bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation and comparision of GaAs, AlGaAs and GaInP barriers in InGaAs quantum well lasers
Authors: Huibo Yuan , Li Lin , Zeng Lina , Zhang Jing , Li Zaijin , Qu Yi , Ma Xiaohui , Liu Guojun
Published: September 2019

InGaAs quantum wells with GaAs, AlGaAs and GaInP barriers have been simulated, respectively. The InGaAs/GaInP structure reveals a high material gain which could be nearly 1.4 times of that of InGaAs/GaAs. Threshold current of InGaAs/GaInP structure is less than half of InGaAs/AlGaAs. A high slope efficiency of 1.57 W/A from InGaAs/GaInP structure is observed with indium content as high as 0.35. InGaAs/GaInP structure will be the most appropriate candidate to fabricate a laser diode with high slope efficiency and low threshold current.
Research on image monitoring method of electron beam selection melting
Authors: Wang Jiaming , Yin Bohua , Xu Guanglu , Liu Junbiao , Wang Yan , Han Li
Published: September 2019

In order to overcome the problem that the lack of real-time detection technology and the existing detection methods cannot select the process area flexibly in the process of electron beam selective melting, this paper presents a digital electronic imaging method which can monitor the roughness and tiny flaws on the surface of components layer by layer. The digital electronic images were produced by detecting both secondary electrons (SE) and backscattered electrons (BSE) originating from interactions between the electron beam and the metal powder. The imaging principle and the hardware circuit of the system are introduced in detail. Finally, the effectiveness of this design is verified by the experiments.
Experimental Investigation on the Spatial-temporal Evolution of the hole formation during Laser Helical Drilling
Authors: Dong Y W , Wu Z P , Yan W G , Li X J , You Y C
Published: September 2019

In order to study the influence of process parameters of femtosecond laser helical machining on the formation of micro-holes, we selected main parameters of the femtosecond laser helical drilling process, used 304 stainless steel as the target material, designed a 5-factor and 5-level orthogonal experiment based on the L
25 (56) orthogonal table, and analyzed the significance levels of the impacts of single pulse energy, repetition rate, rotation rate, rate of focus downward movement, and air-blowing pressure on the ablation depth. Based on back propagation (BP) neural network, we established the relationship model between five factors and the material ablation depth, and trained the network with orthogonal experiment data. We used the data of the additional drilling experiments to test the generalization ability of the established network, and the results show that the prediction error of the model is within 3%. We designed a single-factor experiment for the characteristic parameter of the helical drilling--the rate of focus downward movement--and obtained the effect of the rate of focus downward movement on the formation of the micro-holes during the process of femtosecond laser helical drilling.
Application of Blockchain Technology in Energy Internet Market and Transaction
Authors: Zhu Xingxiong
Published: September 2019

Based on the blockchain technology, important datas such as transactions, scheduling, finance, and energy contracts are distributedly recorded, various resources such as distributed energy generation, energy transmission, energy consumption, and energy storage are aggregated for collaborative optimization control and market trading. In this paper, we build blockchain-based new generation energy Internet with extensive interconnection, intelligent decision making, real-time interaction, and open sharing. The application of blockchain technology in energy Internet includes photovoltaic energy microgrid, blockchain-based energy Internet entities, blockchain-based power trading, and energy asset securitization. Technical frameworks for energy Internet market trading system based on blockchain technology are proposed. Distributed energy ledger and energy trading smart contract are utilized. Distributed trading rules, algorithms and processes of energy system and microgrid are established. Energy Internet transactions and payment settlement system are constructed. Energy producers and consumers trade peer-to-peer on the platform to improve system efficiency and security.
Traditioanl Settlements Study on Sciences of Human Settlements in Erhai Lake Region
Authors: Yang Rongbin , Yang Dayu
Published: September 2019

Five systems of sciences of human settlements are adopted in this paper. The research objects are Malong site of Cangshan Mountain, Nanzhao Taihe City site, Dali Ancient City, Xizhou Ancient Village, Shuanglang Ancient Town and Jinsuo Island Village. All the research objects are near the Erhai Lake region and they are traditional settlements with different historical periods. The natural, human, social, residential and supportive systems of traditional settlements are analyzed as well. The environmental and ecological view of complying with nature, the social and economic view of emphasizing development and the cultural and technical view of embodying characteristics of traditional settlements in Erhai Lake region are also concluded. This paper offers theoretical references for the sustainable development of traditional human settlements.
Investigation and Measurement Analysis of Campus Noise Pollution Based on a University in Hengyang
Authors: Zhang Xin , Hu Yan , Ran Xuanhao , Zhang Yang , Zhong Yi , Zeng Jueting , Zheng Huihui
Published: September 2019

In view of the increasingly serious problem of noise pollution in students’ life and study in the process of building campus culture, this paper analyzed the acoustic environment and acoustic comfort of a college in Hengyang by means of questionnaires, on-site measurement and mathematical model evaluation. After field measurement, the survey found that students are mainly concentrated in dormitory, teaching building and library. The over-standard rates for each location were 87.5%, 54.2%/50%, and 37.5%, respectively. Then this paper used the mathematical model based on fuzzy matrix method to calculate that the membership degree of college acoustic environmental quality belongs to slight pollution is the largest, which is 0.3775. It is advised that relevant departments should adopt a restriction strategy on the noise source to change the acoustic environment and sound comfort of the school.
Long-term analysis of the relationship between urban heat island and economic development over 34 major cities in China
Authors: Niu Lu , Tang Ronglin
Published: September 2019

Exploring the relationship between surface urban heat island (SUHI) effect and urban economic development is a problem that people pay attention to for a long time. In this paper, we use MODIS surface temperature data to calculate the SUHI intensity of 34 major cities in mainland China from 2003 to 2017. Then we first analyze the relationship between annual average SUHI intensity and urban annual gross domestic product (GDP). A good linear relationship is found in most cities in north and northeast China with the coefficient of determination (R2) reaching 0.63 at most. In addition, the relationship between SUHI intensity and GDP during the day is significantly better than that at night. These conclusions can provide a new insight for people to understand the impact of urban heat island effect on urban economic development in the future.
Implementation problems and outlook of the “Environmental Protection Tax Law of the People’s Republic of China”
Authors: Liu Lanlan
Published: September 2019

As an important measure of tax reform adopted by China to realize ecological civilization, the “Environmental Protection Tax Law of the People’s Republic of China” (hereinafter abbreviated as the “Environmental Protection Tax Law”) has been implemented for around one year, but defects of the “Environmental Protection Tax Law” have emerged both in the content of its clauses and its tax levitation and management mechanism. This paper focuses on studying problems with the clause content and tax levitation and management mechanism of the “Environmental Protection Tax Law” at an attempt to propose effective countermeasures for these problems.
Research on Investigation and Countermeasure of Low Carbon Consumption of College Students
Authors: Huang Shiguo , Liu Peibiao
Published: September 2019

The most important influencing factor of global greenhouse effect is the excessive carbon dioxide emissions, and one of the important ways to affect carbon emissions is people’s daily life. College students are a special group. This paper takes the college students in Changqing university town of Jinan as an example to investigate their cognition and action on low carbon consumption at the present stage, hoping to take this as a breakthrough and encourage the whole community to actively participate in the activities of low carbon consumption. The results show that the status quo of College Students’ low carbon consumption is related to their gender, family address, educational background and other basic factors, low carbon consumption behavior is influenced by low carbon consumption awareness, social responsibility awareness and personal consumption concept, college students’ consumption is tending to low carbon nowadays, but there are obstacles to carry out low carbon consumption in an all-round way. Therefore, from the perspective of the government, universities and college students themselves, this paper puts forward the relevant countermeasures to promote low carbon consumption behavior.
Accumulation characteristics of CO2-bearing natural gas reservoir in Xudong area of Xujiaweizi fault depression
Authors: Wang Zhiguo
Published: September 2019

In the north of Songliao basin, some high CO2 gas reservoirs have been found while great breakthroughs have been made in hydrocarbon natural gas. Based on the analysis of the reservoir characteristics of CO2 gas reservoirs in Xudong area, this paper clarifies that the Yingcheng formation CO2 is inorganic gas, volcanic rock is the main reservoir, and establishes the differential accumulation model of CO2 gas reservoirs in the study area, which can also guide further research and exploration.
Object-oriented monitoring of coal mine land use change
Authors: Yuan Xitun , Xing Lei , Gao Wenjin , Gao Pengwei , Zhao Xin , Chang Jinzhong
Published: September 2019

Taking Dongsheng district of Erdos City in Inner Mongolia as the research area, we used the object-oriented classification method to monitor the land use change in recent years. The images of the three periods were classified into vegetation, residential area, water body, the mining area as well as the bare land, of which the accuracy rate has reached 86%. The results were produced by statistically analyzing. From 2006 to 2011, the vegetation was badly damaged, including the expanding residential areas and mining areas. The residential area was constantly expanding between 2011 and 2018, but the total area of the mining area and vegetation cover has not changed much. The area after the mining has been re-greened, which is conducive to the coordinated development of that area.
Method for crop classification based on multi-source remote sensing data
Authors: Shi Yun , Li Jie , Ma Donghui , Zhang Tongkang , Li Qianwen
Published: September 2019

Using remote sensing images to classify crops to obtain spatial distribution of different crops is of great significance for crop yield estimation and agricultural policy formulation. Due to the phenomenon of the same spectrum from different materials or the phenomenon of the same materials with different spectrum, it is difficult to obtain accurate crop classification results from single-phase images. We take a farm in Lintong District of Xi’an as the research area. The crops in this study area are mostly cross-planted, and the planting area is small, so it is difficult for the traditional classification method. In order to increase classification accuracy, a multi-level classification method is proposed in this paper. The Sentinel-1 backscattering coefficient (Sigma) of image is used to pre-classify the ground in the study area, and the Sentinel-2 images which cover the crop growth cycle in the study area are used to construct a normalized vegetation index (NDVI) time series to distinguish the growth differences of different crops. Combined with field survey data and phenological characteristics of crops, on the basis of pre-classification, SVM (Support Vector Machine) method is used to classify Sentinel-2 images. The classification accuracy reaches 98.07%, which is much higher than the minimum distance, Mahalanobis distance, neural network, expert decision tree, object-oriented and other classification methods.
Optimization of Energy Consumption of the Ultrasonic Pretreatment on Sludge Disintegration
Authors: Zhao Yi-Hua , Zhang Bo , Tao Jun , Li Qi , Lv Bin
Published: September 2019

Anaerobic digestion is a widely used method to treat sludge, while its application was limited by its ineffective hydrolysis rate. Ultrasonic pretreatment could enhance the hydrolysis rate of sludge, while the development of ultrasonic had been restricted by the high energy consumption, it was necessary to optimize the energy consumption. Disintegration degree was analysed by the particle size, SCOD increase, soluble proteins and carbohydrates of the sludge before the after the ultrasonic pretreatment, the relationship between the specific energy input and the disintegration degree was discussed. The results showed that after ultrasonic disintegration, the concentration of SCOD, soluble protein and carbohydrate increased with the increase of ultrasonic time and ultrasonic power. High power ultrasonic could effectively disintegrate sludge in a short disintegration time, while low power ultrasonic needed a long time to disintegrate sludge. And under the same specific energy consumption conditions, the combination of lower power density and longer ultrasonic time could obtain better disintegration degree than the combination of higher power density and shorter time. It was confirmed that the energy utilization efficiency of the lower power density and the longer time combination was higher.
Performance Evaluation and Optimization Analysis of Zero Discharge Device for Desulfurization Wastewater Based on Spray Drying Technology
Authors: Wang Renlei , Dai Yu , Zhang Shanshan , Lan Yonglong
Published: September 2019

The original desulphurization wastewater treatment system was reformed by spray drying technology in a thermal power plant, and the performance of the modified system was evaluated. The results show that the treatment capacity of the system is above 5m3/h. It can meet the requirements of zero discharge of desulphurization wastewater in power plant, and has many characteristics, such as simple process, reliable technology, stable operation, convenient operation and so on. At the same time, some suggestions for further optimization and improvement are put forward in view of the existing problems.
Cause investigation analysis and experimental argumentation about acidic water in the oil shale open pit of Maoming City
Authors: Zhou Junguang , Ji Wang , Sha Chang , Pan Chaoyi , Guo Qingwei , Wang Jingsong , Cheng Sili
Published: September 2019

This paper analyzes the sources and causes of the natural history of Maoming city open pit water, combined with the experimental research on the reasons of present continuous mine water acidification, and taking the total mass of H+ dissolved in water as an indicator. The results show that the main reason for the continuous acidification of the open pit mine is the accumulation of contaminated soil at random and the leaching of acid from the soil. Acidic substances mainly come from the accumulated waste slag around the pit. In the background of the construction of open-pit mine ecological park, that rain, vegetation restoration, river governance slag pollution is the key to acidic mine water.
The impact of Income Gap on Environmental Pollution: empirical evidence from China’s energy producing regions
Authors: Chen Min
Published: September 2019

Previous studies have suggested that the widening of the income distribution gap usually leads to the delay of the turning point of the environmental Kuznets curve. As far as an energy producing area in the western region is concerned, this paper argues that the rich have a strong ability to pay for the cost of mobility. This gap in income distribution leads the rich to emigrate to areas of higher environmental quality to reduce their demand for environmental governance in the region. At the level, in the case of the total supply of environmental governance, the lower demand for environmental governance in the region will lead to the lack of environmental governance and the deterioration of environmental quality in the region. This paper proves the above point by establishing a two-region spatial flow model, and the test results of time series data of environmental governance investment in northern Shaanxi also support this conclusion.Therefore, from the perspective of rich immigrants, this paper expounds the internal mechanism that the widening income distribution gap will lead to the decline of environmental quality in the region. Finally, some policy suggestions are put forward, such as raising the tax rate of resources and environment. Or reducing the tax rate of individual income, combining the principle that who pollutes and governs with the principle of using environmental products and who pays.
Adsorption of Ammonium Ion Using Zeolite, Chitosan, Bleached Fibre and Activated Carbon
Authors: Safie N N , Zahrim A Y , Rajin M , Ismail N M , Saalah S , Anisuzzaman S M , Rahayu A D , Huslyzam H , Jennisha R , Calvin T T H
Published: September 2019

Several materials have been studied for the adsorption of ammonium ion from synthetic solution. Zeolite is having the highest adsorption capacity (3.160 mg/g) with fast reaction time followed by chitosan (2.5770 mg/g). Activated carbon derived from Tarap (Artocarpus odoratissimus) and rice husk shows better performance than the low cost bleached fibres.
Carbon dioxide capture using waste tire based adsorbent
Authors: Duduku K , Anisuzzaman S M , Bono  , Teo B K , Rao V V B
Published: September 2019

In this study, a waste tire derived activated carbon (AC) was assessed as a solid sorbent for CO2 capture. The objectives of this study is to determine the effectiveness of AC from waste rubber tire via chemically activation with potassium hydroxide (KOH) as a low cost solid adsorbent on the adsorption of CO2 from the mixture of N2 and CO2 at different adsorption temperature, adsorption flow rate and impregnation ratio. The reactor temperatures were 30°C, 40 °C and 50°C and the flow rate was 50 cm3/min, with an impregnation ratio of 1 and 1.5. The breakthrough time was found to decrease with increasing of impregnation ratio of KOH and decreasing of adsorption temperature and flow rate. The AC with 1.5 KOH impregnation ratio has shown the best CO2 adsorption capacity among the adsorbents studied and the adsorption capacity is 238.7mg/g of adsorbent at 30°C.
Observation on the drag reducing effect of low concentration chitosan solution in turbulent pipe flow
Authors: Asidin M. A. , Suali E. , Jusnukin T. , Lahin F. A.
Published: September 2019

Polymer-based drag reducing agent (DRA) is used widely in various industries due to its ability to enhance fluid flow as well as economically beneficial to various sectors. This study is conducted to observe the drag reducing effect of chitosan as DRA and observed its effect on the turbulent flow inside the pipe. The experiment is conducted in a closed loop circulation system where water is the transport medium. The pipe system consist of acrylic pipes with 0.013 m, 0.025 m and 0.038 m diameter. The chitosan was extracted from shrimp shells and five different concentration of chitosan were tested. The degree of deacetylation of the chitosan shows 97% which indicates its solubility in water. It was found that the highest drag reduction percentage were obtained from 0.038 m pipe of 33 ppm concentration which is 28%. The flow pattern inside the pipe is also analysed and discussed in this study
Optimisation of parameters for detection of manganese ion using electrochemical method
Authors: Gilbert R , Siddiquee S , Saallah S , Lal Tamrin M
Published: September 2019

An electrochemical method was detected a heavy metal ion of manganese (Mn2+) based on bare gold electrode (AuE). The bare AuE was optimized including various type of electrolytes, redox indicators, pH, scan rate and accumulation time using cyclic voltammetry (CV). From the CV results, the optimal conditions of Mn2+ were found of Tris-HCl (0.1 M, pH 2) buffer for electrolytes supported by 5 mM Prussian blue as a redox indicator with scan rate of 100 mVs-1 and accumulation time of 2 s, respectively. Differential pulse voltammetry (DPV) method was detected with different concentrations of Mn2+ on the ranged from 0.05 to 1.0 ppm with limit of detection (LOD) of 0.075 mg L−1 (S/N=3). A linear regression was found of 0.9659 (r2). The above results indicated that the bare AuE was unable to detect of Mn2+ below safety level. So, the proposed method suggests to detect below safety level of Mn2+ based on the further modification of AuE with high sensitivity, selectivity and accuracy.
Spark plasma sintering of Inconel 738LC: densification and microstructural characteristics
Authors: Ogunbiyi O F , Sadiku E R , Jamiru T , Adesina O T , Beneke L W
Published: September 2019

The optimization of sintering temperature in the production of nickel-based superalloy was investigated. Mixed elemental powders of Inconel 738LC superalloy was fabricated at different sintering temperature ranging between 900 and 1200 °C, with a heating rate of 100 °C min−1, pressure of 50 MPa and 5 min holding time. The microstructures, phase analyses, densification and microhardness tests were conducted by using scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), x-ray Diffraction (XRD), polarized optical microscope (POM), micro-hardness testing machine, and Archimedes’ method respectively. Results revealed the formation of intermetallic phases in the microstructure, irrespective of the sintering temperature. The relative density increased with increasing sintering temperature, as the highest relative density of 98.4% was attained at 1200 °C and with a corresponding microhardness value of 362.25 Hv. There was a marginal decrease in grain size with increasing temperature, thereby resulted in reduced grain growth. This implies that the SPS technology is appropriate for the fabrication of nickel-based superalloy.
(Un)knowability and knowledge iteration
Authors: Liu Sebastian
Published: September 2019

The KK principle states that knowing entails knowing that one knows. This historically popular principle has fallen out of favour among many contemporary philosophers in light of putative counterexamples. Recently, some have defended more palatable versions of KK by weakening the principle. These revisions remain faithful to their predecessor in spirit while escaping crucial objections. This paper examines the prospects of such a strategy. It is argued that revisions of the original principle can be captured by a generalized knowledge iteration principle, Weak-KK, which states that knowing entails the possibility of knowing that one knows. But Weak-KK is vulnerable to an unknowability result and therefore must be rejected. The arguments here suggest that retreating to weaker iteration principles is not an option for the KK enthusiast.
The total dispersal kernel: a review and future directions
Authors: Rogers Haldre S , Beckman Noelle G , Hartig Florian , Johnson Jeremy S , Pufal Gesine , Shea Katriona , Zurell Damaris , Bullock James M , Cantrell Robert Stephen , Loiselle Bette , Pejchar Liba , Razafindratsima Onja H , Sandor Manette E , Schupp Eugene W , Strickland W Christopher , Zambrano Jenny
Published: September 2019

The distribution and abundance of plants across the world depends in part on their ability to move, which is commonly characterized by a dispersal kernel. For seeds, the total dispersal kernel (TDK) describes the combined influence of all primary, secondary and higher-order dispersal vectors on the overall dispersal kernel for a plant individual, population, species or community. Understanding the role of each vector within the TDK, and their combined influence on the TDK, is critically important for being able to predict plant responses to a changing biotic or abiotic environment. In addition, fully characterizing the TDK by including all vectors may affect predictions of population spread. Here, we review existing research on the TDK and discuss advances in empirical, conceptual modelling and statistical approaches that will facilitate broader application. The concept is simple, but few examples of well-characterized TDKs exist. We find that significant empirical challenges exist, as many studies do not account for all dispersal vectors (e.g. gravity, higher-order dispersal vectors), inadequately measure or estimate long-distance dispersal resulting from multiple vectors and/or neglect spatial heterogeneity and context dependence. Existing mathematical and conceptual modelling approaches and statistical methods allow fitting individual dispersal kernels and combining them to form a TDK; these will perform best if robust prior information is available. We recommend a modelling cycle to parameterize TDKs, where empirical data inform models, which in turn inform additional data collection. Finally, we recommend that the TDK concept be extended to account for not only where seeds land, but also how that location affects the likelihood of establishing and producing a reproductive adult, i.e. the total effective dispersal kernel.
How Can the Typhoid Fever Surveillance in Africa and the Severe Typhoid Fever
in Africa Programs Contribute to the Introduction of Typhoid Conjugate
Vaccines?
Authors: Jeon Hyon Jin , Im Justin , Haselbeck Andrea , Holm Marianne , Rakotozandrindrainy Raphaël , Bassiahi Abdramane Soura , Panzner Ursula , Mogeni Ondari D , Seo Hye Jin , Lunguya Octavie , Jacobs Jan , Okeke Iruka N , Terferi Mekonnen , Owusu-Dabo Ellis , Dougan Gordon , Carey Megan , Steele A Duncan , Kim Jerome H , Clemens John D , Andrews Jason R , Park Se Eun , Baker Stephen , Marks Florian
Published: September 2019

Background

The World Health Organization now recommends the use of typhoid conjugate vaccines (TCVs) in typhoid-endemic countries, and Gavi, the Vaccine Alliance, added TCVs into the portfolio of subsidized vaccines. Data from the Severe Typhoid Fever in Africa (SETA) program were used to contribute to TCV introduction decision-making processes, exemplified for Ghana and Madagascar.

Methods

Data collected from both countries were evaluated, and barriers to and benefits of introduction scenarios are discussed. No standardized methodological framework was applied.

Results

The Ghanaian healthcare system differs from its Malagasy counterpart: Ghana features a functioning insurance system, antimicrobials are available nationwide, and several sites in Ghana deploy blood culture–based typhoid diagnosis. A higher incidence of antimicrobial-resistant Salmonella Typhi is reported in Ghana, which has not been identified as an issue in Madagascar. The Malagasy people have a low expectation of provided healthcare and experience frequent unavailability of medicines, resulting in limited healthcare-seeking behavior and extended consequences of untreated disease.

Conclusions

For Ghana, high typhoid fever incidence coupled with spatiotemporal heterogeneity was observed. A phased TCV introduction through an initial mass campaign in high-risk areas followed by inclusion into routine national immunizations prior to expansion to other areas of the country can be considered. For Madagascar, a national mass campaign followed by routine introduction would be the introduction scenario of choice as it would protect the population, reduce transmission, and prevent an often-deadly disease in a setting characterized by lack of access to healthcare infrastructure. New, easy-to-use diagnostic tools, potentially including environmental surveillance, should be explored and improved to facilitate identification of high-risk areas.
Point-of-care testing for measuring haemolymph glucose in invertebrates is not a valid method
Authors: Principe Silas C , Augusto Alessandra , Costa Tânia M
Published: September 2019

Lay summary

Measuring physiological parameters in the field is a challenge, so point-of-care devices are increasingly being used by conservation physiologists to assess blood parameters in non-human animals. We tested a glucose meter in two invertebrates (crab and mussel) and highlight the need for caution when using such devices in invertebrates.
Financial Development, Default Rates and Credit Spreads
Authors: Peri Alessandro , Rachedi Omar
Published: September 2019

US corporate default rates increased dramatically from an annual average of 0.32% between 1950 and 1984 up to 1.65% since 1985. Meanwhile, credit spreads rose by just 6 basis points. We argue that financial development—intended as an exogenous reduction in the fixed cost of borrowing—accounts for this evidence. In a heterogeneous firm model financial development boosts both default rates and firms’ expected recovery rates. These two effects offset each other, muting the change in the credit spreads. The model explains 63% of the rise in default rates and predicts a 6 basis point drop in the credit spreads.
A Systematic Literature Review of Reviews on the Effectiveness of Chlamydia Testing
Authors: Wong William Chi Wai , Lau Stephanie Tsz Hei , Choi Edmond Pui Hang , Tucker Joseph D , Fairley Christopher K , Saunders John M
Published: September 2019

Chlamydia trachomatis is the most common bacterial sexually transmitted infection, causing significant morbidity and economic burden. Strategies like national screening programs or home-testing kits were introduced in some developed countries, yet their effectiveness remains controversial. In this systematic review, we examined reviews of chlamydia screening interventions to assess their effectiveness and the elements that contribute to their success to guide public policy and future research. We assessed English material published after 2000 in PubMed, the Cochrane Library, the British Nursing Index, Medical Database, and Sociological Abstracts, in addition to World Health Organization Global Health Sector Strategies, the European Center for Disease Prevention and Control guidelines, and the Prospective Register of Systematic Reviews. Systematic reviews that focused on chlamydia screening interventions were included. Using the socioecological model, we examined the levels of interventions that may affect the uptake of chlamydia screening. A total of 19 systematic reviews were included. Self-collection in home-testing kits significantly increased screening among girls and women 14–50 years of age. At the organizational level, using electronic health records and not creating additional costs facilitated testing. At the community level, outreach interventions in community and parent centers and homeless shelters achieved high screening rates. At the policy level, interventions with educational and advisory elements could result in significant improvements in screening rates.
Access to medicines through health systems in low- and middle-income countries
Authors: Ozawa Sachiko , Shankar Raja , Leopold Christine , Orubu Samuel
Published: September 2019

Nearly 2 billion people globally have no access to essential medicines. This means essential medicines are unavailable, unaffordable, inaccessible, unacceptable or of low quality for more than a quarter of the population worldwide. This supplement demonstrates the implications of poor medicine access and highlights recent innovations to improve access to essential medicines by presenting new research findings from low- and middle-income countries (LMICs). These studies answer key questions such as: Can performance-based financing improve availability of essential medicines? How affordable are cardiovascular treatments for children? Which countries’ legal frameworks promote universal access to medicines? How appropriately are people using medicines? Do poor-quality medicines impact equity? Answers to these questions are important as essential medicines are vital to the Sustainable Development Goals and are central to the goal of achieving Universal Health Coverage. Access to affordable, quality-assured essential medicines is crucial to reducing the financial burden of care, preventing greater pain and suffering, shortening the duration of illness, and averting needless disabilities and deaths worldwide. This supplement was organized by the Medicines in Health Systems Thematic Working Group of Health Systems Global, a membership organization dedicated to promoting health systems research and knowledge translation. The five studies in the supplement further our understanding by showcasing recent successes and challenges of improving access to quality-assured medicines through health systems in LMICs.
Progress in the genetic analysis of Parkinson’s disease
Authors: Singleton Andrew , Hardy John
Published: September 2019

The pace of genetic discovery in complex disease has accelerated exponentially over the last decade. Our fund of knowledge of the foundational genetics in disease has never been as great. There is a clear path forward to the resolution of the genetic architecture toward a point at which we will saturate the biological understanding of disease through genetics. This understanding continues to provide fundamental insights into disease biology and, with the advent of new data and methodologies, the path from gene to function is becoming clearer and cleaner. In this opinion piece, we discuss progress in the genetics of Parkinson disease. We explore what genetics has revealed thus far in the context of disease biology. We highlight mitophagy/autophagy, dopamine metabolism and the adaptive immune system. We try and link these findings together to give a holistic view of pathogenesis with the underlying theme that disease pathogenesis relates to a failure of damage response pathways. In the 1990s, Parkinson’s disease was regarded a non-genetic disorder. Since that time, however, a huge number of Mendelian loci and risk loci have been identified by positional cloning and by genome-wide association studies. In this review, it is not our intent to list each gene and locus and review their identification [Hernandez, D.G., Reed, X. and Singleton, A.B. (2016) Genetics in Parkinson disease: Mendelian versus non-Mendelian inheritance. J. Neurochem., 139 Suppl 1, 59–74] but rather to outline the pathogenetic mechanisms that these analyses are revealing and then, given the large number of loci already identified, to lay out what we hope future analyses may help us understand, both in terms of disease mechanisms and for risk prediction for the syndrome.
Using human Pompe disease-induced pluripotent stem cell-derived neural cells to identify compounds with therapeutic potential
Authors: Huang Hsiang-Po , Chiang Wei , Stone Lee , Kang Chun-Kai , Chuang Ching-Yu , Kuo Hung-Chih
Published: September 2019

Pompe disease (OMIM # 232300) is a glycogen storage disease caused by autosomal recessive mutations of the gene encoding alpha-1,4-glucosidase (GAA; EC 3.2.1.20). Despite the relatively effective employment of enzyme replacement therapy, some critical medical issues still exist in patients with this disease, including the persistence of abnormalities in the central nervous system (CNS), probably because of the inability of the recombinant GAA to pass through the blood–brain barrier. To address this issue, identification of more therapeutic agents that target the CNS of patients with Pompe disease may be required. In this study, we derived neuronal cells from Pompe disease-induced pluripotent stem cells (Pom-iPSCs) and proved that they are able to recapitulate the hallmark cellular and biochemical phenotypes of Pompe disease. Using the Pom-iPSC-derived neurons as an in vitro drug-testing model, we then identified three compounds, ebselen, wortmannin and PX-866, with therapeutic potential to alleviate Pompe disease-associated pathological phenotypes in the neurons derived from Pom-iPSCs. We confirmed that all three compounds were able to enhance the GAA activity in the Pom-iPSC-derived neurons. Moreover, they were able to enhance the GAA activity in several important internal organs of GAA-deficient mice when co-injected with recombinant human GAA, and we found that intraperitoneal injection of ebselen was able to promote the GAA activity of the GAA-heterozygous mouse brain. Our results prove the usefulness of Pom-iPSC-derived neuronal populations for identifying new compounds with therapeutic potential.
Petro-RMB? The oil trade and the internationalization of the renminbi
Authors: Kamel Maha , Wang Hongying
Published: September 2019

In this article, we examine China's promotion of the renminbi (RMB) in international oil trade and explore its implications for the international currency system in the short and the long term. The article traces the rise of the RMB in international oil trade in recent years and provides an analysis of its impact on the internationalization of the Chinese currency. We argue that despite the increasing use of the yuan in oil trade in recent years, in the short term it is highly unlikely that a petro-RMB system will emerge to rival the petrodollar system. Unlike the petrodollar, which combines the qualities of a master currency, a top currency and a negotiated currency, China lacks the economic leadership and the political and geopolitical leverages to make the RMB a major petrocurrency. Although the emergence of the RMB-denominated Shanghai oil futures is an important development, the absence of highly developed financial markets and a strong legal system in China hinders its potential. In the long run, the RMB may take on a more prominent role in the international oil trade as China's weight as an oil importer rises. More importantly, the overuse of financial sanctions by the US government has begun to undermine the role of the dollar within and beyond the oil trade. In addition, the rise of alternative energy sources will diminish the centrality of oil in the world economy, thus reducing the significance of petrocurrencies—whether the dollar or the RMB—in shaping the international currency system.
Reconsidering African Refugee Law
Authors: Cantor David James , Chikwanha Farai
Published: September 2019

Fifty years have now passed since the 1969 Convention Governing the Specific Aspects of Refugee Problems in Africa was adopted by the Organization of African Unity (OAU). Within international refugee law, the OAU Refugee Convention (OAU Convention) is often taken to encapsulate the ‘African’ legal approach to refugees. This anniversary represents an opportune moment to review the state of ‘African’ refugee law. This article seeks to contribute to that regional undertaking by providing insights based on a comparative analysis of national refugee laws in African States.

 This encompasses consideration of how national law engages with the OAU Convention, as a centre of gravity for refugee law development in the region, but it extends also to exploring whether an ‘African’ approach to refugee law can be discerned in the novel ways in which the national refugee laws of African States (i) implement other refugee and human rights law treaties, and (ii) create new refugee law rules without precedent in treaty law. By building a more comprehensive picture of comparative refugee law in Africa, the study aims to complement existing refugee law studies in Africa that focus mainly on the international law level or on local implementation within only one or two States.
What’s Inside the Box? Mapping Agency and Conflict within Victims’ Organizations
Authors: Rudling Adriana
Published: September 2019

Abstract∞

This article provides a better understanding of victims’ individual-level agency and their differences in terms of transitional justice preferences and capabilities by inquiring into intra-organizational conflict. While it is primarily conceptual, it combines secondary literature with case study material from Colombia and Panama, converging on Latin America as a geographical area and the crime of forced disappearance. Tracing the evolution of the 2004/2005 fragmentation of the Colombian Association of Relatives of Detained Disappeared Persons, it argues that victims’ collective action and perceived homogeneity is a performance that builds on much internal negotiation between members. When deliberations have clear winners, they end in adjustments of the mission statement of the group, purges and voluntary member withdrawal, but fragmentations result from situations where the leaders of opposing coalitions are evenly matched and their proposals equally engaging to peers.
Quality control circle: a tool for enhancing perceptions of patient safety culture among hospital staff in Chinese hospitals
Authors: Zhang Dan , Liao Meixia , Zhou Yiping , Liu Tingfang
Published: September 2019

Objective

To explore whether quality control circle (QCC) is associated with hospital staff’s perceptions of patient safety culture (PSC).

Design

A cross-sectional survey in 12 public hospitals from October to December 2018 and a longitudinal survey in one public hospital from November 2017 to November 2018.

Setting

In 12 public hospitals from six provinces located in eastern, central and western of China, and one public hospital in eastern China.

Participants

In total, 811 and 102 hospital staff participated in the cross-sectional survey and the longitudinal survey, respectively. These participants included doctors, nurses, medical technicians and administrative staff.

Main Outcome Measures

Hospital staff’s perceptions of PSC were measured by the Hospital Survey on Patient Safety Culture (HSOPSC) questionnaire. The association between QCC implementation and PSC was identified by univariate analysis and multiple linear regression analysis.

Results

Univariate analysis showed that the staff from hospitals that had implemented QCC received significantly higher HSOPSC scores than those from hospitals where QCC had not been implemented (3.73 ± 0.61 vs. 3.57 ± 0.41, P < 0.05). The QCC implementation was a significant predictor in the established multiple linear regression model. One year after QCC implementation, the hospital involved in the longitudinal survey scored higher in HSOPSC than before (3.75 ± 0.42 vs. 3.60 ± 0.36, P < 0.001).

Conclusions

QCC implementation was positively associated with PSC and the former could promote the establishment of the latter. It is suggested that QCC can play an active role in enhancing PSC so as to further improve patient safety management.
Post-transcriptional regulation of inflammation by RNA-binding proteins via cis-elements of mRNAs
Authors: Uchida Yutaro , Chiba Tomoki , Kurimoto Ryota , Asahara Hiroshi
Published: September 2019

In human genome, there are approximately 1,500 RNA-binding proteins (RBPs). They can regulate mRNA stability or translational efficiency via ribosomes and these processes are known as ‘post-transcriptional regulation’. Accumulating evidences indicate that post-transcriptional regulation is the determinant of the accurate levels of cytokines mRNAs. While transcriptional regulation of cytokines mRNAs has been well studied and found to be important for the rapid induction of mRNA and regulation of the acute phase of inflammation, post-transcriptional regulation by RBPs is essential for resolving inflammation in the later phase, and their dysfunction may lead to severe autoimmune diseases such as rheumatoid arthritis or systemic lupus erythematosus. For post-transcriptional regulation, RBPs recognize and directly bind to cis-regulatory elements in 3′ untranslated region of mRNAs such as AU-rich or constitutive decay elements and play various roles. In this review, we summarize the recent findings regarding the role of RBPs in the regulation of inflammation.
Estimating the Term Structure with Linear Regressions: Getting to the Roots of the Problem
Authors: Goliński Adam , Spencer Peter
Published: September 2019

Linear estimators of the affine term structure model are inconsistent since they cannot reproduce the factors used in estimation. This is a serious handicap empirically, giving a worse fit than the conventional ML estimator that ensures consistency. We show that a simple self-consistent estimator can be constructed using the eigenvalue decomposition of a regression estimator. The remaining parameters of the model follow analytically. Estimates from this model are virtually indistinguishable from that of the ML estimator. We apply the method to estimate various models of U.S. Treasury yields. These exercises greatly extend the range of models that can be estimated.
Biodiversity of Hematophagous Diptera (Culicidae and Psychodidae) in a Small Hydroelectric Power Station and Surrounding Area in the State of Minas Gerais, Brazil
Authors: Rêgo Felipe Dutra , de Oliveira Maria Angélica , Carvalho Gustavo Mayr de Lima , Andrade Filho José Dilermando
Published: September 2019

Hydroelectric power stations may affect the population dynamics of mosquitoes and sand flies, a group with impact on public health due to the possibility to transmit pathogens to humans. This work characterized and compared the fauna of mosquitoes and sand flies in a hydroelectric power station and peridomicile areas in the State of Minas Gerais, Brazil. Insect collections were performed in August 2015 at dry season and February 2016 in rainy season. Ten HP light traps were set at each of two sites for three consecutive days in each of two seasons (dry and rainy). Furthermore, collections with Shannon traps were made in each sampling area (hydropower plant and peridomicile area) from 4:00 p.m. being shut down at 8:00 p.m. for two consecutive days in each of two seasons (dry and rainy). In total, 1,222 insects from 13 genera and 27 species were collected. The most plentiful species were respectively Culex declarator (Dyar and Knab, 1906) and Pintomyia pessoai (Coutinho & Barretto, 1940). A high number of insects (78.5%) were collected during the rainy period (P < 0.05). About equitability, statistical significance was observed in the peridomicile area (dry season J = 0.75 and rainy season J = 0.82). The highest values of species diversity were observed in the hydropower plant (H = 2.68) and peridomicile area (H = 2.38) both in the rainy season with statistical significance comparing with dry season. Our results demonstrate that the occurrence of vector species in this region increases the potential risk of transmission of pathogens, especially arbovirus and Leishmania Ross, 1903.