bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Extracellular Vesicles Secreted in Lentiviral Producing HEK293SF Cell Cultures
Authors: Do Minh Aline , Star Alexandra T. , Stupak Jacek , Fulton Kelly M. , Haqqani Arsalan S. , Gélinas Jean-François , Li Jianjun , Twine Susan M. , Kamen Amine A.
Published: April 2021

Lentiviral vectors (LVs) are a powerful tool for gene and cell therapy and human embryonic kidney cells (HEK293) have been extensively used as a platform for production of these vectors. Like most cells and cellular tissues, HEK293 cells release extracellular vesicles (EVs). EVs released by cells share similar size, biophysical characteristics and even a biogenesis pathway with cell-produced enveloped viruses, making it a challenge to efficiently separate EVs from LVs. Thus, EVs co-purified with LVs during downstream processing, are considered “impurities” in the context of gene and cell therapy. A greater understanding of EVs co-purifying with LVs is needed to enable improved downstream processing. To that end, EVs from an inducible lentivirus producing cell line were studied under two conditions: non-induced and induced. EVs were identified in both conditions, with their presence confirmed by transmission electron microscopy and Western blot. EV cargos from each condition were then further characterized by a multi-omic approach. Nineteen proteins were identified by mass spectrometry as potential EV markers to differentiate EVs in LV preparations. Lipid composition of EV preparations before and after LV induction showed similar enrichment in phosphatidylserine. RNA cargos in EVs showed enrichment in transcripts involved in viral processes and binding functions. These findings provide insights on the product profile of lentiviral preparations and could support the development of improved separation strategies aimed at removing co-produced EVs.
ER Stress, UPR Activation and the Inflammatory Response to Viral Infection
Authors: Cirone Mara
Published: April 2021

The response to invading pathogens such as viruses is orchestrated by pattern recognition receptor (PRR) and unfolded protein response (UPR) signaling, which intersects and converges in the activation of proinflammatory pathways and the release of cytokines and chemokines that harness the immune system in the attempt to clear microbial infection. Despite this protective intent, the inflammatory response, particularly during viral infection, may be too intense or last for too long, whereby it becomes the cause of organ or systemic diseases itself. This suggests that a better understanding of the mechanisms that regulate this complex process is needed in order to achieve better control of the side effects that inflammation may cause while potentiating its protective role. The use of specific inhibitors of the UPR sensors or PRRs or the downstream pathways activated by their signaling could offer the opportunity to reach this goal and improve the outcome of inflammation-based diseases associated with viral infections.
Viruses of Microbes 2020: The Latest Conquest on Viruses of Microbes
Authors: Quax Tessa E. F. , De Paepe Marianne , Holmfeldt Karin
Published: April 2021

This Special Issue celebrates viruses of microbes: those viruses that infect archaea, bacteria and microbial eukaryotes [...]
Sequence Length of HIV-1 Subtype B Increases over Time: Analysis of a Cohort of Patients with Hemophilia over 30 Years
Authors: Cho Young-Keol , Kim Jung-Eun , Foley Brian T.
Published: April 2021

We aimed to investigate whether the sequence length of HIV-1 increases over time. We performed a longitudinal analysis of full-length coding region sequences (FLs) during an HIV-1 outbreak among patients with hemophilia and local controls infected with the Korean subclade B of HIV-1 (KSB). Genes were amplified by overlapping RT-PCR or nested PCR and subjected to direct sequencing. Overall, 141 FLs were sequentially determined over 30 years in 62 KSB-infected patients. Phylogenetic analysis indicated that within KSB, two FLs from plasma donors O and P comprised two clusters, together with 8 and 12 patients with hemophilia, respectively. Signature pattern analysis of the KSB of HIV-1 revealed 91 signature nucleotide residues (1.1%). In total, 48 and 43 signature nucleotides originated from clusters O and P, respectively. Six positions contained 100% specific nucleotide(s) in clusters O and P. In-depth FL analysis for over 30 years indicated that the KSB FL significantly increased over time before combination antiretroviral therapy (cART) and decreased with cART. This increase occurred due to the significant increase in env and nef genes, originating in the variable regions of both genes. The increase in sequence length of HIV-1 over time suggests an evolutionary direction.
Inhibitors of Protein Glycosylation Are Active against the Coronavirus Severe Acute Respiratory Syndrome Coronavirus SARS-CoV-2
Authors: Rajasekharan Sreejith , Milan Bonotto Rafaela , Nascimento Alves Lais , Kazungu Yvette , Poggianella Monica , Martinez-Orellana Pamela , Skoko Natasa , Polez Sulena , Marcello Alessandro
Published: April 2021

Repurposing clinically available drugs to treat the new coronavirus disease 2019 (COVID-19) is an urgent need in the course of the Severe Acute Respiratory Syndrome coronavirus (SARS-CoV-2) pandemic, as very few treatment options are available. The iminosugar Miglustat is a well-characterized drug for the treatment of rare genetic lysosome storage diseases, such as Gaucher and Niemann-Pick type C, and has also been described to be active against a variety of enveloped viruses. The activity of Miglustat is here demonstrated in the micromolar range for SARS-CoV-2 in vitro. The drug acts at the post-entry level and leads to a marked decrease of viral proteins and release of infectious viruses. The mechanism resides in the inhibitory activity toward α-glucosidases that are involved in the early stages of glycoprotein N-linked oligosaccharide processing in the endoplasmic reticulum, leading to a marked decrease of the viral Spike protein. Indeed, the antiviral potential of protein glycosylation inhibitors against SARS-CoV-2 is further highlighted by the low-micromolar activity of the investigational drug Celgosivir. These data point to a relevant role of this approach for the treatment of COVID-19.
Vaccination with Prion Peptide-Displaying Polyomavirus-Like Particles Prolongs Incubation Time in Scrapie-Infected Mice
Authors: Eiden Martin , Gedvilaite Alma , Leidel Fabienne , Ulrich Rainer G. , Groschup Martin H.
Published: April 2021

Prion diseases like scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle or Creutzfeldt–Jakob disease (CJD) in humans are fatal neurodegenerative diseases characterized by the conformational conversion of the normal, mainly α-helical cellular prion protein (PrPC) into the abnormal β-sheet rich infectious isoform PrPSc. Various therapeutic or prophylactic approaches have been conducted, but no approved therapeutic treatment is available so far. Immunisation against prions is hampered by the self-tolerance to PrPC in mammalian species. One strategy to avoid this tolerance is presenting PrP variants in virus-like particles (VLPs). Therefore, we vaccinated C57/BL6 mice with nine prion peptide variants presented by hamster polyomavirus capsid protein VP1/VP2-derived VLPs. Mice were subsequently challenged intraperitoneally with the murine RML prion strain. Importantly, one group exhibited significantly increased mean survival time of 240 days post-inoculation compared with 202 days of the control group. These data show that immunisation with VLPs presenting PrP peptides may represent a promising strategy for an effective vaccination against transmissible spongiform encephalitis agents.
Arsenicals, the Integrated Stress Response, and Epstein–Barr Virus Lytic Gene Expression
Authors: Lee Jaeyeun , Stone Jennifer , Desai Prashant , Kosowicz John G. , Liu Jun O. , Ambinder Richard F.
Published: April 2021

Following our observation that clofoctol led to Epstein–Barr virus (EBV) lytic gene expression upon activation of the integrated stress response (ISR), we decided to investigate the impact of As2O3 on viral lytic gene expression. As2O3 has also been reported to activate the ISR pathway by its activation of the heme-regulated inhibitor (HRI). Our investigations show that As2O3 treatment leads to eIF2α phosphorylation, upregulation of ATF4 and TRB3 expression, and an increase of EBV Zta gene expression in lymphoid tumor cell lines as well as in naturally infected epithelial cancer cell lines. However, late lytic gene expression and virion production were blocked after arsenic treatment. In comparison, a small molecule HRI activator also led to increased Zta expression but did not block late lytic gene expression, suggesting that As2O3 effects on EBV gene expression are also mediated through other pathways.
A Comparative Analysis of Hidden Markov Model, Hybrid Support Vector Machines, and Hybrid Artificial Neural Fuzzy Inference System in Reservoir Inflow Forecasting (Case Study: The King Fahd Dam, Saudi Arabia)
Authors: Alquraish Mohammed M. , Abuhasel Khaled A. , Alqahtani Abdulrahman S. , Khadr Mosaad
Published: April 2021

The precise prediction of the streamflow of reservoirs is of considerable importance for many activities relating to water resource management, such as reservoir operation and flood and drought control and protection. This study aimed to develop and evaluate the applicability of a hidden Markov model (HMM) and two hybrid models, i.e., the support vector machine-genetic algorithm (SVM-GA) and artificial neural fuzzy inference system-genetic algorithm (ANFIS-GA), for reservoir inflow forecasting at the King Fahd dam, Saudi Arabia. The results obtained by the HMM model were compared with those for the two hybrid models ANFIS-GA and SVM-GA, and with those for individual SVM and ANFIS models based on performance evaluation indicators and visual inspection. The results of the comparison revealed that the ANFIS-GA model and ANFIS model provided superior results for forecasting monthly inflow with satisfactory accuracy in both training (R2 = 0.924, 0.857) and testing (R2 = 0.842, 0.810) models. The performance evaluation results for the developed models showed that the GA-induced improvement in the ANFIS and SVR forecasts was matched by an approximately 25% decrease in RMSE and around a 13% increase in Nash–Sutcliffe efficiency. The promising accuracy of the proposed models demonstrates their potential for applications in monthly inflow forecasting in the present semiarid region.
A Random Forest Model for the Prediction of FOG Content in Inlet Wastewater from Urban WWTPs
Authors: Mateo Pérez Vanesa , Mesa Fernández José Manuel , Villanueva Balsera Joaquín , Alonso Álvarez Cristina
Published: April 2021

The content of fats, oils, and greases (FOG) in wastewater, as a result of food preparation, both in homes and in different commercial and industrial activities, is a growing problem. In addition to the blockages generated in the sanitary networks, it also represents a difficulty for the performance of wastewater treatment plants (WWTP), increasing energy and maintenance costs and worsening the performance of downstream treatment processes. The pretreatment stage of these facilities is responsible for removing most of the FOG to avoid these problems. However, so far, optimization has been limited to the correct design and initial installation dimensioning. Proper management of this initial stage is left to the experience of the operators to adjust the process when changes occur in the characteristics of the wastewater inlet. The main difficulty is the large number of factors influencing these changes. In this work, a prediction model of the FOG content in the inlet water is presented. The model is capable of correctly predicting 98.45% of the cases in training and 72.73% in testing, with a relative error of 10%. It was developed using random forest (RF) and the good results obtained (R2 = 0.9348 and RMSE = 0.089 in test) will make it possible to improve operations in this initial stage. The good features of this machine learning algorithm had not been used, so far, in the modeling of pretreatment parameters. This novel approach will result in a global improvement in the performance of this type of facility allowing early adoption of adjustments to the pretreatment process to remove the maximum amount of FOG.
Projection of Future Drought Characteristics under Multiple Drought Indices
Authors: Khan Muhammad Imran , Zhu Xingye , Jiang Xiaoping , Saddique Qaisar , Saifullah Muhammad , Niaz Yasir , Sajid Muhammad
Published: April 2021

Drought is a natural phenomenon caused by the variability of climate. This study was conducted in the Songhua River Basin of China. The drought events were estimated by using the Reconnaissance Drought Index (RDI) and Standardized Precipitation Index (SPI) which are based on precipitation (P) and potential evapotranspiration (PET) data. Furthermore, drought characteristics were identified for the assessment of drought trends in the study area. Short term (3 months) and long term (12 months) projected meteorological droughts were identified by using these drought indices. Future climate precipitation and temperature time series data (2021–2099) of various Representative Concentration Pathways (RCPs) were estimated by using outputs of the Global Circulation Model downscaled with a statistical methodology. The results showed that RCP 4.5 have a greater number of moderate drought events as compared to RCP 2.6 and RCP 8.5. Moreover, it was also noted that RCP 8.5 (40 events) and RCP 4.5 (38 events) showed a higher number of severe droughts on 12-month drought analysis in the study area. A severe drought conditions projected between 2073 and 2076 with drought severity (DS-1.66) and drought intensity (DI-0.42) while extreme drying trends were projected between 2097 and 2099 with drought severity (DS-1.85) and drought intensity (DI-0.62). It was also observed that Precipitation Decile predicted a greater number of years under deficit conditions under RCP 2.6. Overall results revealed that more severe droughts are expected to occur during the late phase (2050–2099) by using RDI and SPI. A comparative analysis of 3- and 12-month drying trends showed that RDI is prevailing during the 12-month drought analysis while almost both drought indices (RDI and SPI) indicated same behavior of drought identification at 3-month drought analysis between 2021 and 2099 in the research area. The results of study will help to evaluate the risk of future drought in the study area and be beneficial for the researcher to make an appropriate mitigation strategy.
Impact of Future Land-Use/Cover Change on Streamflow and Sediment Load in the Be River Basin, Vietnam
Authors: Khoi Dao Nguyen , Loi Pham Thi , Sam Truong Thao
Published: April 2021

Evaluation of the influence of land-use/cover (LUC) change on water and sediment fluxes from river basins is essential for proposing adaptation and mitigation strategies, but as of yet little information is available, especially in the tropics. For this motivation, the objective of this study was to assess the impact of scenarios of LUC change on streamflow and sediment load in the Be River Basin using the Dynamic Conversion of Land-Use and its Effects (Dyna-CLUE) model and the Soil and Water Assessment Tool (SWAT) model. The Dyna-CLUE and SWAT models were calibrated and validated against observed data in the period of 1980–2010. Three future LUC scenarios in 2030, 2050, and 2070 were generated utilizing the calibrated Dyna-CLUE model based on the historical conversion of forest land to agricultural land and urban area in the study region. Subsequently, the calibrated SWAT model was used to simulate the changes in streamflow and sediment load under these three future LUC scenarios. Results indicated that the annual streamflow and sediment load were estimated to be approximately 287.35 m3/s and 101.23 × 103 ton/month for the baseline period. Under the influence of future LUC scenarios, the annual streamflow and sediment load would experience increases of 0.19% to 0.45% and 0.22% to 0.68%, respectively. In addition, the 5th and 95th percentile values of streamflow and sediment load are predicted to rise in the context of future LUC change. The results achieved from the present study will support the managers and policy makers proposing appropriate solutions for sustainable water resources management and sediment control in the context of LUC change.
Combining Process Modelling and LCA to Assess the Environmental Impacts of Wastewater Treatment Innovations
Authors: Paulu Aleš , Bartáček Jan , Šerešová Markéta , Kočí Vladimír
Published: April 2021

Alternative wastewater treatment (WWT) technologies with lower environmental impacts seem to be the way forward in the pursuit of sustainable wastewater treatment plants (WWTPs). Process modelling of material and energy flows together with life-cycle assessment (LCA) can help to better understand these impacts and show the right direction for their development. Here, we apply this combined approach to three scenarios: conventional WWT; conventional WWT + chemically enhanced primary treatment (CEPT); conventional WWT + CEPT + side stream partial nitritation/anammox (PN/A). For each scenario, equations were developed to calculate chemical oxygen demand and nitrogen flow (solid and dissolved form) through the WWTP and to estimate the energy demands of its unit operations. LCA showed that the main environmental impact categories for all scenarios were global warming potential (GWP), eutrophication potential (EP) and marine aquatic eco-toxicity potential (MAETP). Compared with conventional WWT, CEPT and CEPT combined with PN/A resulted in a higher sum of normalized and weighed environmental indicators, by 19.5% and 16.4%, respectively (20.0% and 18.3% including biogenic carbon). Interestingly, the environmentally positive features of the alternative scenarios were often traded-off against other increased negative impacts. This suggests that further development is needed to consider these technologies a sustainable alternative.
Cyber—Physical Attack Detection in Water Distribution Systems with Temporal Graph Convolutional Neural Networks
Authors: Tsiami Lydia , Makropoulos Christos
Published: April 2021

Prompt detection of cyber–physical attacks (CPAs) on a water distribution system (WDS) is critical to avoid irreversible damage to the network infrastructure and disruption of water services. However, the complex interdependencies of the water network’s components make CPA detection challenging. To better capture the spatiotemporal dimensions of these interdependencies, we represented the WDS as a mathematical graph and approached the problem by utilizing graph neural networks. We presented an online, one-stage, prediction-based algorithm that implements the temporal graph convolutional network and makes use of the Mahalanobis distance. The algorithm exhibited strong detection performance and was capable of localizing the targeted network components for several benchmark attacks. We suggested that an important property of the proposed algorithm was its explainability, which allowed the extraction of useful information about how the model works and as such it is a step towards the creation of trustworthy AI algorithms for water applications. Additional insights into metrics commonly used to rank algorithm performance were also presented and discussed.
Deep Learning Based Approach to Classify Saline Particles in Sea Water
Authors: Alshehri Mohammed , Kumar Manoj , Bhardwaj Akashdeep , Mishra Shailendra , Gyani Jayadev
Published: April 2021

Water is an essential resource that facilitates the existence of human life forms. In recent years, the demand for the consumption of freshwater has substantially increased. Seawater contains a high concentration of salt particles and salinity, making it unfit for consumption and domestic use. Water treatment plants used to treat seawater are less efficient and reliable. Deep learning systems can prove to be efficient and highly accurate in analyzing salt particles in seawater with higher efficiency that can improve the performance of water treatment plants. Therefore, this work classified different concentrations of salt particles in water using convolutional neural networks with the implementation of transfer learning. Salt salinity concentration images were captured using a designed Raspberry Pi based model and these images were further used for training purposes. Moreover, a data augmentation technique was also employed for the state-of-the-art results. Finally, a deep learning neural network was used to classify saline particles of varied concentration range images. The experimental results show that the proposed approach exhibited superior outcomes by achieving an overall accuracy of 90% and f-score of 87% in classifying salt particles. The proposed model was also evaluated using other evaluation metrics such as precision, recall, and specificity, and showed robust results.
A Moment-Based Chezy Formula for Bed Shear Stress in Varied Flow
Authors: Elgamal Mohamed
Published: April 2021

Despite its limitations, the Chezy bed shear stress formula is commonly used in depth-averaged flow numerical models as closure for estimating mutual tractive stresses with underneath boundaries. This paper proposes a novel moment-based formula that could be considered a revised version of the Chezy formula and can be used to estimate local variations of the bed shear stress under more complex and varied flow conditions with accelerating–decelerating flow fields. The formula depends on two velocity scales: the depth-averaged velocity, Uo, and a new moment-based velocity scale, u1. The new formula is calibrated using 10 experiments for flow over fixed bedforms, and the calibration coefficient is found to linearly correlate with h/Δ and h/zo ratios. The formula is also applied for the case of air flow across a negative step, jet water flow downstream a gate, and 2D water flow downstream an oblique negative step, and reasonably satisfactory agreement with the measured data is found. The new formula could be used in vertically averaged and moment models to disclose part of the information already lost by the vertical integration procedure.
Heavy Metals Removal from Electroplating Wastewater by Waste Fiber-Based Poly(amidoxime) Ligand
Authors: Rahman Md. Lutfor , Wong Zhi Jian , Sarjadi Mohd Sani , Soloi Sabrina , Arshad Sazmal E. , Bidin Kawi , Musta Baba
Published: April 2021

An efficient and economical treatment technology for heavy metal removal from the electroplating wastewaters is needed for the water purification. Therefore, pure cellulosic materials were derived from two waste fiber (pandanus fruit and durian rind) and conversion of the cellulose into the poly(acrylonitrile)-grafted material was accomplished by free radical grafting system. Thereafter, poly(amidoxime) ligand was produced from the grafted materials. Sorption capacity (qe) of several toxic metals ions was found to be high, e.g., copper capacity (qe) was 298.4 mg g−1 at pH 6. In fact, other metal ions, such as cobalt chromium and nickel also demonstrated significant sorption capacity at pH 6. Sorption mechanism played acceptable meet with pseudo second-order rate of kinetic pattern due to the satisfactory correlation with the experimental sorption values. A significant correlation coefficient (R2 > 0.99) with Langmuir model isotherm showed the single or monolayer sorption occurred on the surfaces. The reusability study showed that the polymer ligand can be useful up to six cycles with minimum loss (7%) of efficiency and can be used in the extraction of toxic metal ions present in the wastewaters. Therefore, two types of electroplating wastewater were used in this study, one containing high concentration of copper (23 ppm) and iron (32 ppm) with trace level of others heavy metals (IWS 1) and another containing high concentration of copper (85.7 ppm) only with trace level of others heavy metals (IWS 2). This polymeric ligand showed acceptable removal magnitude, up to 98% of toxic metal ions can be removed from electroplating wastewater.
Applicability Study of Hydrological Period Identification Methods: Application to Huayuankou and Lijin in the Yellow River Basin, China
Authors: Chen Xingtong , Wang Xiujie , Lian Jijian
Published: April 2021

Identifying implicit periodicities in hydrological data is significant for managing river–basin water resources and establishing flood forecasting systems. However, the complexity and randomness of hydrological systems make it difficult to detect hidden oscillatory characteristics. This study discusses the performance and applicability of five period identification methods, namely periodograms, autocorrelation analysis (AA), maximum entropy spectral analysis (MESA), wavelet analysis (WA), and the Hilbert–Huang transform (HHT). The annual and monthly runoff data are sampled from two stations (Huayuankou and Lijin on the Yellow River in China) in the years 1949–2015. The conclusions are as follows: (i) All methods identify the significant periods of 6 months, 12 months, and 18–19 months, which have relatively high energy of peaks; (ii) WA and HHT perform best when dealing with nonstationary time series, but they are ineffective for identifying large-scale periods; (iii) MESA has high resolution and stability but is prone to oscillate at small-scale periods when applied to monthly series; and (iv) periodograms and AA are relatively simple, but their results lack stability and are significantly affected by the data length—the resolution of AA is too low when applied to annual data, and periodograms can easily produce “false peaks”. Generally, it is better to apply multiple methods comprehensively than each method singularly, and this can be effective in reducing subjective influences.
Objectives, Keys and Results in the Water Networks to Reach the Sustainable Development Goals
Authors: Mercedes Garcia Angel Valentin , López-Jiménez Petra Amparo , Sánchez-Romero Francisco-Javier , Pérez-Sánchez Modesto
Published: April 2021

The world is continuously searching for ways to improve how water is used for energy. As the population increases, so do the needs for natural resources and, in turn, the needs for energy. This research sought to show how the world has tried to achieve more sustainable forms of pressurized water distribution and to show the results that have been obtained. In this sense, technologies have been used for the production of clean energy, energy recovery instead of dissipation, reprogramming of pumping stations and hybrid systems. In many cases, much lower water and energy requirements are achieved and, in turn, greenhouse gas emissions related to water use are reduced. Sixty-one different water systems were analyzed considering different energy, economic and environmental indicators. The different operation range of these indicators were defined according to sustainable indicators.
A Modified Distributed CN-VSA Method for Mapping of the Seasonally Variable Source Areas
Authors: Panjabi Kishore , Rudra Ramesh , Goel Pradeep , Ahmed Syed , Gharabaghi Bahram
Published: April 2021

Many watershed models employ the Soil Conservation Service Curve Number (SCS-CN) approach for runoff simulation based on soil and land use information. These models implicitly assume that runoff is generated by the Hortonian process and; therefore, cannot correctly account for the effects of topography, variable source area (VSA) and/or soil moisture distribution in a watershed. This paper presents a new distributed CN-VSA method that is based on the SCS-CN approach to estimate runoff amount and uses the topographic wetness index (TWI) to distribute the runoff-generating areas within the watershed spatially. The size of the saturated-watershed areas and their spatial locations are simulated by assuming an average annual value of potential maximum retention. However, the literature indicates significant seasonal variation in potential maximum retention which can considerably effect water balance and amount of nonpoint source pollution. This paper focuses on developing a modified distributed CN-VSA method that accounts for the seasonal changes in the potential maximum retention. The results indicate that the modified distributed CN-VSA approach is better than distributed CN-VSA to simulate runoff amount and spatial distribution of runoff-generating areas. Overall, the study results are significant for improved understanding of hydrological response of watershed where seasonal factors describe the potential maximum retention, and, thus, saturation excess runoff generation in the watershed.
Numerical Analysis of Free-Surface Flows over Rubber Dams
Authors: Chu Chia-Ren , Tran Truc Thi Thu , Wu Tso-Ren
Published: April 2021

This study integrates a large eddy simulation (LES) model and volume of fluid (VOF) method to simulate the free-surface flows over inflexible circular-crested dams of different shapes. The simulated water depths and pressures on the dam surface are validated by the results of laboratory experiments. Then the numerical model examines the effects of the water depths and the Reynolds number on the hydrodynamic force and the discharge coefficient. The simulation results reveal that the time-averaged drag coefficient decreases as the downstream water depth H2 increases, while the influence of water depth H2 on the lift coefficients is less significant. Furthermore, the discharge coefficients of circular and elliptical dams, computed from the simulated velocity profiles over the crest of the dam, agree with the formulae suggested by previous studies when the downstream depth H2/H1 < 0.90. In contrast, the discharge coefficient of a tear-shape dam is slightly larger than those of circular dams.
Heat Recovery from Wastewater—A Review of Available Resource
Authors: Nagpal Himanshu , Spriet Jan , Murali Madhu , McNabola Aonghus
Published: April 2021

The EU Directive 2018/2001 recognized wastewater as a renewable heat source. Wastewater from domestic, industrial and commercial developments maintains considerable amounts of thermal energy after discharging into the sewer system. It is possible to recover this heat by using technologies like heat exchangers and heat pumps; and to reuse it to satisfy heating demands. This paper presents a review of the literature on wastewater heat recovery (WWHR) and its potential at different scales within the sewer system, including the component level, building level, sewer pipe network level, and wastewater treatment plant (WWTP) level. A systematic review is provided of the benefits and challenges of WWHR across each of these levels taking into consideration technical, economic and environmental aspects. This study analyzes important attributes of WWHR such as temperature and flow dynamics of the sewer system, impacts of WWHR on the environment, and legal regulations involved. Existing gaps in the WWHR field are also identified. It is concluded that WWHR has a significant potential to supply clean energy at a scale ranging from buildings to large communities and districts. Further attention to WWHR is needed from the research community, policymakers and other stakeholders to realize the full potential of this valuable renewable heat source.
Ecology and Genetics of Cyperus fuscus in Central Europe—A Model for Ephemeral Wetland Plant Research and Conservation
Authors: Kúr Pavel , Píšová Soňa , Tremetsberger Karin , Dřevojan Pavel , Kącki Zygmunt , Böckelmann Jörg , Bernhardt Karl-Georg , Hroudová Zdenka , Mesterházy Attila , Šumberová Kateřina
Published: April 2021

The ecology and species diversity of ephemeral wetland vegetation have been fairly well studied, but the biology of its characteristic species has rarely been investigated holistically. Here we combine previous results on the genetic diversity of a suitable model species (the diploid Cyperus fuscus) with new data on its historical and recent occurrence, its ecological and climatic niche, and the associated vegetation. Analysis of phytosociological relevés from Central Europe revealed a broad ecological niche of C. fuscus with an optimum in the Isoëto-Nanojuncetea class, extending to several other vegetation types. Overall species composition in the relevés highlight C. fuscus as a potential indicator of habitat conditions suitable for a range of other threatened taxa. Analysis of historical records of C. fuscus from the Czech Republic showed an increasing trend in the number of localities since the 1990s. It seems that recent climate warming allows the thermophilous C. fuscus to expand its range into colder regions. Isoëto-Nanojuncetea and Bidentetea species are well represented in the soil seed bank in both riverine and anthropogenic habitats of C. fuscus. Vegetation diversity has a weak negative effect and anthropogenic (compared to riverine) habitats have a strong negative effect on genetic diversity in this species.
A Comparison of Technology Teacher′s Personal Background, Teaching Environment, Behavior and Psychological Characteristics of Korean and U.S.: Using TALIS 2018 data
Authors:   Korean Technology Education Association, Kim Young-Heung
Published: April 2021

The purpose of this study was to compare the human background and environment and behavioral and psychological characteristics of Korean and American technical teachers. Subject to analysis are 214 South Korean and 675 U.S. technology teachers who participated in TALIS 2018 survey. Major research results show that Korean and American technology teachers tend to be similar to middle school teachers. Second, the annual working hours of Korean technical teachers are less than those of the United States, but there is a lot of administrative time, and there is a relatively little time to allocate to classes and professional development. Third, Korean technical teachers are relatively lacking in professional efforts such as obtaining degrees to develop expertise, and activities to develop curriculum contents and teaching methods are active, but efforts related to innovation such as multiculturalism and ICT utilization are lacking. Fourth, Korean technical teachers lack high-dimensional teaching

activities and are having difficulty guiding students. Fifth, Korean technical teachers have less class cooperation activities among fellow teachers. Sixth, Korean technical teachers choose teaching as motivation for personal usefulness, such as job stability and time-lapse. Seventh, Korean technical teachers have a relatively lower sense of effectiveness than the United States, especially having difficulty in class management, and low job satisfaction, which makes them less satisfied with their working environment.
Community Health Center Efficiency. The Impact of Organization Design and Local Context: The Case of Indonesia
Authors: Miharti Suwatin , Wittek Rafael , Los Bart , Heyse Liesbet
Published: May 2021

Background: The decentralization of the Indonesian healthcare system, launched in the year 2000, allowed the authorities of local community health centers (CHCs) to tailor their services to the needs of their clients. Many observers see this as an opportunity to increase CHC efficiency. Building on the Context Design Performance Framework, this paper assesses the extent to which efficiency variations between CHCs can be explained by the degree of fit between their organizational design characteristics and aspects of the communities in which they are embedded. Methods: Data envelopment analysis (DEA) was applied to construct a measure of CHC efficiency for a sample of 598 CHCs in 2011, drawn from a publicly available Ministry of Health (MoH) dataset. Tobit regression analysis was applied to assess the impact of organization design and community characteristics and their interplay on efficiency. Results: Large variations in CHC efficiency were discovered, suggesting that not all CHCs are equally capable of finding the optimal design to operate most efficiently. A significant inverted U-shape relationship was found for the organization design-efficiency link: efficiency is highest for CHCs with 1-2 horizontal units and decreases for CHCs exceeding or not reaching this number. No significant association was found between community characteristics (proportion of poor people, remote location of CHC) and CHC efficiency. Conclusion: Organizational design matters for CHC efficiency, but no evidence was found for the hypothesis that a better fit between community characteristics and CHC design increases efficiency. A potential reason for this might be that CHC management’s main design challenge is how to cope with the scarce availability of well-trained health personnel.
The Electronic Health Insurance Card for Asylum-Seekers in Berlin: Effects on the Local Health System
Authors: Gottlieb Nora , Ohm Vanessa , Knörnschild Miriam
Published: May 2021

Background: In debates on asylum-seekers’ access to healthcare it is frequently claimed that restrictions are necessary to prevent unduly high health service utilization and costs. Within Germany, healthcare provision for asylum-seekers varies across the different states. Berlin’s authorities removed some barriers to healthcare for asylum-seekers by introducing an electronic health insurance card (HIC) in 2016. We used the HIC introduction in Berlin as an opportunity to investigate the effects of improved healthcare access for asylum-seekers on the local health system. Methods: The study applied a mixed-methods design. A cost analysis compared expenses for outpatient and inpatient health services for asylum-seekers before and after the HIC introduction, based on aggregate claims data and information on expenses for humanitarian healthcare provision that were retrieved from the Berlin authorities. Semi-structured interviews with 12 key informants explored organizational effects like administrative workloads and ethical dilemmas for staff. We performed a content analysis and used respondent validation to enhance the accuracy and trustworthiness of our results. Results: The HIC has reduced bureaucratic complexity and administrative workloads; it has enabled unprecedented financial transparency and control; and it has mitigated ethical tensions. All the while, average per person expenses for outpatient health services have declined since the HIC introduction. However, our cost analysis also indicates a rise in the utilization and costs of inpatient care. Conclusion: The HIC introduction in Berlin suggests that the removal of barriers to healthcare for asylum-seekers can create win-win-situations by reducing administrative workloads, advancing financial transparency, and mitigating ethical tensions, whilst cutting the costs of outpatient healthcare provision. Removing barriers to healthcare thus appears to be a more prudent policy choice than maintaining mechanisms of restriction and control. However, high inpatient care utilization and costs warrant further research.
The Trends of Urolithiasis Therapeutic Interventions over the Last 20 Years: A Bibliographic Study
Authors: Abedi Amir Reza , Razzaghi Mohammadreza , Montazeri Saeed , Allameh Farzad
Published: May 2021

Introduction: The clinical and economic burden of kidney stones is a challenge for the healthcare system. There is a limited bibliometric project exploring the literature trends on ‘urolithiasis’ and its related management. Methods: A systematic review was conducted to discover the related abstracts regarding each specific issue, investigated year by year from May 2000 to May 2020 (20 years). To make an effective comparison, the statistics resulting from every single study were allocated to two 10-year periods: period 1 (2000 to 2010) and period 2 (2010 to 2020). In this study, we included all English language articles, all non-English articles with English abstracts, and studies in which interventions were used for stone removal, including laser technology. Also, we excluded the studies without a published abstract, an intervention or a laser, animal and in vitro studies, and case reports. Results: These articles are about ureteroscopy (URS) (n=10360, 33.45%), percutaneous nephrolithotomy (PCN) (n =10790, 34.84%) and extra-corporeal shockwave lithotripsy (ESWL) (n=9846, 31.76%). When evaluating the two time periods, there were 9912 studies available in period one, which increased by ×2.12 times (112.71% rise) to 21084 studies in period two (P = 0.001). The increase was 133%, 103.51%, and 70.4% for URS, PCN, and SWL respectively. A total of 855 studies on Laser application via URS were published on PubMed over a 20-year period. There was an increasing trend toward using laser application via URS over the study period. Also, there were 230 articles published in period one, which increased by nearly 2.71 times (rise of 171.73%) to 625 papers in period two (P<0.001). There was an increasing trend toward using laser application via PCN; 126 papers were published in period one, which increased by nearly 3.05 times (rise of 205.5%) to 385 papers in period two (P = 0.002). Conclusion: The minimal invasive interventions for stone removal, including URS and PCN, increased dramatically in the last decade, and the use of lasers in stone treatment increased significantly in the last decade.
Blue Light Photodynamic Therapy With Curcumin and Riboflavin in the Management of Periodontitis: A Systematic Review
Authors: Etemadi Ardavan , Hamidain Mehdi , Parker Steven , Chiniforush Nasim
Published: May 2021

Introduction: The aim of this article was to evaluate reports in the scientific literature that used antimicrobial photodynamic therapy (aPDT) with a blue light source and curcumin and riboflavin as photosensitizers in the management of periodontitis. Methods: The search was conducted in electronic databases, including PubMed, Web of Science, and Scopus, with the keywords "photodynamic therapy", "antimicrobial photodynamic therapy", "laser activated disinfection", "photoactivated disinfection", "light activated disinfection" "LED", "Periodontitis", "Curcumin", "Riboflavin", and "periodontitis" from 2012 to 2020. Results: After evaluating a total of 24 relevant articles, 13 articles were selected, full texts were read, and the data were extracted and placed in a table. Conclusion: Reviewing articles showed that curcumin as a photosensitizer activated by a blue wavelength is effective in the elimination of the various bacterial species involved in periodontal disease, and to the best of our knowledge, there is no study that has shown this substance does not reduce bacteria. According to the result of the articles, riboflavin as a photosensitizer activated by blue light can reduce bacteria that are involved in periodontitis, but other studies have reported that blue light alone can also reduce bacteria significantly. Therefore, more in-vitro and clinical trial studies are needed to give a more conclusive opinion on the effectiveness of riboflavin as a photosensitizer in the treatment of periodontitis.
Effect of Light-Emitting Diode Phototherapy on Allograft Bone After Open Sinus Lift Surgery: A Randomized Clinical Trial (Concurrent Parallel)
Authors: Arshad Mahnaz , Ghanavati Zahra , Aminishakib Pouyan , Rasouli Kamran , Shirani Gholamreza
Published: May 2021

Introduction: Phototherapy with a light-emitting diode (LED) is used in medicine due to its potential bio-stimulatory effects on the human body. However, controversy still exists regarding the efficacy of low-level laser therapy (LLLT) and phototherapy with LED. This in vivo study aimed to quantitatively and qualitatively assess the newly formed bone following LED phototherapy of the human maxillary sinuses. Methods: This randomized clinical trial (concurrent parallel) was conducted on 44 patients in two groups (n=22) at the Implant Department of Tehran University of Medical Sciences. Randomization was done by a random sequence generator program. The inclusion criteria were absence of chronic sinusitis and chronic bone marrow conditions, no history of surgery at the site, absence of diabetes mellitus, no history of chemotherapy or radiotherapy, maxillary premolar edentulism, and signing informed consent forms. Group A underwent LED phototherapy with 620 ± 2 nm wavelength for 20 minutes daily for a total of 21 days after sinus lift surgery. Group B served as the control group and did not receive phototherapy. After 6 months, the grafted sites were re-opened for implant placement, and bone biopsy samples were obtained using a trephine bur. The samples were stained with hematoxylin and eosin and inspected under a light microscope. The results were statistically analyzed using the Mann-Whitney U test. Both the surgeon and pathologist were blinded to the group allocation of patients. Results: Forty tissue specimens were analyzed. Insignificant differences existed between the two groups in terms of the degree of inflammation, bone quality, and maturity of collagen. Histological analyses revealed no significant difference in the mineralized areas of bone between the two groups (P>0.05). Conclusion: The results indicated that LED phototherapy cannot significantly enhance osteogenesis after sinus lift surgery. No side effects were observed in the experimental group.
Orkidelerin Geleneksel Kullanımları, Fitokimyasal İçerikleri ve Biyolojik Aktiviteleri
Authors: AYTAR Erdi Can , ÖZDENER KÖMPE Yasemin
Published: May 2021

Orkideler renk, boyut, çiçeklenme şekilleri ve aynı zamanda koku özellikleri bakımından oldukça çeşitlilik gösteren bitkilerdir. Yayılış alanları tropikal bölgelerden yüksek dağlara kadar değişmektedir. Orkideler öncelikle süs bitkisi olarak yetiştirilse de polisakkaritler ve alkaloidler gibi kimyasal bileşenler açısından da zengindirler. Bundan dolayı ilaç ve gıda sanayisinde dünyanın farklı yerlerinde ve kültürlerinde kullanılmaktadırlar. Sekonder metabolitler, moleküler ağırlığı düşük organik bileşikler olarak tanımlanır. Bu bileşikler birincil olarak büyüme ve gelişmeden sorumlu olmasa da stres gibi özel koşullar altında üretilirler. Tıbbi orkidelerde, bugüne kadar farklı sekonder metabolit sınıfları bildirilmiştir ve bunların farmasötik alanda önemli bir rol oynadıkları gösterilmiştir. Bu çalışmada, orkideleri geleneksel kullanımları, biyolojik aktiviteleri ve biyoaktif bileşikleri açısından incelemek amaçlanmıştır. Bu türlerin ayrıntılı şekilde incelenmesinin hem toplum sağlığına hem de ulusal ekonomiye katkıda bulunulacağı düşünülmektedir.
Prioritizing Achievable Goals for Food Security in the Developing World
Authors: Rajaram Sanjaya , Ginkel Maarten van
Published: May 2021

Many solutions have been proposed to address food security. We present here a prioritized set of actions achievable within the next 2–10 years. By taking a systems approach we follow the impact pathway backwards starting from the needs and desires of the end-users to eventually define the research agenda that will exactly address those targeted solutions with positive impacts. The following actions emerge as high-priority and achievable in the near future: new research tools to study food systems; dis-aggregated intra-household surveys to reveal within-family inequalities in food access; increased scientific consensus on climate change impacts in sub-Saharan Africa; rapid response measures to address sudden emergencies, such as capturing excess rainfall water; financial tools to enable rapid responses with recovery measures afterwards; consideration of restrictions that excess heat and humidity impose on human productivity; secure land ownership and tenure rights to encourage long-term agricultural investment; mechanization at all stages along the food system.