bluuebunny/crossref_metadata_2025 huggingface dataset:
The Serum Concentrations of Hedgehog-Interacting Protein, a Novel Biomarker, Were Decreased in Overweight or Obese Subjects
Authors: Chou Hsuan-Wen , Hung Hao-Chang , Lin Ching-Han , Lin An-Chi , Du Ye-Fong , Cheng Kai-Pi , Li Chung-Hao , Chang Chih-Jen , Wu Hung-Tsung , Ou Horng-Yih
Published: February 2021

Although it was known that obesity is an independent risk factor for metabolic disorders including diabetes, the factors that link these diseases were obscure. The Hedgehog-interacting protein (Hhip) is a negative regulator in tissue remodeling, and inhibits the proliferation of adipocytes, and promotes their differentiation. In addition, Hhip was positively associated with diabetes. However, the relationship between Hhip and obesity in the human body remains unclear. An analysis of the relationship between Hhip and normal weight, overweight, and obesity levels. Participants receiving a physical checkup were recruited. Anthropometric and biochemical data were collected. Serum Hhip levels were determined by enzyme-linked immunosorbent assay (ELISA). Subjects were classified into normal-weight, overweight, and obese groups based on their body mass index (BMI). The association between Hhip and obesity was examined by multivariate linear regression analysis. In total, 294 subjects who were either of a normal weight (n = 166), overweight (n = 90), or obese (n = 38) were enrolled. Hhip concentrations were 6.51 ± 4.86 ng/mL, 5.79 ± 4.33 ng/mL, and 3.97 ± 3.4 ng/mL in normal-weight, overweight, and obese groups, respectively (p for trend = 0.032). Moreover, the regression analysis showed that BMI (β = −0.144, 95% confidence interval (CI) = −0.397−0.046, p = 0.013) was negatively associated with Hhip concentrations after adjusting for sex and age. Being overweight (β = −0.181, 95% CI = −3.311−0.400, p = 0.013) and obese (β = −0.311, 95% CI = −6.393−2.384, p < 0.001) were independently associated with Hhip concentrations after adjusting for sex, age, fasting plasma glucose, the insulin level, and other cardiometabolic risk factors. Our results showed that overweight and obese subjects had lower Hhip concentrations than those of normal weight. Being overweight and obese were negatively associated with Hhip concentrations. Hhip might be a link between obesity and diabetes.
Changes in Free-Living and Particle-Associated Bacterial Communities Depending on the Growth Phases of Marine Green Algae, Tetraselmis suecica
Authors: Park Bum Soo , Choi Won-Ji , Guo Ruoyu , Kim Hansol , Ki Jang-Seu
Published: February 2021

Bacteria are remarkably associated with the growth of green algae Tetraselmis which are used as a feed source in aquaculture, but Tetraselmis-associated bacterial community is characterized insufficiently. Here, as a first step towards characterization of the associated bacteria, we investigated the community composition of free-living (FLB) and particle-associated (PAB) bacteria in each growth phase (lag, exponential, stationary, and death) of Tetraselmis suecica P039 culture using pyrosequencing. The percentage of shared operational taxonomic units (OTUs) between FLB and PAB communities was substantially high (≥92.4%), but their bacterial community compositions were significantly (p = 0.05) different from each other. The PAB community was more variable than the FLB community depending on the growth phase of T. suecica. In the PAB community, the proportions of Marinobacter and Flavobacteriaceae were considerably varied in accordance with the cell number of T. suecica, but there was no clear variation in the FLB community composition. This suggests that the PAB community may have a stronger association with the algal growth than the FLB community. Interestingly, irrespective of the growth phase, Roseobacter clade and genus Muricauda were predominant in both FLB and PAB communities, indicating that bacterial communities in T. suecica culture may positively affect the algae growth and that they are potentially capable of enhancing the T. suecica growth.
Use of Underwater Acoustics in Marine Conservation and Policy: Previous Advances, Current Status, and Future Needs
Authors: Guan Shane , Brookens Tiffini , Vignola Joseph
Published: February 2021

The interdisciplinary field of assessing the impacts of sound on marine life has benefited largely from the advancement of underwater acoustics that occurred after World War II. Acoustic parameters widely used in underwater acoustics were redefined to quantify sound levels relevant to animal audiometric variables, both at the source and receiver. The fundamental approach for assessing the impacts of sound uses a source-pathway-receiver model based on the one-way sonar equation, and most numerical sound propagation models can be used to predict received levels at marine animals that are potentially exposed. However, significant information gaps still exist in terms of sound source characterization and propagation that are strongly coupled with the type and layering of the underlying substrate(s). Additional challenges include the lack of easy-to-use propagation models and animal-specific statistical detection models, as well as a lack of adequate training of regulatory entities in underwater acoustics.
VD-PQ; A Velocity-Dependent Viscous Damping Model for Wave-Structure Interaction Analysis
Authors: Michailides Constantine
Published: February 2021

For the analysis and design of coastal and offshore structures, viscous loads represent one of the most influential parameters that dominate their response. Very commonly, the potential flow theory is used for identifying the excitation wave loads, while the viscous damping loads are taken into consideration as distributed drag type loads and/or as linear and quadratic damping loads approximated with the use of motion decay curves of the structure in specific degrees of freedom. In the present paper, is developed and proposed a numerical analysis method for addressing wave-structure interaction effects through a velocity-dependent viscous damping model. Results derived by a computational fluid dynamics model are coupled with a model that uses the boundary element method for the estimation of the viscous damping loads iteratively in every time-step of the analysis. The computational fluid dynamics model solves the Navier–Stokes equations considering incompressible flow, while the second model solves the modified Cummins Equation of motion of the structure in the time domain. Details about the development of the coupling method and the velocity-dependent viscous damping (VD-PQ) are presented. The coupling between the different models is realized through a dynamic-link library. The proposed coupling method is applied for the case of a wave energy converter. Results derived with the use of the developed numerical analysis method are compared against experimental data and relevant numerical analysis predictions. The importance of considering the instantaneous velocity of the structure in estimating the viscous damping loads is demonstrated. The proposed numerical analysis method for estimating the viscous damping loads provides good accuracy compared to experimental data and, at the same time, low computational cost.
Use of Ecoacoustics to Characterize the Marine Acoustic Environment off the North Atlantic French Saint-Pierre-et-Miquelon Archipelago
Authors: Nguyen Hong Duc Paul , Cazau Dorian , White Paul R. , Gérard Odile , Detcheverry Joël , Urtizberea Frank , Adam Olivier
Published: February 2021

Visual observations of the marine biodiversity can be difficult in specific areas for different reasons, including weather conditions or a lack of observers. In such conditions, passive acoustics represents a potential alternative approach. The objective of this work is to demonstrate how information about marine biodiversity can be obtained via detailed analysis of the underwater acoustic environment. This paper presents the first analysis of the Saint-Pierre-and-Miquelon (SPM) archipelago underwater acoustic environment. In order to have a better knowledge about the marine biodiversity of SPM, acoustic recordings were sampled at different time periods to highlight seasonal variations over several years. To extract information from these acoustic recordings, standard soundscape and ecoacoustic analysis workflow was used to compute acoustic metrics such as power spectral density, third-octave levels, acoustic complexity index, and sound pressure levels. The SPM marine acoustic environment can be divided into three main sound source classes: biophony, anthrophony, and geophony. Several cetacean species were encountered in the audio recordings including sperm whales (which were detected by visual observations and strandings of 3 males in 2014), humpback, and blue whales.
Filtering Activity and Nutrient Release by the Keratose Sponge Sarcotragus spinosulus Schmidt, 1862 (Porifera, Demospongiae) at the Laboratory Scale
Authors: Trani Roberta , Corriero Giuseppe , de Pinto Maria Concetta , Mercurio Maria , Pazzani Carlo , Pierri Cataldo , Scrascia Maria , Longo Caterina
Published: February 2021

Sponges are an important constituent of filter-feeder benthic communities, characterized by high ecological plasticity and abundance. Free bacteria constitute an important quota of their diet, making them excellent candidates in aquaculture microbial bioremediation, where bacteria can be a serious problem. Although there are studies on this topic, certain promising species are still under investigation. Here we report applied microbiological research on the filtering activity of Sarcotragus spinosulus on two different concentrations of the pathogenic bacterium Vibrio parahaemolyticus in a laboratory experiment. To evaluate the effects of the filtration on the surrounding nutrient load, the release of ammonium, nitrate, and phosphate was also measured. The results obtained showed the efficient filtration capability of S. spinosulus as able to reduce the Vibrio load with a maximum retention efficiency of 99.72% and 99.35% at higher and lower Vibrio concentrations, respectively, and remarkable values of clearance rates (average maximum value 45.0 ± 4.1 mL h−1 g DW−1) at the highest Vibrio concentration tested. The nutrient release measured showed low values for each considered nutrient category at less than 1 mg L−1 for ammonium and phosphate and less than 5 mg L−1 for nitrate. The filtering activity and nutrient release by S. spinosulus suggest that this species represents a promising candidate in microbial bioremediation, showing an efficient capability in removing V. parahaemolyticus from seawater with a contribution to the nutrient load.
Seakeeping Tests of a FOWT in Wind and Waves: An Analysis of Dynamic Coupling Effects and Their Impact on the Predictions of Pitch Motion Response
Authors: Amaral Giovanni , Mello Pedro , do Carmo Lucas , Alberto Izabela , Malta Edgard , Simos Alexandre , Franzini Guilherme , Suzuki Hideyuki , Gonçalves Rodolfo
Published: February 2021

The present work highlights some of the dynamic couplings observed in a series of tests performed in a wave basin with a scaled-model of a Floating Offshore Wind Turbine (FOWT) with semi-submersible substructure. The model was moored by means of a conventional chain catenary system and an actively controlled fan was used for emulating the thrust loads during the tests. A set of wave tests was performed for concomitant effects of not aligned wave and wind. The experimental measurements illustrate the main coupling effects involved and how they affect the FOWT motions in waves, especially when the floater presents a non-negligible tilt angle. In addition, a frequency domain numerical analysis was performed in order to evaluate its ability to capture these effects properly. The influence of different modes of fan response, floater trim angles (changeable with ballast compensation) and variations in the mooring stiffness with the offsets were investigated in the analysis. Results attest that significant changes in the FOWT responses may indeed arise from coupling effects, thus indicating that caution must be taken when simplifying the hydrodynamic frequency-domain models often used as a basis for the simulation of FOWTs in waves and in optimization procedures for the design of the floater and mooring lines.
Improving Near Miss Detection in Maritime Traffic in the Northern Baltic Sea from AIS Data
Authors: Du Lei , Valdez Banda Osiris A. , Goerlandt Floris , Kujala Pentti , Zhang Weibin
Published: February 2021

Ship collision is the most common type of accident in the Northern Baltic Sea, posing a risk to the safety of maritime transportation. Near miss detection from automatic identification system (AIS) data provides insight into maritime transportation safety. Collision risk always triggers a ship to maneuver for safe passing. Some frenetic rudder actions occur at the last moment before ship collision. However, the relationship between ship behavior and collision risk is not fully clarified. Therefore, this work proposes a novel method to improve near miss detection by analyzing ship behavior characteristic during the encounter process. The impact from the ship attributes (including ship size, type, and maneuverability), perceived risk of a navigator, traffic complexity, and traffic rule are considered to obtain insights into the ship behavior. The risk severity of the detected near miss is further quantified into four levels. This proposed method is then applied to traffic data from the Northern Baltic Sea. The promising results of near miss detection and the model validity test suggest that this work contributes to the development of preventive measures in maritime management to enhance to navigational safety, such as setting a precautionary area in the hotspot areas. Several advantages and limitations of the presented method for near miss detection are discussed.
Oil Spill Modeling: A Critical Review on Current Trends, Perspectives, and Challenges
Authors: Keramea Panagiota , Spanoudaki Katerina , Zodiatis George , Gikas Georgios , Sylaios Georgios
Published: February 2021

Several oil spill simulation models exist in the literature, which are used worldwide to simulate the evolution of an oil slick created from marine traffic, petroleum production, or other sources. These models may range from simple parametric calculations to advanced, new-generation, operational, three-dimensional numerical models, coupled to meteorological, hydrodynamic, and wave models, forecasting in high-resolution and with high precision the transport and fate of oil. This study presents a review of the transport and oil weathering processes and their parameterization and critically examines eighteen state-of-the-art oil spill models in terms of their capacity (a) to simulate these processes, (b) to consider oil released from surface or submerged sources, (c) to assimilate real-time field data for model initiation and forcing, and (d) to assess uncertainty in the produced predictions. Based on our review, the most common oil weathering processes involved are spreading, advection, diffusion, evaporation, emulsification, and dispersion. The majority of existing oil spill models do not consider significant physical processes, such as oil dissolution, photo-oxidation, biodegradation, and vertical mixing. Moreover, timely response to oil spills is lacking in the new generation of oil spill models. Further improvements in oil spill modeling should emphasize more comprehensive parametrization of oil dissolution, biodegradation, entrainment, and prediction of oil particles size distribution following wave action and well blow outs.
A Survey of Marine Coastal Litters around Zhoushan Island, China and Their Impacts
Authors: Ma Xuehua , Zhou Yi , Yang Luyi , Tong Jianfeng
Published: February 2021

Rapid development of the economy increased marine litter around Zhoushan Island. Social-ecological scenario studies can help to develop strategies to adapt to such change. To investigate the present situation of marine litter pollution, a stratified random sampling (StRS) method was applied to survey the distribution of marine coastal litters around Zhoushan Island. A univariate analysis of variance was conducted to access the amount of litter in different landforms that include mudflats, artificial and rocky beaches. In addition, two questionnaires were designed for local fishermen and tourists to provide social scenarios. The results showed that the distribution of litter in different landforms was significantly different, while the distribution of litter in different sampling points had no significant difference. The StRS survey showed to be a valuable method for giving a relative overview of beach litter around Zhoushan Island with less effort in a future survey. The questionnaire feedbacks helped to understand the source of marine litter and showed the impact on the local environment and economy. Based on the social-ecological scenarios, governance recommendations were provided in this paper.
Numerical Study of Hydrodynamics of Heavily Loaded Hard-Chine Hulls in Calm Water
Authors: Wheeler Miles P. , Matveev Konstantin I. , Xing Tao
Published: February 2021

Hard-chine boats are usually intended for high-speed regimes where they operate in the planing mode. These boats are often designed to be relatively light, but there are special applications that may occasionally require fast boats to be heavily loaded. In this study, steady-state hydrodynamic performance of nominal-weight and overloaded hard-chine hulls in calm water is investigated with computational fluid dynamics solver program STAR-CCM+. The resistance and attitude values of a constant-deadrise reference hull and its modifications with more pronounced bows of concave and convex shapes are obtained from numerical simulations. On average, 40% heavier hulls showed about 30% larger drag over the speed range from the displacement to planing modes. Among the studied configurations, the hull with a concave bow is found to have 5–12% lower resistance than the other hulls in the semi-displacement regime and heavy loadings and 2–10% lower drag in the displacement regime and nominal loading, while this hull is also capable of achieving fast planing speeds at the nominal weight with typical available thrust. The near-hull wave patterns and hull pressure distributions for selected conditions are presented and discussed as well.
New Xerophilic Species of Penicillium from Soil
Authors: Rodríguez-Andrade Ernesto , Stchigel Alberto M. , Cano-Lira José F.
Published: February 2021

Soil is one of the main reservoirs of fungi. The aim of this study was to study the richness of ascomycetes in a set of soil samples from Mexico and Spain. Fungi were isolated after 2% w/v phenol treatment of samples. In that way, several strains of the genus Penicillium were recovered. A phylogenetic analysis based on internal transcribed spacer (ITS), beta-tubulin (BenA), calmodulin (CaM), and RNA polymerase II subunit 2 gene (rpb2) sequences showed that four of these strains had not been described before. Penicillium melanosporum produces monoverticillate conidiophores and brownish conidia covered by an ornate brown sheath. Penicillium michoacanense and Penicillium siccitolerans produce sclerotia, and their asexual morph is similar to species in the section Aspergilloides (despite all of them pertaining to section Lanata-Divaricata). P. michoacanense differs from P. siccitolerans in having thick-walled peridial cells (thin-walled in P. siccitolerans). Penicillium sexuale differs from Penicillium cryptum in the section Crypta because it does not produce an asexual morph. Its ascostromata have a peridium composed of thick-walled polygonal cells, and its ascospores are broadly lenticular with two equatorial ridges widely separated by a furrow. All four new species are xerophilic. Despite the genus Penicillium containing more than 480 known species, they are rarely reported as xerophilic.
Management of Metastatic Spinal Cord Compression in Secondary Care: A Practice Reflection from Medway Maritime Hospital, Kent, UK
Authors: Shah Sidrah , Kutka Mikolaj , Lees Kathryn , Abson Charlotte , Hadaki Maher , Cooke Deirdre , Neill Cherie , Sheriff Matin , Karathanasi Afroditi , Boussios Stergios
Published: February 2021

Introduction: Malignant spinal cord compression (MSCC) is one of the most devastating complications of cancer. This event requires rapid decision-making on the part of several specialists, given the risk of permanent spinal cord injury or death. The goals of treatment in spinal metastases are pain control and improvement of neurological function. There can be challenges in delivering prompt diagnosis and treatment in a secondary care setting. We have reflected on the experience of managing MSCC in a district general setting. Aim: Our retrospective audit identified 53 patients with suspected MSCC who entered the relevant pathway from April 2017 to March 2018 at Medway, United Kingdom (UK). Our audit standards were set out by Medway Maritime Hospital and Maidstone and Tunbridge Wells NHS Trust MSCC working group members, using a combination of published evidence and best practice. Results: The patients with suspected MSCC were 53 and 29 of them (54.7%) had confirmed MSCC. The most common malignancies within the confirmed MSCC were lung (11 patients, 37.9%), breast (5 patients 17.2%), and renal (3 patients, 10.3%), followed by prostate, myeloma and carcinoma of unknown primary (2 patients (6.9%) each), as well as pancreatic, colorectal, lymphoma and, bladder (1 patient (3.4%) each). A magnetic resonance imaging (MRI) scan was performed in 48 patients (90.5%); the majority (31 patients, 64.6%) underwent the MRI within the first 24 h, whereas 3 patients had the investigation between 24 and 72 h from the admission. Among the 29 patients with confirmed MSCC, 6 (20.6%) were treated with surgical decompression, while 20 (69%) received radiotherapy (RT) and 3 (10.3%) best supportive care, respectively. Median time to surgery was 5 days (ranged between 2 and 8 days), whereas for RT 44.4 h (ranged between 24 and 72 h). Finally, all 3 patients that decided on symptom control were referred to a palliative care team within the first 24 h following the MRI scan. Conclusions: MSCC is frequently presented outside tertiary care. This may cause subsequent delays in investigation, diagnosis, and treatment, which can be improved by following a fast track referral pathway.
Variations of Serum Oxidative Stress Biomarkers under First-Line Antituberculosis Treatment: A Pilot Study
Authors: Meca Andreea-Daniela , Turcu-Stiolica Adina , Stanciulescu Elena Camelia , Andrei Ana Marina , Nitu Floarea Mimi , Banita Ileana Monica , Matei Marius , Pisoschi Catalina-Gabriela
Published: February 2021

Tuberculosis (TB) is one of the highest infectious burdens worldwide, and pathogenesis is yet incompletely elucidated. Bacilli dissemination is due to poor antioxidant defense mechanisms and intensified oxidative stress. There are few recent studies that analyzed and compared free radicals or antioxidant status before and after anti-TB treatment. Hence, the present study underlines the need to identify oxidative stress as it could be a useful tool in TB monitorisation. Thirty newly diagnosed patients with pulmonary TB were included after signing an informed consent. Blood was collected before receiving first-line anti-tubercular therapy (T0) and after 60 days (T2). Spectrophotometric methods were used to quantify oxidative parameters (TBARS—thiobarbituric acid reactive species); enzymatic antioxidants such as SOD (superoxide dismutase), CAT (catalase), GPx (glutathione peroxidase), and TAC (total antioxidant capacity); and non-enzymatic antioxidants such as GSH (reduced glutathione). A moderate positive correlation was found between GSH and TAC (r = 0.63, p-value = 0.046) and GSH and SOD (r = 0.64, p-value = 0.041) at T2. Increased values of GSH, CAT, and SOD were noted at T2 in comparison with T0, while GPx, TAC, and TBARS decreased at T2. A better monitorisation in TB could be based on oxidative stress and antioxidant status. Nevertheless, restoring redox host balance could reduce TB progression.
HPMA Copolymer-Based Nanomedicines in Controlled Drug Delivery
Authors: Chytil Petr , Kostka Libor , Etrych Tomáš
Published: February 2021

Recently, numerous polymer materials have been employed as drug carrier systems in medicinal research, and their detailed properties have been thoroughly evaluated. Water-soluble polymer carriers play a significant role between these studied polymer systems as they are advantageously applied as carriers of low-molecular-weight drugs and compounds, e.g., cytostatic agents, anti-inflammatory drugs, antimicrobial molecules, or multidrug resistance inhibitors. Covalent attachment of carried molecules using a biodegradable spacer is strongly preferred, as such design ensures the controlled release of the drug in the place of a desired pharmacological effect in a reasonable time-dependent manner. Importantly, the synthetic polymer biomaterials based on N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers are recognized drug carriers with unique properties that nominate them among the most serious nanomedicines candidates for human clinical trials. This review focuses on advances in the development of HPMA copolymer-based nanomedicines within the passive and active targeting into the place of desired pharmacological effect, tumors, inflammation or bacterial infection sites. Specifically, this review highlights the safety issues of HPMA polymer-based drug carriers concerning the structure of nanomedicines. The main impact consists of the improvement of targeting ability, especially concerning the enhanced and permeability retention (EPR) effect.
Evaluation of the Accuracy of Machine Learning Predictions of the Czech Republic’s Exports to the China
Authors: Suler Petr , Rowland Zuzana , Krulicky Tomas
Published: February 2021

The objective of this contribution is to predict the development of the Czech Republic’s (CR) exports to the PRC (People’s Republic of China) using ANN (artificial neural networks). To meet the objective, two research questions are formulated. The questions focus on whether growth in the CR’s exports to the PRC can be expected and whether MLP (Multi-Layer Perceptron) networks are applicable for predicting the future development of the CR’s exports to the PRC. On the basis of previously obtained historical data, ANN with the best explanatory power are generated. For the purpose specified, three experiments are carried out, the results of which are described in detail. For the first, second and third experiments, ANN for predicting the development of exports are generated on the basis of a time series with a 1-month, 5-month and 10-month time delay, respectively. The generated ANN are the MLP and regression time series neural networks. The MLP turn out to be the most efficient in predicting the future development of the CR’s exports to the PRC. They are also able to predict possible extremes. It is also determined that the USA–China trade war has significantly affected the CR’s exports to the PRC.
Drive Mechanisms of Soil Quality Changes in Peri-Urban Areas
Authors: Liu Hongbin , Lyu Jie
Published: February 2021

The driving mechanism of soil quality (SQ) has important implications for arable land protection, sustainable agricultural development and ecological environment conservation. This study builds a “perception–response” theoretical framework to investigate how farmers’ land use behavior may affect SQ from the temporal and spatial perspectives. Based on soil sampling data, farmer survey data and socioeconomic statistical data collected in a typical peri-urban area of northeast China, geo-statistical analysis and econometric models have been applied to examine the effect of farmers’ land use behavior (FLUB) on SQ. The results show that during 1980–2010, the target of FLUB has been shifted from “grain output maximization” to “grain output and profit maximization” and then to “profit maximization”. The FLUB, including land use pattern, land use degree and land input intensity, also show obvious differences in space. These differences result in distinct impacts on the variation of SQ in time and space. Generally, the soil organic matter (OM) tends to decline, the available nitrogen (AVN) and available phosphorus (ANP) tend to rise, while the available potassium (AVK) increases after an initial decline. Moreover, the further distance from the city center, the greater the spatial variation of SQ in space. These findings are not only helpful from a theoretical and practical significance for policy-makers to improve SQ in the outskirts of metropolitan areas, but also make an important contribution to the sustainable development of peri-urban agriculture (PUA).
The Expansion Mechanism of Rural Residential Land and Implications for Sustainable Regional Development: Evidence from the Baota District in China’s Loess Plateau
Authors: Chen Zongfeng , Liu Xueqi , Lu Zhi , Li Yurui
Published: February 2021

Rural residential land is the main space of a farmer’s life, rural culture, and social relations. Prior research of rural residential land has focused more on its evolvement in plain and traditional agricultural areas. Yet, there is no clear picture of rural residential land expansion, especially in ecologically fragile areas. This study analyzed the characteristics of rural residential land expansion based on 30 m spatial resolution land-use datasets of the Baota District of Yan’an City, Shannxi Province, and further explored the influencing factors and mechanisms of rural residential land expansion through binary logistic regression (BLR) modeling. Our findings indicated that the area of rural residential land in the Baota District increased by 116.16% during 1990–2015. More than 75% of the residential land expansion came from the occupation of cropland. Moreover, rural residential land expansion was heterogeneous in the rural regional system. The expansion scale, speed, and mode diversity of rural residential land decreased with the increased distance to urban built-up areas. Geographical conditions and resource endowments are the primary internal driving factors; urbanization and policy implementation are two major external driving forces. The authors suggest that the realization of regional sustainable development in ecologically fragile areas should strengthen urban–rural integration, focus on constructing central towns, and ensure ecological protection measures.
Qualifying Land Use and Land Cover Dynamics and Their Impacts on Ecosystem Service in Central Himalaya Transboundary Landscape Based on Google Earth Engine
Authors: Gu Changjun , Zhang Yili , Liu Linshan , Li Lanhui , Li Shicheng , Zhang Binghua , Cui Bohao , Rai Mohan Kumar
Published: February 2021

Land use and land cover (LULC) changes are regarded as one of the key drivers of ecosystem services degradation, especially in mountain regions where they may provide various ecosystem services to local livelihoods and surrounding areas. Additionally, ecosystems and habitats extend across political boundaries, causing more difficulties for ecosystem conservation. LULC in the Kailash Sacred Landscape (KSL) has undergone obvious changes over the past four decades; however, the spatiotemporal changes of the LULC across the whole of the KSL are still unclear, as well as the effects of LULC changes on ecosystem service values (ESVs). Thus, in this study we analyzed LULC changes across the whole of the KSL between 2000 and 2015 using Google Earth Engine (GEE) and quantified their impacts on ESVs. The greatest loss in LULC was found in forest cover, which decreased from 5443.20 km2 in 2000 to 5003.37 km2 in 2015 and which mainly occurred in KSL-Nepal. Meanwhile, the largest growth was observed in grassland (increased by 548.46 km2), followed by cropland (increased by 346.90 km2), both of which mainly occurred in KSL-Nepal. Further analysis showed that the expansions of cropland were the major drivers of the forest cover change in the KSL. Furthermore, the conversion of cropland to shrub land indicated that farmland abandonment existed in the KSL during the study period. The observed forest degradation directly influenced the ESV changes in the KSL. The total ESVs in the KSL decreased from 36.53 × 108 USD y−1 in 2000 to 35.35 × 108 USD y−1 in 2015. Meanwhile, the ESVs of the forestry areas decreased by 1.34 × 108 USD y−1. This shows that the decrease of ESVs in forestry was the primary cause to the loss of total ESVs and also of the high elasticity. Our findings show that even small changes to the LULC, especially in forestry areas, are noteworthy as they could induce a strong ESV response.
Defining the Peri-Urban: A Multidimensional Characterization of Spatio-Temporal Land Use along an Urban–Rural Gradient in Dar es Salaam, Tanzania
Authors: Wolff Saskia , Mdemu Makarius V. , Lakes Tobia
Published: February 2021

Highly dynamic peri-urban areas, particularly in the Global South, face many challenges including a lack of infrastructure, ownership conflicts, land degradation, and sustainable food production. This study aims to assess spatial land use characteristics and processes in peri-urban areas using the case of Dar es Salaam, Tanzania. A mixed-method approach was applied, consisting of expert interviews and spatial data analysis, on a local scale along an urban–rural gradient. Expert interviews were conducted during a field study and analyzed regarding the characteristics and processes of peri-urban land development. A GIS-based analysis of land use patterns was applied using satellite imagery and Open Street Map data to identify a number of variables, such as building density and proximity to environmental features. Results show specific patterns of land use indicators, which can be decreasing (e.g., house density), increasing (e.g., tree coverage), static (e.g., house size), or randomly distributed (e.g., distance to river), along a peri-urban gradient. Key findings identify lack of service structures and access to public transport as major challenges for the population of peri-urban areas. The combination of qualitative expert interviews and metrics-based quantitative spatial pattern analysis contributes to improved understanding of the patterns and processes in peri-urban land use changes.
The Impact of New Urbanization Policy on In Situ Urbanization—Policy Test Based on Difference-in-Differences Model
Authors: Peng Jing , Liu Yanhong , Wang Qi , Tu Guoping , Huang Xinjian
Published: February 2021

Compared with traditional urbanization, new urbanization is more closely aligned with China’s basic national conditions and reflects the basic goal of sustainable development. As the main method of new urbanization, in situ urbanization can make up for the shortcomings of traditional urbanization. The establishment of national new urbanization pilot areas is an important element of the new urbanization policy. This paper tests the policy effect of the National New-type Urbanization Plan (2014–2020) on in situ urban development through the establishment of pilot areas. We found the following: (1) In the central region, the establishment of new urbanization pilot areas has not played a significant role in promoting the process of in situ urbanization. By dividing the central cities into Yangtze River and non–Yangtze River Economic Belt areas, we also find that the effect of the new urbanization policy is not obvious, for these cities are not located in the Yangtze River Economic Belt. (2) The central cities located in the Yangtze River Economic Belt have seen significant policy effects due to their advantages in transportation, resources, industry, labor, etc. The establishment of new urbanization pilot areas has a significant promoting effect on the process of in situ urbanization.
Biochemical Characterization, Specificity and Inhibition Studies of HTLV-1, HTLV-2, and HTLV-3 Proteases
Authors: Kassay Norbert , Mótyán János András , Matúz Krisztina , Golda Mária , Tőzsér József
Published: February 2021

The human T-lymphotropic viruses (HTLVs) are causative agents of severe diseases including adult T-cell leukemia. Similar to human immunodeficiency viruses (HIVs), the viral protease (PR) plays a crucial role in the viral life-cycle via the processing of the viral polyproteins. Thus, it is a potential target of anti-retroviral therapies. In this study, we performed in vitro comparative analysis of human T-cell leukemia virus type 1, 2, and 3 (HTLV-1, -2, and -3) proteases. Amino acid preferences of S4 to S1′ subsites were studied by using a series of synthetic oligopeptide substrates representing the natural and modified cleavage site sequences of the proteases. Biochemical characteristics of the different PRs were also determined, including catalytic efficiencies and dependence of activity on pH, temperature, and ionic strength. We investigated the effects of different HIV-1 PR inhibitors (atazanavir, darunavir, DMP-323, indinavir, ritonavir, and saquinavir) on enzyme activities, and inhibitory potentials of IB-268 and IB-269 inhibitors that were previously designed against HTLV-1 PR. Comparative biochemical analysis of HTLV-1, -2, and -3 PRs may help understand the characteristic similarities and differences between these enzymes in order to estimate the potential of the appearance of drug-resistance against specific HTLV-1 PR inhibitors.
F1099L-CFTR (c.3297C>G) has Impaired Channel Function and Associates with Mild Disease Phenotypes in Two Pediatric Patients
Authors: Zhang Xiaoying , Hothi Jaspal S. , Zhang Yanhui H. , Ren Aixia , Rock Michael J. , Srinivasan Saumini , Stokes Dennis C. , Naren Anjaparavanda P. , Zhang Weiqiang
Published: February 2021

(1) Background: many rare cystic fibrosistransmembrane conductance regulator (CFTR) mutations remain poorly characterized with regard to functional consequences of the mutation. We present the clinical features of two pediatric cystic fibrosis (CF) subjects who are heterozygous for F1099L (c.3297C>G), one with G551D (a class III mutation) and one with 3849 + 10kbC->T (a class V mutation). We also identified the molecular defect(s) that are associated with F1099L mutation to correlate with the clinical features that we observed; (2) Methods: clinical findings and history were extracted from the electronic medical record and de-identified. F1099L-CFTR protein expression level and maturation status, channel function, and the effects of CFTR modulation on these characteristics were investigated using western blotting and iodide efflux assay; (3) Results: these two subjects have mild CF phenotypes when F1099L is combined with two known disease-causing mutations. F1099L-CFTR has a moderate defect in processing and maturation, causing fewer CFTR channels at the cell surface and, therefore, impaired channel activities. These defects could be effectively corrected using VX-809 (lumacaftor); and, (4) Conclusions: our biochemical data correlate with the disease manifestations and suggest that F1099L is potentially a CF-causing mutation. The study expands our knowledge of rare CFTR mutations and may help in developing effective therapies for subjects with F1099L mutation.
Modeling Adhesive Hysteresis
Authors: Wang Anle , Zhou Yunong , Müser Martin H.
Published: February 2021

When an elastomer approaches or retracts from an adhesive indenter, the elastomer’s surface can suddenly become unstable and reshape itself quasi-discontinuously, e.g., when small-scale asperities jump into or snap out of contact. Such dynamics lead to a hysteresis between approach and retraction. In this study, we quantify numerically and analytically the ensuing unavoidable energy loss for rigid indenters with flat, Hertzian and randomly rough profiles. The range of adhesion turns out to be central, in particular during the rarely modeled approach to contact. For example, negligible traction on approach but quite noticeable adhesion for nominal plane contacts hinges on the use of short-range adhesion. Central attention is paid to the design of cohesive-zone models for the efficient simulation of dynamical processes. Our study includes a Griffith’s type analysis for the energy lost during fracture and regeneration of a flat interface. It reveals that the leading-order corrections of the energy loss are due to the finite-range adhesion scale at best, with the third root of the linear mesh size, while leading-order errors in the pull-off force disappear linearly.
Synthesis and Characterization of N-Substituted Polyether-Block-Amide Copolymers
Authors: Ye Jyun-Yan , Peng Kuo-Fu , Zhang Yu-Ning , Huang Szu-Yuan , Liang Mong
Published: February 2021

A series of N-substituted polyether-block-amide (PEBA-X%) copolymers were prepared by melt polycondensation of nylon-6 prepolymer and polytetramethylene ether glycol at an elevated temperature using titanium isopropoxide as a catalyst. The structure, thermal properties, and crystallinity of PEBA-X% were investigated using nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, wide angle X-ray diffraction, and thermogravimetric analysis. In general, the crystallinity, melting point, and thermal degradation temperature of PEBA-X% decreased as the incorporation of N-methyl functionalized groups increased, owing to the disruption caused to the structural regularity of the copolymer. However, in N-acetyl functionalized analogues, the crystallinity first dropped and then increased because of a new γ form arrangement that developed in the microstructure. After the cross-linking reaction of the N-methyl-substituted derivative, which has electron-donating characteristics, with poly(4,4′-methylenebis(phenyl isocyanate), the decomposition temperature of the resulting polymer significantly increased, whereas no such improvements could be observed in the case of the electro-withdrawing N-acetyl-substituted derivative, because of the incompleteness of its cross-linking reaction.
Mapping the Magnetic Coupling of Self-Assembled Fe3O4 Nanocubes by Electron Holography
Authors: López-Conesa Lluís , Martínez-Boubeta Carlos , Serantes David , Estradé Sonia , Peiró Francesca
Published: February 2021

The nanoscale magnetic configuration of self-assembled groups of magnetite 40 nm cubic nanoparticles has been investigated by means of electron holography in the transmission electron microscope (TEM). The arrangement of the cubes in the form of chains driven by the alignment of their dipoles of single nanocubes is assessed by the measured in-plane magnetic induction maps, in good agreement with theoretical calculations.
Phase Change Materials Composite Based on Hybrid Aerogel with Anisotropic Microstructure
Authors: Li Chen , Zhang Dong , Ren Wanwan
Published: February 2021

Phase change materials (PCMs) can be thermally enhanced by reduced graphene oxide (rGO)/expanded graphite (EG) aerogel with anisotropic microstructure. An rGO/EG aerogel with anisotropic microstructure was prepared by directionally freezing aqueous suspensions of graphene oxide (GO) and EG, followed by a freeze-drying process and thermal reduction at 250 °C. The anisotropic microstructure of rGO/EG aerogel composite PCM was confirmed by scanning electron microscopy (SEM), thermal conductivity tests and infrared images. The thermal conductivity of PCMs increased remarkably with rGO/EG aerogel. Compared with the thermal conductivity of pure paraffin, it increased by about 50~300% in the longitudinal direction and increased by about 25–150% in the transversal direction. The enhancement of thermal conductivity was attributed to the improvement of the thermal pathway provided by rGO/EG aerogel and the decrease of the interfacial thermal resistance between PCM and fillers. Meanwhile, rGO/EG aerogel was combined with paraffin only by physical adsorption, and no chemical interaction occurs between them, leading to no effect on the phase change behavior. In addition, the addition of rGO/EG aerogel led to a slight increase in the latent heat of the paraffin in the composite PCM.
Single Chain Mean-Field Theory Study on Responsive Behavior of Semiflexible Polymer Brush
Authors: Niu Yingli , Bu Xiangyu , Zhang Xinghua
Published: February 2021

The application of single chain mean-field theory (SCMFT) on semiflexible chain brushes is reviewed. The worm-like chain (WLC) model is the best mode of semiflexible chain that can continuously recover to the rigid rod model and Gaussian chain (GC) model in rigid and flexible limits, respectively. Compared with the commonly used GC model, SCMFT is more applicable to the WLC model because the algorithmic complexity of the WLC model is much higher than that of the GC model in self-consistent field theory (SCFT). On the contrary, the algorithmic complexity of both models in SCMFT are comparable. In SCMFT, the ensemble average of quantities is obtained by sampling the conformations of a single chain or multi-chains in the external auxiliary field instead of solving the modified diffuse equation (MDE) in SCFT. The precision of this calculation is controlled by the number of bonds Nm used to discretize the chain contour length L and the number of conformations M used in the ensemble average. The latter factor can be well controlled by metropolis Monte Carlo simulation. This approach can be easily generalized to solve problems with complex boundary conditions or in high-dimensional systems, which were once nightmares when solving MDEs in SCFT. Moreover, the calculations in SCMFT mainly relate to the assemble averages of chain conformations, for which a portion of conformations can be performed parallel on different computing cores using a message-passing interface (MPI).
Microstructure and Wear Resistance of Multi-Layer Ni-Based Alloy Cladding Coating on 316L SS under Different Laser Power
Authors: Qian Shaoxiang , Dai Yibo , Guo Yuhang , Zhang Yongkang
Published: February 2021

We prepared three kinds of Ni based alloy cladding coatings on 316L stainless steel at different power levels. The microstructure of the cladding layer was observed and analyzed by XRD, metallographic microscope, and SEM. The hardness of the cladding layer was measured, and the wear resistance of it was tested by a friction instrument. The results show that the effect of laser cladding is good, and it has good metallurgical bonding with the substrate. Different microstructures such as dendritic and equiaxed grains can be observed in the cladding layer. With the increase in laser power, more equiaxed and columnar dendrites can be observed. The phase composition of the cladding layer is mainly composed of γ–Ni solid solution and some intermetallic compounds such as Ni3B, Cr5B3, and Ni17Si3. The results of EDS show that there are some differences in the distribution of C and Si between dendrites. The hardness of the cladding layer is about 600 HV0.2, which is about three times of the substrate (~200 HV0.2). Through the analysis of the wear morphology, the substrate wear is serious, there are serious shedding, mainly adhesive wear, and abrasive wear. However, the wear of the cladding layer is slight, which is abrasive wear, and there are some grooves on the surface.