bluuebunny/crossref_metadata_2025 huggingface dataset:
A Semantic Segmentation Method for Dam Leakage Detection Based on FCN
Authors: Zhang Jun , Yan Zhaohui , Ma Xinlong , Cai Xingguo
Published: November 2020

Leakage is an important factor affecting the safety of the dam. In the past, manual inspection is a significant way to monitor leakage risk. However, it is time-consuming, inefficient and difficult to quantitative evaluate such as the leakage area. A semantic segmentation method based on the fully convolutional network is proposed to replace the manual inspection for the dam leakage automatic detection. Thirty-eight high-resolution images of dam leakage are collected. FCN-8s and VGG16 backbone are adopted. The results indicated that the FCN-8s achieves the mIoU to 0.59 on the test set, which proves to be an efficient way to detect the dam leakage.
Calculation Method of Marine Ship Fuel Consumption
Authors: Li Jing , Jia Yuanming
Published: November 2020

Based on the current situation of fuel consumption management and technical measures of marine transportation ships in domestic shipping enterprises, this paper determined the calculation model of fuel consumption of marine transportation ships, and provided technical support for shipping enterprises to formulate energy consumption assessment index of single ship and realize fine management over energy consumption. It is verified by an example that the error of the calculation model is small.
Research on Highway Slope Monitoring Data Prediction Based on Long Short-term Memory Network
Authors: Zhang Jianbo , Peng Ting , Mo Linhai , Hu Xu , Wang Xiaoling
Published: November 2020

This paper first analyzes the basic structure and operation principle of Long Short-Term Memory Network (LSTM), and combines the characteristics of road slope monitoring data to determine the data form of the input layer and the type of activation function. Then, combined with the slope displacement monitoring data, a slope monitoring data prediction model based on LSTM is constructed, and the main structural parameters of the LSTM are optimized to predict the slope monitoring data. Finally, the data prediction results are analyzed, and the reliability of the prediction results is verified by analyzing the influence of the number of monitoring data samples on the prediction results.
Research on Certification Method of Greenhouse Gas Emission Reduction in Dry Bulk Cargo Terminal Horizontal Transportation Optimization Project
Authors: Li Jing , Zhou Yiying
Published: November 2020

In the process of dry bulk cargo terminal horizontal transportation, a large amount of greenhouse gas and pollutant emissions will be produced if the equipment which can consume liquid fossil fuel is used. This paper quantifies the calculation method of greenhouse gas emission reduction in dry bulk cargo terminal horizontal transportation process optimization project by comparing the research before and after the dry bulk cargo terminal horizontal transportation process optimization project, and provides technical support for such port projects to participate in carbon emission trading.
Numerical Study on Karst Treatment Technology of Wuhan Metro Line 6
Authors: Xu Hai-Qing , Xiao Cheng-Jing , Liu Wen-Li , Zuo Yong-Zhe , Wei Chao-Qun
Published: November 2020

Taking Wuhan Metro Line 6 karst crossing area as the research object, combined with on-site survey data, a reasonable karst treatment technical plan is proposed. The finite difference numerical calculation method was used to carry out numerical calculation research on the treatment effect of karst treatment technology in the study area. The research results show that after grouting reinforcement, the maximum settlement of tunnel segments is 19.5mm, which is 73% less than before reinforcement, and the treatment effect is better. The lining deformation is within the allowable deformation value after the reinforcement of the three rows of jet grouting piles. The maximum value of the stress of the jet grouting piles is lower than the design value of the shear strength of the high jetting walls, indicating that the treatment technology can play a good supporting role when completely collapsed Without destruction.
A Brief Analysis on Application of the Half Pavilion in Garden
Authors: Li Yuanyuan , Shen Shengling , Dong Chaoran , Lu Danni
Published: November 2020

The half pavilion exists as a special form of pavilion, and its application is the perfect interpretation of Chinese traditional philosophical thought of “harmony between the heaven and human” in the gardens, which is the crystallization of the wisdom of ancient people. In the Chinese classical gardens, the particularity of the half pavilion gives viewers a sense of experience with thousands of pavilions. Every scene and every half pavilion has a new experience and aesthetic feeling. In addition to its own aesthetic value, the external shape of the half pavilion is also of exploratory significance in its integration with the surrounding environment, showing its concept of adapting to local conditions, harmony between the heaven and man, and interacting with the surrounding environment. This paper studies the half pavilion preserved from ancient times in the Chinese gardens, and explores from the external characteristics of the half pavilion and spatial layout of the gardens. In terms of how to use it in the gardens, so as to find inspiration and provide new heuristics for modern designs.
Evaluation of Social and Economic Benefits of Demand Response
Authors: Zhang Gao , Xue Song , Zhang Xiaoxuan
Published: November 2020

The rapid development of demand response has realized the transformation of power system operation from isolated decision to interconnected communication, which is of great significance for improving power network flexibility, security and reliability. Also, by introducing demand response, power network investment for satisfying peak load could be delayed, while renewable energy consumption and power network economic operation could be promoted simultaneously. Based on the practice of demand response in China as well as to further encourage the application of demand response, this paper proposes a social and economic benefit evaluation model for demand response. Combined with the reality of China’s electric power system operation, social and economic benefits of demand response are scientifically evaluated. Also, capital requirements for China to promote the application of demand response is analysed and practical measures for demand response application are put forward.
The Influence of SLS Process Parameters on the Tensile Strength of PA2200 Powder
Authors: Hou Gaoyan , Zhu Hong , Xie Dan
Published: November 2020

In the process of selective laser sintering, the forming parameters will affect the dimensional accuracy and performance of the forming parts. At present, there is no reference standard for the optimal forming parameters of PA material. Aiming at this problem, the three factors of laser power, scanning pitch and scanning speed are analyzed, and the influence of the tensile strength of PA2200 material forming parts is analyzed. Through theoretical and experimental analysis, the optimal combination of process parameters is obtained by orthogonal experiment. The best combination of parameters is laser power 40W, scanning speed 3000mm/s, scanning pitch 0.4mm, and tensile strength up to 46.42MPa.
CFD Simulation of Single-phase Flow Characteristics and Pressure Drop in SiC Hollow-strut Foam Microchannel Reactors
Authors: Zhang Ye , Gao Yong , Yang Zhenming , Zhang Jinsong
Published: November 2020

Microchannel reactors (MCR) have received considerable attention by researchers in recent years. A novel hollow-strut ceramic foam microchannel reactor (HSCF-MCR) taking the material and structural advantages of SiC foam was proposed. The reactor could be used as a structural scaffold for continuous gas or liquid phase flow and reaction because all of its struts are hollow and interconnected with each other. The three-dimensional (3-D) microstructure of the SiC foam was characterized by SEM and micro-CT method. Based on the tetrakaidecahedron cell model, computational fluid dynamics (CFD) method was utilized to analyze the single-phase flow characteristics and pressure drop of HSCF-MCR. The 3-D interconnected structure can form the static mixing effect of the flow fields inside the foam microchannel and strengthen the mass transfer process. Both channel diameter D and cell size L of the foam play a vital role in the pressure drop gradient δ of the fluid flowing through HSCF-MCR. When the ratio of D to L is controlled as 0.1, δ is minimized. The CFD simulation results contribute to the structural optimization and energy saving of HSCF-MCR for its applications in the future.
Steam Turbine Performance Evaluation Based on Principal Component Analysis and Information Entropy
Authors: Lu Chengbin , Zhang Taiyan , Liu Xiaofeng , Yao Yongling , Chen Huagui
Published: November 2020

Information entropy and fuzzy analytical theory were combined and applied on the state assessment of power plant steam turbine unit. This method can be combined with the measured data of power plant, and made a comprehensive evaluation of the different working conditions. Fuzzy analysis of the original matrix can be a evaluation matrix, and the information entropy was introduced to solve the problem of calculating the weight of multi attribute factor set. Once the attribute weight is determined, the comprehensive evaluation value corresponding to the different working conditions can be defined and calculated. The results obtained by this method were compared with those obtained by the principal component analysis method. And the results obtained by information entropy method were objective and unique. The superiority of the method was verified. Under all conditions, the comprehensive evaluation value can be used as one index of the thermal archives as a benchmark for fault diagnosis, which provided a new idea and evaluation method for steam turbine fault diagnosis, and had a strong basic research and practical application value.
SNR enhancement for the second harmonics in fluxgate sensor
Authors: Zhang Chenhao , Zhang Yiming , Gao Junxia , Li Yunyun
Published: November 2020

The fluxgate sensor uses the nonlinear characteristics of soft magnetic materials to measure the geostationary magnetic field, which has the characteristics of high sensitivity, wide magnetic measurement range and easy portability, and is widely used in geological exploration, navigation, space technology and other fields. In this paper, the research is based on the second harmonic method of the development of fluxgate sensor, since the second harmonic contains static magnetic field direction and amplitude information, so the second harmonic signal to noise ratio enhancement can effectively improve the resolution of the fluxgate sensor. In this paper, the induction signal is first resonated to the second harmonic frequency using a resonant circuit, and then filtered after an amplification circuit, the second harmonic signal-to-noise ratio is significantly enhanced by 13 times.
Finite Element Analysis and Experimental Verification on Joint with CFST Columns and Unequal Height Steel Beams
Authors: Ji Jing , Zeng Wen , Xu Ming , Li Zhihui , Jiang Liangqin
Published: November 2020

In order to study the mechanical properties of joints with CFST columns and unequal height steel beams, based on the simplified mechanical model and reasonable material constitutive model, the finite element model of this kind of joints is established by using ABAQUS finite element software, and four joints are simulated and analyzed and the load-displacement hysteretic curves and skeleton curves of the specimens are obtained. The results show that the hysteretic curves of this kind of joints are relatively full, and it has strong energy consumption capacity. Comparing the simulated hysteretic and skeleton curves with the existing test results, the two are in good agreement, which verifies the rationality and feasibility of the finite element modelling. Finally, the seismic strengthening measures of this kind of joint are given, which lays the foundation for the subsequent research on the seismic performance of the frame with this kind of joint.
Quantum Chemistry Study on Scale and Corrosion Inhibition Performance of Polyaspartic Acid
Authors: Cheng Yushan , Chen Min , Xiao Ju , Xing Naihao , Huang Changshan
Published: November 2020

The corrosion and scale inhibitions performance of polyaspartic acid (PASP) was invesgated based on the quantum chemistry calculation method of semi-empirical method by using the software of GaussView 6 and Gaussian 16.The calculation results show that, for scale inhibition, as the nitrogen atoms of PASP molecules and the oxygen atoms in carboxyl group were electronegative, which caused the electrostatic interaction to happen easily between the oxygen ions of carboxyl and the calciumions on the calcite surface, in addition, the space between the two nitrogen, oxygen ions in PASP molecule was exactly matched the space between the calcium ions on the calcite surface, the adsorption effect of the scale inhibitor to the calcite surface was obviously improved, thereby, the aim that inhibiting CaCO3 scale was achieved, the calculation results were in accordance with the test results. For corrosion inhibition performance, the HOMO energy, the LUMO energy and the difference of the two values was gotten through the calculation. The results were coincident with the mechanism description, and the calculation results were consistent with the test results.
Research on the Influence of Different Flocculants on Concrete Performance
Authors: You Renliang , Qiu Yuetao , Zhang Pan , Pan Zhifeng
Published: November 2020

By adding different types and amounts of flocculants into concrete, the effects of different types and amounts of flocculants on the initial flow performance, slump retention performance and compressive strength of concrete at different ages were studied. The test results show that PAM-3 has the greatest influence on the performance of concrete. When the content of PAM-3 exceeds 0.48g/15L, the compressive strength of concrete will be reduced. When the content of PAM-1 and PAM-2 is less than 0.24g/15L, it has no obvious influence on concrete performance. When PAC content is less than 1.8g/15L, it has no obvious influence on concrete performance. Increasing the amount of concrete admixture can alleviate the adverse effect of flocculant on concrete to a certain extent.
Study on the Influence of HPMC on Rheological Parameters of Cement Paste and Properties of Concrete
Authors: Zhong Lina , Chen Guorong , Fang Yunhui
Published: November 2020

The effects of hydroxypropyl methyl cellulose ether (HPMC) with different viscosities on rheological parameters of cement paste and properties of concrete mixed with polycarboxylic superplasticizer (PCE) were studied. The results show that the addition of HPMC with different viscosities can increase the plastic viscosity of the cement paste. High-viscosity HPMC can obtain higher plastic viscosity at a lower dosage, and lower-viscosity HPMC requires a higher dosage to achieve higher plastic viscosity.The mixing of HPMC with different viscosities into concrete can effectively reduce the bleeding rate of concrete, the 3 d compressive strength is slightly reduced, and the 28 d compressive strength is slightly increased.
Application of Microfiltration membrane Technology in Water treatment
Authors: Wang Chao , Wang Yian , Qin Hui , Lin Hua , Chhuon Kong
Published: November 2020

In wastewater treatment, membrane technology is called a major technology in the field of water treatment in the 21st century. With the development of membrane technology and the development of other emerging technologies in combination, microfiltration membrane technology is widely used in the treatment of various types of wastewater such as radioactive wastewater and heavy metal wastewater. The application of microfiltration technology in radioactive and heavy metal wastewater is described. It provides a solid guarantee for deepening the research and application of water treatment.
Synthesis and Application of Aliphatic Superplasticizer by Two-stage Acetone Process
Authors: Du Ke Lu
Published: November 2020

Aliphatic superplasticizer is a kind of admixture that is widely used in concrete. This article propose a two-stage acetone method is based on existing raw materials and technology. An aliphatic superplasticizer with higher water reduction rate and slump retention performance. It has been verified by experiments that compared with the aliphatic superplasticizer collected in the market, it has obvious advantages in the initial water reduction rate and slump retention performance.
Residual stress distribution and surface geometry of medical Ti13Nb13Zr alloy treated by laser shock peening with flat-top laser beam
Authors: Zhu Ran , Zhang Yongkang , Lin Chaohui , Chen Yu
Published: November 2020

The metallic implants made of Ti13Nb13Zr alloy are usually used under the action of the cyclic loads conditions and fatigue failure occurs occasionally. Laser shock peening (LSP) is an innovative surface treatment process, which has been used to improve the fatigue life of metallic materials. The present research was performed on the Ti13Nb13Zr alloy subject to laser modification in order to determine the effects on the residual stress distribution and surface geometry. A neodymium doped yttrium lithium fluoride (Nd: YLF) pulse laser with a flat-top beam was applied at three different overlapping rates (10%, 30%, 50%), laser pulse energies (5J, 6J, 7J), and impact times (1 impact, 2 impacts, 3 impacts), respectively. The residual stresses were determined by X-ray diffractometer with sin 2ψ method. Firstly, the 30% overlap was chosen by comparing the residual stresses induced by LSP with different overlapping rates. Then, the effects of laser energies and impact times on surface residual stresses, in-depth residual stresses, surface deformation, and surface roughness were investigated and compared. The results showed that the residual stresses, surface deformation, and surface roughness increase with the increasing laser energies and impact times. The effected layer depth of residual stress is about 1058 μm with the 6J laser energy.
Semi-automatic segmentation of whole-body images in longitudinal studies
Authors: Grossiord Eloïse , Risser Laurent , Kanoun Salim , Aziza Richard , Chiron Harold , Ysebaert Loïc , Malgouyres François , Ken Soléakhéna
Published: November 2020

We propose a semi-automatic segmentation pipeline designed for longitudinal studies considering structures with large anatomical variability, where expert interactions are required for relevant segmentations. Our pipeline builds on the regularized Fast Marching (rFM) segmentation approach by Risser et al (2018). It consists in transporting baseline multi-label FM seeds on follow-up images, selecting the relevant ones and finally performing the rFM approach. It showed increased, robust and faster results compared to clinical manual segmentation. Our method was evaluated on 3D synthetic images and patients’ whole-body MRI. It allowed a robust and flexible handling of organs longitudinal deformations while considerably reducing manual interventions.
Piezoelectric sensors fabricated by depositing solution-grown ZnO nanorods on flexible graphene-derivative electrodes
Authors: Sinar Dogan , Knopf George K
Published: November 2020

Zinc oxide nanorods (ZnO-NRs) with high-aspect ratios can significantly enhance the voltage output of mechanically flexible piezoelectric materials. A versatile chemical synthesis process for growing long narrow ZnO-NR from nanoparticle (NP) seeds by regulating the polarity of reaction solvents is introduced in this paper. The efficient nanorod (NR) growth method produces large quantities of high-aspect ratio ZnO-NRs in the reaction solvent. For ultra-small NP seeds (AVG 10.54 nm, SD 3.69), the synthesis process creates NRs with a minimal lateral growth (AVG 13.92 nm, SD 4.77) and significant longitudinal growth (AVG 150.85 nm, SD 64.93). The average aspect ratio of ZnO-NRs in the solution is ∼10.8 (SD 2.48). Once synthesized, the ZnO-NRs are mixed with polydimethylsiloxane (PDMS) to create a thin flexible piezoelectric layer/film. The composite polymer material is spin coated on an inkjet printed graphene/carboxymethyl cellulose (G-CMC) interdigitated electrode (IDE) to form the piezoelectric layer. A dielectrophoretic alignment technique is then used to reposition the NR orientations in the composite prior to final polymer curing. In this study, three different piezoelectric composites are investigated and compared: polyhedral NPs (ZnO-NP/PDMS), non-aligned nanorods (ZnO-NRNA/PDMS), and aligned nanorods (ZnO-NRA/PDMS). Each composite is deposited on a similar IDE and tested for impact loading and low frequency mechanical bending. Under bending, the NP ZnO-NP/PDMS sensor generated 3–4 mV while the non-aligned NR ZnO-NRNA/PDMS sensor produced 70–80 mV. In contrast, the horizontally aligned NR ZnO-NRA/PDMS sensor generated 150–170 mV under the same bending conditions.
Nitrogen balance and use efficiency on dairy farms in Japan: a comparison among farms at different scales
Authors: Toda Misato , Motoki Juri , Uchida Yoshitaka
Published: November 2020

In recent decades, the rate of milk production per unit land area and per cow has increased with the intensification of the dairy system. The possible environmental risks arising from nutrients surpluses, such as nitrogen (N), are often evaluated using the N balance approach. In Hokkaido, the biggest dairy farming area in Japan, many dairy farms have started introducing a new dairy farming system called the total mixed ration (TMR) and biogas system. Feed and manure are managed at a community scale in these systems while each farm focuses primarily on milking cows. Thus, calculating the N balance for this system is complicated. Therefore, this study aimed to evaluate the N surplus and use efficiency (NUE), focusing mainly on the community-based dairy farming system, as described above. We investigated twenty dairy farms comprising a TMR centre (TMR-based farms) and nineteen conventional dairy farms (conventional farms). The Hokkaido dairy farms had a smaller N surplus and higher NUE than farms in other countries. The whole farm N surplus and NUE ranged from −163 to 701 kg N ha−1 and from 20% to 171% with median values of 40.5 kg N ha−1 and 69.5%, respectively. One of the possible reasons for the smaller N surplus and higher NUE is a lower stocking rate (averaged 1.3 cows ha−1) on Hokkaido dairy farms. There were strong relationships between feed N and N surplus because the studied dairy farms depended on purchased feed. In the comparison between the TMR centre and conventional dairy farms, the milk production level per cow and stocking rate tended to increase, and variations between farms decreased on the TMR-based farms. Increasing the amount of home-grown feed with pasture management is essential to decreasing N surplus for the new dairy farming systems.
Friendship, family, love
Authors: Hamlin William M.
Published: November 2020

“Friendship, family, love” locates some of Montaigne’s pronouncements on these topics in a Renaissance context. At the time, the word amitié covered a broader spectrum of love than friendship—though Montaigne’s friendship with la Boétie was tinged with eroticism. What are we to make of his disparaging comments about women? Surprisingly aware of the sexual double standards of his day, Montaigne believed that a good marriage resembled a friendship and that books—“children of the mind”—were as significant as flesh-and-blood children. What would his wife and daughter think of these writings, and how should we judge his shifting claims?
Introduction
Authors: Masur Louis P.
Published: November 2020

The introduction outlines the structure of this VSI and summarizes its aims, which include to seek to explain what happened during the Civil War, outline how the events transpired, and analyze what it all meant. Slavery caused the Civil War, but in what ways? Disagreements over questions of sovereignty and constitutional authority caused the Civil War, but how? Northerners and Southerners saw themselves as different, but why did those differences turn lethal and ultimately lead to horrific violence?
The origins of the Civil War
Authors: Masur Louis P.
Published: November 2020

“The origins of the civil war” summarizes the years leading up to the war, which were characterized by increasing conflict over slavery and government authority. Starting with the close of the revolutionary era, attempts to compromise on slavery in the territories and maintain a delicate balance of free and slave states became increasingly challenging. In 1831, Nat Turner’s violent slave rebellion struck fear into the South, as did an emerging abolitionist movement. In the 1850s, a series of spiralling events led to protests and armed conflict. Once Abraham Lincoln won the Electoral College without carrying a single slave state, many Southerners saw secession as a necessity.
1861
Authors: Masur Louis P.
Published: November 2020

“1861” describes the events of that year, which began with the appointment of Jefferson Davis as president of the Confederacy. Following the Confederate bombardment of Fort Sumter, Lincoln called for troops, appointed George McClellan to command Union forces, and imposed a blockade against the South. The first battles were chaotic. Union forces (“Yankees”) benefited from greater manpower and technology; Southerners (“Rebels”) had a stronger military tradition and familiar terrain. Although the war did not begin with the aim of abolishing slavery, the institution played a role in military and diplomatic developments. Abolitionists hoped that Union war aims would transform into a struggle against slavery.
1863
Authors: Masur Louis P.
Published: November 2020

“1863” begins with Lincoln’s signing of the Emancipation Proclamation on January 1 . Authorizing the enlistment of black soldiers, the proclamation helped change the Union’s fortunes and those of African Americans. Confederate forces faced heavy losses at Gettysburg and Vicksburg. In New York, riots related to conscription erupted, with much of the violence directed against the black community. In his address at Gettysburg, Lincoln invoked the Declaration of Independence and started looking beyond the war to the terms of reconstruction. However, with an election on the horizon, the country remained divided.
1864
Authors: Masur Louis P.
Published: November 2020

“1864” demonstrates that the Union defeats across Virginia in that year came at a politically precarious time for Abraham Lincoln, with rivals angling for the Republication presidential nomination and Confederates hoping for his defeat. News that Atlanta had fallen revived Northern morale and Lincoln’s chances for re-election. Though the election campaign turned nasty, characterized by race baiting and fears of “miscegenation.” Lincoln was re-elected by an overwhelming margin, supported by the votes of Union soldiers. The new vice-president was Andrew Johnson, a prominent War Democrat. Meanwhile, Jefferson Davis had no choice but to watch Confederate ranks thin as a result of battle, disease, and desertion.
Epilogue
Authors: Masur Louis P.
Published: November 2020

The epilogue looks at the Civil War and Lincoln’s assassination and legacy through the eyes of the poet Walt Whitman. Volunteering in Washington’s hospitals during the war, Whitman frequently glimpsed the president. Though they never met, Whitman admired Lincoln and praised his leadership. Whitman wrote poems about Lincoln’s death, as well as prose in which he struggled to define and understand the “four years of bleeding, murky, murderous war” and the people’s role in fighting and dying for the nation. Whitman never stopped thinking about the Civil War, but he realized that it never could—and perhaps never should—be properly described.
2. Making things happen—catalysis
Authors: Engel Paul
Published: November 2020

‘Making things happen—catalysis’ examines chemical catalysis, considering what makes a reaction go or not go and how enzymes catalyse particular chemical reactions. This process is not unique to living systems, although enzymes are both more potent and more selective than catalysts encountered elsewhere in chemistry. A catalyst is an agent that speeds up a chemical reaction but remains unchanged itself at the end of the process. Since a catalyst is not altered or used up, it can be used over and over again.
3. The chemical nature of enzymes
Authors: Engel Paul
Published: November 2020

‘The chemical nature of enzymes’ evaluates the chemical nature of enzymes. To discover the chemical nature of enzymes, it was essential to obtain them in a pure form. To this end, the early biochemists devised various procedures, including fractionation and column chromatography. However, purification of enzymes led to controversy, which ultimately revealed that enzymes are proteins. Proteins are biological polymers, that is, they are built of similar units joined end to end to form very large molecules. Chemically, a protein molecule is a linear polypeptide.
5. Enzymes in action
Authors: Engel Paul
Published: November 2020

‘Enzymes in action’ explores a few interesting examples which illustrate the sophistication and subtlety of enzymes in action. One function of the digestive system is to dismantle food proteins, releasing the amino acids for one’s own use. For this, there is a set of enzymes called proteinases. The zymogen is an inactive enzyme precursor that is only ‘switched on’ at the appropriate time so that the potent protein degrading activity appears when, and only when, the food is there to keep it fully occupied in gainful activity.
7. Enzymes and disease
Authors: Engel Paul
Published: November 2020

‘Enzymes and disease’ assesses how, in relation to medical science, enzymes may be the problem or they might offer the solution. What happens if enzymes are faulty in some way? Enzyme defects lead to diseases such as alkaptonuria, phenylketonuria, Sudden Infant Death Syndrome (SIDS), and Jamaican Vomiting Sickness. On the other hand, there are often situations in which humans deliberately seek to damp down the activity of normally functioning enzymes in human bodies, and this is how many drugs work. Enzymes, human or otherwise, are also nowadays widely used as agents for diagnosis or therapy.
8. Enzymes as tools
Authors: Engel Paul
Published: November 2020

‘Enzymes as tools’ addresses the application of enzymes on the industrial stage. In the past, there were considerable barriers to this wider application of enzymes: enzymes were typically fragile and unsuitable for robust industrial handling. By using genetic methods and unusual organisms enzymologists today are able to obtain sturdy enzymes in amounts that make them economically realistic for industrial use, and supplying these enzymes is the central business of a number of large companies. One of the largest markets for enzymes is as additives in washing powders for clothes and in tablets for dishwashers. Other areas of application for enzymes include food production, hair removal, farming and waste treatment, and industrial chemistry.
9. Enzymes and genes—new horizons
Authors: Engel Paul
Published: November 2020

‘Enzymes and genes—new horizons’ studies molecular genetics. It details how the method of ‘site-directed mutagenesis’ opened the door to what rapidly became known as protein engineering. Initially, people wondered whether mutated proteins would fold up properly. Occasionally they did not, but, overall, protein engineering has been remarkably successful and has become a powerful tool for pure research, allowing one to test the contribution of different parts of a protein structure with surgical precision. Amino acid dehydrogenases are a family of enzymes. There have been three breakthrough discoveries in modern molecular genetics that rely on remarkable enzymes. These discoveries have transformed biotechnology, biology, and people’s lives.
1. The making of magma
Authors: Branney Michael J. , Zalasiewicz Jan
Published: November 2020

‘The making of magma’ discusses the formation of magma. Volcanism is driven by prodigious amounts of heat from deep inside the Earth that partly melts rock to form magma, which accumulates and evolves deep underground, and may drive powerful eruptions that expel ash and lava on to the surface, creating a volcano. This process can be studied by inferences based upon volcano behaviour, seismic information, chemical tracers in volcanic materials, experimentation, and other clues. From enormous, diffuse networks deep in the Earth, the magma rises and gathers together in the crust as a complex system of interconnected fractures, reservoirs, and conduits. These magma reservoirs can be detected by seismic imaging.
4. Lava
Authors: Branney Michael J. , Zalasiewicz Jan
Published: November 2020

‘Lava’ focuses on lava. Within a kilometre or two of the ground surface, the rise of hot magma is accelerated by the growth of gas bubbles which increase the magma’s buoyancy. If the gases can readily escape from the magma, the magma may ascend more slowly without being ripped apart, and it eventually emerges from the volcano as a lava flow. There are many different types of lava flows: pahoehoe, a’a, block-lavas, inflated lavas, and lava domes, which decrepitate to form hazardous ‘block-and-ash flows’.
6. Hidden volcanoes
Authors: Branney Michael J. , Zalasiewicz Jan
Published: November 2020

‘Hidden volcanoes’ highlights ancient volcanoes, which offer crucial perspectives that would not be clear from the study of modern volcanoes alone. Exhumed (uplifted and dissected) volcanoes provide vital glimpses deep inside a volcano, including how they work. They are windows showing what really happens when hot magma interacts with bedrock, ice-sheets, lakes, and deep oceans. Ancient volcanoes also reveal how volcanic processes vary with time. They have enabled us to discover new and awesome styles of eruption. Examples are described, from the highest mountain in Wales, Yr Wyddfa, or Snowdon, which was an explosive caldera volcano that emerged from shallow seas. Also described are ‘Large igneous provinces’, diamond-bearing volcanoes, and the most ancient volcanism on Earth.
7. Volcanoes, climate, and the biosphere
Authors: Branney Michael J. , Zalasiewicz Jan
Published: November 2020

‘Volcanoes, climate, and the biosphere’ explores how volcanism has perturbed both climate and the complement of living organisms on Earth, both locally and globally. Volcanic outbursts, depending on their nature and scale, may cause global warming or global cooling. In the historical record, even geologically modest eruptions have had dramatic repercussions. Volcanoes can affect local weather. It is possible that climate change can, in turn, affect volcanism.
9. Volcanoes beyond Earth
Authors: Branney Michael J. , Zalasiewicz Jan
Published: November 2020

‘Volcanoes beyond Earth’ highlights volcanoes on other planets. There are many more volcanoes on Venus than there are on Earth, and many remain active. In the absence of plate tectonics and the kind of tectonic forces that raise Earth-style mountain belts, and of streams, rivers, and shorelines, it is volcanism and volcanic products that dominate the surface of this planet. Fossil volcanism occurs in the Moon, Mercury, and Mars; Io, the hypervolcanic moon of Jupiter; and the ice volcanoes of the Solar System. There is potential for volcanism on exoplanets within distant planetary systems.
When does Something ‘Belong’ to a Culture?
Authors: Thomas Joshua Lewis
Published: November 2020

Cultural appropriation can be understood as involving members of one culture taking or adopting objects or practices which ‘belong’ to another culture in the sense of being affiliated or connected to that other culture in a unique or special way. But what constitutes this ‘belonging’ precisely? This paper proposes that belonging, in the targeted sense, is determined by meaningful connections between an object or practice and the relevant culture—in other words, connections that could be described as the thing’s ‘meanings’. Such meanings primarily include relations of causality, teleology, and symbolic representation. After expounding this account, the paper closes with a word of caution. The term ‘belongs’ is sometimes ambiguous, indicating both affiliation and legal or moral property rights. Despite this, belonging as affiliation or meaningful connectedness is not equivalent to rightful ownership. Nor does the former, by itself, entail the latter.
The politics of autocratic survival in Equatorial Guinea: Co-optation, restrictive institutional rules, repression, and international projection
Authors: Sá Ana Lúcia , Rodrigues Sanches Edalina
Published: November 2020

Equatorial Guinea is not only one of the world’s most authoritarian regimes but also a striking case of regime and leader survival. This small, oil-rich state and personalist regime defies conventional wisdom because it is both far more resilient and faces far fewer threats from within the regime and from opposition political parties than other resource-rich states. But how does the regime manage to survive? This study argues that four key mechanisms interact to explain Equatorial Guinea’s record of authoritarian survival. Firstly, co-optation (via patronage, party, and cabinet appointments) which President Teodoro Obiang Nguema Mbasogo and the regime party—Partido democrático de guinea ecuatorial—have used to build internal cohesion and fragment opposition. Secondly, the crafting of restrictive institutional rules (party and electoral laws) that, combined with informal rules, aim to protect the regime’s interests and make participation in political opposition more costly. Thirdly, the use of (selective and diffuse) repression to shield the regime and shrink the living space of challengers. Finally, the regime’s international linkages and projection to gain credibility and offset pressure for change. We argue that autocrats’ survival depends on their ability to play a strategic two-level game: domestic and international.
The Hybridization of Street Offending in the Netherlands
Authors: Roks Robert A , Leukfeldt E Rutger , Densley James A
Published: November 2020

Based on the results of two research projects from the Netherlands, this paper explores how street-oriented persons adapt and use digital technologies by focussing on the changing commission of instrumental, economically motivated, street crime. Our findings show how social media are used by street offenders to facilitate or improve parts of the crime script of already existing criminal activities but also how street offenders are engaging in criminal activities not typically associated with the street, like phishing and fraud. Taken together, this paper documents how technology has permeated street life and contributed to the ‘hybridization’ of street offending in the Netherlands—i.e. offending that takes place in person and online, often at the same time.
Real-Time Investigation of a Large Nosocomial Influenza A Outbreak Informed by Genomic Epidemiology
Authors: Javaid Waleed , Ehni Jordan , Gonzalez-Reiche Ana S , Carreño Juan Manuel , Hirsch Elena , Tan Jessica , Khan Zenab , Kriti Divya , Ly Thanh , Kranitzky Bethany , Barnett Barbara , Cera Freddy , Prespa Lenny , Moss Marie , Albrecht Randy A , Mustafa Ala , Herbison Ilka , Hernandez Matthew M , Pak Theodore R , Alshammary Hala A , Sebra Robert , Smith Melissa L , Krammer Florian , Gitman Melissa R , Sordillo Emilia Mia , Simon Viviana , van Bakel Harm
Published: November 2020

Background

Nosocomial respiratory virus outbreaks represent serious public hgealth challenges. Rapid and precise identification of cases and tracing of transmission chains is critical to end outbreaks and to inform prevention measures.

Methods

We combined conventional surveillance with influenza A virus (IAV) genome sequencing to identify and contain a large IAV outbreak in a metropolitan healthcare system. A total of 381 individuals, including 91 inpatients and 290 healthcare workers (HCWs), were included in the investigation.

Results

During a 12-day period in early 2019, infection preventionists identified 89 HCWs and 18 inpatients as cases of influenza-like illness (ILI), using an amended definition without the requirement for fever. Sequencing of IAV genomes from available nasopharyngeal specimens identified 66 individuals infected with a nearly identical strain of influenza A H1N1pdm09 (43 HCWs, 17 inpatients, and 6 with unspecified affiliation). All HCWs infected with the outbreak strain had received the seasonal influenza virus vaccination. Characterization of 5 representative outbreak viral isolates did not show antigenic drift. In conjunction with IAV genome sequencing, mining of electronic records pinpointed the origin of the outbreak as a single patient and a few interactions in the emergency department that occurred 1 day prior to the index ILI cluster.

Conclusions

We used precision surveillance to delineate a large nosocomial IAV outbreak, mapping the source of the outbreak to a single patient rather than HCWs as initially assumed based on conventional epidemiology. These findings have important ramifications for more-effective prevention strategies to curb nosocomial respiratory virus outbreaks.
AcanR3990 qPCR: A Novel, Highly Sensitive, Bioinformatically-Informed Assay to Detect Angiostrongylus cantonensis Infections
Authors: Sears William J , Qvarnstrom Yvonne , Dahlstrom Eric , Snook Kirsten , Kaluna Lisa , Baláž Vojtech , Feckova Barbora , Šlapeta Jan , Modry David , Jarvi Susan , Nutman Thomas B
Published: November 2020

Background

Angiostrongylus cantonensis (Ac), or the rat lungworm, is a major cause of eosinophilic meningitis. Humans are infected by ingesting the 3rd stage larvae from primary hosts, snails, and slugs, or paratenic hosts. The currently used molecular test is a qPCR assay targeting the ITS1 rDNA region (ITS1) of Ac.

Methods

In silico design of a more sensitive qPCR assay was performed based on tandem repeats predicted to be the most abundant by the RepeatExplorer algorithm. Genomic DNA (gDNA) of Ac were used to determine the analytical sensitivity and specificity of the best primer/probe combination. This assay was then applied to clinical and environmental samples.

Results

The limit of detection of the best performing assay, AcanR3990, was 1 fg (the DNA equivalent of 1/100 000 dilution of a single 3rd stage larvae). Out of 127 CDC archived CSF samples from varied geographic locations, the AcanR3990 qPCR detected the presence of Ac in 49/49 ITS1 confirmed angiostrongyliasis patients, along with 15/73 samples previously negative by ITS1 qPCR despite strong clinical suspicion for angiostrongyliasis. Intermediate hosts (gastropods) and an accidental host, a symptomatic horse, were also tested with similar improvement in detection observed. AcanR3990 qPCR did not cross-react in 5 CSF from patients with proven neurocysticercosis, toxocariasis, gnathostomiasis, and baylisascariasis. AcanR3990 qPCR failed to amplify genomic DNA from the other related Angiostrongylus species tested except for Angiostrongylus mackerrasae (Am), a neurotropic species limited to Australia that would be expected to present with a clinical syndrome indistinguishable from Ac.

Conclusion

These results suggest AcanR3990 qPCR assay is highly sensitive and specific with potential wide applicability as a One Health detection method for Ac and Am.
Kaldor–Verdoorn’s law and institutions: evidence from Brazilian municipalities
Authors: Iasco Pereira Hugo Carcanholo , Romero João P , Medeiros Victor
Published: November 2020

Recent works on economic growth stress the importance of institutions as the main determinant of productivity growth. Yet, this literature disregards the effects of demand growth on productivity growth, as suggested by Kaldor–Verdoorn’s law. The objective of this paper was to test the direct and indirect impacts of institutions on productivity growth, controlling for human and physical capital, as well as for demand growth. Tests were performed for Brazilian municipalities and two measures of institutions were explored. Instrumental variables were used to cope with the endogeneity between economic performance and institutions. The regression results suggest that both supply-side factors and demand growth are important to explain productivity growth. Most importantly, by considering the interaction between demand growth and institutions, the results indicate that in municipalities with inclusive institutions and higher human capital, productivity growth responds more strongly to demand growth.
Decreased layer specific longitudinal strain in myocardial segments supplied by stenosed LAD coronary artery: analysis for baseline, peak and recovery phase of stress echocardiography
Authors: Kowalczyk E , Kasprzak J.D , Hamala P , Nowak B , Nowakowski R , Trzos E , Lipiec P , Wierzbowska-Drabik K
Published: November 2020

Background

Despite wide utility of global longitudinal strain in the assessment of left ventricular function up to now little is known about layer specific quantification of myocardial function during stress tests and its potential for ischemia detection.

Purpose

To investigate diagnostic utility of layer specific LS during stress echocardiography using marker segments in patients with established Left Anterior Descending (LAD) coronary artery status.

Methods

We retrospectively analyzed 63 patients (mean age 62.5±9.9 years, 62% males) with suspected coronary artery disease, who had performed dobutamine stress echocardiography (DSE). Layer specific speckle tracking LS analyses were performed during rest, maximal stress and recovery. As a marker for LAD (segment most probably supplied by this artery) we used mid-anterior left ventricle segments. LAD status were established with coronary angiography or angioCT and consider as significant if ≥70% stenosis was present.

Results

In our study group 14 patients had significantly stenosed LAD (group 1) and 24 had normal coronaries (group 2). We detected significantly lowered absolute values of strain in endocardial and mid-myocardial layers of segments supplied by stenosed LAD at rest for endocardium −8.6% (group 1) vs −13.4% (group 2); p=0.045; and mid-myocardium −7.3% (group 1) vs −11.2% (group 2); p=0.044. Moreover, we observed similar trend at recovery, however without reaching statistical significance.

Conclusions

Longitudinal strain analysis focused on segments supplied by assessed coronary artery my provide quantitative data confirming ischemia in the settings of rest and stress echocardiography. Our pilot study suggest that for inotropic agents like dobutamine the potential ischemic dysfunction may be however masked at peak stage of the test.

Funding Acknowledgement

Type of funding source: None