bluuebunny/crossref_metadata_2025 huggingface dataset:
Postural and Trunk Responses to Unexpected Perturbations Depend on the Velocity and Direction of Platform Motion
Authors: ZEMKOVÁ E. , KOVÁČIKOVÁ Z. , JELEŇ M. , NEUMANNOVÁ K. , JANURA M.
Published: February 2020

This study compares postural and trunk responses to translating platform perturbations of varied velocities and directions. A group of 18 young and physically active subjects were exposed to a set of postural perturbations at varied velocities (5, 10, 15, and 20 cm/s) and directions of platform movement (forward, backward, left-lateral, and right-lateral). The center of pressure (CoP) displacement measurement, in addition to the trunk motion (representing the center of mass (CoM) displacement), were both monitored. Results identified that the CoP displacement increased from slow to faster velocities of platform motion more widely in both anterior and posterior directions (50.4 % and 48.4 %) as compared to the CoM displacement (17.8 % and 14.9 %). However a greater increase in the peak CoM velocity (70.3 % and 69.6 %) and the peak CoM acceleration (60.5 % and 53.1 %) was observed. The values in the anterior and posterior direction only differed significantly at the highest velocity of platform motion (i.e. 20 cm/s). A similar tendency was observed in the medio-lateral direction, but there were no significant differences in any parameter in the left-lateral and right-lateral direction. The velocity of the platform motion highly correlated with peak velocity (r=0.92-0.97, P<0.01) and moderately with amplitude of trunk displacement (r=0.56-0.63, P<0.05). These findings indicate that the velocity of perturbation alters peak CoM velocity rather than the magnitude of CoM displacement. The effect of the direction of perturbations on the trunk response emerges only at a high velocity of platform motion, such that the peak CoM velocity and peak CoM acceleration are significantly greater in anterior than posterior direction.
Evaluación de la Hidrólisis enzimática de plumas de pollo para la obtención de Queratina
Authors: Viloria Sierra Lilibeth , Azabache Zarta María Paula , Agudelo Valencia Rafael Nikolay , Hernández Fernández Javier Adolfo
Published: February 2020

Esta investigación pretende dar un valor agregado a los desechos de plumas de la industria de cría y beneficio de aves obteniendo queratina por medio de hidrólisis enzimática. La hidrólisis se llevó a cabo con la enzima Blue G, un diseño experimental de tipo central compuesto, tomando como factores el pH (8 a 9), temperatura (20 °C a 30 °C) y dosis de enzima (0.03 g a 0.05 g), y como respuesta la concentración de proteína en el extracto empleando para ello el método de Bradford y electroforesis en gel SDS-PAGE para conocer la pureza. Los resultados se estudiaron por un análisis de varianza y por la metodología superficie de respuesta obteniendo a un pH de 8 y temperatura de 25°C una concentración máxima de 2,106 mg/ml que corresponde a un porcentaje de masa de 8,42 siendo el pH y la temperatura (°C) los factores significativos de la hidrólisis.
Reducción de transmisión para vehículo todo terreno con realidad aumentada e ingeniería asistida por computadora
Authors: Cuautle Gutiérrez Luis , Cordero Guridi José de Jesús
Published: February 2020

La transmisión en un automóvil es responsable de brindar la fuerza necesaria para superar las condiciones del recorrido. Esta investigación presenta la reducción dimensional de la caja de transmisión de un vehículo todo terreno de una universidad privada mexicana para mejorar su desempeño en una competencia nacional. Se empleó una metodología de diseño y desarrollo de producto utilizando una aplicación de realidad aumentada para validar la nueva geometría y disminuir el volumen actual de la caja, así como su posición correcta en el vehículo. Mediante el diseño asistido por computadora se garantizó que la carcasa podrá operar bajo condiciones adecuadas con un bajo nivel de vibraciones del sistema. Los resultados obtenidos muestran una reducción de 0.8 litros en volumen y un peso inferior en la transmisión en un 31%, además del desarrollo de una aplicación móvil para emular la posición en la estructura del vehículo.
Oxidative Damage to Various Root and Shoot Tissues of Durum and Soft Wheat Seedlings during Salinity
Authors: Kononenko Neonila , Baranova Ekaterina , Dilovarova Tatyana , Akanov Eduard , Fedoreyeva Larisa
Published: February 2020

The toxicity of high concentrations of sodium chloride creates significant difficulties in realizing the productivity potential of wheat. The development of effective test systems for the identification and selection of resistant genotypes is an urgent task given the global increase in soil salinity in agricultural land. To identify the characteristics of the plant’s reaction to the toxic effect of sodium chloride, wheat genotypes with different resistance to ionic toxicity (the Orenburgskaya 10 and Orenburgskaya 22 varieties) were used. In model experiments, we used fluorescence, light-optical and electron microscopy to characterize the structural and functional features of the cells of the roots of wheat seedlings, and cytological markers suitable for creating a test system for the early diagnosis of the sensitivity of wheat genotypes to sodium chloride were established. The response of the plants to the effects of sodium chloride was assessed by changes in biometric data, respiration rate, peculiarities in the accumulation of reactive oxygen species (ROS) and mitochondrial staining, and the quantitative assessment of coleoptile cell viability as putative sensitivity markers. In the sodium chloride-sensitive genotype (Orenburgskaya 10), toxic effects resulted in oxidative damage in the root cells, while in the resistant genotype (Orenburgskaya 22), oxidative damage to the cells was minimal. A high level of expression of mitochondrial superoxide dismutase (MnSOD) was found in the roots of the Orenburgskaya 22 variety. The identification and functional analysis of cytological and molecular markers provide the basis for further studies of the resistance of wheat to sodium chloride stress.
Comparisons of Chlorophyll Fluorescence and Physiological Characteristics of Wheat Seedlings Influenced by Iso-Osmotic Stresses from Polyethylene Glycol and Sodium Chloride
Authors: Lan Chiu-Yueh , Lin Kuan-Hung , Chen Chun-Liang , Huang Wen-Dar , Chen Chang-Chang
Published: February 2020

Wheat (Triticum aestivum) cultivar Taichung SEL.2 (TCS2) is a salt-tolerance variety, but the mechanism involved remains unclear. This study aims to distinguish between the non-ionic osmotic and salt-mediated physiological effects on TCS2. Osmotic agents polyethylene glycol (PEG) and sodium chloride (NaCl) were applied at three iso-osmotic levels, level 1 containing 24% (w/v) PEG and 200 mM NaCl, level 2 containing 26.5% (w/v) PEG and 250 mM NaCl), and level 3 containing 29% (w/v) PEG and 300 mM NaCl, respectively. According to the investigation of chlorophyll fluorescence in the better NaCl-treated seedlings, maximal quantum yield of photosystem II (PSII) (Fv/Fm) and significant higher effective quantum yield of PSII (ΦPSII) at level 3 were observed. Meanwhile, the non-photochemical quenching of PSII (NPQ) and the quantum yield of regulated energy dissipation of PSII [Y(NPQ)] were significantly higher in the NaCl-treated seedlings, and the quantum yield of non-regulated energy dissipation of PSII [Y(NO)] in the NaCl-treated seedlings was lower than the PEG-treated ones at level 2 and level 3. Furthermore, the less extensive degradation of photosynthetic pigments, the better ascorbate peroxidase (APX) activity and the less accumulation of malondialdehyde (MDA) were also observed in NaCl-treated seedlings. In the morphological traits, shoot elongation in NaCl-treated seedlings was also preserved. These results suggest that TCS2 is more resistant to NaCl-induced osmotic stress than to the PEG-induced stress. This study contributes to plant breeder interest in drought- and/or salt-tolerant wheat varieties.
Declining Prevalence of Methicillin-Resistant Staphylococcus aureus Septic Arthritis and Osteomyelitis in Children: Implications for Treatment
Authors: Weiss Lindsay , Lansell Amanda , Figueroa Janet , Suchdev Parminder S. , Kirpalani Anjali
Published: February 2020

This study sought to assess clinical characteristics and differences in outcomes between children with Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-sensitive Staphylococcus aureus (MSSA) osteomyelitis or septic arthritis and whether initial antibiotic regimen affects patient outcomes. We analyzed records of children ages 15 days to 18 years admitted between 2009 and 2016 to two tertiary children’s hospitals who were diagnosed with an osteoarticular infection and had a microorganism identified. A total of 584 patients met inclusion criteria, of which 365 (62.5%) had a microbiological diagnosis. MSSA was the most common pathogen identified (45.5%), followed by MRSA (31.2%). Compared to MSSA, patients with MRSA had a higher initial C-reactive protein and longer hospitalization. Patients whose initial antibiotic regimens included vancomycin had a longer hospitalization than those initiated on clindamycin without vancomycin, even after removing sicker patients admitted to the pediatric intensive care unit. While MRSA was associated with increased severity of osteoarticular infections compared to MSSA, the incidence of MRSA has been declining at our institution. Patients with longer lengths of stay were more likely to be on vancomycin. Clindamycin should be considered in the initial antibiotic regimen for osteomyelitis and septic arthritis with ongoing surveillance of local microbiology and outcomes.
Evaluation of Regional Air Quality Models over Sydney, Australia: Part 2, Comparison of PM2.5 and Ozone
Authors: Guérette Elise-Andrée , Chang Lisa Tzu-Chi , Cope Martin E. , Duc Hiep N. , Emmerson Kathryn M. , Monk Khalia , Rayner Peter J. , Scorgie Yvonne , Silver Jeremy D. , Simmons Jack , Trieu Toan , Utembe Steven R. , Zhang Yang , Paton-Walsh Clare
Published: February 2020

Accurate air quality modelling is an essential tool, both for strategic assessment (regulation development for emission controls) and for short-term forecasting (enabling warnings to be issued to protect vulnerable members of society when the pollution levels are predicted to be high). Model intercomparison studies are a valuable support to this work, being useful for identifying any issues with air quality models, and benchmarking their performance against international standards, thereby increasing confidence in their predictions. This paper presents the results of a comparison study of six chemical transport models which have been used to simulate short-term hourly to 24 hourly concentrations of fine particulate matter less than and equal to 2.5 µm in diameter (PM2.5) and ozone (O3) for Sydney, Australia. Model performance was evaluated by comparison to air quality measurements made at 16 locations for O3 and 5 locations for PM2.5, during three time periods that coincided with major atmospheric composition measurement campaigns in the region. These major campaigns included daytime measurements of PM2.5 composition, and so model performance for particulate sulfate (SO42−), nitrate (NO3−), ammonium (NH4+) and elemental carbon (EC) was evaluated at one site per modelling period. Domain-wide performance of the models for hourly O3 was good, with models meeting benchmark criteria and reproducing the observed O3 production regime (based on the O3/NOx indicator) at 80% or more of the sites. Nevertheless, model performance was worse at high (and low) O3 percentiles. Domain-wide model performance for 24 h average PM2.5 was more variable, with a general tendency for the models to under-predict PM2.5 concentrations during the summer and over-predict PM2.5 concentrations in the autumn. The modelling intercomparison exercise has led to improvements in the implementation of these models for Sydney and has increased confidence in their skill at reproducing observed atmospheric composition.
Self-assembly Synthesis of Molecularly Imprinted Polymers for the Ultrasensitive Electrochemical Determination of Testosterone
Authors: Liu Kai-Hsi , O’Hare Danny , Thomas James L. , Guo Han-Zhang , Yang Chien-Hsin , Lee Mei-Hwa
Published: February 2020

Molecularly imprinted polymers (MIPs) can often bind target molecules with high selectivity and specificity. When used as MIPs, conductive polymers may have unique binding capabilities; they often contain aromatic rings and functional groups, which can undergo π-π and hydrogen bonding interactions with similarly structured target (or template) molecules. In this work, an electrochemical method was used to optimize the synthetic self-assembly of poly(aniline-co-metanilic acid) and testosterone, forming testosterone-imprinted electronically conductive polymers (TIECPs) on sensing electrodes. The linear sensing range for testosterone was from 0.1 to 100 pg/mL, and the limit of detection was as low as ~pM. Random urine samples were collected and diluted 1000-fold to measure testosterone concentration using the above TIECP sensors; results were compared with a commercial ARCHITECT ci 8200 system. The testosterone concentrations in the tested samples were in the range of 0.33 ± 0.09 to 9.13 ± 1.33 ng/mL. The mean accuracy of the TIECP-coated sensors was 90.3 ± 7.0%.
Preclinical Intracranial Aneurysm Models: A Systematic Review
Authors: Strange Fabio , Grüter Basil E , Fandino Javier , Marbacher Serge
Published: February 2020

Intracranial aneurysms (IA) are characterized by weakened cerebral vessel walls that may lead to rupture and subarachnoid hemorrhage. The mechanisms behind their formation and progression are yet unclear and warrant preclinical studies. This systematic review aims to provide a comprehensive, systematic overview of available animal models for the study of IA pathobiology. We conducted a systematic literature search using the PubMed database to identify preclinical studies employing IA animal models. Suitable articles were selected based on predefined eligibility criteria following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included studies were reviewed and categorized according to the experimental animal and aneurysm model. Of 4266 returned results, 3930 articles were excluded based on the title and/or abstract and further articles after screening the full text, leaving 123 studies for detailed analysis. A total of 20 different models were found in rats (nine), mice (five), rabbits (four), and dogs (two). Rat models constituted the most frequently employed intracranial experimental aneurysm model (79 studies), followed by mice (31 studies), rabbits (12 studies), and two studies in dogs. The most common techniques to induce cerebral aneurysms were surgical ligation of the common carotid artery with subsequent induction of hypertension by ligation of the renal arteries, followed by elastase-induced creation of IAs in combination with corticosterone- or angiotensin-induced hypertension. This review provides a comprehensive summary of the multitude of available IA models to study various aspects of aneurysm formation, growth, and rupture. It will serve as a useful reference for researchers by facilitating the selection of the most appropriate model and technique to answer their scientific question.
High Refractive Index Inverse Vulcanized Polymers for Organic Photonic Crystals
Authors: Tavella Christian , Lova Paola , Marsotto Martina , Luciano Giorgio , Patrini Maddalena , Stagnaro Paola , Comoretto Davide
Published: February 2020

Photonic technologies are nowadays dominated by highly performing inorganic structures that are commonly fabricated via lithography or epitaxial growths. Unfortunately, the fabrication of these systems is costly, time consuming, and does not allow for the growth of large photonic structures. All-polymer photonic crystals could overcome this limitation thanks to easy solubility and melt processing. On the other hand, macromolecules often do not offer a dielectric contrast large enough to approach the performances of their inorganic counterparts. In this work, we demonstrate a new approach to achieve high dielectric contrast distributed Bragg reflectors with a photonic band gap that is tunable in a very broad spectral region. A highly transparent medium was developed through a blend of a commercial polymer with a high refractive index inverse vulcanized polymer that is rich in sulfur, where the large polarizability of the S–S bond provides refractive index values that are unconceivable with common non-conjugated polymers. This approach paves the way to the recycling of sulfur byproducts for new high added-value nano-structures.
Readiness, Roles, and Responsibilities of Stakeholders for Sustainable Mobile Learning Adoption in Higher Education
Authors: Okai-Ugbaje Safiya , Ardzejewska Kathie , Imran Ahmed
Published: February 2020

The extant literature on mobile learning in higher education has mainly focused on students and academics. This study conducted in a Nigerian university considered a wider group of stakeholders (students, academics, IT personnel, and administrative leaders) in its investigation of stakeholders’ awareness, willingness, and readiness for mobile learning adoption, using a mixed methods approach. The findings revealed that while the awareness of mobile learning amongst students was low, they were keen on adoption. Academics were more tentative, for while they were willing, it was clear that a shift in their teaching philosophy and pedagogy would be required for mobile learning to work effectively. For those in IT and administrative leadership roles, their perceptions were more resource-focused. While this study only considered the views of internal stakeholders, it also uncovered the need for the involvement of external stakeholders. Building on these findings, a strategy table which outlines the roles and responsibilities of each stakeholder group was created. The table provides a blueprint which otherwise has been missing, to guide sustainable mobile learning adoption and implementation not only in higher education in developing countries, but which may have more global appeal.
Conflicting Demands of Chemistry and Inclusive Teaching—A Video-Based Case Study
Authors: Abels Simone , Koliander Brigitte , Plotz Thomas
Published: February 2020

Almost every country in the world is obligated to implement education policies to enable an inclusive school system. However, implementing techniques to be inclusive in schools is a major challenge to teachers, especially to those teaching a subject at secondary level and higher. Most of the literature concerning inclusive science education was published in recent years, and is more normative than empirical. Teachers struggle to transfer these normative demands to their accustomed way of teaching science. In this study, we analyze conflicts a teacher experiences when teaching a so-called ‘hard science’ like chemistry at an inclusive school. On the one hand, inclusive science education should facilitate participation in science specific learning processes for all learners. This broad perspective on inclusion demands that everyone can take part in everyday classroom life. On the other hand, chemistry strives for the understanding of abstract concepts, theories and models, which forms a barrier to learning chemistry for many people. This paper presents an explorative case study focusing on these conflicting demands. To reconstruct the inconsistencies, we analyzed a videotaped teacher–student discourse on atoms. Using the documentary method, a qualitative approach developed by the sociologist Ralf (Bohnsack et al., 2010). distinguishing between explicit and implicit knowledge, it was possible to reveal the orientational frameworks guiding the teacher’s actions. On the surface level, traditional scientific educational approaches structure the discourse. Reconstruction of the discourse is deep, as evidence was found for a participation-oriented framework as well as for the challenges the conflicting demands of chemistry and inclusive teaching put on teaching. We implicate that future professional development courses must not only concentrate on combining chemistry with inclusive pedagogies, i.e., how to teach, but also on the reflection of implicit beliefs concerning inclusive chemistry teaching.
Fluency Interventions for Elementary Students with Reading Difficulties: A Synthesis of Research from 2000–2019
Authors: Hudson Alida , Koh Poh Wee , Moore Karol A. , Binks-Cantrell Emily
Published: February 2020

Oral reading fluency (ORF) deficits are a hallmark of reading difficulties. The impact of fluency struggles extends beyond word-level difficulties to include deficits in reading comprehension. Sixteen empirical studies conducted in 2000–2019 that examined ORF interventions among elementary students identified as having reading difficulties were reviewed to identify the characteristics (e.g., instructional variables, group size, type of interventionist) of effective ORF interventions and their impact on English oral reading fluency and reading comprehension outcomes. The systematic review revealed that interventions reported centered around repeated reading procedures (86.5%). Across the 16 studies, outcomes for oral reading fluency varied widely and most focused on speed and rate aspects rather than prosody. Effect sizes for rate and accuracy measures ranged from negligible to large (i.e., 0.01 to 1.18) and three studies found large effects for prosody outcomes. Effect sizes for reading comprehension ranged between non-significant and large significant effects. Findings support the use of repeated reading of text to build up ORF of students with reading difficulties. Interventions that were found to be most effective were those that were conducted one-on-one with a trained model of fluent word reading and accuracy. Findings also point to three gaps in our understanding: (1) the efficacy of interventions other than repeated reading, (2) effects of ORF interventions on prosody outcomes, and (3) sustainability of outcomes.
A Low Cross-Polarization Configuration Method for Phased Array Radar Antenna
Authors: Li Yongzhen , Wang Zhanling , Pang Chen , Wang Xuesong
Published: February 2020

The cross-polarization isolation (CPI) is a key parameter to assess the dual-polarization antenna because the cross-polarization closely affects the antenna application. A polarization state configuration (PSC) approach is proposed to configure the polarization state of the polarimetric phased array radar antenna. Unlike the traditional fixed polarization states such as the linear polarization (LP) and the circular polarization (CP), the PSC method modulates the polarization state of the radiated wave continuously. In addition, the optimal excitation magnitude and phase of the dual-polarization element is calculated, thereby maximizing the CPI. Most of the configured polarization state is the elliptical polarization (EP), and a lower cross-polarization level and higher CPI could be obtained. This method could expand the acceptable angle range when compared with the LP and CP waves. Numerical simulations and comparisons are conducted to manifest the validity of the proposed method.
A Study on the Analytic Power Estimation of the Electromagnetic Resonant Energy Harvester for the High-Speed Train
Authors: Kim Jaehoon
Published: February 2020

This study is intended to identify the applicability of energy harvesting technologies that are regarded as new electrical power sources for the sensors on high-speed trains. The analytic estimation research is conducted on the amount of electric energy harvested from the high-speed trains, operating at a maximum speed of over 400km/h to verify the applicability of the energy harvesting technology converting the vibration energy of axle and bogie into electric power. Based on the data of the vibration acceleration on the axles and bogies, which were measured by using a 500 Hz analog filter, an analytic estimation on the amount of power harvested by an electromagnetic resonant harvester is conducted through the analysis of the main frequency. The power of the electromagnetic resonant harvester is based on a theoretical model of the mass-spring-damper system, and the harvested power from the axles and bogies in the vertical direction is analytically estimated in this study. The analytic calculations typically give the target value for the final performance of the electromagnetic resonant energy harvester. The targets of the analytic estimations are given to provide the basis for the detailed design and to give a basis for defining the basic design parameters of the electromagnetic resonant energy harvester.
A New Flux Linkage Estimation with Drift Cancellation Technique for Switched Reluctance Machines
Authors: de Paula Marcelo Vinícius , dos Santos Barros Tárcio André
Published: February 2020

Assessing the flux linkage is an important feature for electric machines, including switched reluctance machines. However, sensor calibration errors and noise impose a problem known as drift, which is caused by the integration process used to estimate the flux linkage. This paper proposes a flux linkage estimation with a drift cancellation technique. The technique accounts for the switched reluctance machine’s working and driving principles. Simulation and experimental results are used to validate the proposed method. Additionally, a goodness-of-fit analysis is performed to support the outcomes. A R 2 factor of 0.9823 is found between the experimentally and simulation-estimated flux linkage. The results indicate that the method works properly and may be further used in control techniques and iron losses estimation.
Classification of Transition Human Activities in IoT Environments via Memory-Based Neural Networks
Authors: Acampora Giovanni , Minopoli Gianluca , Musella Francesco , Staffa Mariacarla
Published: February 2020

Human activity recognition is a crucial task in several modern applications based on the Internet of Things (IoT) paradigm, from the design of intelligent video surveillance systems to the development of elderly robot assistants. Recently, machine learning algorithms have been strongly investigated to improve the recognition task of human activities. Though, in spite of these research activities, there are not so many studies focusing on the efficient recognition of complex human activities, namely transitional activities, and there is no research aimed at evaluating the effects of noise in data used to train algorithms. In this paper, we bridge this gap by introducing an innovative activity recognition system based on a neural classifier endowed with memory, able to optimize the performance of the classification of both transitional and non-transitional human activities. The system recognizes human activities from unobtrusive IoT devices (such as the accelerometer and gyroscope) integrated in commonly used smartphones. The main peculiarity provided by the proposed system is related to the exploitation of a neural network extended with short-term memory information about the previous activities’ features. The experimental study proves the reliability of the proposed system in terms of accuracy with respect to state-of-the-art classifiers and the robustness of the proposed framework with respect to noise in data.
Experimental Study on the Mechanical Properties of Biomass Briquettes from a Mixture of Rice Husk and Pine Sawdust
Authors: Niño Andrés , Arzola Nelson , Araque Oscar
Published: February 2020

In search of guaranteeing global energy requirements, waste from different agricultural, forestry and industrial sources is presented as a renewable and sustainable energy source. The manufacture of solid fuels from biomass based on the densification of this to improve its mechanical and energy properties is one of the mechanisms of viable energy production from the technical-economic point of view. The biomass mixture is one of the topics currently researched, in which various factors can affect the final behavior of the briquettes. In this research the influence on the mechanical properties of briquettes obtained from the mixture between two biomasses is studied: rice husk and pine sawdust. A mixed factorial experimental factorial design is used, in which the process temperature, the proportion of the rice husk biomass over the total mass, and the compaction time are defined as experimental factors. Experimental statistical models are obtained that partially explain the behavior of several responses that characterize the mechanical properties of the briquettes based on the selected independent parameters. It was found that the mechanical durability of the briquettes is higher than 97.5%, meets the existing standards, like German Institute for Standardization (DIN) 51731, Theological Institute Batista Ebenézer (ITEBE) SS187120 or International Organization for Standardization (ISO) 17225-2, for a compaction temperature of 110 °C and a proportion of rice husk that does not exceed 60% of the total biomass mixture in the briquette. The compaction time was also statistically significant to achieve a briquettes density and an appropriate elasticity modulus in the briquettes. The results of this research are of interest and can serve as a starting point for the design of the industrial process of densification of these two mixed biomasses.
Effects of Elevated CO2 Concentration and Nitrogen Addition on Soil Respiration in a Cd-Contaminated Experimental Forest Microcosm
Authors: Yao Bo , Hu Qiwu , Zhang Guihua , Yi Yafeng , Xiao Meijuan , Wen Dazhi
Published: February 2020

Forests near rapidly industrialized and urbanized regions are often exposed to elevated CO2, increased N deposition, and heavy metal pollution. To date, the effects of elevated CO2 and/or increased N deposition on soil respiration (Rs) under heavy metal contamination are unclear. In this study, we firstly investigated Rs in Cd-contaminated model forests with CO2 enrichment and N addition in subtropical China. Results showed that Rs in all treatments exhibited similar clear seasonal patterns, with soil temperature being a dominant control. Cadmium addition significantly decreased cumulative soil CO2 efflux by 19% compared to the control. The inhibition of Rs caused by Cd addition was increased by N addition (decreased by 34%) was partially offset by elevated CO2 (decreased by 15%), and was not significantly altered by the combined N addition and rising CO2. Soil pH, microbial biomass carbon, carbon-degrading hydrolytic enzymes, and fine root biomass were also significantly altered by the treatments. A structural equation model revealed that the responses of Rs to Cd stress, elevated CO2, and N addition were mainly mediated by soil carbon-degrading hydrolytic enzymes and fine root biomass. Overall, our findings indicate that N deposition may exacerbate the negative effect of Cd on Rs in Cd-contaminated forests and benefit soil carbon sequestration in the future at increasing atmospheric CO2 levels.
Soil Microbial Biomass and Community Composition Relates to Poplar Genotypes and Environmental Conditions
Authors: Karliński Leszek , Ravnskov Sabine , Rudawska Maria
Published: February 2020

Poplars, known for their diversity, are trees that can develop symbiotic relationships with several groups of microorganisms. The genetic diversity of poplars and different abiotic factors influence the properties of the soil and may shape microbial communities. Our study aimed to analyse the impact of poplar genotype on the biomass and community composition of the microbiome of four poplar genotypes grown under different soil conditions and soil depths. Of the three study sites, established in the mid-1990s, one was near a copper smelter, whereas the two others were situated in unpolluted regions, but were differentiated according to the physicochemical traits of the soil. The whole-cell fatty acid analysis was used to determine the biomass and proportions of gram-positive, gram-negative and actinobacteria, arbuscular fungi (AMF), other soil fungi, and protozoa in the whole microbial community in the soil. The results showed that the biomass of microorganisms and their contributions to the community of organisms in the soil close to poplar roots were determined by both factors: the tree-host genotype and the soil environment. However, each group of microorganisms was influenced by these factors to a different degree. In general, the site effect played the main role in shaping the microbial biomass (excluding actinobacteria), whereas tree genotype determined the proportions of the fungal and bacterial groups in the microbial communities and the proportion of AMF in the fungal community. Bacterial biomass was influenced more by site factors, whereas fungal biomass more by tree genotype. With increasing soil depth, a decrease in the biomass of all microorganisms was observed; however, the proportions of the different microorganisms within the soil profile were the result of interactions between the host genotype and soil conditions. Despite the predominant impact of soil conditions, our results showed the important role of poplar genotype in shaping microorganism communities in the soil.
Responses of Korean Pine to Proactive Managements under Climate Change
Authors: Liu Kai , He Hongshi , Xu Wenru , Du Haibo , Zong Shengwei , Huang Chao , Wu Miaomiao , Tan Xinyuan , Cong Yu
Published: February 2020

Proactive managements, such as the resistant and the adaptive treatments, have been proposed to cope with the uncertainties of future climates. However, quantifying the uncertainties of forest response to proactive managements is challenging. Korean pine is an ecologically and economically important tree species in the temperate forests of Northeast China. Its dominance has evidently decreased due to excessive harvesting in the past decades. Understanding the responses of Korean pine to proactive managements under the future climates is important. In this study, we evaluated the range of responses of Korean pine to proactive managements under Representative Concentration Pathway (RCP) 8.5 scenarios from four General Circulation Models (GCMs). We coupled an ecosystem process-based model, LINKAGES, and a forest landscape model, LANDIS PRO, to simulate scenarios of management and climate change combinations. Our results showed that the resistant and the adaptive treatment scenarios increased Korean pine importance (by 14.2% and 42.9% in importance value), dominance (biomass increased by 9.2% and 25.5%), and regeneration (abundance <10 years old increased by 286.6% and 841.2%) throughout the simulation. Results indicated that proactive managements promoted the adaptability of Korean pine to climate change. Our results showed that the variations of Korean pine response to climate change increased (ranging from 0% to 5.8% for importance value, 0% to 4.3% for biomass, and 0% to 85.4% for abundance) throughout the simulation across management scenarios. Our result showed that regeneration dictated the uncertainties of Korean pine response to climate change with a lag effect. We found that the effects of proactive managements were site-specific, which was probably influenced by the competition between Korean pine and the rare and protected broadleaf tree species. We also found that the adaptive treatment was more likely to prompt Korean pine to migrate into its suitable habitats and promoted it to better cope with climate change. Thus, the adaptive treatment is proposed for Korean pine restoration under future climates.
First Age-Estimation Model for Dracaena ombet and Dracaena draco subsp. caboverdeana
Authors: Lengálová Klára , Kalivodová Hana , Habrová Hana , Maděra Petr , Tesfamariam Berihu , Šenfeldr Martin
Published: February 2020

Research Highlights: The first model for crown age estimation was developed for Dracaena ombet Heuglin ex Kotschy and Peyr. and D. draco subsp. caboverdeana Marrero Rodr. and R. Almeida. Background and Objectives: Dracaena species are monocotyledon trees without annual tree rings. Most arborescent dragon tree species are endangered; thus, it is important to determine the age structures of these populations for proper conservation management strategies, and for modelling of population trends. For these reasons, it is necessary to develop a methodology of crown age estimation. Materials and Methods: Field data were collected in the Desa’a Forest (Ethiopia) and in Santo Antão (Cape Verde Islands). Trees within each age class, as expressed by the number of branch orders, were measured. The diameter at breast height, tree height, stem height, number of branch orders, number of all leaf rosettes and number of flowering leaf rosettes within the crown were recorded for each sampled tree. The flowering probabilities were counted as input data for the model used. Results: The duration of the interval between flowering events was 5.23 years for D. ombet and 4.94 years for D. draco subsp. caboverdeana. The crown of the oldest tree of D. ombet with 18 branch orders was estimated to be 94.2 years old, and the crown of the oldest tree of D. draco subsp. caboverdeana with 22 branch orders was estimated to be 108.6 years old.
Complete Chloroplast Genome of Michelia shiluensis and a Comparative Analysis with Four Magnoliaceae Species
Authors: Deng Yanwen , Luo Yiyang , He Yu , Qin Xinsheng , Li Chonggao , Deng Xiaomei
Published: February 2020

Michelia shiluensis is a rare and endangered magnolia species found in South China. This species produces beautiful flowers and is thus widely used in landscape gardening. Additionally, its timber is also used for furniture production. As a result of low rates of natural reproduction and increasing levels of human impact, wild M. shiluensis populations have become fragmented. This species is now classified as endangered by the IUCN. In the present study, we characterized the complete chloroplast genome of M. shiluensis and found it to be 160,075 bp in length with two inverted repeat regions (26,587 bp each), a large single-copy region (88,105 bp), and a small copy region (18,796 bp). The genome contained 131 genes, including 86 protein-coding genes, 37 tRNAs, and 8 rRNAs. The guanine-cytosine content represented 39.26% of the overall genome. Comparative analysis revealed high similarity between the M. shiluensis chloroplast genome and those of four closely related species: Michelia odora, Magnolia laevifolia, Magnolia insignis, and Magnolia cathcartii. Phylogenetic analysis shows that M. shiluensis is most closely related to M. odora. The genomic information presented in this study is valuable for further classification, phylogenetic studies, and to support ongoing conservation efforts.
Slope Position Rather Than Thinning Intensity Affects Arbuscular Mycorrhizal Fungi (AMF) Community in Chinese Fir Plantations
Authors: Xu Xuelei , Wang Xinjie , Cleary Michelle , Wang Ping , Lu Nini , Sun Yujun , Rönnberg Jonas
Published: February 2020

Background and Objectives: Arbuscular mycorrhizal fungi (AMF) play a crucial role in individual plant capability and whole ecosystem sustainability. Chinese fir, one of the most widely planted tree species in southern China, forms associations with AMF. However, it is still unclear what impacts thinning management applied to Chinese fir plantations has on the structure and diversity of soil AMF communities. This research attempts to bridge this knowledge gap. Materials and Methods: A thinning experiment was designed on different slope positions in Chinese fir plantations to examine the impacts of slope position and thinning intensity on colonization, diversity, and community composition of AMF. Results: Our research showed that the altitudinal slope position had significant effects on colonization, diversity, and community composition of AMF in Chinese fir plantations. In addition, the interaction between slope position and thinning intensity had significant effects on AMF diversity. Colonization by AMF on the lower slope position was significantly higher than on the upper slope position, while AMF diversity on the upper slope position was higher than on the middle and lower slope positions. Glomus was the most abundant genus in all slope positions, especially on the middle and lower slope positions. The relative abundance of Diversispora was significantly different among slope positions with absolute dominance on the upper slope position. Scutellospora was uniquely found on the upper slope position. Furthermore, soil Mg and Mn contents and soil temperature positively affected AMF community composition at the operational taxonomic unit (OTU) level. Conclusions: These findings suggested that slope position should be considered in the management of Chinese fir plantations. Furthermore, both chemical fertilization and AMF augmentation should be undertaken on upper hill slope positions as part of sustainable management practices for Chinese fir plantations.
N-of-1 Trials: Evidence-Based Clinical Care or Medical Research that Requires IRB Approval? A Practical Flowchart Based on an Ethical Framework
Authors: Stunnenberg Bas C. , Deinum Jaap , Nijenhuis Tom , Huysmans Frans , van der Wilt Gert Jan , van Engelen Baziel G.M. , van Agt Frans
Published: February 2020

N-of-1 trials can provide high-class evidence on drug treatment effectiveness at the individual patient level and have been given renewed interest over the past decade due to improvements of the initial single patient design. Despite these recent developments, there is still no consensus under what circumstances N-of-1 trials should be considered as part of evidence-based clinical care and when they represent medical research with need for institutional review board (IRB) approval. This lack of consensus forms an obstacle for a more widespread implementation of N-of-1 trials. Based upon the existing literature, we as a group of researchers involved in N-of-1 trials and members of the IRB of a tertiary academic referral center, designed a practical flowchart based on an ethical framework to help make this distinction. The ethical framework together with a practical flowchart are presented in this communication.
Safe-Haven Assets, Financial Crises, and Macroeconomic Variables: Evidence from the Last Two Decades (2000–2018)
Authors: Tronzano Marco
Published: February 2020

This paper focuses on three “safe haven” assets (gold, oil, and the Swiss Franc) and examines the impact of recent financial crises and some macroeconomic variables on their return co-movements during the last two decades. All financial crises produced significant increases in conditional correlations between these asset returns, thus revealing consistent portfolio shifts from more traditional towards safer financial instruments during turbulent periods. The world equity risk premium stands out as the most relevant macroeconomic variable affecting return co-movements, while economic policy uncertainty indicators also exerted significant effects. Overall, this evidence points out that gold, oil, and the Swiss currency played an important role in global investors’ portfolio allocation choices, and that these assets preserved their essential “safe haven” properties during the period examined.
The FPIC Principle Meets Land Struggles in Cambodia, Indonesia and Papua New Guinea
Authors: Filer Colin , Mahanty Sango , Potter Lesley
Published: February 2020

Social and environmental safeguards are now commonplace in policies and procedures that apply to certain kinds of foreign investment in developing countries. Prominent amongst these is the principle of free, prior and informed consent (FPIC), which is commonly tied to policies and procedures relating to investments that have an impact on ‘indigenous peoples’. This paper treats international safeguards as a possible manifestation of what Karl Polanyi called the ‘double movement’ in the operation of a capitalist market economy. Our concern here is with the way that the FPIC principle has been applied in struggles over the alienation of land and associated natural resources claimed by indigenous peoples or customary landowners in three developing countries—Cambodia, Indonesia and Papua New Guinea. Case studies of recent land struggles in these countries are used to illustrate the existence of a spectrum in which the application of the FPIC principle may contribute more or less to the defence of customary rights. On one hand, it may be little more than a kind of ‘performance’ that simply adds some extra value to a newly created commodity. On the other hand, it may sometimes enable local or indigenous communities and their allies in ‘civil society’ to mount an effective defence of their rights in opposition to the processes of alienation or commodification. The paper finds that all three countries have political regimes and national policy frameworks that are themselves resistant to the imposition of social and environmental safeguards by foreign investors or international financial institutions. However, they differ widely in the extent to which they make institutional space for the FPIC principle to become the site of a genuine double movement of the kind that Polanyi envisaged.
Positive Solutions for a Class of p-Laplacian Hadamard Fractional-Order Three-Point Boundary Value Problems
Authors: Xu Jiafa , Jiang Jiqiang , O’Regan Donal
Published: February 2020

In this paper, using the Avery–Henderson fixed point theorem and the monotone iterative technique, we investigate the existence of positive solutions for a class of p-Laplacian Hadamard fractional-order three-point boundary value problems.
Virological and Clinical Outcome of DAA Containing Regimens in a Cohort of Patients in Calabria Region (Southern Italy)
Authors: Scaglione Vincenzo , Mazzitelli Maria , Costa Chiara , Pisani Vincenzo , Greco Giuseppe , Serapide Francesca , Lionello Rosaria , La Gamba Valentina , Marascio Nadia , Trecarichi Enrico Maria , Torti Carlo
Published: February 2020

Background and objectives: In Italy, Hepatitis C Virus (HCV) infections are most prevalent in people older than 50 years of age, who often experience multi-morbidities, take co-medications, and have a long history of liver disease. These characteristics could potentially affect tolerability of HCV treatments and adherence in this subgroup. After achievement of sustained virological response (SVR), retention into care is very important both to detect the onset of possible complications and prevent further infections. In this study, SVR rates and retention into care of patients treated with directly acting antivirals (DAAs) of a single-center cohort in Southern Italy were evaluated. Materials and Methods: Patients treated with directly acting antivirals from 2014 to 2018 were included. Patients were stratified by age (i.e., <65 vs. ≥65 years) and by cirrhosis presence (i.e., liver stiffness >14.6 KPa or clinical/ultrasound cirrhosis vs. absence of these criteria). Primary outcome was availability of SVR at Weeks 12–24 after the end of treatment. Inter- and intra-group comparisons were performed along the follow-up for significant laboratory parameters. Results: In total, 212 patients were treated; 184 (87%) obtained SVR after the first treatment course and 4 patients after retreatment. Twenty-two (10.4%) patients were lost to follow-up before assessment of SVR, and two patients died before the end of treatment for liver decompensation. Considering only the first treatment episode, per protocol analysis (i.e., excluding patients lost to follow-up) showed the following rates of SVR: 97% (overall), 97% (older age group), 96% (age group <65 years), 94% (cirrhotics), and 100% (non-cirrhotics). By contrast, at the intention to treat analysis (i.e., patients lost were computed as failures), SVR percentages were significantly lower for patients <65 years of age (80%) and for non-cirrhotics (85%). Conclusions: High rates of SVR were obtained. However, younger patients and those without cirrhosis displayed an apparent high risk of being lost to follow-up. This may have important implications: since those who are lost may transmit HCV in case SVR is not achieved, these subpopulations should receive appropriate counselling during treatment.