for B11 and B53, the others are the original factors. Finally, we listed relevant suggested measures to help SMEs, government departments and financial institutions overcome the key barriers.
A Robust Image Watermarking Scheme Based on SVD in the Spatial Domain
Authors: Zhang Heng , Wang Chengyou , Zhou Xiao
Published: August 2017

With the development of image processing technology, the copyright protection of digital images has become an urgent problem to be solved. As an effective method, the robust digital watermarking technique emerges at a historic moment. Currently, most robust watermarking schemes are performed in the transform domains, such as the discrete cosine transform (DCT) and singular value decomposition (SVD). Compared with spatial domain watermarking schemes, these methods have achieved good performance, such as better robustness and higher security. However, the computational complexity increases with the use of forward and reverse transforms. In this paper, we analyze the SVD-based watermarking scheme and its impact on the spatial domain. Based on this analysis and the mathematical characteristics of SVD, we present a robust image watermarking scheme where a binary watermark is embedded into the largest singular value of each image block in the spatial domain. Several experiments are conducted to verify the performance of the proposed watermarking scheme. The experimental results show that compared with the existing SVD domain watermarking schemes, our proposed method has maintained good robustness against various attacks. Moreover, it avoids the false positive problem existing in traditional SVD-based watermarking schemes and has lower computational complexity.
Acetylation- and Methylation-Related Epigenetic Proteins in the Context of Their Targets
Authors: Javaid Nasir , Choi Sangdun
Published: August 2017

The nucleosome surface is covered with multiple modifications that are perpetuated by eight different classes of enzymes. These enzymes modify specific target sites both on DNA and histone proteins, and these modifications have been well identified and termed “epigenetics”. These modifications play critical roles, either by affecting non-histone protein recruitment to chromatin or by disturbing chromatin contacts. Their presence dictates the condensed packaging of DNA and can coordinate the orderly recruitment of various enzyme complexes for DNA manipulation. This genetic modification machinery involves various writers, readers, and erasers that have unique structures, functions, and modes of action. Regarding human disease, studies have mainly focused on the genetic mechanisms; however, alteration in the balance of epigenetic networks can result in major pathologies including mental retardation, chromosome instability syndromes, and various types of cancers. Owing to its critical influence, great potential lies in developing epigenetic therapies. In this regard, this review has highlighted mechanistic and structural interactions of the main epigenetic families with their targets, which will help to identify more efficient and safe drugs against several diseases.
Is Living near Healthier Food Stores Associated with Better Food Intake in Regional Australia?
Authors: Moayyed Hamid , Kelly Bridget , Feng Xiaoqi , Flood Victoria
Published: August 2017

High prevalence of obesity and non-communicable diseases is a global public health problem, in which the quality of food environments is thought to play an important role. Current scientific evidence is not consistent regarding the impact of food environments on diet. The relationship between local food environments and diet quality was assessed across 10 Australian suburbs, using Australian-based indices devised to measure the two parameters. Data of dietary habits from the participants was gathered using a short questionnaire. The suburbs’ Food Environment Score (higher being healthier) was associated with higher consumption of fruit (χ2 (40, 230) = 58.8, p = 0.04), and vegetables (χ2 (40, 230) = 81.3, p = 0.03). The Food Environment Score identified a significant positive correlation with four of the diet scores: individual total diet score (rs = 0.30, p < 0.01), fruit and vegetable score (rs = 0.43, p < 0.01), sugary drink score (rs = 0.13, p < 0.05), and discretionary food score (rs = 0.15, p < 0.05). Moreover, the suburbs’ RFEI (Retail Food Environment Index, higher being unhealthier) showed a significant association with higher consumption of salty snacks (χ2 (24, 230) = 43.9, p = 0.04). Food environments dominated by food outlets considered as ‘healthier’ were associated with healthier population food intakes, as indicated by a higher consumption of fruit, vegetables, and water, as well as a lower consumption of junk food, salty snacks, and sugary drinks. This association suggests that healthier diet quality is associated with healthier food environments in regional Australia.
Effects of Co-Culture Media on Hepatic Differentiation of hiPSC with or without HUVEC Co-Culture
Authors: Freyer Nora , Greuel Selina , Knöspel Fanny , Strahl Nadja , Amini Leila , Jacobs Frank , Monshouwer Mario , Zeilinger Katrin
Published: August 2017

The derivation of hepatocytes from human induced pluripotent stem cells (hiPSC) is of great interest for applications in pharmacological research. However, full maturation of hiPSC-derived hepatocytes has not yet been achieved in vitro. To improve hepatic differentiation, co-cultivation of hiPSC with human umbilical vein endothelial cells (HUVEC) during hepatic differentiation was investigated in this study. In the first step, different culture media variations based on hepatocyte culture medium (HCM) were tested in HUVEC mono-cultures to establish a suitable culture medium for co-culture experiments. Based on the results, two media variants were selected to differentiate hiPSC-derived definitive endodermal (DE) cells into mature hepatocytes with or without HUVEC addition. DE cells differentiated in mono-cultures in the presence of those media variants showed a significant increase (p < 0.05) in secretion of α-fetoprotein and in activities of cytochrome P450 (CYP) isoenzymes CYP2B6 and CYP3A4 as compared with cells differentiated in unmodified HCM used as control. Co-cultivation with HUVEC did not further improve the differentiation outcome. Thus, it can be concluded that the effect of the used medium outweighed the effect of HUVEC co-culture, emphasizing the importance of the culture medium composition for hiPSC differentiation.
Effects of Oxalic Acid on Apis mellifera (Hymenoptera: Apidae)
Authors: Rademacher Eva , Harz Marika , Schneider Saskia
Published: August 2017

Abstract: Oxalic acid dihydrate is used to treat varroosis of Apis mellifera. This study investigates lethal and sublethal effects of oxalic acid dihydrate on individually treated honeybees kept in cages under laboratory conditions as well as the distribution in the colony. After oral application, bee mortality occurred at relatively low concentrations (No Observed Adverse Effect Level (NOAEL) 50 µg/bee; Lowest Observed Adverse Effect Level (LOAEL) 75 µg/bee) compared to the dermal treatment (NOAEL 212.5 µg/bee; LOAEL 250 µg/bee). The dosage used in regular treatment via dermal application (circa 175 µg/bee) is below the LOAEL, referring to mortality derived in the laboratory. However, the treatment with oxalic acid dihydrate caused sublethal effects: This could be demonstrated in an increased responsiveness to water, decreased longevity and a reduction in pH-values in the digestive system and the hemolymph. The shift towards stronger acidity after treatment confirms that damage to the epithelial tissue and organs is likely to be caused by hyperacidity. The distribution of oxalic acid dihydrate within a colony was shown by macro-computed tomography; it was rapid and consistent. The increased density of the individual bee was continuous for at least 14 days after the treatment indicating the presence of oxalic acid dihydrate in the hive even long after a treatment.
Recovery Time of Silicon Photomultiplier with Epitaxial Quenching Resistors
Authors: Jiang Jiali , Jia Jianquan , Zhao Tianqi , Liang Kun , Yang Ru , Han Dejun
Published: August 2017

The silicon photomultiplier (SiPM) is a promising semiconductor device for low-level light detection. The recovery time, or the photon-counting rate of the SiPM is essential for high-flux photon detection in such applications as photon counting computer tomography (CT). A SiPM with epitaxial quenching resistors (EQR SiPM) has advantages in fabricating small APD microcells connected in series with lower quenching resistors, therefore, APD cells with a low RC time constant and a short recovery time can be expected. In this report, the recovery time of EQR SiPM has been investigated using both the double light pulse method and the waveform analysis method. The results show that the recovery time of EQR SiPM is strongly dependent on the size of the active area and the number of fired pixels. For a 3 × 3 mm2 device, while total about 90,000 pixels were fired, the recovery time was 31.1 ± 1.8 ns; while fired pixels were controlled to about 2000, the recovery time decreased significantly to 6.5 ± 0.4 ns; and the recovery time of one fired pixel was 3.1 ± 0.2 ns. For 1.4 × 1.4 mm2 device, the recovery time was 15.2 ± 0.5 ns, while a total of about 20,000 pixels were fired. Effects that may affect the recovery time of the SiPM, including strength of the pulse light, signal transmission time delay, and the readout electronics are discussed.
CaMEL and ADCIRC Storm Surge Models—A Comparative Study
Authors: Akbar Muhammad , Luettich Richard , Fleming Jason , Aliabadi Shahrouz
Published: August 2017

The Computation and Modeling Engineering Laboratory (CaMEL), an implicit solver-based storm surge model, has been extended for use on high performance computing platforms. An MPI (Message Passing Interface) based parallel version of CaMEL has been developed from the previously existing serial version. CaMEL uses hybrid finite element and finite volume techniques to solve shallow water conservation equations in either a Cartesian or a spherical coordinate system and includes hurricane-induced wind stress and pressure, bottom friction, the Coriolis effect, and tidal forcing. Both semi-implicit and fully-implicit time stepping formulations are available. Once the parallel implementation is properly validated, CaMEL is evaluated against ADCIRC, an established storm surge model, using a hindcast of storm surge due to Hurricane Katrina. Observed high water marks are used to verify that both models have comparable accuracy. The effects of time step on the stability and accuracy of the models are investigated and indicate that the semi- and fully-implicit solvers in CaMEL allow the use of larger timesteps than ADCIRC’s explicit and semi-implicit solvers. However, ADCIRC outperforms CaMEL in parallel scalability and execution wall clock times. Wall times of CaMEL improve significantly when the largest stable time step sizes are used in respective models, although ADCIRC still is faster.
Solvent-Mediated Synthesis of M(II)-Coordination Polymer Part 1: Crystal Structure of Poly(1,2-di(4-pyridyl)ethylene-k2N,N')-bis(1,4-benzenediacetato-k4O,O′,O′′,O′′')zinc(II)], C22H18ZnN2O4
Authors: Adalikwu Stephen , Offiong Offiong , Ayi Ayi
Published: August 2017

An interaction of water-methanol solution of sodium1,4-benzenediacetate (bda) and 4,4′-bipyridylethelene (bpee) with aqueous solution of Zn(NO3)2·6H2O at room temperature yielded colourless crystals of 1 after three weeks in a sealed glass tube. The compound with composition C22H18ZnN2O4 crystallizes in monoclinic space group P21/c, with the following cell dimensions: a = 10.4566(2), b = 13.3085(2), c = 13.7189(2) Å, β = 101.491(1)°. In the structure of 1, two Zn(II) neighbours are connected by two bda ligands adopting chelating and bidentate-bridging coordination modes to form a dimeric unit (Zn2O8N4) with the Zn–Zn distance of 4.0432(6) Å. The carboxyl-bridged dimeric units are extended along the [001] direction by bpee co-ligands and further linked by bda ligand to form a three-dimensional network structure. The IR shows the characteristic bands of the carboxylates at 1611/1507 cm−1 and 1424/1373 cm−1, respectively, for asymmetric and symmetric stretching −CO2− vibrations. The separation ∆[νasym(CO2−) − νsym(CO2−)] values of 187 and 134 cm−1 are indicative of chelating and bidentate bridging coordination modes of the carboxylate to the metal centre.
High-Yield One-Pot Recovery and Characterization of Nanostructured Cobalt Oxalate from Spent Lithium-Ion Batteries and Successive Re-Synthesis of LiCoO2
Authors: Park Young , Lim Hana , Moon Ji-Hoon , Lee Ho-Nyun , Son Seong , Kim Hansung , Kim Hyun-Jong
Published: August 2017

A complete recycling process for the cathode material of spent lithium-ion batteries is demonstrated with a simple two-step process comprised of one-pot cobalt recovery to nanostructured materials and single step synthesis of LiCoO2. For the facile and efficient recovery of cobalt, we employ malic acid as a leaching agent and oxalic acid as a precipitating agent, resulting in nanostructured cobalt oxalate. X-ray diffraction and Fourier transform infrared spectroscopy (FT-IR) analysis clearly show that cobalt species are simultaneously leached and precipitated as cobalt oxalate with a high yield of 99.28%, and this material can then be used as a reactant for the synthesis of LiCoO2 for use as a cathode material. In addition to its advantages in simplifying the process, the proposed method allows for not only enhancing the efficiency of cobalt recovery, but also enabling reaction without a reducing agent, H2O2. Through successive single-step reaction of the obtained cobalt oxalate without any purification process, LiCoO2 is also successfully synthesized. The effect of the annealing temperature during synthesis on the nanostructure and charge–discharge properties is also investigated. Half-cell tests with recycled LiCoO2 exhibit a high discharge capacity (131 mA·h·g−1) and 93% charge–discharge efficiency.
Microstructural, Mechanical, Texture and Residual Stress Characterizations of X52 Pipeline Steel
Authors: Lavigne Olivier , Kotousov Andrei , Luzin Vladimir
Published: August 2017

In this paper, the microstructural and mechanical properties of a high-strength low-alloy (HSLA) API 5L X52 steel, which is widely utilized in the construction of gas pipelines, were characterized with optical microscopy, electron backscatter diffraction, and standard mechanical tests. The outcomes of these characterizations were used to evaluate the strengthening contributions of the solid solution, grain size, dislocations, and precipitates to the overall strength of the steel. In addition, texture and residual stresses were determined with neutron diffraction. The residual stresses were found to be low in comparison with the expected stresses due to the operating pressure. However, these stresses could contribute to the initiation and propagation of stress corrosion cracking at the outer surface of the pipe. Neutron diffraction results also suggested that the outer surface of the pipe had a texture that is expected to have a low resistance to high pH stress corrosion cracking. Both conclusions were found to be consistent with field observations.
A Compact 2-DOF Piezoelectric-Driven Platform Based on “Z-Shaped” Flexure Hinges
Authors: Li Jianping , Liu Hui , Zhao Hongwei
Published: August 2017

A compact 2-DOF (two degrees of freedom) piezoelectric-driven platform for 3D cellular bio-assembly systems has been proposed based on “Z-shaped” flexure hinges. Multiple linear motions with high resolution both in x and y directions are achieved. The “Z-shaped” flexure hinges and the parallel-six-connecting-rods structure are utilized to obtain the lowest working stress while compared with other types of flexure hinges. In order to achieve the optimized structure, matrix-based compliance modeling (MCM) method and finite element method (FEM) are used to evaluate both the static and dynamic performances of the proposed 2-DOF piezoelectric-driven platform. Experimental results indicate that the maximum motion displacements for x-stage and y-stage are lx = 17.65 μm and ly = 15.45 μm, respectively. The step response time for x-stage and y-stage are tx = 1.7 ms and ty = 1.6 ms, respectively.
Artesunate Activates the Intrinsic Apoptosis of HCT116 Cells through the Suppression of Fatty Acid Synthesis and the NF-κB Pathway
Authors: Chen Xiao , Wong Yin , Lim Teck , Lim Wei , Lin Qingsong , Wang Jigang , Hua Zichun
Published: August 2017

The artemisinin compounds, which are well-known for their potent therapeutic antimalarial activity, possess in vivo and in vitro antitumor effects. Although the anticancer effect of artemisinin compounds has been extensively reported, the precise mechanisms underlying its cytotoxicity remain under intensive study. In the present study, a high-throughput quantitative proteomics approach was applied to identify differentially expressed proteins of HCT116 colorectal cancer cell line with artesunate (ART) treatment. Through Ingenuity Pathway Analysis, we discovered that the top-ranked ART-regulated biological pathways are abrogation of fatty acid biosynthetic pathway and mitochondrial dysfunction. Subsequent assays showed that ART inhibits HCT116 cell proliferation through suppressing the fatty acid biosynthetic pathway and activating the mitochondrial apoptosis pathway. In addition, ART also regulates several proteins that are involved in NF-κB pathway, and our subsequent assays showed that ART suppresses the NF-κB pathway. These proteomic findings will contribute to improving our understanding of the underlying molecular mechanisms of ART for its therapeutic cytotoxic effect towards cancer cells.
Isolation and Purification of Three Ecdysteroids from the Stems of Diploclisia glaucescens by High-Speed Countercurrent Chromatography and Their Anti-Inflammatory Activities In Vitro
Authors: Fang Lei , Li Jialian , Zhou Jie , Wang Xiao , Guo Lanping
Published: August 2017

High-speed counter-current chromatography was used to separate and purify ecdysteroids for the first time from the stems of Diploclisia glaucescens using a two-phase solvent system composed of ethyl acetate–n-butanol–ethanol–water (3:0.2:0.8:3, v/v). Three ecdysteroids were obtained from 260 mg of ethyl acetate extract of the residue obtained after evaporation of the crude ethanolicextractof D. glaucescens in one-step separation, which were identified as paristerone (I, 30.5 mg), ecdysterone (II, 7.2 mg), and capitasterone (III, 8.1 mg) by electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR). Their anti-inflammatory activities were evaluated by measuring the inhibitory ratios of β-glucuronidase release in rat polymorphonuclear leukocytes (PMNs) induced by platelet-activating factor. Compounds I–III showed significant anti-inflammatory activities with IC50-values ranging from 1.51 to 11.68 μM, respectively.
Organic Catalysis for Ring-Opening Graft Polymerization of p-Dioxanone with Xylan in Ionic liquid
Authors: Zhang Xueqin , Liu Chuanfu , Zhang Aiping , Sun Runcang
Published: August 2017

Recently, organic catalysis has become a powerful alternative to the use of more traditional metal-based catalysts. In this study, 4-dimethylaminopyridine (DMAP), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) were applied to mediate the ring-opening graft polymerization (ROGP) of p-dioxanone (PDO) with xylan-based hemicelluloses in ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl). Excellent control of the molar ratio of the catalyst to anhydroxylose units (AXU) in xylan was found for a good tuning of the weight percent gain (WPG) of xylan-graft-poly(p-dioxanone) (xylan-g-PPDO) copolymers. As a result, the maximum WPG of xylan-g-PPDO copolymers was 431.07% (DMAP/AXU of 2/1), 316.72% (DBU/AXU of 0.2/1), and 323.15% (TBD/AXU of 0.2/1), respectively. The structure of xylan-g-PPDO copolymers was characterized with FT-IR and NMR. The thermal properties of copolymers were investigated using thermogravimetric analysis (TGA/DTG) and differential scanning calorimetry (DSC), and a significant difference was observed regarding the transition temperature (Tg), melting temperature (Tm), and crystallization temperature (Tc).
The Distribution of Nanoclay Particles at the Interface and Their Influence on the Microstructure Development and Rheological Properties of Reactively Processed Biodegradable Polylactide/Poly(butylene succinate) Blend Nanocomposites
Authors: Salehiyan Reza , Ray Suprakas , Bandyopadhyay Jayita , Ojijo Vincent
Published: August 2017

The present work investigates the distribution of nanoclay particles at the interface and their influence on the microstructure development and non-linear rheological properties of reactively processed biodegradable polylactide/poly(butylene succinate) blend nanocomposites. Two types of organoclays, one is more hydrophilic (Cloisite®30B (C30B)) and another one is more hydrophobic (BetsopaTM (BET)), were used at different concentrations. Surface and transmission electron microscopies were respectively used to study the blend morphology evolution and for probing the dispersion and distribution of nanoclay platelets within the blend matrix and at the interface. The results suggested that both organoclays tended to localize at the interface between the blend’s two phases and encapsulate the dispersed poly(butylene succinate) phase, thereby suppressing coalescence. Using small angle X-ray scattering the probability of finding neighboring nanoclay particles in the blend matrix was calculated using the Generalized Indirect Fourier Transformation technique. Fourier Transform-rheology was utilized for quantifying nonlinear rheological responses and for correlating the extent of dispersion as well as the blend morphological evolution, for different organoclay loadings. The rheological responses were in good agreement with the X-ray scattering and electron microscopic results. It was revealed that C30B nanoparticles were more efficient in stabilizing the morphologies by evenly distributing at the interface. Nonlinear coefficient from FT-rheology was found to be more pronounced in case of blends filled with C30B, indicating better dispersion of C30B compare with BET which was in agreement with the SAXS results.
Christian Churches and the Boko Haram Insurgency in Cameroon: Dilemmas and Responses
Authors: Michael Kpughe Lang
Published: August 2017

The spillover of the terrorist activities of Boko Haram, a Nigerian jihadi group, into Cameroon’s north has resulted in security challenges and humanitarian activity opportunities for Christian churches. The insurgents have attacked and destroyed churches, abducted Christians, worsened Muslim-Christian relations, and caused a humanitarian crisis. These ensuing phenomena have adversely affected Christian churches in this region, triggering an aura of responses: coping strategies, humanitarian work among refugees, and inter-faith dialogue. These responses are predicated on Christianity’s potential as a resource for peace, compassion, and love. In this study we emphasize the role of Christian churches in dealing with the Boko Haram insurgency. It opens with a presentation of the religious configuration of Cameroon, followed by a contextualization of Boko Haram insurgency in Cameroon’s north. The paper further examines the brutality meted out on Christians and church property. The final section is an examination of the spiritual, humanitarian, and relief services provided by churches. The paper argues that although Christian churches have suffered at the hands of Boko Haram insurgents, they have engaged in various beneficial responses underpinned by the Christian values of peace and love.
Towards an Operational Use of Geophysics for Archaeology in Henan (China): Methodological Approach and Results in Kaifeng
Authors: Masini Nicola , Capozzoli Luigi , Chen Panpan , Chen Fulong , Romano Gerardo , Lu Peng , Tang Panpan , Sileo Maria , Ge Qifeng , Lasaponara Rosa
Published: August 2017

One of the major issues in buried archeological sites especially if characterized by intense human activity, complex structures, and several constructive phases, is: to what depth conduct the excavation? The answer depends on a number of factors, among these one of the most important is the a priori and reliable knowledge of what the subsoil can preserve. To this end, geophysics (if used in strong synergy with archaeological research) can help in the planning of time, depth, and modes of excavation also when the physical characteristics of the remains and their matrix are not ideal for archaeo-geophysical applications. This is the case of a great part of the archaeological sites in Henan, the cradle of the most important cultures in China and the seat of several capitals for more than two millennia. There, the high depth of buried remains covered by alluvial deposits and the building materials, mainly made by rammed earth, did not favor the use of geophysics. In this paper, we present and discuss the GPR and ERT prospection we conducted in Kaifeng (Henan, China), nearby a gate of the city walls dated to the Northern Song Dynasty. The integration of GPR and ERT provided useful information for the identification and characterization of archaeological remains buried at different depths. Actually, each geophysical technique, GPR frequency (used for the data acquisition) as well as each way to analyze and visualize the results (from radargrams to time slice) only provided partial information of little use if alone. The integration of the diverse techniques, data processing and visualization enabled us to optimize the penetration capability, the resolution for the detection of archaeological features and their interpretation. Finally, the results obtained from the GPR and ERT surveys were correlated with archaeological stratigraphy, available nearby the investigated area. This enabled us to further improve the interpretation of results from GPR and ERT survey and also to date the anthropogenic layers from Qing to Yuan Dynasty.
Mapping Aboveground Carbon in Oil Palm Plantations Using LiDAR: A Comparison of Tree-Centric versus Area-Based Approaches
Authors: Nunes Matheus , Ewers Robert , Turner Edgar , Coomes David
Published: August 2017

Southeast Asia is the epicentre of world palm oil production. Plantations in Malaysia have increased 150% in area within the last decade, mostly at the expense of tropical forests. Maps of the aboveground carbon density (ACD) of vegetation generated by remote sensing technologies, such as airborne LiDAR, are vital for quantifying the effects of land use change for greenhouse gas emissions, and many papers have developed methods for mapping forests. However, nobody has yet mapped oil palm ACD from LiDAR. The development of carbon prediction models would open doors to remote monitoring of plantations as part of efforts to make the industry more environmentally sustainable. This paper compares the performance of tree-centric and area-based approaches to mapping ACD in oil palm plantations. We find that an area-based approach gave more accurate estimates of carbon density than tree-centric methods and that the most accurate estimation model includes LiDAR measurements of top-of-canopy height and canopy cover. We show that tree crown segmentation is sensitive to crown density, resulting in less accurate tree density and ACD predictions, but argue that tree-centric approach can nevertheless be useful for monitoring purposes, providing a method to detect, extract and count oil palm trees automatically from images.
An Optimized, Data Distribution Service-Based Solution for Reliable Data Exchange Among Autonomous Underwater Vehicles
Authors: Rodríguez-Molina Jesús , Bilbao Sonia , Martínez Belén , Frasheri Mirgita , Cürüklü Baran
Published: August 2017

Major challenges are presented when managing a large number of heterogeneous vehicles that have to communicate underwater in order to complete a global mission in a cooperative manner. In this kind of application domain, sending data through the environment presents issues that surpass the ones found in other overwater, distributed, cyber-physical systems (i.e., low bandwidth, unreliable transport medium, data representation and hardware high heterogeneity). This manuscript presents a Publish/Subscribe-based semantic middleware solution for unreliable scenarios and vehicle interoperability across cooperative and heterogeneous autonomous vehicles. The middleware relies on different iterations of the Data Distribution Service (DDS) software standard and their combined work between autonomous maritime vehicles and a control entity. It also uses several components with different functionalities deemed as mandatory for a semantic middleware architecture oriented to maritime operations (device and service registration, context awareness, access to the application layer) where other technologies are also interweaved with middleware (wireless communications, acoustic networks). Implementation details and test results, both in a laboratory and a deployment scenario, have been provided as a way to assess the quality of the system and its satisfactory performance.
Energy-Based Metrics for Arthroscopic Skills Assessment
Authors: Poursartip Behnaz , LeBel Marie-Eve , McCracken Laura , Escoto Abelardo , Patel Rajni , Naish Michael , Trejos Ana
Published: August 2017

Minimally invasive skills assessment methods are essential in developing efficient surgical simulators and implementing consistent skills evaluation. Although numerous methods have been investigated in the literature, there is still a need to further improve the accuracy of surgical skills assessment. Energy expenditure can be an indication of motor skills proficiency. The goals of this study are to develop objective metrics based on energy expenditure, normalize these metrics, and investigate classifying trainees using these metrics. To this end, different forms of energy consisting of mechanical energy and work were considered and their values were divided by the related value of an ideal performance to develop normalized metrics. These metrics were used as inputs for various machine learning algorithms including support vector machines (SVM) and neural networks (NNs) for classification. The accuracy of the combination of the normalized energy-based metrics with these classifiers was evaluated through a leave-one-subject-out cross-validation. The proposed method was validated using 26 subjects at two experience levels (novices and experts) in three arthroscopic tasks. The results showed that there are statistically significant differences between novices and experts for almost all of the normalized energy-based metrics. The accuracy of classification using SVM and NN methods was between 70% and 95% for the various tasks. The results show that the normalized energy-based metrics and their combination with SVM and NN classifiers are capable of providing accurate classification of trainees. The assessment method proposed in this study can enhance surgical training by providing appropriate feedback to trainees about their level of expertise and can be used in the evaluation of proficiency.
An Ultra-Low Power Turning Angle Based Biomedical Signal Compression Engine with Adaptive Threshold Tuning
Authors: Zhou Jun , Wang Chao
Published: August 2017

Intelligent sensing is drastically changing our everyday life including healthcare by biomedical signal monitoring, collection, and analytics. However, long-term healthcare monitoring generates tremendous data volume and demands significant wireless transmission power, which imposes a big challenge for wearable healthcare sensors usually powered by batteries. Efficient compression engine design to reduce wireless transmission data rate with ultra-low power consumption is essential for wearable miniaturized healthcare sensor systems. This paper presents an ultra-low power biomedical signal compression engine for healthcare data sensing and analytics in the era of big data and sensor intelligence. It extracts the feature points of the biomedical signal by window-based turning angle detection. The proposed approach has low complexity and thus low power consumption while achieving a large compression ratio (CR) and good quality of reconstructed signal. Near-threshold design technique is adopted to further reduce the power consumption on the circuit level. Besides, the angle threshold for compression can be adaptively tuned according to the error between the original signal and reconstructed signal to address the variation of signal characteristics from person to person or from channel to channel to meet the required signal quality with optimal CR. For demonstration, the proposed biomedical compression engine has been used and evaluated for ECG compression. It achieves an average (CR) of 71.08% and percentage root-mean-square difference (PRD) of 5.87% while consuming only 39 nW. Compared to several state-of-the-art ECG compression engines, the proposed design has significantly lower power consumption while achieving similar CRD and PRD, making it suitable for long-term wearable miniaturized sensor systems to sense and collect healthcare data for remote data analytics.
Design of a New Ultracompact Resonant Plasmonic Multi-Analyte Label-Free Biosensing Platform
Authors: Dell’Olio Francesco , Conteduca Donato , De Palo Maripina , Ciminelli Caterina
Published: August 2017

In this paper, we report on the design of a bio-multisensing platform for the selective label-free detection of protein biomarkers, carried out through a 3D numerical algorithm. The platform includes a number of biosensors, each of them is based on a plasmonic nanocavity, consisting of a periodic metal structure to be deposited on a silicon oxide substrate. Light is strongly confined in a region with extremely small size (=1.57 μm2), to enhance the light-matter interaction. A surface sensitivity Ss = 1.8 nm/nm has been calculated together with a detection limit of 128 pg/mm2. Such performance, together with the extremely small footprint, allow the integration of several devices on a single chip to realize extremely compact lab-on-chip microsystems. In addition, each sensing element of the platform has a good chemical stability that is guaranteed by the selection of gold for its fabrication.
Thermal Infrared Pedestrian Image Segmentation Using Level Set Method
Authors: Qiao Yulong , Wei Ziwei , Zhao Yan
Published: August 2017

The edge-based active contour model has been one of the most influential models in image segmentation, in which the level set method is usually used to minimize the active contour energy function and then find the desired contour. However, for infrared thermal pedestrian images, the traditional level set-based method that utilizes the gradient information as edge indicator function fails to provide the satisfactory boundary of the target. That is due to the poorly defined boundaries and the intensity inhomogeneity. Therefore, we propose a novel level set-based thermal infrared image segmentation method that is able to deal with the above problems. Specifically, we firstly explore the one-bit transform convolution kernel and define a soft mark, from which the target boundary is enhanced. Then we propose a weight function to adaptively adjust the intensity of the infrared image so as to reduce the intensity inhomogeneity. In the level set formulation, those processes can adaptively adjust the edge indicator function, from which the evolving curve will stop at the target boundary. We conduct the experiments on benchmark infrared pedestrian images and compare our introduced method with the state-of-the-art approaches to demonstrate the excellent performance of the proposed method.
Activity Recognition Invariant to Sensor Orientation with Wearable Motion Sensors
Authors: Yurtman Aras , Barshan Billur
Published: August 2017

Most activity recognition studies that employ wearable sensors assume that the sensors are attached at pre-determined positions and orientations that do not change over time. Since this is not the case in practice, it is of interest to develop wearable systems that operate invariantly to sensor position and orientation. We focus on invariance to sensor orientation and develop two alternative transformations to remove the effect of absolute sensor orientation from the raw sensor data. We test the proposed methodology in activity recognition with four state-of-the-art classifiers using five publicly available datasets containing various types of human activities acquired by different sensor configurations. While the ordinary activity recognition system cannot handle incorrectly oriented sensors, the proposed transformations allow the sensors to be worn at any orientation at a given position on the body, and achieve nearly the same activity recognition performance as the ordinary system for which the sensor units are not rotatable. The proposed techniques can be applied to existing wearable systems without much effort, by simply transforming the time-domain sensor data at the pre-processing stage.
Mobilizing Conflict Testimony: A Lens of Mobility for the Study of Documentary Practices in the Kashmir Conflict
Authors: Kramer Max
Published: August 2017

In this paper I introduce a lens of mobility for the study of documentary film practices and gender in zones of conflict. By drawing on my qualitative research regarding the practice of the independent filmmaker Iffat Fatima, I will argue that a lens of mobility helps to grasp highly mobile media practices both conceptually and methodologically. Through a lens of mobility, my focus lies on the potential of documentary film to open the imaginative boundaries of conflict zones and to politically and emotionally mobilize the testimony offered from everyday life in a highly militarized zone. This specifically requires the tracing of moments of political mobilization beyond cognitive questions of conflicting narratives and representations.