bluuebunny/crossref_metadata_2025 huggingface dataset:
Robust Sliding Mode Control of PMSM Based on Rapid Nonlinear Tracking Differentiator and Disturbance Observer
Authors: Zhou Zhanmin , Zhang Bao , Mao Dapeng
Published: March 2018

Torque ripples caused by cogging torque, flux harmonics, and current measurement error seriously restrict the application of a permanent magnet synchronous motor (PMSM), which has been paid more and more attention for the use in inertial stabilized platforms. Sliding mode control (SMC), in parallel with the classical proportional integral (PI) controller, has a high advantage to suppress the torque ripples as its invariance to disturbances. However, since the high switching gain tends to cause chattering and it requires derivative of signals which is not readily obtainable without an acceleration signal sensor. Therefore, this paper proposes a robust SMC scheme based on a rapid nonlinear tracking differentiator (NTD) and a disturbance observer (DOB) to further improve the performance of the SMC. The NTD is employed to providing the derivative of the signal, and the DOB is utilized to estimate the system lumped disturbances, including parameter variations and external disturbances. On the one hand, DOB can compensate the robust SMC speed controller, it can reduce the chattering of SMC on the other hand. Experiments were carried out on an ARM and DSP-based platform. The obtained experimental results demonstrate that the robust SMC scheme has an improved performance with inertia stability and it exhibits a satisfactory anti-disturbance performance compared to the traditional methods.
Real-Time Processing Library for Open-Source Hardware Biomedical Sensors
Authors: Molina-Cantero Alberto , Castro-García Juan , Lebrato-Vázquez Clara , Gómez-González Isabel , Merino-Monge Manuel
Published: March 2018

Applications involving data acquisition from sensors need samples at a preset frequency rate, the filtering out of noise and/or analysis of certain frequency components. We propose a novel software architecture based on open-software hardware platforms which allows programmers to create data streams from input channels and easily implement filters and frequency analysis objects. The performances of the different classes given in the size of memory allocated and execution time (number of clock cycles) were analyzed in the low-cost platform Arduino Genuino. In addition, 11 people took part in an experiment in which they had to implement several exercises and complete a usability test. Sampling rates under 250 Hz (typical for many biomedical applications) makes it feasible to implement filters, sliding windows and Fourier analysis, operating in real time. Participants rated software usability at 70.2 out of 100 and the ease of use when implementing several signal processing applications was rated at just over 4.4 out of 5. Participants showed their intention of using this software because it was percieved as useful and very easy to use. The performances of the library showed that it may be appropriate for implementing small biomedical real-time applications or for human movement monitoring, even in a simple open-source hardware device like Arduino Genuino. The general perception about this library is that it is easy to use and intuitive.
Significant Indicators and Determinants of Happiness: Evidence from a UK Survey and Revealed by a Data-Driven Systems Modelling Approach
Authors: Gu Yuanlin , Wei Hua-Liang
Published: March 2018

This study aims to establish a quantitative relationship between lifestyle and happiness in the UK based on over 10,000 surveyed samples with 63 lifestyle variables from the UK Understanding Society Data. Transparent parametric models are built and a number of significant explanatory variables (lifestyle indicators) have been identified using a systems engineering modelling approach. Specifically; based on the traditional orthogonal forward regression (OFR) algorithm; the study introduces a new metrics; with which the impacts of lifestyle variables (and/or their interactions) can be quantitatively measured and identified one by one. These identified significant indicators provide a meaningful parsimonious representation of the relationship between happiness and lifestyle; revealing how happiness quantitatively depends on lifestyle; and how the lifestyle variables interactively affect happiness. For example; the quantitative results of a linear model indicate that lifestyle variables such as ‘health’; ‘income’; and ‘retirement’; impacts happiness significantly. Furthermore; the results of a bilinear model show that some interaction variables such as ‘retired’ together with ‘elder’; ‘fair health’ together with ‘low-income’ and so on; are significantly related to happiness.
Identification of Population Growth and Distribution, Based on Urban Zone Functions
Authors: Malik Ida , Dewancker Bart
Published: March 2018

Population growth and distribution are still widely seen from the perspective of urban areas. Though the city has many zones with various functions, so comes the question, what zone will have population growth and hold the highest population growth distribution? And why would residents choose that zone? The study was conducted in Bandar Lampung, Indonesia, using population data from 2004 to 2011 (8 years) and urban zoning data from government documents. The results show that the conservation zone has the highest population growth and receives the highest population growth distribution. This result is confirmed by a cross section survey of respondents who live in the conservation zone. The survey results show that purchase, wide land, environment, and native inhabitants are variables affecting the population’s choice of the conservation zone as their residential location. The study also shows that the zones with the highest population do not automatically have the highest population growth and accommodate the highest population increase. Population analysis using the zonation system can help us better understand population growth and population growth distribution in urban areas.
QSI Methods for Determining the Quality of the Surface Finish of Concrete
Authors: Benito Saorin Francisco , Miñano Belmonte Isabel , Parra Costa Carlos , Rodriguez Lopez Carlos , Valcuende Paya Manuel
Published: March 2018

The surface finish of a concrete element may become an index of its quality, relating the external and internal porosity with the mechanical and durability properties. Few methods are used to determine the surface quality of concrete elements. Mention must be made the Quality Surface Index (QSI) proposes a simplified method to quantify the surface occupied by the pores in relation with the total surface inspected, analyzing groups of pores by their diameter. The method of the CIB W29 (Commission W29 “Concrete Surface Finishings”) proposes an inspection of the concrete element and its visual comparison with some standard templates. Finally, the digital processing of images allows the zones with surface defects to be delimited and quantified according to premises of quality introduced into the control software. These three methods are employed in this work and are applied in three concrete walls situated three meters from the observer (M-1, M-2 and M-3). Following the conversion of the results of the method with ImageJ and QSI, the results suppose differences that go from 0.1 tenths (2%) for M-3 up to 0.3 tenths (8%) for M-1. All values are within the obtained range with CIB W29 templates. This can validate the QSI and digital processing methods and allows a quick verification of the results. With the digital method, it is obtained that 23.5% of the total pores of M-1 have a diameter of less than 10 mm2 and 44% of less than 100 mm2. For M-2 and M-3 the proportions of pores with a dimension below 10 mm2 is of 43.1% and 27.7%, respectively, and that 77.5% and 60.7% are smaller than 100 mm2. From all the above it can be highlighted that M-1 is the one with the lowest amount of pores, however the proportion of the largest is greater than for M-2 and M-3. In the case of M-3, although it has a lower proportion of larger pores than M-1, its greater amount means it is the worst in terms of surface finish of the three.
Quantitative Determination of Potable Cold Water Consumption in German Hospitals
Authors: González Alfonso , García-Sanz-Calcedo Justo , Salgado David
Published: March 2018

A hospital’s water installations are critical for its function, but the environmental cost is high. This study quantifies the mean potable cold water consumption (PCWC) in 19 hospitals belonging to the German Public Health System. The hospital floor area ranges from 3000 to 151,000 m2 and the number of beds from 45 to 1003 beds. To this end, 60 Eco-Management and Audit Scheme statements were analyzed corresponding to the period 2005–2015 in accordance with their geographic location, heating-degree-days per year, cold-degree-days per year, hospital category depending on the number of beds, floor area, and number of workers. It was found that PCWC is greater in hospitals located in areas with greater heating-degree-days per year. The potential mean annual savings estimated were 8,600,000 m3 of water equivalent to 15,000,000 euros, 4000 MWh energy, and 30,000 tons of CO2 emissions. It was concluded that, to determine the mean annual water consumption, it is preferable to use the number of beds as reference indicator, and the value of the consumption as reference indicator was proposed as 103 m3 per bed per year.
Quantifying and Monetizing Renewable Energy Resiliency
Authors: Anderson Kate , Laws Nicholas , Marr Spencer , Lisell Lars , Jimenez Tony , Case Tria , Li Xiangkun , Lohmann Dag , Cutler Dylan
Published: March 2018

Energy resiliency has been thrust to the forefront by recent severe weather events and natural disasters. Billions of dollars are lost each year due to power outages. This article highlights the unique value renewable energy hybrid systems (REHS), comprised of solar, energy storage, and generators, provide in increasing resiliency. We present a methodology to quantify the amount and value of resiliency provided by REHS, and ways to monetize this resiliency value through insurance premium discounts. A case study of buildings in New York City demonstrates how implementing REHS in place of traditional backup diesel generators can double the amount of outage survivability, with an added value of $781,200. For a Superstorm Sandy type event, results indicate that insurance premium reductions could support up to 4% of the capital cost of REHS, and the potential exists to prevent up to $2.5 billion in business interruption losses with increased REHS deployment.
Spatial Spillover Effects of Environmental Pollution in China’s Central Plains Urban Agglomeration
Authors: Xiong Lichun , De Jong Martin , Wang Fengting , Cheng Baodong , Yu Chang
Published: March 2018

Promoting the rise of Central China is one of the most important national strategies regarding the promotion of China’s economic development. However, the environmental issues in the central regions have become remarkably severe. It is therefore worthwhile exploring how economic development and environmental protection can be coordinated. Focusing on the 29 prefecture-level cities in the Central Plains Urban Agglomeration, the authors empirically analyze the relationship between the economy and the environment from 2004 to 2014. The combined methods of the spatial autocorrelation model, the environmental Kuznets curve, and the global spatial correlation test are systematically employed. The results show that: (1) a strong spatial correlation exists between industrial wastewater discharge, industrial sulfur dioxide, and dust emissions in the Central Plains Urban Agglomeration; (2) the relationship between the economy and the environment of this urban agglomeration reveals an inverted “U” curve, which confirms the classical environmental Kuznets curve hypothesis. Industrial dust emissions have surpassed the inflection point of the Kuznets curve, but its spatial spillover effect still remains strong. This is caused by an accumulation effect and a lag effect; (3) the proportion of the secondary industry and population has a strong positive effect on pollution discharge; investments in science and technology have a certain inhibitory effect on industrial sulfur dioxide emission. Moreover, an increase in the number of industrial enterprises has a negative effect on industrial wastewater emission. At the end, the authors put forward policy recommendations regarding the establishment of a joint supervisory department and unified environmental standards at the regional level to deal with the spillover effects of pollution.
Knowledge Graph in Smart Education: A Case Study of Entrepreneurship Scientific Publication Management
Authors: Chi Yang , Qin Yue , Song Rui , Xu Hao
Published: March 2018

In recent years, with the rapid growth of science and innovation, plenty of constantly-updated scientific achievements containing innovative knowledge can be acquired and used to solve problems. However, most undergraduate students and non-researchers cannot use them efficiently. In traditional teacher-centric education, education for sustainability is often marginalized and the interdisciplinary demand is neglected. Additionally, it fails to provide education for learners to connect abstract knowledge with actual world problems. This paper presents the design of a scientific publication management model to integrate scientific metadata based on the knowledge graph and data analysis technologies. Based on this model, an interdisciplinary transregional multiple application platform could be realized for scientific resource retrieval and analysis, the purpose of which is to enhance scientific retrieval efficiency and reduce learning difficulty in the scientific domains and encourage non-researchers to utilize scientific resources in their study and work. Finally, to evaluate this model, the use of the case of an entrepreneurship scientific publication management prototype system was implemented. This work not only favors student’s learning for sustainability through analysis and knowledge management functions, but also promotes their awareness, comprehensive thinking, and the skills to deal with the issues of sustainability in their future work.
Landfill Site Selection by Weighted Overlay Technique: Case Study of Al-Kufa, Iraq
Authors: Al-Anbari Mohammad , Thameer Mohanad , Al-Ansari Nadhir
Published: March 2018

Landfill siting is a hard and complex process. For this reason, it is considered as one of the major problems in waste management. This is due to the fact that a number of factors are involved within the process such as such as inhabitants’ growth, rapid economic growth, living standards improvements, etc. In Iraq, landfill siting does not follow environmental regulations. Al-Kufa city located is located south-western part of Iraq (area of 550 km2 and inhabitants 372,760). Existing landfills are not selected according to the environmental standards. Landfill site that is required was achieved using a multi-criteria decision analysis (MCDA) and spatial overlay analysis using a geographic information system (GIS). Many factors were considered in the siting process; including geology, water supplies resources, urban centers, sensitive sites, and wells. AHP (analytic hierarchy process) method was used in weighting the criteria used. The result showed that there are six sites most suitable covering an area about (113) km2.
A Study on the Spontaneous Representation of Animals in Young Children’s Drawings of Plant Life
Authors: Villarroel José , Antón Alvaro , Zuazagoitia Daniel , Nuño Teresa
Published: March 2018

Previous research indicates that complex biological concepts may be successfully introduced in preschool age, provided that suitable educational interventions are designed for the initial stages of education. In this regard, there is evidence that a basic understanding of the issue of the ecological interactions among organisms may be achieved in the preschool years. With this in mind, this research project tests the assumption that recognising the fact that plants and animals are not isolated creatures, but live engaged in constant interactions in nature, may begin to be understood in early education. To that end, this study examines the content of free drawings that a sample of 328 children aged four to seven years of age, undertook when explaining their understanding of plant life. Data regarding the type and frequency of the depictions of animals found in the children’s graphic explanations on flora is collected and read in conjunction with participants’ gender and academic level. The results show that a substantial proportion of the children in the sample spontaneously drew illustrations of animals in their graphic explanations concerning vegetable life and, more significantly, some pictures show plants and animals engaged in clear contact. This is the case, despite the fact that the drawing activity had been focused solely on the issue of plant life and no indication linked to depicting other kinds of living things mentioned during the activity. The conclusions discuss the data collected in connection with the growing number of research projects that study the question of how young children begin to embrace the fundamental biological concepts that pave the way to the understanding of natural phenomena and make the public capable of making responsible choices when it comes to sustainability issues.
Gypsum and Legume Residue as a Strategy to Improve Soil Conditions in Sustainability of Agrosystems of the Humid Tropics
Authors: De Moura Emanoel , Portela Stefanny , Macedo Vinicius , Sena Virley , Sousa Carlos , Aguiar Alana
Published: March 2018

Gypsum combined with leguminous residue may extend rootability and improve growth and maize grain yield. The aim of this study was to evaluate the combined effects of gypsum and leguminous residue on soil rootability in the root zone and on maize grain yield in a cohesive tropical soil. We used seven treatments: (i) control; (ii) urea; (iii) leguminous; (iv) 6 t/ha of gypsum with leguminous or (v) with urea or (vi) with both; and (vii) 12 t/ha of gypsum with urea and leguminous. Gypsum was applied in January 2010 and soil samples were analyzed in 2012–2015. Maize was sown in 2011–2013 and 2015, when maize yield was determined. Soil penetration strength and the analysis of plant tissue was performed in 2015. The leaf area index, nitrogen accumulation amount, total N concentration and amount of N remobilization were also determined in 2015. Gypsum with leguminous residue modified the root zone by increasing calcium and organic matter levels and by reducing soil penetration strength. The leaf area index and the remobilization of nitrogen to grains increased, due to greater uptake before and after tasseling. The gypsum and leguminous residue combination is a more suitable strategy to improve agrosystems in cohesive soils of the humid tropics.
P2P Network Lending, Loss Given Default and Credit Risks
Authors: Zhou Guangyou , Zhang Yijia , Luo Sumei
Published: March 2018

Peer-to-peer (P2P) network lending is a new mode of internet finance that still holds credit risk as its main risk. According to the internal rating method of the New Basel Accord, in addition to the probability of default, loss given default is also one of the important indicators of evaluation credit risks. Proceeding from the perspective of loss given default (LGD), this paper conducts an empirical study on the probability distribution of LGDs of P2P as well as its influencing factors with the transaction data of Lending Club. The results show that: (1) the LGDs of P2P loans presents an obvious unimodal distribution, the peak value is relatively high and tends to concentrate with the decrease of the borrower’s credit rating, indicating that the distribution of LGDs of P2P lending is similar to that of unsecured bonds; (2) The total asset of the borrower has no significant impact on LGD, the credit rating and the debt-to-income ratio exert a significant negative impact, while the term and amount of the loan produce a relatively strong positive impact. Therefore, when evaluating the borrower’s repayment ability, it is required to pay more attention to its assets structure rather than the size of its total assets. When carrying out risk control for the P2P platform, it is necessary to give priority to the control of default rate.
Towards a Sustainable Sun, Sea, and Sand Tourism: The Value of Ocean View and Proximity to the Coast
Authors: Mendoza-González Gabriela , Martínez M. , Guevara Roger , Pérez-Maqueo Octavio , Garza-Lagler María , Howard Alan
Published: March 2018

Coastal tourism is expanding worldwide, mostly owing to the attraction to relevant ecosystem services such as the scenic beauty and recreational activities. The aim of this study was to analyze the value of these, using hedonic analysis by assessing how prices of hotel rooms are related to the scenic view, location, non-ecosystem amenities, and size of the hotels in three touristic areas of Veracruz, México. We found that, besides the size of the hotel and the number of non-ecosystem amenities, room prices increased by 8% and 57%, depending on the ocean view and accessibility to the beach, respectively. These results help to understand why hotels are built very close to the coastline, despite the high risk of extreme and frequent meteorological events. The unorganized and intense development of the tourist industry may act in contrast to the necessity for conservation of the natural ecosystems, rendering this activity highly unsustainable. The question is how to deal with the dilemma of tourism growth and conservation. We suggest some alternatives that might help with the conservation of natural ecosystems, while maintaining the combined provision of simultaneous coastal ecosystem services such as an aesthetically pleasing view and recreation, as well as additional services such as storm protection.
Opening the Black-Box in Lifelong E-Learning for Employability: A Framework for a Socio-Technical E-Learning Employability System of Measurement (STELEM)
Authors: Martínez-Cerdá Juan-Francisco , Torrent-Sellens Joan , González-González Inés , Ficapal-Cusí Pilar
Published: March 2018

Human beings must develop many skills to cope with the large amount of challenges that currently exist in the world: media empowerment for an active and democratic citizenship, knowledge acquisition and conversion for lifelong and life-wide learning, 21st century skills for matching demand and supply in labor markets, and dispositional employability for unpredictable future career success. One of the tools for achieving these is online education, in which students have the chance to manage their own time, content, and goals. Thus, this paper analyzes these issues from the perspective of skills gained through e-learning and validates the Socio-Technical E-learning Employability System of Measurement (STELEM) framework. The research was carried out with former students of the Universitat Oberta de Catalunya. Exploratory and confirmatory factorial analyses validate several consistent and reliable scales in two areas: (i) employability, based on educational social capital, media empowerment, knowledge acquisition, knowledge conversion, literacy, digitalness, collaboration, resilience, proactivity, identity, openness, motivation, organizational culture, and employment security; and (ii) socio-technical systems existing in this open online university, based on its information and communications technology (ICT), learning tasks, as well as student-centered and organizational approaches. The research provides two new psychometrical scales that are useful for the evaluation, monitoring, and assessment of relationships and influences between socio-technical e-learning organizations and employability skills development, and proposes a set of indicators related to human and social capital, valid in employability contexts.
Turning Farmers into Business Partners through Value Co-Creation Projects. Insights from the Coffee Supply Chain
Authors: Candelo Elena , Casalegno Cecilia , Civera Chiara , Mosca Fabrizio
Published: March 2018

This study examines the empowerment of low-power, vulnerable stakeholders of global, complex supply chains as one effective strategy to increase value co-creation and to moderate the vulnerabilities that threaten supply chain resilience. Previous scholars have indicated the necessity of investigating the concept of value co-creation further by including various stakeholder perspectives and suggesting systems of evaluation. This research thus focuses on low-power smallholder farmers within the coffee supply chain by qualitatively evaluating the effectiveness of value co-creation projects. The study also analyzes the extent of development and the nature of empowerment initiatives designed conjointly by nongovernmental organizations (NGOs) and coffee roasters that are addressed to farmers. The mixed qualitative methodology includes a literature review, interviews, focus groups, and content analysis of 20 value co-creation projects conducted in various developing and emerging coffee-producing countries. The research proposes a theoretical framework employed to conduct focus groups with Brazilian coffee farmers. This framework empirically demonstrates that these farmers are in the process of becoming business partners of the coffee supply chain thanks to various empowerment initiatives, common to most of the analyzed projects, that appear to moderate specific vulnerabilities of the coffee supply chain and therefore benefit supply chain resilience.
Ephemeral-Secret-Leakage Secure ID-Based Three-Party Authenticated Key Agreement Protocol for Mobile Distributed Computing Environments
Authors: Liu Chao-Liang , Tsai Wang-Jui , Chang Ting-Yi , Liu Ta-Ming
Published: March 2018

A three-party Authenticated Key Agreement (AKA) protocol in the distributed computing environment is a client that requests services from an application server through an authentication server. The authentication server is responsible for authenticating the participating entities and helping them to construct a common session key. Adopting the Key Transfer Authentication Protocol (KTAP) in such an environment, the authentication server is able to monitor the communication messages to prevent and trace network crime. However, the session key in the KTAP setting is created only by the authentication server and is vulnerable to the resilience of key control. On the other hand, with the rapid growth of network technologies, mobile devices are widely used by people to access servers in the Internet. Many AKA protocols for mobile devices have been proposed, however, most protocols are vulnerable to Ephemeral Secret Leakage (ESL) attacks which compromise the private keys of clients and the session key by an adversary from eavesdropped messages. This paper proposes a novel ESL-secure ID-based three-party AKA protocol for mobile distributed computing environments based on ESL-secure ID-based Authenticated Key Exchange (ID-AKE) protocol. The proposed protocol solves the key control problem in KTAP while retaining the advantages of preventing and tracing network crime in KTAP and also resists ESL attacks. The AVISPA tool simulation results confirm the correctness of the protocol security analysis. Furthermore, we present a parallel version of the proposed ESL-secure ID-based three-party AKA protocol that is communication-efficient.
Adding Feedbacks and Non-Linearity to the Neoclassical Growth Model: A New Realm for System Dynamics Applications
Authors: Režný Lukáš , Bureš Vladimír
Published: March 2018

Modelling of economic systems is traditionally associated with a mathematical formalism that has its drawbacks and limitations. This study applies system dynamics as a specific modelling technique that enables us to modify and elaborate existing economic models and improve them both from a theoretical perspective and for practical applications. More specifically, the Solow-Swan growth model is enriched by feedback and non-linearity based on its extension by the energy sector. The influence and role of renewable resources are considered in this enhancement. The developed model is tested in two different scenarios and utilizes sensitivity analysis as the primary tool. Acquired outcomes offer a new perspective on the economy–energy nexus based on real data and demonstrate that system dynamics can be successfully used as a modelling tool even in the theoretical economics as a traditional discipline.
“Appropriate Treatment” and Therapeutic Window in Spasticity Treatment with IncobotulinumtoxinA: From 100 to 1000 Units
Authors: Ianieri Giancarlo , Marvulli Riccardo , Gallo Giulia Alessia , Fiore Pietro , Megna Marisa
Published: March 2018

Many neurological diseases (ischemic and hemorrhagic stroke, multiple sclerosis, infant cerebral palsy, spinal cord injuries, traumatic brain injury, and other cerebrovascular disorders) may cause muscle spasticity. Different therapeutic strategies have been proposed for the treatment of spasticity. One of the major treatments for tone modulation is botulinum toxin type A (BTX-A), performed in addition to other rehabilitation strategies based on individualized multidisciplinary programs aimed at achieving certain goals for each patient. Therapeutic plans must be precisely defined as they must balance the reduction of spastic hypertonia and retention of residual motor function. To perform and optimize the treatment, an accurate clinical and instrumental evaluation of spasticity is needed to determine how this symptom is invalidating and to choose the best doses, muscles and times of injection in each patient. We introduce an “appropriate treatment” and no “standard or high dosage treatment” concept based on our retrospective observational study on 120 patients lasting two years, according to the larger Therapeutic Index and Therapeutic Window of Incobotulinumtoxin A doses from 100 to 1000 units. We studied the efficiency and safety of this drug considering the clinical spasticity significance for specialist physicians and patients.
Dose-Response Modelling of Paralytic Shellfish Poisoning (PSP) in Humans
Authors: Arnich Nathalie , Thébault Anne
Published: March 2018

Paralytic shellfish poisoning (PSP) is caused by a group of marine toxins with saxitoxin (STX) as the reference compound. Symptoms in humans after consumption of contaminated shellfish vary from slight neurological and gastrointestinal effects to fatal respiratory paralysis. A systematic review was conducted to identify reported cases of human poisoning associated with the ingestion of shellfish contaminated with paralytic shellfish toxins (PSTs). Raw data were collected from 143 exposed individuals (113 with symptoms, 30 without symptoms) from 13 studies. Exposure estimates were based on mouse bioassays except in one study. A significant relationship between exposure to PSTs and severity of symptoms was established by ordinal modelling. The critical minimal dose with a probability higher than 10% of showing symptoms is 0.37 µg STX eq./kg b.w. This means that 10% of the individuals exposed to this dose would have symptoms (without considering the severity of the symptoms). This dose is four-fold lower than the lowest-observed-adverse-effect-level (LOAEL) established by the European Food Safety Authority (EFSA, 2009) in the region of 1.5 μg STX eq./kg b.w. This work provides critical doses that could be used as point of departure to update the acute reference dose for STX. This is the first time a dose-symptoms model could be built for marine toxins using epidemiological data.
Camelid Single-Domain Antibodies (VHHs) against Crotoxin: A Basis for Developing Modular Building Blocks for the Enhancement of Treatment or Diagnosis of Crotalic Envenoming
Authors: Luiz Marcos , Pereira Soraya , Prado Nidiane , Gonçalves Naan , Kayano Anderson , Moreira-Dill Leandro , Sobrinho Juliana , Zanchi Fernando , Fuly André , Fernandes Cleberson , Zuliani Juliana , Soares Andreimar , Stabeli Rodrigo , Fernandes Carla
Published: March 2018

Toxic effects triggered by crotalic envenoming are mainly related to crotoxin (CTX), composed of a phospholipase A2 (CB) and a subunit with no toxic activity (CA). Camelids produce immunoglobulins G devoid of light chains, in which the antigen recognition domain is called VHH. Given their unique characteristics, VHHs were selected using Phage Display against CTX from Crotalus durissus terrificus. After three rounds of biopanning, four sequence profiles for CB (KF498602, KF498603, KF498604, and KF498605) and one for CA (KF498606) were revealed. All clones presented the VHH hallmark in FR2 and a long CDR3, with the exception of KF498606. After expressing pET22b-VHHs in E. coli, approximately 2 to 6 mg of protein per liter of culture were obtained. When tested for cross-reactivity, VHHs presented specificity for the Crotalus genus and were capable of recognizing CB through Western blot. KF498602 and KF498604 showed thermostability, and displayed affinity constants for CTX in the micro or nanomolar range. They inhibited in vitro CTX PLA2 activity, and CB cytotoxicity. Furthermore, KF498604 inhibited the CTX-induced myotoxicity in mice by 78.8%. Molecular docking revealed that KF498604 interacts with the CA–CB interface of CTX, seeming to block substrate access. Selected VHHs may be alternatives for the crotalic envenoming treatment.
Expression of TIM-3 on Plasmacytoid Dendritic Cells as a Predictive Biomarker of Decline in HIV-1 RNA Level during ART
Authors: Font-Haro Albert , Janovec Vaclav , Hofman Tomas , Machala Ladislav , Jilich David , Melkova Zora , Weber Jan , Trejbalova Katerina , Hirsch Ivan
Published: March 2018

Depletion and functional impairment of circulating plasmacytoid dendritic cells (pDCs) are characteristic attributes of HIV-1-infection. The mechanism of dysfunction of pDCs is unclear. Here, we studied the development of phenotype of pDCs in a cohort of HIV-1-infected individuals monitored before the initiation and during a 9-month follow up with antiretroviral therapy (ART). Using polychromatic flow cytometry, we detected significantly higher pDC-surface expression of the HIV-1 receptor CD4, regulatory receptor BDCA-2, Fcγ receptor CD32, pDC dysfunction marker TIM-3, and the marker of killer pDC, TRAIL, in treatment-naïve HIV-1-infected individuals before initiation of ART when compared to healthy donors. After 9 months of ART, all of these markers approached but did not reach the expression levels observed in healthy donors. We found that the rate of decline in HIV-1 RNA level over the first 3 months of ART negatively correlated with the expression of TIM-3 on pDCs. We conclude that immunogenic phenotype of pDCs is not significantly restored after sustained suppression of HIV-1 RNA level in ART-treated patients and that the level of the TIM-3 expressed on pDCs in treatment naïve patients could be a predictive marker of the rate of decline in the HIV-1 RNA level during ART.
Simian Varicella Virus Infects Enteric Neurons and α4β7 Integrin-Expressing Gut-Tropic T-Cells in Nonhuman Primates
Authors: Ouwendijk Werner , Van Veen Suzanne , Mehraban Tamana , Mahalingam Ravi , Verjans Georges
Published: March 2018

The pathogenesis of enteric zoster, a rare debilitating complication of reactivation of latent varicella-zoster virus (VZV) in the enteric nervous system (ENS), is largely unknown. Infection of monkeys with the closely related Varicellovirus simian varicella virus (SVV) mimics VZV disease in humans. In this study, we determined the applicability of the SVV nonhuman primate model to study Varicellovirus infection of the ENS. We confirmed VZV infection of the gut in latently infected adults and demonstrated that SVV DNA was similarly present in gut of monkeys latently infected with SVV using quantitative real-time PCR. In situ analyses showed that enteric neurons expressed SVV open reading frame (ORF) 63 RNA, but not viral nucleocapsid proteins, suggestive of latent ENS infection. During primary infection, SVV-infected T-cells were detected in gut-draining mesenteric lymph nodes and located in close vicinity to enteric nerves in the gut. Furthermore, flow cytometric analysis of blood from acutely SVV-infected monkeys demonstrated that virus-infected T-cells expressed the gut-homing receptor α4β7 integrin. Collectively, the data demonstrate that SVV infects ENS neurons during primary infection and supports the role of T-cells in virus dissemination to the gut. Because SVV reactivation can be experimentally induced, the SVV nonhuman primate model holds great potential to study the pathogenesis of enteric zoster.
Influence of Carbon Source on the Efficiency of Nitrogen Removal and Denitrifying Bacteria in Biofilm from Bioelectrochemical SBBRs
Authors: Kłodowska Izabella , Rodziewicz Joanna , Janczukowicz Wojciech , Cydzik-Kwiatkowska Agnieszka , Rusanowska Paulina
Published: March 2018

Bioelectrochemical sequencing batch biofilm reactors (SBBRs) may be used as post-anoxic reactors. The aim of this study was to determine how nitrate removal depends on the type of external carbon source and the electric current density (J). The effect of citric acid and potassium bicarbonate on N removal efficiency and the denitrifying bacteria biofilm community at an electric current density of 105 and 210 mA/m2 was determined. Nitrogen removal efficiency depended on the density of the electric current and the carbon source. The highest efficiency of N removal was in the reactor with 210 mA/m2 and citric acid. Regardless of the J value, the addition of an external carbon source to the reactors resulted in a 4–6 fold increase in the relative number of denitrifying bacteria in the biomass in relation to the reactor operated without an electric current flow and organics in the influent. The highest number of denitrifiers was observed in the reactor with an inorganic carbon source and with a density of 105 mA/m2. The main factor determining the shifts in composition of the denitrifying bacteria was the electric current flow. In the reactors operated with the electric current flow, Thauera aminoaromatica MZ1T occurred in the reactors with potassium bicarbonate while Alicycliphilus denitrificans K601 preferred citric acid.
How Does Season Affect Passage Performance and Fatigue of Potamodromous Cyprinids? An Experimental Approach in a Vertical Slot Fishway
Authors: Romão Filipe , Santos José , Katopodis Christos , Pinheiro António , Branco Paulo
Published: March 2018

Most fishway studies are conducted during the reproductive period, yet uncertainty remains on whether results may be biased if the same studies were performed outside of the migration season. The present study assessed fish passage performance of a potamodromous cyprinid, the Iberian barbel (Luciobarbus bocagei), in an experimental full-scale vertical slot fishway during spring (reproductive season) and early-autumn (non-reproductive season). Results revealed that no significant differences were detected on passage performance metrics, except for entry efficiency. However, differences between seasons were noted in the plasma lactate concentration (higher in early-autumn), used as a proxy for muscular fatigue after the fishway navigation. This suggests that, for potamodromous cyprinids, the evaluation of passage performance in fishways does not need to be restricted to the reproductive season and can be extended to early-autumn, when movements associated with shifts in home range may occur. The increased effort during the non-reproductive period suggests that adapting the operational regime of fishways, at biologically meaningful seasons in a year, should be assessed by considering the physiological state of the target species.
The Effect of Particle Size on Sediment Accumulation in Permeable Pavements
Authors: Hill Kelly , Beecham Simon
Published: March 2018

This paper investigates the sediment retention behaviour of laboratory-based permeable pavements using mono-sized sediments that were representative of the sizes typically found in urban stormwater. The sediments were applied in two cycles, namely in order of increasing and decreasing size. The results indicated that most of the sediment accumulation could be attributed to the depth of the pavement and the material used in the joint and bedding aggregates. Most of the sediment was retained in the bedding and surface layers, and little difference to the retention was made by the incorporation of a basecourse layer. When the mono-sized sediments were added in decreasing size order with the coarsest sediments applied first, the overall rate of retention increased.
Prevalence of Meticillin-Resistant Staphylococcus aureus Colonisation amongst Residents in Maltese Nursing Homes
Authors: Borg Ryan Fredi , Gatt Christine , Borg Michael A
Published: March 2018

Since the 1960’s, meticillin-resistant Staphylococcus aureus (MRSA) has become a major pathogen with ever-increasing incidence rates of hospital-acquired and community-acquired infections. Malta has currently one of the highest rates of hospital-acquired and community-acquired infections in Europe. In addition, reports have estimated community carriage at more than 8%. MRSA carriage in homes for the elderly is very important because these residents are often hospitalized and therefore serve as a source of transmission. The aims of this study were to establish the prevalence of MRSA nasal carriage amongst residents in nursing homes in Malta, to determine their antibiotic susceptibility and to determine the significance of specific risk factors found in the literature. Nasal swabs were taken from 397 randomly chosen residents in 10 governmental nursing homes. A short questionnaire including possible risk factors reported to be associated with MRSA nasal carriage was also filled. MRSA carriage amongst nursing home residents was 19.4% (95% CI 17.6 – 21.2%) ranging from 0% to 25% amongst the nursing homes studied. Logistic regression analyses indicated that previous hospital admission was the only risk factor that was found to be significantly (OR: 1.956, p: 0.011; 95CI 1.163 - 3.290) associated with MRSA nasal colonization amongst nursing home residents. A high carriage rate of MRSA was identified in Maltese nursing care residents which can contribute to maintaining MRSA incidence in hospitals. Possible interventions include screening of these patients when they are admitted to an acute care facility and possible decolonization attempts in the nursing homes.
Nanoreactors for green catalysis
Authors: De Martino M Teresa , Abdelmohsen Loai K E A , Rutjes Floris P J T , van Hest Jan C M
Published: March 2018

Sustainable and environmentally benign production are key drivers for developments in the chemical industrial sector, as protecting our planet has become a significant element that should be considered for every industrial breakthrough or technological advancement. As a result, the concept of green chemistry has been recently defined to guide chemists towards minimizing any harmful outcome of chemical processes in either industry or research. Towards greener reactions, scientists have developed various approaches in order to decrease environmental risks while attaining chemical sustainability and elegancy. Utilizing catalytic nanoreactors for greener reactions, for facilitating multistep synthetic pathways in one-pot procedures, is imperative with far-reaching implications in the field. This review is focused on the applications of some of the most used nanoreactors in catalysis, namely: (polymer) vesicles, micelles, dendrimers and nanogels. The ability and efficiency of catalytic nanoreactors to carry out organic reactions in water, to perform cascade reaction and their ability to be recycled will be discussed.
Dark Matter in Ultra-diffuse Galaxies in the Virgo Cluster from Their Globular Cluster Populations
Authors: Toloba Elisa , Lim Sungsoon , Peng Eric , Sales Laura V. , Guhathakurta Puragra , Mihos J. Christopher , Côté Patrick , Boselli Alessandro , Cuillandre Jean-Charles , Ferrarese Laura , Gwyn Stephen , Lançon Ariane , Muñoz Roberto , Puzia Thomas
Published: March 2018

We present Keck/DEIMOS spectroscopy of globular clusters (GCs) around the ultra-diffuse galaxies (UDGs) VLSB−B, VLSB−D, and VCC615 located in the central regions of the Virgo cluster. We spectroscopically identify 4, 12, and 7 GC satellites of these UDGs, respectively. We find that the three UDGs have systemic velocities (V
sys) consistent with being in the Virgo cluster, and that they span a wide range of velocity dispersions, from ∼16 to ∼47 km s−1, and high dynamical mass-to-light ratios within the radius that contains half the number of GCs (

,

,

, respectively). VLSB−D shows possible evidence for rotation along the stellar major axis and its V
sys is consistent with that of the massive galaxy M84 and the center of the Virgo cluster itself. These findings, in addition to having a dynamically and spatially (∼1 kpc) off-centered nucleus and being extremely elongated, suggest that VLSB−D could be tidally perturbed. On the contrary, VLSB−B and VCC615 show no signs of tidal deformation. Whereas the dynamics of VLSB−D suggest that it has a less massive dark matter halo than expected for its stellar mass, VLSB−B and VCC615 are consistent with a ∼1012
M
⊙ dark matter halo. Although our samples of galaxies and GCs are small, these results suggest that UDGs may be a diverse population, with their low surface brightnesses being the result of very early formation, tidal disruption, or a combination of the two.
An Enigmatic Population of Luminous Globular Clusters in a Galaxy Lacking Dark Matter
Authors: van Dokkum Pieter , Cohen Yotam , Danieli Shany , Kruijssen J. M. Diederik , Romanowsky Aaron J. , Merritt Allison , Abraham Roberto , Brodie Jean , Conroy Charlie , Lokhorst Deborah , Mowla Lamiya , O’Sullivan Ewan , Zhang Jielai
Published: March 2018

We recently found an ultra diffuse galaxy (UDG) with a half-light radius of R

e
 = 2.2 kpc and little or no dark matter. The total mass of NGC1052–DF2 was measured from the radial velocities of bright compact objects that are associated with the galaxy. Here, we analyze these objects using a combination of Hubble Space Telescope (HST) imaging and Keck spectroscopy. Their average size is

pc and their average ellipticity is

. From a stacked Keck spectrum we derive an age of ≳9 Gyr and a metallicity of [Fe/H] = −1.35 ± 0.12. Their properties are similar to ω Centauri, the brightest and largest globular cluster in the Milky Way, and our results demonstrate that the luminosity function of metal-poor globular clusters is not universal. The fraction of the total stellar mass that is in the globular cluster system is similar to that in other UDGs, and consistent with “failed galaxy” scenarios, where star formation terminated shortly after the clusters were formed. However, the galaxy is a factor of ∼1000 removed from the relation between globular cluster mass and total galaxy mass that has been found for other galaxies, including other UDGs. We infer that a dark matter halo is not a prerequisite for the formation of metal-poor globular cluster-like objects in high-redshift galaxies.
Tubuca alcocki, a new pseudocryptic species of fiddler crab from the Indian Ocean, sister to the southeastern African T. urvillei (H. Milne Edwards, 1852) (Crustacea, Decapoda, Brachyura, Ocypodidae)
Authors: Shih Hsi-Te , Chan Benny K.K. , Ng Peter K.L.
Published: March 2018

A new pseudocryptic species of fiddler crab,Tubucaalcockisp. n., is described from the northern Indian Ocean. The new species was previously identified withT.urvillei(H. Milne Edwards, 1852), but can be distinguished by the structures of the anterolateral angle of the carapace and male first gonopod. The molecular data of the mitochondrial cytochrome oxidase subunit I gene shows that both are sister taxa and the divergence time is estimated at 2.2 million years ago, around the beginning of the Pleistocene. While the new species is widely distributed in the northern part of Indian Ocean, occurring from the Red Sea to India and the Andaman Sea;T.urvilleisensu stricto has a more restricted range, and is known only from southeastern Africa.