bluuebunny/crossref_metadata_2025 huggingface dataset:
Interaction between students and class teachers in vocational education and training: ‘Safety distance is needed’
Authors: Ryökkynen Sanna , Pirttimaa Raija , Kontu Elina
Published: January 2020

Interaction between students and teachers is fundamental and has therefore been widely studied in education. However, there have been few studies on intensive spe-cial support being provided to vocational education and training (VET) students. Firstly, the focus of this article is on students’ perceptions of interactions with their class teachers. Students (aged 17–34 years) from four Finnish vocational institutions providing intensive special support were interviewed. According to the findings, the demands students placed on their class teachers and for interactions with them were modest and their perceptions of both were favourable. Interactions seemed to be study-orientated and class teachers behaved as active initiators, with students echo-ing their opinions. Students’ narratives excluded future career plans, talking about students’ strengths or future ambitions or dreams. Secondly, the aim of this study is to review Finnish VET critically. In the reformed VET system, competence-based ori-entation emphasises individual guidance and support. Therefore, as the dialogue between teacher and student seems to enable successful trajectories, it is essential to make this apparent. Part of education’s larger purpose is to make room for students’ voices and interpretations during their study, which includes both acquiring qualifi-cations to undertake certain work, and subjectification as an empowering element and socialisation of the social, cultural and political order.
Performance of Medicago sativa Grown in Clay Soil Favored by Compost or Farmyard Manure to Mitigate Salt Stress
Authors: Mbarki Sonia , Skalicky Milan , Talbi Ons , Chakraborty Amrita , Hnilicka Frantisek , Hejnak Vaclav , Zivcak Marek , Brestic Marian , Cerda Artemi , Abdelly Chedly
Published: January 2020

The use of saline water for the irrigation of forage crops to alleviate water scarcity has become necessary in semi-arid and arid regions and researchers have been seeking ways to offset the harmful results of soil salinity. Soil amendments with compost, manure and other organic material provide a valuable source of plant nutrients and appear to speed up soil recovery. The aim of this study was to compare the benefits of farmyard manure and a municipal solid waste (MSW) compost (40 mg ha−1) for raising alfalfa (Medicago sativa, cv. Gabès) under salt-water irrigation. Both compost and manure improved plant mineral uptake and growth of alfalfa cultivated in clay soil. Using compost in clay soil increased the content of copper (Cu), cadmium (Cd), and zinc (Zn) in plant tissues compared to manure, while the bio-accumulation factor (BAF) of Cu, Pb and Zn was higher in plants grown with manure compared to MSW compost with salt stress. Compost addition could enhance alfalfa growth under salt stress, which depends on salt doses and can greatly improve the recovery effects in a cost-effective way, although additional amendment type should receive special attention in order to be used as a tool for sustainable agriculture.
Cellular and Molecular Adaptation of Bovine Granulosa Cells and Oocytes under Heat Stress
Authors: Khan Adnan , Khan Muhammad Zahoor , Umer Saqib , Khan Ibrar Muhammad , Xu Huitao , Zhu Huabin , Wang Yachun
Published: January 2020

Heat stress has long been recognized as a challenging issue that severely influences the reproductive functions of dairy cattle, disrupting oocyte development during fetal growth. These detrimental effects of heat stress are the result of either the hyperthermia associated with heat stress or the physiological adjustments made by the heat-stressed animal to regulate body temperature. In addition, elevated temperatures have been implicated in increasing the production of reactive oxygen species. Thus, understanding the impact of heat stress on reproductive functions, from a cellular to molecular level, might help in selecting heat-resilient dairy cattle and developing heat stress mitigation strategies. In the present paper, we have attempted to describe the changes in the reproductive system and function of dairy cattle in response to heat stress by reviewing the latest literature in this area. The review provides useful knowledge on the cellular and genetic basis of oocyte and granulosa cells in heat-stressed dairy cattle, which could be helpful for future research in this area.
Exploring the Use of a Qualitative Behavioural Assessment Approach to Assess Emotional State of Calves in Rodeos
Authors: Rizzuto Sally , Evans Di , Wilson Bethany , McGreevy Paul
Published: January 2020

There are longstanding disagreements between the rodeo industry stakeholders and animal welfare advocates about the wellbeing of the animals used in events. The current study aims to determine whether qualitative behavioural assessment (QBA) is effective in identifying the emotional state of calves in so-called calf-roping events. Still images of calves captured from videos of calf-roping were shown to two groups: practitioners (n = 7) and students (n = 16). For each image, they scored (on a scale of 1–10) 12 descriptive terms—e.g., stressed, energetic, confused, frightened—based on how strongly they thought the animal was experiencing that emotion. Scores were analysed using Factor Analysis and Ordinal Logistic Regression models, while inter-rater reliability was assessed using Intra-Class Correlation Coefficients. The same imagery (video and images) were analysed for behaviours associated with the calves’ ears, neck, legs and tail to develop a behavioural ethogram, which was analysed with Binary Logistic Regression and Anova wrapping. The students were also surveyed to assess their empathy towards animals. The chase phase attracted significantly higher scores for stressed (µ = 5.0, p < 0.001), agitated (µ = 5.1, p < 0.001), anxious (µ = 5.0, p < 0.001) and frightened (µ = 5.0, p < 0.001), and the behavioural ethogram revealed that calves commonly galloped (p < 0.001) and held their tails rigidly during this phase (p = 0.010). In contrast, the recovery phase was characterised by significantly higher scores for calm (µ = 3.0, p < 0.001), contented (µ = 2.7, p < 0.001) and relieved (µ = 1.6, p < 0.001), and calves moved slower (p < 0.001) with more neutral ear positions (ears axial p = 0.008, ears forward p = 0.010). A clear pre- and post-rope effect was evident, showing that QBA indicated that calves were anxious while being chased and were relieved when they had been released. The survey data revealed that students who had more empathy for animals in pain and for those used in experiments were more empathetic towards calves during the chase phase. They felt that calves being chased were agitated, anxious, stressed, frightened and confused. These results confirm that QBA has the potential as a tool for assessing the welfare of animals used in rodeos.
A New Approach for Accurate Detection of Chromosome Rearrangements That Affect Fertility in Cattle
Authors: Jennings Rebecca L. , Griffin Darren K. , O’Connor Rebecca E.
Published: January 2020

Globally, cattle production has more than doubled since the 1960s, with widespread use of artificial insemination (AI) and an emphasis on a small pool of high genetic merit animals. Selecting AI bulls with optimal fertility is, therefore, vital, as impaired fertility reduces genetic gains and production, resulting in heavy financial and environmental losses. Chromosome translocations, particularly the 1;29 Robertsonian translocation, are a common cause of reduced fertility; however, reciprocal translocations are significantly underreported due to the difficulties inherent in analysing cattle chromosomes. Based on our porcine work, we have developed an approach for the unambiguous detection of Robertsonian and reciprocal translocations, using a multiple-hybridization probe detection strategy. We applied this method on the chromosomes of 39 bulls, detecting heterozygous and homozygous 1;29 translocations and a 12;23 reciprocal translocation in a total of seven animals. Previously, karyotype analysis was the only method of diagnosing chromosomal rearrangements in cattle, and was time-consuming and error-prone. With calving rates of only 50–60%, it is vital to reduce further fertility loss in order to maximise productivity. The approach developed here identifies abnormalities that DNA sequencing will not, and has the potential to lead to long-term gains, delivering meat and milk products in a more cost-effective and environmentally-responsible manner to a growing population.
Can Enterocin M in Combination with Sage Extract Have Beneficial Effect on Microbiota, Blood Biochemistry, Phagocytic Activity and Jejunal Morphometry in Broiler Rabbits?
Authors: Pogány Simonová Monika , Chrastinová Ľubica , Kandričáková Anna , Gancarčíková Soňa , Bino Eva , Plachá Iveta , Ščerbová Jana , Strompfová Viola , Žitňan Rudolf , Lauková Andrea
Published: January 2020

The present study investigated the effects of enterocin (Ent) M and sage extract alone and also in combination on the gut microflora, phagocytic activity, blood biochemistry, and morphometry of rabbits. Sixty-four rabbits (aged five weeks, M91 meatline, both sexes) were divided into three experimental groups: E (EntM; 50 µL/animal/day), S (sage; 10 µL/animal/day), and E + S (EntM + sage) groups and control group (C). The additives were administered in drinking water for a period of 21 days. Dietary supplementation of EntM and sage significantly reduced the coliforms (E: p < 0.001; S: p < 0.001; E + S: p < 0.001) in feces, while simultaneous addition of EntM and sage decreased enterococci (E + S: p < 0.0001), lactic acid bacteria (E + S: p < 0.01), and coagulase-positive staphylococci (E + S: p < 0.0001) in the appendix. Sage addition reduced HDL (S: p < 0.001) and LDL cholesterol (S: p < 0.001; E + S: p < 0.001), LDL/HDL ratio (S: p < 0.001; E + S: p < 0.01), and increased urea (S: p < 0.01; E + S: p < 0.001) and creatinine (S: p < 0.001; E + S: p < 0.001) in serum. EntM and sage application, alone or in combination, improve the jejunal morphometry (p < 0.0001) in rabbits.
Scavenging of Sub-Micron to Micron-Sized Microbial Aerosols during Simulated Rainfall
Authors: Moore Rachel A. , Hanlon Regina , Powers Craig , Schmale David G. , Christner Brent C.
Published: January 2020

The processes removing aerosols from the atmosphere during rainfall are generically referred to as scavenging. Scavenging influences aerosol distributions in the atmosphere, with consequent effects on cloud properties, radiative forcing, and human health. In this study, we investigated the below-cloud scavenging process, specifically focusing on the scavenging of 0.2 to 2 µm-sized microbial aerosols by populations of water drops with average diameters of 3.0 and 3.6 mm. Rainfall was simulated in convective boundary layer air masses by dispensing the water drops from a 55 m bridge and collecting them at ground level. Particles and microbial cells scavenged by the water drops were visualized, enumerated, and sized using scanning electron and epifluorescence microscopy. Aerosolized particles and DNA-containing microbial cells of 2 µm diameter were scavenged at efficiencies similar to those reported previously in empirical studies; however, the efficiencies derived for smaller aerosols were significantly higher (one to three orders of magnitude) than those predicted by microphysical modeling. Application of the derived scavenging efficiencies to cell data from rainfall implies that, on average, approximately 50 to 70% of the 1 µm microbial cells in the precipitation originated from within the cloud. Further study of submicron to micron-sized aerosol scavenging over a broader raindrop size distribution would improve fundamental understanding of the scavenging process and the capacity to estimate (bio)aerosol abundances in the source cloud through analysis of rainfall.
S-Nitroso-N-Acetyl-D-Penicillamine Modified Hyperbranched Polyamidoamine for High-Capacity Nitric Oxide Storage and Release
Authors: Hopkins Sean P. , Frost Megan C.
Published: January 2020

Synthetic nitric oxide (NO)-donating materials have been shown to have many beneficial effects when incorporated into biomedical materials. When released in the correct dosage, NO has been shown to increase the biocompatibility of blood and tissue contacting materials, but materials are often limited in the amount of NO that can be administered over a period of time. To address this, hyperbranched polyamidoamine (HPAMAM) was modified with the S-nitrosothiol, S-nitroso-N-acetyl-D-penicillamine, and nitrosated to form a controlled, high-capacity NO-donating compound (SNAP-HPAMAM). This compound has the potential of modifying polymers to release NO over long periods of time by being blended into a variety of base polymers. Nitric oxide release was triggered by photoinitiation and through passive ion-mediated release seen under physiological conditions. A material that delivers the beneficial dose of NO over a long period of time would be able to greatly increase the biocompatibility of long-term implantable devices. Structural analysis of a generation 2 HPAMAM molecule was done through Fourier transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance spectroscopy (NMR), and matrix assisted laser desorption ionization, time of flight (MALDI-TOF) mass spectrometry. The NO capacity of the finalized generation 2 SNAP-HPAMAM compound was approximately 1.90 ± 0.116 µmol NO/mg. Quantification of the functional groups in the compound proved that an average of 6.40 ± 0.309 reactive primary amine sites were present compared to the 8 reactive sites on a perfectly synthesized generation 2 dendrimer. There is a substantial advantage of using the hyper-branched HPAMAM over purified dendrimers in terms of reduced labor and expense while still providing a high-capacity NO donor that can be blended into different polymer matrices.
Contribution of mTOR and PTEN to Radioresistance in Sporadic and NF2-Associated Vestibular Schwannomas: A Microarray and Pathway Analysis
Authors: Gugel Isabel , Ebner Florian H. , Grimm Florian , Czemmel Stefan , Paulsen Frank , Hagel Christian , Tatagiba Marcos , Nahnsen Sven , Tabatabai Ghazaleh
Published: January 2020

The use of radiation treatment has increased for both sporadic and neurofibromatosis type 2 (NF2)-associated vestibular schwannoma (VS). However, there are a subset of radioresistant tumors and systemic treatments that are seldom used in these patients. We investigated molecular alterations after radiation in three NF2-associated and five sporadically operated recurrent VS after primary irradiation. We compared these findings with 49 non-irradiated (36 sporadic and 13 NF2-associated) VS through gene-expression profiling and pathway analysis. Furthermore, we stained the key molecules of the distinct pathway by immunohistochemistry. A total of 195 differentially expressed genes in sporadic and NF2-related comparisons showed significant differences based on the criteria of p value < 0.05 and a two-fold change. These genes were involved in pathways that are known to be altered upon irradiation (e.g., mammalian target of rapamycin (mTOR), phosphatase and tensin homolog (PTEN) and vascular endothelial growth factor (VEGF) signaling). We observed a combined downregulation of PTEN signaling and an upregulation of mTOR signaling in progressive NF2-associated VS after irradiation. Immunostainings with mTOR and PTEN antibodies confirmed the respective molecular alterations. Taken together, mTOR inhibition might be a promising therapeutic strategy in NF2-associated VS progress after irradiation.
Adipose Stem Cell-Derived Extracellular Vesicles Induce Proliferation of Schwann Cells via Internalization
Authors: Haertinger Maximilian , Weiss Tamara , Mann Anda , Tabi Annette , Brandel Victoria , Radtke Christine
Published: January 2020

Recent studies showed a beneficial effect of adipose stem cell-derived extracellular vesicles (ADSC-EVs) on sciatic nerve repair, presumably through Schwann cell (SC) modulation. However, it has not yet been elucidated whether ADSC-EVs exert this supportive effect on SCs by extracellular receptor binding, fusion to the SC membrane, or endocytosis mediated internalization. ADSCs, ADSC-EVs, and SCs were isolated from rats and characterized according to associated marker expression and properties. The proliferation rate of SCs in response to ADSC-EVs was determined using a multicolor immunofluorescence staining panel followed by automated image analysis. SCs treated with ADSC-EVs and silica beads were further investigated by 3-D high resolution confocal microscopy and live cell imaging. Our findings demonstrated that ADSC-EVs significantly enhanced the proliferation of SCs in a time- and dose-dependent manner. 3-D image analysis revealed a perinuclear location of ADSC-EVs and their accumulation in vesicular-like structures within the SC cytoplasm. Upon comparing intracellular localization patterns of silica beads and ADSC-EVs in SCs, we found striking resemblance in size and distribution. Live cell imaging visualized that the uptake of ADSC-EVs preferentially took place at the SC processes from which the EVs were transported towards the nucleus. This study provided first evidence for an endocytosis mediated internalization of ADSC-EVs by SCs and underlines the therapeutic potential of ADSC-EVs in future approaches for nerve regeneration.
TRPC Channels: Dysregulation and Ca2+ Mishandling in Ischemic Heart Disease
Authors: Falcón Débora , Galeano-Otero Isabel , Martín-Bórnez Marta , Fernández-Velasco María , Gallardo-Castillo Isabel , Rosado Juan A. , Ordóñez Antonio , Smani Tarik
Published: January 2020

Transient receptor potential canonical (TRPC) channels are ubiquitously expressed in excitable and non-excitable cardiac cells where they sense and respond to a wide variety of physical and chemical stimuli. As other TRP channels, TRPC channels may form homo or heterotetrameric ion channels, and they can associate with other membrane receptors and ion channels to regulate intracellular calcium concentration. Dysfunctions of TRPC channels are involved in many types of cardiovascular diseases. Significant increase in the expression of different TRPC isoforms was observed in different animal models of heart infarcts and in vitro experimental models of ischemia and reperfusion. TRPC channel-mediated increase of the intracellular Ca2+ concentration seems to be required for the activation of the signaling pathway that plays minor roles in the healthy heart, but they are more relevant for cardiac responses to ischemia, such as the activation of different factors of transcription and cardiac hypertrophy, fibrosis, and angiogenesis. In this review, we highlight the current knowledge regarding TRPC implication in different cellular processes related to ischemia and reperfusion and to heart infarction.
The Rare IL22RA2 Signal Peptide Coding Variant rs28385692 Decreases Secretion of IL-22BP Isoform-1, -2 and -3 and Is Associated with Risk for Multiple Sclerosis
Authors: Gómez-Fernández Paloma , Lopez de Lapuente Portilla Aitzkoa , Astobiza Ianire , Mena Jorge , Urtasun Andoni , Altmann Vivian , Matesanz Fuencisla , Otaegui David , Urcelay Elena , Antigüedad Alfredo , Malhotra Sunny , Montalban Xavier , Castillo-Triviño Tamara , Espino-Paisán Laura , Aktas Orhan , Buttmann Mathias , Chan Andrew , Fontaine Bertrand , Gourraud Pierre-Antoine , Hecker Michael , Hoffjan Sabine , Kubisch Christian , Kümpfel Tania , Luessi Felix , Zettl Uwe K. , Zipp Frauke , Alloza Iraide , Comabella Manuel , Lill Christina M. , Vandenbroeck Koen
Published: January 2020

The IL22RA2 locus is associated with risk for multiple sclerosis (MS) but causative variants are yet to be determined. In a single nucleotide polymorphism (SNP) screen of this locus in a Basque population, rs28385692, a rare coding variant substituting Leu for Pro at position 16 emerged significantly (p = 0.02). This variant is located in the signal peptide (SP) shared by the three secreted protein isoforms produced by IL22RA2 (IL-22 binding protein-1(IL-22BPi1), IL-22BPi2 and IL-22BPi3). Genotyping was extended to a Europe-wide case-control dataset and yielded high significance in the full dataset (p = 3.17 × 10−4). Importantly, logistic regression analyses conditioning on the main known MS-associated SNP at this locus, rs17066096, revealed that this association was independent from the primary association signal in the full case-control dataset. In silico analysis predicted both disruption of the alpha helix of the H-region of the SP and decreased hydrophobicity of this region, ultimately affecting the SP cleavage site. We tested the effect of the p.Leu16Pro variant on the secretion of IL-22BPi1, IL-22BPi2 and IL-22BPi3 and observed that the Pro16 risk allele significantly lowers secretion levels of each of the isoforms to around 50%–60% in comparison to the Leu16 reference allele. Thus, our study suggests that genetically coded decreased levels of IL-22BP isoforms are associated with augmented risk for MS.
Integrating Agriculture and Ecosystems to Find Suitable Adaptations to Climate Change
Authors: Thayer Anastasia W. , Vargas Aurora , Castellanos Adrian A. , Lafon Charles W. , McCarl Bruce A. , Roelke Daniel L. , Winemiller Kirk O. , Lacher Thomas E.
Published: January 2020

Climate change is altering agricultural production and ecosystems around the world. Future projections indicate that additional change is expected in the coming decades, forcing individuals and communities to respond and adapt. Current research efforts typically examine climate change effects and possible adaptations but fail to integrate agriculture and ecosystems. This failure to jointly consider these systems and associated externalities may underestimate climate change impacts or cause adaptation implementation surprises, such as causing adaptation status of some groups or ecosystems to be worsened. This work describes and motivates reasons why ecosystems and agriculture adaptation require an integrated analytical approach. Synthesis of current literature and examples from Texas are used to explain concepts and current challenges. Texas is chosen because of its high agricultural output that is produced in close interrelationship with the surrounding semi-arid ecosystem. We conclude that future effect and adaptation analyses would be wise to jointly consider ecosystems and agriculture. Existing paradigms and useful methodology can be transplanted from the sustainable agriculture and ecosystem service literature to explore alternatives for climate adaptation and incentivization of private agriculturalists and consumers. Researchers are encouraged to adopt integrated modeling as a means to avoid implementation challenges and surprises when formulating and implementing adaptation.
De novo Phasing Xenons Observed in the Frog Ependymin-Related Protein
Authors: Park SangYoun
Published: January 2020

Pressurizing Xe or Kr noble gas into the protein crystal for de novo phasing has been one method of choice when the introduction of other heavy-atom compounds fails. One reason is because, unlike other heavy-atom compounds, their immobilized sites are mostly hydrophobic cavities. Previously, the structure of frog ependymin-related protein (EPDR) has been determined using a single wavelength anomalous diffraction (SAD) on a Xe-pressurized crystal. Since no report on the four Xe binding sites has been made, these sites are analyzed in this study. Of the four Xe atoms, three are found along the hydrophobic interfaces created by the two crystallographic symmetry mates of EPDR. One final Xe atom occupies a Ca2+-binding site of the native protein entirely stabilized by the polar atoms of the surrounding EDPR residues. We believe that this atypical Xe location is very unique and merits further study.
Evaluation of Enamel Topography after Debonding Orthodontic Ceramic Brackets by Different Er,Cr:YSGG and Er:YAG Lasers Settings
Authors: Hoteit Marwan , Nammour Samir , Zeinoun Toni
Published: January 2020

In the last decade, the success of lasers in simplifying many dental procedures has heightened the need for research in the orthodontic field, in order to evaluate the benefits of laser-assisted ceramic brackets debonding. Conventional ceramic brackets removal delivers a high shear bond strength (SBS), which might lead to enamel damage. Nowadays, debonding ceramic brackets by Er:YAG laser seems a viable alternative technique; however, there is no data on the use of Er,Cr:YSGG in the literature. We aimed to evaluate the difference in enamel topography derived from different erbium laser settings used during debonding. One hundred and eighty bovine incisors teeth were randomly divided into fifteen experimental groups, according to different erbium laser settings using scanning methods. SBS testing was performed after debonding; stereomicroscopic and SEM analyses were done after cleaning the remaining adhesive so as to assess the incidence of enamel microcracks formation and enamel loss. There were no statistically significant differences between the proportions of teeth with normal enamel topography within the control group when compared with any of the Er:YAG groups. However, the proportion of teeth with a normal enamel topography in Er,Cr:YSGG was 4 W/20 Hz (83.3%) and in Er:YAG was 5 W/20 Hz (91.7%), which was statistically significantly higher than the control group (41.7%). The selection of erbium lasers’ optimal parameters during debonding influences the enamel topography. When considering the evaluation of both microscopic and statistical analyses, irradiation by Er:YAG (120 mJ/40 Hz) displayed a significant reduction in microcracks compared with conventional debonding, even though some microstructural changes in the enamel could be noted. Er,Cr:YSGG (4 W/20 Hz) respected the enamel topography the most out of the studied groups.
Osseous Healing in Surgically Prepared Bone Defects Using Different Grafting Materials: An Experimental Study in Pigs
Authors: Titsinides Savvas , Karatzas Theodore , Perrea Despoina , Eleftheriadis Efstathios , Podaropoulos Leonidas , Kalyvas Demos , Katopodis Christos , Agrogiannis George
Published: January 2020

Regeneration of large jaw bone defects still remains a clinical challenge. To avoid incomplete bone repair, bone grafts have been advocated to support the healing process. This study comparatively evaluated new bone formation among a synthetic graft substitute, a human bone derivative, and a bovine xenograft. Materials were placed in 3 out of the 4 bone cavities, while 1 deficit was left empty, serving as a control, in mono-cortical defects, surgically prepared in the porcine calvaria bone. Animals were randomized in 2 groups and euthanized at 8 and 12 weeks. Harvested tissue specimens were qualitatively evaluated by histology. New bone formation was quantitatively measured by histomorphometry. Maximum new bone formation was noticed in defects grafted with beta-tricalcium phosphate b-TCP compared to the other bone substitutes, at 8 and 12 weeks post-surgery. Bovine and human allograft induced less new bone formation compared to empty bone cavity. Histologic analysis revealed that b-TCP was absorbed and substituted significantly, while bovine and human allograft was maintained almost intact in close proximity with new bone. Based on our findings, higher new bone formation was detected in defects filled with b-TCP when compared to bovine and human graft substitutes.
Accuracy of Maternal Reports of Young Children’s Dental Disease Status: Avon Longitudinal Study of Parents and Children
Authors: Akinkugbe Aderonke A. , Brickhouse Tegwyn H. , Bandyopadhyay Dipankar , Nascimento Marcelle M.
Published: January 2020

Background: Parental reports of their children’s health status is integral to pediatric medical and dental care. Therefore, understanding the accuracy of such reports is vital. Our objectives were to (1) assess the correlation between maternal reports of their children’s indicators of caries experience (subjective assessment) and actual caries status determined by oral examination (objective assessment), and (2) identify potential modifiers of this correlation. Methods: Longitudinal data from the Avon longitudinal study of parents and children (n = 1429) was used to assess the correlation between maternal reports of the number of missing and filled teeth of children aged 38 months, 54 months, and 5.5 years and clinical oral examinations of decayed, missing and filled teeth conducted when the same children were 31, 43 months, and five years of age. Homogeneity chi-square tests assessed differences in correlations according to sociodemographic factors. Results: Overall, we found a statistically significant correlation that was weak to moderate in magnitude. Maternal reports of missing teeth at 38 months was significantly correlated with decayed teeth, 0.27 (p < 0.001); missing teeth, 0.23 (p < 0.001), and the decayed, missing and filled (dmft) index, 0.35 (p < 0.001) based on oral examination at 31 months. A maternal report of filled teeth at 54 months was significantly correlated with decayed teeth, 0.30 (p < 0.001); filled teeth 0.30 (p < 0.001), and dmft 0.40 (p < 0.001) at 43 months. Mothers tended to underestimate the extent of missing and filled teeth in their children irrespective of the child’s age, but the extent of underestimation was greater among younger children. Maternal age, education level, and whether the child had ever visited a dentist were significant modifiers of subjective and objective caries assessments. Conclusions: From a clinical and dental public health perspective, our findings of a weak to moderate correlation of maternal assessments of their children’s caries experience may be concerning when reporting the burden of dental diseases in large population studies or for surveillance purposes that rely on self-reported measures and must therefore be utilized with caution because of the potential to result in underestimated disease burden.
Theory of Response to Perturbations in Non-Hermitian Systems Using Five-Hilbert-Space Reformulation of Unitary Quantum Mechanics
Authors: Znojil Miloslav
Published: January 2020

Non-Hermitian quantum-Hamiltonian-candidate combination H λ of a non-Hermitian unperturbed operator H = H 0 with an arbitrary “small” non-Hermitian perturbation λ W is given a mathematically consistent unitary-evolution interpretation. The formalism generalizes the conventional constructive Rayleigh–Schrödinger perturbation expansion technique. It is sufficiently general to take into account the well known formal ambiguity of reconstruction of the correct physical Hilbert space of states. The possibility of removal of the ambiguity via a complete, irreducible set of observables is also discussed.
Numerical Study of Nanofluid Irreversibilities in a Heat Exchanger Used with an Aqueous Medium
Authors: Ovando-Chacon Guillermo Efren , Ovando-Chacon Sandy Luz , Rodriguez-Leon Abelardo , Diaz-Gonzalez Mario , Hernandez-Zarate Jorge Arturo , Servin-Martinez Alberto
Published: January 2020

Heat exchangers play an important role in different industrial processes; therefore, it is important to characterize these devices to improve their efficiency by guaranteeing the efficient use of energy. In this study, we carry out a numerical analysis of flow dynamics, heat transfer, and entropy generation inside a heat exchanger; an aqueous medium used for oil extraction flows through the exchanger. Hot water flows on the shell side; nanoparticles have been added to the water in order to improve heat transfer toward the cold aqueous medium flowing on the tube side. The aqueous medium must reach a certain temperature in order to obtain its oil extraction properties. The analysis is performed for different Richardson numbers (Ri = 0.1–10), nanofluid volume fractions (φ = 0.00–0.06), and heat exchanger heights (H = 0.6–1.0). Results are presented in terms of Nusselt number, total entropy generation, Bejan number, and performance evaluation criterion. Results showed that heat exchanger performance increases with the increase in Ri when Ri > 1 and when reducing H.
Modeling Bed Shear Stress Distribution in Rectangular Channels Using the Entropic Parameter
Authors: Mirauda Domenica , Russo Maria Grazia
Published: January 2020

The evaluation of bed shear stress distribution is fundamental to predicting the transport of sediments and pollutants in rivers and to designing successful stable open channels. Such distribution cannot be determined easily as it depends on the velocity field, the shape of the cross section, and the bed roughness conditions. In recent years, information theory has been proven to be reliable for estimating shear stress along the wetted perimeter of open channels. The entropy models require the knowledge of the shear stress maximum and mean values to calculate the Lagrange multipliers, which are necessary to the resolution of the shear stress probability distribution function. This paper proposes a new formulation which stems from the maximization of the Tsallis entropy and simplifies the calculation of the Lagrange coefficients in order to estimate the bed shear stress distribution in open-channel flows. This formulation introduces a relationship between the dimensionless mean shear stress and the entropic parameter which is based on the ratio between the observed mean and maximum velocity of an open-channel cross section. The validity of the derived expression was tested on a large set of literature laboratory measurements in rectangular cross sections having different bed and sidewall roughness conditions as well as various water discharges and flow depths. A detailed error analysis showed good agreement with the experimental data, which allowed linking the small-scale dynamic processes to the large-scale kinematic ones.
Investigation of Dilution Effect on CH4/Air Premixed Turbulent Flame Using OH and CH2O Planar Laser-Induced Fluorescence
Authors: Yang Li , Weng Wubin , Zhu Yanqun , He Yong , Wang Zhihua , Li Zhongshan
Published: January 2020

Diluting the combustion mixtures is one of the advanced approaches to reduce the NOx emission of methane/air premixed turbulent flame, especially with high diluents to create a distributed reaction zone and mild combustion, which can lower the temperature of reaction zone and reduce the formation of NOx. The effect of N2/CO2 dilution on the combustion characteristics of methane/air premixed turbulent flame with different dilution ratio and different exit Reynolds number was conducted by OH-PLIF and CH2O-PLIF. Results show that the increase of dilution ratio can sharply reduce the concentration of OH and CH2O, and postpone the burning of fuel. Compared with the ultra-lean combustion, the dilution weakens the combustion more obviously. For different dilution gases, the concentration of OH in the combustion zone varies greatly, while the concentration of CH2O in the unburned zone is less affected by different dilution gas. The CO2 dilution has a more significant effect on OH concentration than N2 with the given dilution ratio, but a similar effect on the concentration of CH2O in the preheat zone of flame. However, dilution does not have much influence on the flame structure with the given turbulent intensity.
Evolution of Virtual Water Transfers in China’s Provincial Grids and Its Driving Analysis
Authors: Zhang Yiyi , Hou Shengren , Liu Jiefeng , Zheng Hanbo , Wang Jiaqi , Zhang Chaohai
Published: January 2020

In China, electricity transmission has increased rapidly over the past decades, and a large amount of virtual water is delivered from power generation provinces to load hubs. Understanding the evolution of the virtual water network embodied in electricity transmission is vital for mitigating water scarcity. However, previous studies mainly calculated the virtual water transferred in short periods in low-spatial resolution and failed to reveal driving forces of the evolution of virtual water. To solve this problem, we investigated the historical evolution of the virtual water network and virtual scarce water network embodied in interprovincial electricity transmission between 2005 and 2014. The driving forces of the evolution of virtual (scarce) water networks were analyzed at both national level and provincial level. The results show that the overall virtual water transmission and virtual scarce water transmission increased by five times, and the direction was mainly from southwest and northwest provinces to eastern provinces. Sichuan, Yunnan, and Guizhou played an increasingly important role in virtual water exporting, and northwestern provinces had dominated the virtual scarce water exporting in the decade. At the national level, the increase of virtual water is mainly driven by the change of power generation mix and power transmission. At the provincial level, the increase of virtual water transmission in the largest virtual water exporter (Sichuan) is driven by the power generation mix and the power transmission, between 2005 and 2010, and 2010 and 2014, respectively. Considering the expanding of electricity transmission, the development of hydropower in the southwestern provinces and other renewable energies (solar and wind) in the northeastern provinces would overall mitigate the water scarcity in China.
A New Model for Environmental Assessment of the Comminution Process in the Chain of Biomass Energy Processing †
Authors: Kruszelnicka Weronika
Published: January 2020

Acquiring energy contained in biomass requires its prior appropriate preparation. These treatments require some energy inputs, which significantly affect the reduction of the energy and the environmental balance in the entire life cycle of the biomass energy processing chain. In connection with the above, the aim of this work is to develop a methodology for the environmental assessment of biomass grinding in the processing chain for energy purposes. The research problem is formulated as follows: Is it possible to provide an assessment model that takes into account the environmental inputs and benefits of the grinding process of biomass intended for further energy use (for example, combustion)? How do the control variables of the grinding machine affect the environmental process evaluation? In response to these research problems, an original, carbon dioxide emission assessment index of the biomass grinding process was developed. The model was verified by assessing the process of rice and maize grinding on a real object—a five-disc mill—with various speed settings of the grinding disc. It was found that the carbon dioxide emission assessment model developed provides the possibility of comparing grinding processes and identifying the grinding process with a better CO2 emission balance, where its values depend on the control parameters of the mill.
The Influence of pH on the Combustion Properties of Bio-Coal Following Hydrothermal Treatment of Swine Manure
Authors: Smith Aidan Mark , Ekpo Ugochinyere , Ross Andrew Barry
Published: January 2020

The application of excessive amounts of manure to soil prompted interest in using alternative approaches for treating slurry. One promising technology is hydrothermal carbonisation (HTC) which can recover nutrients such as phosphorus and nitrogen while simultaneously making a solid fuel. Processing manure under acidic conditions can facilitate nutrient recovery; however, very few studies considered the implications of operating at low pH on the combustion properties of the resulting bio-coal. In this work, swine manure was hydrothermally treated at temperatures ranging from 120 to 250 °C in either water alone or reagents including 0.1 M NaOH, 0.1 M H2SO4, and finally 0.1 M organic acid (CH3COOH and HCOOH). The influence of pH on the HTC process and the combustion properties of the resulting bio-coals was assessed. The results indicate that pH has a strong influence on ash chemistry, with decreasing pH resulting in an increased removal of ash. The reduction in mineral matter influences the volatile content of the bio-coal and its energy content. As the ash content in the final bio-coal reduces, the energy density increases. Treatment at 250 °C results in a more “coal like” bio-coal with fuel properties similar to that of lignite coal and a higher heating value (HHV) ranging between 21 and 23 MJ/kg depending on pH. Processing at low pH results in favourable ash chemistry in terms of slagging and fouling. Operating at low pH also appears to influence the level of dehydration during HTC. The level of dehydration increases with decreasing pH, although this effect is reduced at higher temperatures. At higher-temperature processing (250 °C), operating at lower pH increases the yield of bio-coal; however, at lower temperatures (below 200 °C), the reverse is true. The lower yields obtained below 200 °C in the presence of acid may be due to acid hydrolysis of carbohydrate in the manure, whereas, at the higher temperatures, it may be due to the acid promoting polymerisation.
Design and Analysis of a Novel Magnetic Coupler of an In-Wheel Wireless Power Transfer System for Electric Vehicles
Authors: Hwang Young Jin , Jang Jae Young
Published: January 2020

Electric vehicle (EVs), which use an electric motor, are expected to replace internal combustion engine vehicles. However, to date EVs are not highly attractive to consumers due to their unsatisfactory battery charging characteristics and high cost. In particular, the existing conductive charging method makes it more difficult to spread EVs due to the inconvenience of charging and the risk of electric shock. The wireless power transfer (WPT) system can eliminate all of the charging troubles of EVs. However, the WPT systems in existing EVs have large air gaps between the transmitter coil and the receiver coil, posing a hurdle that prevents success. The large air gap cause issues such as a loose coupling, low efficiency, and troublesome electromagnetic compatibility (EMC). An in-wheel WPT system can serve as a solution to address the issues arising due to the large air gap. In this paper, we propose a magnetic coupler structure of an in-wheel WPT system for EV applications. A design of two coils is introduced, in which the transmitter coil and receiver coil are designed based on a design method. Moreover, the pad structure according to the ferromagnetic core geometry is designed and discussed. The aim of this research is to find a suitable configuration of the magnetic coupler for an in-wheel WPT system. The values of the coupling coefficients according the magnetic coupler structure are determined. This paper is expected to provide a good reference for further research, including work on the manufacturing of a prototype.
Direct and Indirect Environmental Aspects of an Electric Bus Fleet Under Service
Authors: Varga Bogdan Ovidiu , Mariasiu Florin , Miclea Cristian Daniel , Szabo Ioan , Sirca Anamaria Andreea , Nicolae Vlad
Published: January 2020

The reduction of pollutant emissions in the field of transportation can be achieved by developing and implementing electric propulsion technologies across a wider range of transportation types. This solution is seen as the only one that can offer, in areas of urban agglomeration, a reduction of the emissions caused by the urban transport to zero, as well as an increase in the degree of the health of the citizens. This paper presents an analysis of the direct and indirect environmental aspects of a fleet of real electric buses under service in the city of Cluj-Napoca, Romania. The solution of using 41 electric buses to replace Euro-3 diesel buses (with high pollution levels) in the city’s transport system eliminates a local amount of 668.45 tons of CO2 and 6.41 tons of NOx—pollutant emissions directly associated with harmful effects on human health—annually.
Consumption versus Technology: Drivers of Global Carbon Emissions 2000–2014
Authors: Jiborn Magnus , Kulionis Viktoras , Kander Astrid
Published: January 2020

This study utilizes recently published environmental extensions to the World Input–Output Database (WIOD) to compare production-based, consumption-based and technology-adjusted carbon emissions for 44 countries and country groups for the period 2000 to 2014. Results show some significant shifts in global emission trends compared to similar studies of the period before 2009. For 20 European Union (EU) countries and the US, emissions decreased over the period regardless of measure, and the same was true for the EU. Since GDP grew in 18 of these countries, the results provide unambiguous evidence for absolute, albeit modest, decoupling of economic growth from carbon emissions. The large increase in global emissions that nevertheless occurred during the period was driven almost entirely by increasing consumption in China and developing countries.
Thermal Energy Storage for Grid Applications: Current Status and Emerging Trends
Authors: Enescu Diana , Chicco Gianfranco , Porumb Radu , Seritan George
Published: January 2020

Thermal energy systems (TES) contribute to the on-going process that leads to higher integration among different energy systems, with the aim of reaching a cleaner, more flexible and sustainable use of the energy resources. This paper reviews the current literature that refers to the development and exploitation of TES-based solutions in systems connected to the electrical grid. These solutions facilitate the energy system integration to get additional flexibility for energy management, enable better use of variable renewable energy sources (RES), and contribute to the modernisation of the energy system infrastructures, the enhancement of the grid operation practices that include energy shifting, and the provision of cost-effective grid services. This paper offers a complementary view with respect to other reviews that deal with energy storage technologies, materials for TES applications, TES for buildings, and contributions of electrical energy storage for grid applications. The main aspects addressed are the characteristics, parameters and models of the TES systems, the deployment of TES in systems with variable RES, microgrids, and multi-energy networks, and the emerging trends for TES applications.
Model-Independent Derivative Control Delay Compensation Methods for Power Systems
Authors: Liu Muyang , Dassios Ioannis , Tzounas Georgios , Milano Federico
Published: January 2020

The paper examines the effectiveness of utilizing the derivatives of time delayed, wide-area signals in mitigating their destabilizing impact on power system dynamic response. In particular, the paper discusses two derivative control-based delay compensation methods, namely proportional-derivative (PD) and predictor-based delay compensation. The two methods are compared in terms of their open-loop signal fidelity and their impact on the closed-loop system stability. The paper also provides a technique to carry out small-signal stability analysis with inclusion of derivative control based compensation, which leads to a Neutral Time-Delay System (NTDS). In addition, we provide a new theorem on the stability of the NTDS. Finally, nonlinear time domain simulations and eigenvalue analysis based on the IEEE 14-bus and New England 39-bus systems were carried out for the sake of comparison of the two delay compensation methods.