bluuebunny/crossref_metadata_2025 huggingface dataset:
Ligand-Based Stability Changes in Duplex DNA Measured with a Microscale Electrochemical Platform
Authors: Robinson Sarah M. , Shen Zuliang , Askim Jon R. , Montgomery Christopher B. , Sintim Herman O. , Semancik Steve
Published: April 2019

Development of technologies for rapid screening of DNA secondary structure thermal stability and the effects on stability for binding of small molecule drugs is important to the drug discovery process. In this report, we describe the capabilities of an electrochemical, microdevice-based approach for determining the melting temperatures (Tm) of electrode-bound duplex DNA structures. We also highlight new features of the technology that are compatible with array development and adaptation for high-throughput screening. As a foundational study to exhibit device performance and capabilities, melting-curve analyses were performed on 12-mer DNA duplexes in the presence/absence of two binding ligands: diminazene aceturate (DMZ) and proflavine. By measuring electrochemical current as a function of temperature, our measurement platform has the ability to determine the effect of binding ligands on Tm values with high signal-to-noise ratios and good reproducibility. We also demonstrate that heating our three-electrode cell with either an embedded microheater or a thermoelectric module produces similar results. The ΔTm values we report show the stabilizing ability of DMZ and proflavine when bound to duplex DNA structures. These initial proof-of-concept studies highlight the operating characteristics of the microdevice platform and the potential for future application toward other immobilized samples.
Sensorimotor Control in Dystonia
Authors: Desrochers Phillip , Brunfeldt Alexander , Sidiropoulos Christos , Kagerer Florian
Published: April 2019

This is an overview of the sensorimotor impairments in dystonia, a syndrome characterized by sustained or intermittent aberrant movement patterns leading to abnormal movements and/or postures with or without a tremulous component. Dystonia can affect the entire body or specific body regions and results from a plethora of etiologies, including subtle changes in gray and white matter in several brain regions. Research over the last 25 years addressing topics of sensorimotor control has shown functional sensorimotor impairments related to sensorimotor integration, timing, oculomotor and head control, as well as upper and lower limb control. In the context of efforts to update the classification of dystonia, sensorimotor research is highly relevant for a better understanding of the underlying pathology, and potential mechanisms contributing to global and regional dysfunction within the central nervous system. This overview of relevant research regarding sensorimotor control in humans with idiopathic dystonia attempts to frame the dysfunction with respect to what is known regarding motor control in patients and healthy individuals. We also highlight promising avenues for the future study of neuromotor control that may help to further elucidate dystonia etiology, pathology, and functional characteristics.
Association between Motivational Climate, Adherence to Mediterranean Diet, and Levels of Physical Activity in Physical Education Students
Authors: González-Valero Gabriel , Ubago-Jiménez José Luis , Ramírez-Granizo Irwin A. , Puertas-Molero Pilar
Published: April 2019

Physical Education is an essential educational area to develop physical-healthy habits and motivational orientations, which are fundamental to guide the situation of future Physical Education teachers. These professionals will have a fundamental role in teaching different types of motivations, active lifestyles, and healthy habits in youths. For this reason, the objective of the study is to know the association between motivational climate, adherence to the Mediterranean Diet (MD), and the practice of physical activity in future Physical Education teachers. A cross-sectional and nonexperimental study was carried out using a single measurement within a single group. The sample consisted of 775 university students from the cities of Andalusia (Spain). Motivational climate was evaluated through the Perceived Motivational Climate in Sport Questionnaire (PMCSQ-2), levels of physical activity were evaluated through the adolescent version of the Physical Activity Questionnaire (PAQ-A), and level of adherence to the MD was assessed through Mediterranean Diet Quality Index (KIDMED). On one hand, the healthy and self-improvement component promoted by physical activity favors an orientation focused on process and learning. Likewise, the competitive component is key to motivation focused on product and social recognition. In addition, future Physical Education teachers should pay special attention to the unequal recognition among members that physical activity can generate, in order to avoid personal disregard and social rejection. The ego climate is related to a high adherence to the MD. On the other hand, the future Physical Education teachers who manifest motivational processes based on fun and their own satisfaction have low levels of adherence to the MD.
Cancer Vaccines Co-Targeting HER2/Neu and IGF1R
Authors: De Giovanni Carla , Landuzzi Lorena , Palladini Arianna , Ianzano Marianna , Nicoletti Giordano , Ruzzi Francesca , Amici Augusto , Croci Stefania , Nanni Patrizia , Lollini Pier-Luigi
Published: April 2019

(1) Background: Human epidermal growth factor receptor 2 (HER2)/neu-driven carcinogenesis is delayed by preventive vaccines able to elicit autochthonous antibodies against HER2/neu. Since cooperation between different receptor tyrosine kinases (RTKs) can occur in human as well as in experimental tumors, we investigated the set-up of DNA and cell vaccines to elicit an antibody response co-targeting two RTKs: HER2/neu and the Insulin-like Growth Factor Receptor-1 (IGF1R). (2) Methods: Plasmid vectors carrying the murine optimized IGF1R sequence or the human IGF1R isoform were used as electroporated DNA vaccines. IGF1R plasmids were transfected in allogeneic HER2/neu-positive IL12-producing murine cancer cells to obtain adjuvanted cell vaccines co-expressing HER2/neu and IGF1R. Vaccination was administered in the preneoplastic stage to mice prone to develop HER2/neu-driven, IGF1R-dependent rhabdomyosarcoma. (3) Results: Electroporated DNA vaccines for murine IGF1R did not elicit anti-mIGF1R antibodies, even when combined with Treg-depletion and/or IL12, while DNA vaccines carrying the human IGF1R elicited antibodies recognizing only the human IGF1R isoform. Cell vaccines co-expressing HER2/neu and murine or human IGF1R succeeded in eliciting antibodies recognizing the murine IGF1R isoform. Cell vaccines co-targeting HER2/neu and murine IGF1R induced the highest level of anti-IGF1R antibodies and nearly significantly delayed the onset of spontaneous rhabdomyosarcomas. (4) Conclusions: Multi-engineered adjuvanted cancer cell vaccines can break the tolerance towards a highly tolerized RTK, such as IGF1R. Cell vaccines co-targeting HER2/neu and IGF1R elicited low levels of specific antibodies that slightly delayed onset of HER2/neu-driven, IGF1R-dependent tumors.
Identification of Cancer Stem Cell Molecular Markers and Effects of hsa-miR-21-3p on Stemness in Esophageal Squamous Cell Carcinoma
Authors: Gao Zhikui , Liu Hui , Shi Yajuan , Yin Lihong , Zhu Yong , Liu Ran
Published: April 2019

Cancer stem cells (CSCs) are closely related to tumor resistance and tumor recurrence in esophageal squamous cell carcinoma (ESCC). The lack of specific biomarkers to identify and isolate CSCs has led to the slow progression of research on CSCs in ESCC. Here, we established a method to identify and isolate CSCs in ESCC using fluorescence-activated cell sorting with combined surface biomarkers including CD71, CD271, and CD338. CD71−/CD271+/CD338+ subpopulation cells possessed more stem cell properties in proliferation, self-renewal, differentiation, metastasis, drug resistance, and tumorigenesis. We further explored possible roles that microRNAs played in stem cells. Using microarrays, we identified that has-miR-21-3p was highly expressed in positive sorted cells, and further functional and Luciferase reporter assays verified that has-miR-21-3p promoted proliferation and anti-apoptosis by regulating TRAF4. We further analyzed the relationship between hsa-miR-21-3p and ESCC in 137 patients with ESCC. Statistical analysis showed that up-regulation of hsa-miR-21-3p was associated with a high risk of ESCC. Collectively, we identified surface biomarkers of stem cells in esophageal squamous cell carcinoma, and discovered thathsa-miR-21-3p may be involved in stemness maintenance by regulating TRAF4.
Dendritic Cells and Cancer: From Biology to Therapeutic Intervention
Authors: Wylie Ben , Macri Christophe , Mintern Justine , Waithman Jason
Published: April 2019

Inducing effective anti-tumor immunity has become a major therapeutic strategy against cancer. Dendritic cells (DC) are a heterogenous population of antigen presenting cells that infiltrate tumors. While DC play a critical role in the priming and maintenance of local immunity, their functions are often diminished, or suppressed, by factors encountered in the tumor microenvironment. Furthermore, DC populations with immunosuppressive activities are also recruited to tumors, limiting T cell infiltration and promoting tumor growth. Anti-cancer therapies can impact the function of tumor-associated DC and/or alter their phenotype. Therefore, the design of effective anti-cancer therapies for clinical translation should consider how best to boost tumor-associated DC function to drive anti-tumor immunity. In this review, we discuss the different subsets of tumor-infiltrating DC and their role in anti-tumor immunity. Moreover, we describe strategies to enhance DC function within tumors and harness these cells for effective tumor immunotherapy.
Cyclin-Dependent Kinase 5 (CDK5)-Mediated Phosphorylation of Upstream Stimulatory Factor 2 (USF2) Contributes to Carcinogenesis
Authors: Chi Tabughang , Horbach Tina , Götz Claudia , Kietzmann Thomas , Dimova Elitsa
Published: April 2019

The transcription factor USF2 is supposed to have an important role in tumor development. However, the regulatory mechanisms contributing to the function of USF2 are largely unknown. Cyclin-dependent kinase 5 (CDK5) seems to be of importance since high levels of CDK5 were found in different cancers associated with high USF2 expression. Here, we identified USF2 as a phosphorylation target of CDK5. USF2 is phosphorylated by CDK5 at two serine residues, serine 155 and serine 222. Further, phosphorylation of USF2 at these residues was shown to stabilize the protein and to regulate cellular growth and migration. Altogether, these results delineate the importance of the CDK5-USF2 interplay in cancer cells.
Transient Receptor Potential Mucolipin-1 Channels in Glioblastoma: Role in Patient’s Survival
Authors: Morelli Maria Beatrice , Amantini Consuelo , Tomassoni Daniele , Nabissi Massimo , Arcella Antonella , Santoni Giorgio
Published: April 2019

A link between mucolipin channels and tumors has been recently suggested. Herein, we aim to investigate the transient receptor potential mucolipin (TRPML)-1 relevance in glioblastoma. The expression of this channel was evaluated via qRT-PCR and immunohistochemistry in biopsies from 66 glioblastoma patients and two human glioblastoma cell lines and compared to normal human brain, astrocytes, and epileptic tissues. The subcellular distribution of TRPML-1 was examined via confocal microscopy in the glioma cell lines. Then, to assess the role of TRPML-1, cell viability assays have been conducted in T98 and U251 cell lines treated with the specific TRPML-1 agonist, MK6-83. We found that MK6-83 reduced cell viability and induced caspase-3-dependent apoptosis. Indeed, the TRPML-1 silencing or the blockage of TRPML-1 dependent [Ca2+]i release abrogated these effects. In addition, exposure of glioma cells to the reactive oxygen species (ROS) inducer, carbonyl cyanide m-chlorophenylhydrazone (CCCP), stimulated a TRPML-1-dependent autophagic cell death, as demonstrated by the ability of the autophagic inhibitor bafilomycin A, the TRPML-1 inhibitor sphingomyelin, and the TRPML-1 silencing to completely inhibit the CCCP-mediated effects. To test a possible correlation with patient’s survival, Kaplan–Meier, univariate, and multivariate analysis have been performed. Data showed that the loss/reduction of TRPML-1 mRNA expression strongly correlates with short survival in glioblastoma (GBM) patients, suggesting that the reduction of TRPML-1 expression represents a negative prognostic factor in GBM patients.
Automated Quantification of Extranuclear ERα Using Phosphor-Integrated Dots for Predicting Endocrine Therapy Resistance in HR+/HER2− Breast Cancer
Authors: Guo Zhaorong , Tada Hiroshi , Kitamura Narufumi , Hamada Yoh , Miyashita Minoru , Harada-Shoji Narumi , Sato Akiko , Hamanaka Yohei , Tsuboi Kouki , Harada Nobuhisa , Takano-Kasuya Mayumi , Okada Hisatake , Nakano Yasushi , Ohuchi Noriaki , Hayashi Shin-ichi , Ishida Takanori , Gonda Kohsuke
Published: April 2019

In addition to genomic signaling, Estrogen receptor alpha (ERα) is associated with cell proliferation and survival through extranuclear signaling contributing to endocrine therapy (ET) resistance. However, the relationship between extranuclear ERα and ET resistance has not been extensively studied. We sought to measure extranuclear ERα expression by immunohistochemistry using phosphor-integrated dots (IHC-PIDs) and to assess its predictive value for ET resistance. After quantitative detection of ERα by IHC-PIDs in vitro, we developed “the nearest-neighbor method” to calculate the extranuclear ERα. Furthermore, tissue sections from 65 patients with HR+/HER2- BC were examined by IHC-PIDs, and the total ERα, nuclear ERα, extranuclear ERα PIDs score, and ratio of extranuclear-to-nuclear ERα (ENR) were measured using the novel method. We demonstrate that quantification of ERα using IHC-PIDs exhibited strong correlations to real-time qRT-PCR (r2 = 0.94) and flow cytometry (r2 = 0.98). High ERα ENR was significantly associated with poor overall survival (p = 0.048) and disease-free survival (DFS) (p = 0.007). Multivariate analysis revealed that the ERα ENR was an independent prognostic factor for DFS [hazard ratio, 3.8; 95% CI, 1.4–11.8; p = 0.006]. Our automated measurement has high accuracy to localize and assess extranuclear ERα. A high ERα ENR in HR+/HER2− BC indicates decreased likelihood of benefiting from ET.
Advances in Targeting the Epidermal Growth Factor Receptor Pathway by Synthetic Products and Its Regulation by Epigenetic Modulators as a Therapy for Glioblastoma
Authors: Nadeem Abbas Muhammad , Kausar Saima , Wang Feng , Zhao Yongju , Cui Hongjuan
Published: April 2019

Glioma is the most common primary tumor of the nervous system, and approximately 50% of patients exhibit the most aggressive form of the cancer, glioblastoma. The biological function of epidermal growth factor receptor (EGFR) in tumorigenesis and progression has been established in various types of cancers, since it is overexpressed, mutated, or dysregulated. Its overexpression has been shown to be associated with enhanced metastatic potential in glioblastoma, with EGFR at the top of a downstream signaling cascade that controls basic functional properties of glioblastoma cells such as survival, cell proliferation, and migration. Thus, EGFR is considered as an important therapeutic target in glioblastoma. Many anti-EGFR therapies have been investigated both in vivo and in vitro, making their way to clinical studies. However, in clinical trials, the potential efficacy of anti-EGFR therapies is low, primarily because of chemoresistance. Currently, a range of epigenetic drugs including histone deacetylase (HDAC) inhibitors, DNA methylation and histone inhibitors, microRNA, and different types of EGFR inhibitor molecules are being actively investigated in glioblastoma patients as therapeutic strategies. Here, we describe recent knowledge on the signaling pathways mediated by EGFR/EGFR variant III (EGFRvIII) with regard to current therapeutic strategies to target EGFR/EGFRvIII amplified glioblastoma.
Rapid Processing of In-Doped ZnO by Spray Pyrolysis from Environment-Friendly Precursor Solutions
Authors: Winkler Nina , Wibowo Adhi , Kubicek Bernhard , Kautek Wolfgang , Ligorio Giovanni , List-Kratochvil Emil , Dimopoulos Theodoros
Published: April 2019

This study focused on the deposition of indium-doped zinc oxide (IZO) films at high growth rates by ultrasonic spray pyrolysis. We investigated the influence of processing parameters, such as temperature and solution flow rate, on the structural, optical, and electrical film properties. For all depositions, low-cost and low-toxicity aqueous solutions and metal salt precursors were used. Through the optimization of the spraying parameters and pattern, a spatially homogeneous IZO layer with transparency greater than 80%, resistivity of 3.82 × 10−3 Ω·cm for a thickness of 1800 nm (sheet resistance of 21.2 Ω/sq), Hall carrier density of 1.36 × 1020 cm−3, Hall mobility of 12.01 cm2 V−1 s−1, and work function of 4.4 eV was obtained. These films are suitable for implementation in optoelectronic and photovoltaic devices.
Association of Non-Carious Cervical Lesions with Oral Hygiene Habits and Dynamic Occlusal Parameters
Authors: Haralur Satheesh B. , Alqahtani Abdulrahman Saad , AlMazni Mohammed Shaya , Alqahtani Mohammad Khalid
Published: April 2019

Dentists routinely encounter non-carious cervical lesions (NCCLs) in daily clinical practices. The dental literature is contradictory regarding the occlusal etiology of NCCLs. NCCL is defined as the loss of dental structure at the cemento–enamel junction, with no association of bacteria. The aim of this study was to evaluate the association of dynamic occlusal factors and dental hygiene practices with NCCLs. In total, 100 participants were selected by the random stratified sampling method, 50 each for control and NCCL groups. Information regarding oral hygiene practices, including frequency, duration, force, and technique of brushing, was recorded. Dynamic occlusal parameters like initial contact, occlusion time (OT), disocclusion time (DT), and center of force were recorded with T-scan analysis. The obtained data were analyzed with Pearson’s correlation and binary logistic regression. We found that 68% of participants in the NCCL group and 31% in the control group utilized the horizontal brushing technique; 46% of NCCL group participants used hard brush against 7% of participants in the control group. The mean OT was 0.727 and 0.516 s for NCCL and control groups, respectively. The OT and left and right lateral DT were strongly related to NCCL, with r-values of 0.661, 0.642, and 0.534, respectively, with p ≤ 0.001. Using a hard toothbrush was found to be associated with NCCL. The NCCL group had extended mean occlusion time and disocclusion time in all eccentric mandibular movements.
Oral Cancer Knowledge, Attitude, and Practice of Dentists in the State of Qatar
Authors: Jboor Diana H. , Al-Darwish Mohammed S. , Nur Ula
Published: April 2019

Objectives: The aim of this study was to assess existing knowledge on oral cancer (OC), attitude toward OC examination, and clinical practice among dentists practicing in the governmental health sector in the State of Qatar, including the influence of personal characteristics. Materials and Methods: All 271 dentists practicing in Primary Health Care Centers (PHCC) and the Hamad Medical Corporation (HMC) were invited to participate in this cross-sectional study. Of these, 177 completed a self-administered, 48-item questionnaire. Based on the responses, knowledge of the risk factors for and clinical presentation of OC was categorized as high, medium, or low, and then further separated into satisfactory (medium/high) and unsatisfactory (low). Information on attitudes toward OC examination and clinical practice was also taken from the questionnaire. Results: The mean score for knowledge of the clinical presentation of OC was 7.59 (standard deviation [SD] = 2.40) out of 14. The mean score for knowledge of the risk factors for OC was 8.96 (SD = 2.31) out of 16. Dentists with ≤10 years of experience were more likely to have satisfactory knowledge of OC compared to dentists with >15 years of experience. Attending a continuous professional development (CPD) course on OC showed a trend with satisfactory clinical knowledge, although it was not statistically significant. Conclusion: This study identified gaps in dentists’ knowledge of OC; dentists demonstrated unsatisfactory knowledge of the clinical presentation of and risk factors for OC. The findings highlighted the need for educational interventions on OC, which are essential to improving health care outcomes and delivery of care.
Drone Laser Scanning for Modeling Riverscape Topography and Vegetation: Comparison with Traditional Aerial Lidar
Authors: Resop Jonathan P. , Lehmann Laura , Hession W. Cully
Published: April 2019

Lidar remote sensing has been used to survey stream channel and floodplain topography for decades. However, traditional platforms, such as aerial laser scanning (ALS) from an airplane, have limitations including flight altitude and scan angle that prevent the scanner from collecting a complete survey of the riverscape. Drone laser scanning (DLS) or unmanned aerial vehicle (UAV)-based lidar offer ways to scan riverscapes with many potential advantages over ALS. We compared point clouds and lidar data products generated with both DLS and ALS for a small gravel-bed stream, Stroubles Creek, located in Blacksburg, VA. Lidar data points were classified as ground and vegetation, and then rasterized to produce digital terrain models (DTMs) representing the topography and canopy height models (CHMs) representing the vegetation. The results highlighted that the lower-altitude, higher-resolution DLS data were more capable than ALS of providing details of the channel profile as well as detecting small vegetation on the floodplain. The greater detail gained with DLS will provide fluvial researchers with better estimates of the physical properties of riverscape topography and vegetation.
New Developments in Statistical Information Theory Based on Entropy and Divergence Measures
Authors: Pardo Leandro
Published: April 2019

In the last decades the interest in statistical methods based on information measures and particularly in pseudodistances or divergences has grown substantially [...]
On the Use of Entropy to Improve Model Selection Criteria
Authors: Murari Andrea , Peluso Emmanuele , Cianfrani Francesco , Gaudio Pasquale , Lungaroni Michele
Published: April 2019

The most widely used forms of model selection criteria, the Bayesian Information Criterion (BIC) and the Akaike Information Criterion (AIC), are expressed in terms of synthetic indicators of the residual distribution: the variance and the mean-squared error of the residuals respectively. In many applications in science, the noise affecting the data can be expected to have a Gaussian distribution. Therefore, at the same level of variance and mean-squared error, models, whose residuals are more uniformly distributed, should be favoured. The degree of uniformity of the residuals can be quantified by the Shannon entropy. Including the Shannon entropy in the BIC and AIC expressions improves significantly these criteria. The better performances have been demonstrated empirically with a series of simulations for various classes of functions and for different levels and statistics of the noise. In presence of outliers, a better treatment of the errors, using the Geodesic Distance, has proved essential.
Energy Use of Flux Salt Recovery Using Bipolar Membrane Electrodialysis for a CO2 Mineralisation Process
Authors: Koivisto Evelina , Zevenhoven Ron
Published: April 2019

Mineral carbonation routes have been extensively studied for almost two decades at Åbo Akademi University, focusing on the extraction of magnesium from magnesium silicates using ammonium sulfate (AS) and/or ammonium bisulfate (ABS) flux salt followed by carbonation. There is, however, a need for proper recovery and recirculation of chemicals involved. This study focused on the separation of AS, ABS and aqueous ammonia using different setups of bipolar membrane electrodialysis using both synthetic and rock-derived solutions. Bipolar membranes offer the possibility to split water, which in turn makes it possible to regenerate chemicals like acids and bases needed in mineral carbonation without excess gas formation. Tests were run in batch, continuous, and recirculating mode, and exergy (electricity) input during the tests was calculated. The results show that separation of ions was achieved, even if the solutions obtained were still too weak for use in the downstream process to control pH. Energy demand for separating 1 kg of NH4+ varied in the range 1.7, 3.4, 302 and 340 MJ/kg NH4+, depending on setup chosen. More work must hence be done in order to make the separation more efficient, such as narrowing the cell width.
Effects of Game-Based Instruction on the Results of Primary School Children Taking a Natural Science Course
Authors: Chen Ming-Hsiu Mia , Tsai Shih-Ting , Chang Chi-Cheng
Published: April 2019

This study explored the effects of scenario simulation games and e-textbooks on the learning outcomes of elementary school students. The study subjects were 60 primary school students classified into two groups: The experimental group was provided with scenario simulation course materials, and the control group received e-textbook materials. The learning outcomes were compared between the two groups, which were further divided by ability level and gender. The female subjects in the experimental group showed slightly less improvement than the experimental group males, who showed significantly greater improvement than the female control group subjects. Use of the e-textbook had a less positive effect on learning outcomes than the scenario simulation game-based instruction.
A Generalised Multifrequency PWM Strategy for Dual Three-Phase Voltage Source Converters
Authors: Riveros Jose A. , Prieto Joel , Rivera Marco , Toledo Sergio , Gregor Raúl
Published: April 2019

Pulse width modulation (PWM) strategies for the control of asymmetrical six-phase drives have been widely studied since the beginning of this century. Nevertheless, space vector modulation (SVM) techniques with multifrequency voltage injection for the control of all the degrees of freedom of the multiphase model is still a subject under research. This paper deals with this topic and introduces a generalised PWM method for a two-level voltage source converters. The architecture was derived by extending a three-phase modulator proposed as an alternative to the widely studied SVM. The proposal computes the duty times straightforwardly with a fast algorithm based on an analytical solution of the voltage-time modulation law. Theoretical derivations supported by experimental results demonstrate the proper synthesis of the multifrequency target voltage in the linear modulation region as well as good frequency behaviour of the presented modulation strategy.
Implementation of User Cuts and Linear Sensitivity Factors to Improve the Computational Performance of the Security-Constrained Unit Commitment Problem
Authors: Marín-Cano Cristian Camilo , Sierra-Aguilar Juan Esteban , López-Lezama Jesús M. , Jaramillo-Duque Álvaro , Villa-Acevedo Walter M.
Published: April 2019

Power system operators must schedule the available generation resources required to achieve an economical, reliable, and secure energy production in power systems. This is usually achieved by solving a security-constrained unit commitment (SCUC) problem. Through a SCUC the System Operator determines which generation units must be on and off-line over a time horizon of typically 24 h. The SCUC is a challenging problem that features high computational cost due to the amount and nature of the variables involved. This paper presents an alternative formulation to the SCUC problem aimed at reducing its computational cost using sensitivity factors and user cuts. Power Transfer Distribution Factors (PTDF) and Line Outage Distribution Factors (LODF) sensitivity factors allow a fast computation of power flows (in normal operative conditions and under contingencies), while the implementation of user cuts reduces computational burden by considering only biding N-1 security constraints. Several tests were performed with the IEEE RTS-96 power system showing the applicability and effectiveness of the proposed modelling approach. It was found that the use of Linear Sensitivity Factors (LSF) together with user cuts as proposed in this paper, reduces the computation time of the SCUC problem up to 97% when compared with its classical formulation. Furthermore, the proposed modelling allows a straightforward identification of the most critical lines in terms of the overloads they produce in other elements after an outage, and the number of times they are overloaded by a fault. Such information is valuable to system planners when deciding future network expansion projects.
Distributed Economic Power Dispatch and Bus Voltage Control for Droop-Controlled DC Microgrids
Authors: Cheng Zhiping , Li Zhongwen , Liang Jing , Gao Jinfeng , Si Jikai , Li Shuhui
Published: April 2019

This paper proposes a distributed economic power dispatch (EPD) and bus voltage control solution for droop-controlled DC microgrids. For the proposed solution, a local power controller and a local voltage controller are added for each distributed generator (DG) to overcome the limitations of the conventional droop control. The power controller generates the first voltage correction term by comparing the local output power of DG with the reference instruction generated by the proposed distributed EPD algorithm, and thus, it can reduce the operation cost of the microgrid by optimally sharing the load demand among all the participating DGs. The voltage controller generates the second voltage correction term by comparing the nominal DC bus voltage value with the average bus voltage generated by the proposed distributed average bus voltage observation (ABVO) algorithm, and thus, it can realize the global bus voltage regulation of the DC microgrid. In contrast with conventional solutions, the control solution can distribute the computational and communication burdens among all the DGs working in parallel, which is more flexible, scalable, and robust against single-point failure. The effectiveness of the proposed control solution is demonstrated through simulation studies.
A Loss-Free Resistor-Based Versatile Ballast for Discharge Lamps
Authors: Valderrama-Blavi Hugo , Leon-Masich Antonio , Olalla Carlos , Cid-Pastor Àngel
Published: April 2019

This paper presents a versatile ballast for discharge lamps, whose operation is based on the notion of a loss-free resistor (LFR). The ballast consists of two stages: (1) a boost converter operating in continuous conduction mode (CCM) and exhibiting an LFR behavior imposed by sliding-mode control; and (2) a resonant inverter supplying the discharge lamp at high frequencies. Thanks to this mode of operation, the power transferred to the lamp is regulated by the LFR input resistance, allowing successful ignition, warm-up, nominal, and dimming operation of a range of discharge lamps, with no need for complex regulation schemes based on lamp models. The versatility of the ballast has been experimentally proven for both conventional and electrodeless discharge lamps. Tests include induction electrodeless fluorescent (IEFL), high-pressure sodium (HPS) vapor, and metal-halide lamps.
Multi-Dimensional Performance Evaluation of Heat Exchanger Surface Enhancements
Authors: Fugmann Hannes , Laurenz Eric , Schnabel Lena
Published: April 2019

Enhanced heat transfer surfaces allow more energy-efficient, compact and lightweight heat exchangers. Within this study, a method for comparing different types of enhancement and different geometries with multiple objectives is developed in order to evaluate new and existing enhancement designs. The method’s objectives are defined as energy, volume, and mass efficiency of the enhancement. They are given in dimensional and non-dimensional form and include limitations due to thermal conductivity within the enhancement. The transformation to an explicit heat transfer rate per dissipated power, volume, or mass is described in detail. The objectives are visualized for different Reynolds numbers to locate beneficial operating conditions. The multi-objective problem is further on reduced to a single-objective problem by means of weighting factors. The implementation of these factors allows a straightforward performance evaluation based on a rough estimation of the energy, volume, and mass importance set by a decision maker.
LCA-Based Comparison of Two Organic Fraction Municipal Solid Waste Collection Systems in Historical Centres in Spain
Authors: Laso Jara , García-Herrero Isabel , Margallo María , Bala Alba , Fullana-i-Palmer Pere , Irabien Angel , Aldaco Rubén
Published: April 2019

Municipal solid waste (MSW) collection is an important issue in the development and management of smart cities, having a significant influence on environmental sustainability. Door-to-door and pneumatic collection are two systems that represent a way of arranging waste collection in city´s historic areas in Spain where conventional street-side container collection is not feasible. Since door-to-door collection generates significant direct greenhouse gas emissions from trucks, pneumatic collection emerges as an alternative to the trucking system. While this technology apparently reduces local direct air emissions, it suffers from a large energy demand derived from vacuum production for waste suction. The introduction of new normative frameworks regarding the selective collection of the biodegradable fraction makes necessary a comprehensive analysis to assess the influence of this fraction collection and its subsequent recycling by anaerobic digestion. As a novelty, this work compares both conventional door-to-door and pneumatic collection systems from a life cycle approach focusing on the biodegradable waste. Results indicate that, in spite of the fact electricity production and consumption have a significant influence on the results, the energy savings from the recycling of the organic fraction are higher than the energy requirements. Therefore, the pneumatic collection could be an environmentally-friendly option for MSW management under a circular economy approach in Spanish city´s historic areas, since wastes could be a material or energy source opportunity.
A Compact Spatial Free-Positioning Wireless Charging System for Consumer Electronics Using a Three-Dimensional Transmitting Coil
Authors: Liang Ziwei , Wang Jianqiang , Zhang Yiming , Jiang Jiuchun , Yan Zhengchao , Mi Chris
Published: April 2019

A compact spatial free-positioning wireless charging system with a novel three-dimensional (3D) transmitting (Tx) coil is proposed to charge consumer electronics in the working area. Because of the strengthened electromagnetic field generated by the proposed 3D Tx coil in the space, this system can charge consumer electronics wirelessly with great tolerance to positional and angular misalignments between the transmitter and receiver. Benefiting from the compact design of the 3D Tx coil, the system can be easily embedded in some corners of office furniture/cubic panels, which will not cause any extra working space consumption when charging devices. The inductor-capacitor-capacitor (LCC) compensation circuit on the Tx side can achieve constant current output, which is independent of load condition and can protect the transmitter. With the LCC compensation circuit, the MOSFETs of the H-bridge high-frequency inverter realized zero voltage switching (ZVS). The small-sized planar receiving (Rx) coil and series (S) compensation circuit is applied to achieve compact receiver design. The theoretical and experimental results show that the spatial free-positioning wireless charging prototype can transfer 5 W to the small-sized receiver in around 350 mm × 225 mm × 200 mm 3D charging area and achieve the highest efficiency of 77.9%.
Mixed Integer Quadratic Programming Based Scheduling Methods for Day-Ahead Bidding and Intra-Day Operation of Virtual Power Plant
Authors: Ko Rakkyung , Kang Daeyoung , Joo Sung-Kwan
Published: April 2019

As distributed energy resources (DERs) proliferate power systems, power grids face new challenges stemming from the variability and uncertainty of DERs. To address these problems, virtual power plants (VPPs) are established to aggregate DERs and manage them as single dispatchable and reliable resources. VPPs can participate in the day-ahead (DA) market and therefore require a bidding method that maximizes profits. It is also important to minimize the variability of VPP output during intra-day (ID) operations. This paper presents mixed integer quadratic programming-based scheduling methods for both DA market bidding and ID operation of VPPs, thus serving as a complete scheme for bidding-operation scheduling. Hourly bids are determined based on VPP revenue in the DA market bidding step, and the schedule of DERs is revised in the ID operation to minimize the impact of forecasting errors and maximize the incentives, thus reducing the variability and uncertainty of VPP output. The simulation results verify the effectiveness of the proposed methods through a comparison of daily revenue.
A Healthy, Energy-Efficient and Comfortable Indoor Environment, a Review
Authors: Šujanová Paulína , Rychtáriková Monika , Sotto Mayor Tiago , Hyder Affan
Published: April 2019

Design strategies for sustainable buildings, that improve building performance and avoid extensive resource utilization, should also promote healthy indoor environments. The following paper contains a review of the couplings between (1) building design, (2) indoor environmental quality and (3) occupant behavior. The paper focuses on defining the limits of adaptation on the three aforementioned levels to ensure the energy efficiency of the whole system and healthy environments. The adaptation limits are described for measurable physical parameters and the relevant responsible human sensory systems, evaluating thermal comfort, visual comfort, indoor air quality and acoustical quality. The goal is to describe the interactions between the three levels where none is a passive participant, but rather an active agent of a wider human-built environment system. The conclusions are drawn in regard to the comfort of the occupant. The study reviews more than 300 sources, ranging from journals, books, conference proceedings, and reports complemented by a review of standards and directives.
Thermal Properties of Residual Agroforestry Biomass of Northern Portugal
Authors: Enes Teresa , Aranha José , Fonseca Teresa , Lopes Domingos , Alves Ana , Lousada José
Published: April 2019

Biomass from forestry and agricultural sector provides an important contribution to encounter the government’s targets for increasing bioenergy production and utilization. Characterization of agricultural and forest wastes are critical for exploiting and utilizing them for energy purpose. In the present work agricultural and forest wastes and shrubs were sampled in two sites in north Portugal (Ave and Sabor basin) and subjected to Higher Heating Value (HHV) and chemical composition quantification. The HHV was evaluated according to the methodology described in Standard DD CEN/TS14918:2005. For the lignin content, the procedure was made by the Klason method and the extractives content was determined with the Soxhlet method. For agricultural and forest wastes the HHV values are identical with a range of 17 to 21 MJ·kg−1. However, shrubs biomass presentx slightly higher and statistically different values from agricultural and forest wastes, varying between 19 and 21 MJ·kg−1. Forest wastes contain higher levels of holocellulose compared to agricultural wastes and, with respect to extractive contents, this trend is the reverse. There is a general tendency for the woody components present thermo-chemical properties more suited for energy purposes, than the residues formed by the branches and leaves.
Timing is Not Everything: Assessing the Efficacy of Pre- Versus Post-Harvest Herbicide Applications in Mitigating the Burgeoning Birch Phenomenon in Regenerating Hardwood Stands
Authors: Royo Alejandro A. , Pinchot Cornelia C. , Stanovick John S. , Stout Susan L.
Published: April 2019

Sweet birch (Betula lenta L.) is aggressively recruiting in temperate forest understories of the eastern United States and often dominates the post-disturbance seedling community, diminishing diversity and hindering sustainable silviculture. The type and timing of silvicultural actions affect birch recruitment via their effects on seedling recruitment, survival, and growth. Here, we examine birch regeneration under two contrasting treatment sequences: pre- versus post-shelterwood harvest herbicide application (H–S vs. S–H) in combination with white-tailed deer (Odocoileus virginianus Zimmerman) browsing (fenced vs. unfenced) at 22 sites in northwestern Pennsylvania, USA. Additionally, we examine how treatments interact with additional site factors, including potential propagule sources and site productivity (i.e., integrated moisture index). We found the S–H sequence initially reduced birch density by 71% relative to the H–S sequence; however, the magnitude of this reduction waned over five growing seasons. Furthermore, birch proliferated following the H–S sequence only where mature birch were present. Deer browsing reduced birch height by 29% relative to fenced areas protected from browsing; however, by the fifth growing season birch seedlings were over twice as tall as other hardwood species across all treatments. Finally, increasingly mesic sites enhanced birch height growth. In sum, although post-harvest herbicide (S–H) provides short-lived control over birch, land managers should also consider browse pressure, seed source, and site productivity, as these may enhance or diminish the efficacy of post-shelterwood herbicide sequence effects on birch.
Establishment of Quercus marilandica Muenchh. and Juniperus virginiana L. in the Tallgrass Prairie of Oklahoma, USA Increases Litter Inputs and Soil Organic Carbon
Authors: Nunes Biral Vanessa C. , Will Rodney E. , Zou Chris B.
Published: April 2019

The establishment of trees in grasslands alters ecosystem processes and services. Litter inputs shift from herbaceous to tree-derived, which affects the litter quantity and quality and may in turn alter soil carbon dynamics and ecosystem-level carbon sequestration. This study determined changes in the quantity of organic matter inputs following encroachment by two native tree species (Quercus marilandica Muenchh. and Juniperus virginiana L.) into a tallgrass prairie in northcentral Oklahoma, and related it to spatial heterogeneity in soil carbon by measuring variables near the stem, under the tree canopy, at the outer edge of the tree canopy, and beyond the tree canopy. Presence of trees increased aboveground litter inputs (dominated by foliage for J. virginiana and acorns for Q. marilandica) and increased the duff and litter layer. Regardless of leaf litter source, decomposition of foliage was slower under the tree canopy than beyond the tree canopy (7% slower) and this change was associated with cooler and potentially drier conditions. However, the foliage of trees decomposed more quickly than grass foliage when measured both beneath and beyond the tree canopy (25% faster). Coarse root biomass was greater under tree canopies than beyond, which increased total root biomass in the deeper soil layer (10–30 cm). The net effect was an approximately 15% increase in soil carbon stock under the trees as compared to areas beyond the tree canopy. Therefore, in addition to greater carbon storage in the aboveground biomass, tree encroachment increases carbon sequestration by increasing soil carbon.
Altitudinal Biodiversity Gradient and Ecological Drivers for Different Lifeforms in the Baotianman Nature Reserve of the Eastern Qinling Mountains
Authors: Zhao Chao , Wang Jing , Yu Fuqin , Zhang Xinghang , Yao Yonghui , Zhang Baiping
Published: April 2019

Variation in species composition between two communities is so-called β diversity, or dissimilarity, and can be separated into two components: turnover and nestedness. However, the mechanisms underlying these two components remain ambiguous, particularly for different lifeforms. In this study, we examined the altitudinal gradient of biodiversity in the Baotianman Nature Reserve of the eastern Qinling Mountains in central China and found that turnover is the predominant process accounting for β diversity, that dispersal limitation is the main factor influencing species diversity, and that its effect on trees is greater than on shrubs, with herbs least affected. Nestedness, in contrast, is less prominent and generally affected by the richness deviation between communities, and the impact of richness deviation is stronger on shrubs than on trees, and in turn, stronger than on herbs. We zoned the altitudinal vegetation communities by pairwise dissimilarity index, and found that the peak value of turnover rather than β diversity indicates the existence of transitional zones; the higher the turnover index, the greater the diversity between communities. Comparatively, nestedness indicates species overlap between communities. The highest nestedness index usually occurs in the interior of vegetation zones. The result of community clustering by pairwise dissimilarity shows that understory species could have been mostly replaced upwards, while the dominant tree species may keep stable, indicating that dispersal limitation works differently for different lifeforms.
An Improved Approach for Text Sentiment Classification Based on a Deep Neural Network via a Sentiment Attention Mechanism
Authors: Li Wenkuan , Liu Peiyu , Zhang Qiuyue , Liu Wenfeng
Published: April 2019

Text sentiment analysis is an important but challenging task. Remarkable success has been achieved along with the wide application of deep learning methods, but deep learning methods dealing with text sentiment classification tasks cannot fully exploit sentiment linguistic knowledge, which hinders the development of text sentiment analysis. In this paper, we propose a sentiment-feature-enhanced deep neural network (SDNN) to address the problem by integrating sentiment linguistic knowledge into a deep neural network via a sentiment attention mechanism. Specifically, first we introduce a novel sentiment attention mechanism to help select the crucial sentiment-word-relevant context words by leveraging the sentiment lexicon in an attention mechanism, which bridges the gap between traditional sentiment linguistic knowledge and current popular deep learning methods. Second, we develop an improved deep neural network to extract sequential correlation information and text local features by combining bidirectional gated recurrent units with a convolutional neural network, which further enhances the ability of comprehensive text representation learning. With this design, the SDNN model can generate a powerful semantic representation of text to improve the performance of text sentiment classification tasks. Extensive experiments were conducted to evaluate the effectiveness of the proposed SDNN model on two real-world datasets with a binary-sentiment-label and a multi-sentiment-label. The experimental results demonstrated that the SDNN achieved substantially better performance than the strong competitors for text sentiment classification tasks.