bluuebunny/crossref_metadata_2025 huggingface dataset:
A Theory of Autofrettage for Open-Ended, Polar Orthotropic Cylinders
Authors: Rynkovskaya Marina , Alexandrov Sergei , Lang Lihui
Published: February 2019

Autofrettage is a widely used process to enhance the fatigue life of holes. In the theoretical investigation presented in this article, a semi-analytic solution is derived for a polar, orthotropic, open-ended cylinder subjected to internal pressure, followed by unloading. Numerical techniques are only necessary to solve a linear differential equation and evaluate ordinary integrals. The generalized Hooke’s law connects the elastic portion of strain and stress. The flow theory of plasticity is employed. Plastic yielding is controlled by the Tsai–Hill yield criterion and its associated flow rule. It is shown that using the strain rate compatibility equation facilitates the solution. The general solution takes into account that elastic and plastic properties can be anisotropic. An illustrative example demonstrates the effect of plastic anisotropy on the distribution of stresses and strains, including residual stresses and strain, for elastically isotropic materials.
Kernel Ridge Regression Model Based on Beta-Noise and Its Application in Short-Term Wind Speed Forecasting
Authors: Zhang Shiguang , Zhou Ting , Sun Lin , Liu Chao
Published: February 2019

The Kernel ridge regression ( K R R) model aims to find the hidden nonlinear structure in raw data. It makes an assumption that the noise in data satisfies the Gaussian model. However, it was pointed out that the noise in wind speed/power forecasting obeys the Beta distribution. The classic regression techniques are not applicable to this case. Hence, we derive the empirical risk loss about the Beta distribution and propose a technique of the kernel ridge regression model based on the Beta-noise ( B N-K R R). The numerical experiments are carried out on real-world data. The results indicate that the proposed technique obtains good performance on short-term wind speed forecasting.
A Generic Framework for Accountable Optimistic Fair Exchange Protocol
Authors: Loh Jia-Ch’ng , Heng Swee-Huay , Tan Syh-Yuan
Published: February 2019

Optimistic Fair Exchange protocol was designed for two parties to exchange in a fair way where an arbitrator always remains offline and will be referred only if any dispute happens. There are various optimistic fair exchange protocols with different security properties in the literature. Most of the optimistic fair exchange protocols satisfy resolution ambiguity where a signature signed by the signer is computational indistinguishable from the one resolved by the arbitrator. Huang et al. proposed the first generic framework for accountable optimistic fair exchange protocol in the random oracle model where it possesses resolution ambiguity and is able to reveal the actual signer when needed. Ganjavi et al. later proposed the first generic framework in the standard model. In this paper, we propose a new generic framework for accountable optimistic fair exchange protocol in the standard model using ordinary signature, convertible undeniable signature, and ring signature scheme as the underlying building blocks. We also provide an instantiation using our proposed generic framework to obtain an efficient pairing-based accountable optimistic fair exchange protocol with short signature.
Some Subclasses of Uniformly Univalent Functions with Respect to Symmetric Points
Authors: Mahmood Shahid , Srivastava Hari M. , Malik Sarfraz Nawaz
Published: February 2019

This article presents the study of certain analytic functions defined by bounded radius rotations associated with conic domain. Many geometric properties like coefficient estimate, radii problems, arc length, integral representation, inclusion results and growth rate of coefficients of Taylor’s series representation are investigated. By varying the parameters in results, several well-known results in literature are obtained as special cases.
On Central Complete and Incomplete Bell Polynomials I
Authors: Kim Taekyun , Kim Dae San , Jang Gwan-Woo
Published: February 2019

In this paper, we introduce central complete and incomplete Bell polynomials which can be viewed as generalizations of central Bell polynomials and central factorial numbers of the second kind, and also as ’central’ analogues for complete and incomplete Bell polynomials. Further, some properties and identities for these polynomials are investigated. In particular, we provide explicit formulas for the central complete and incomplete Bell polynomials related to central factorial numbers of the second kind.
The Inhibitory Effect of Celangulin V on the ATP Hydrolytic Activity of the Complex of V-ATPase Subunits A and B in the Midgut of Mythimna separata
Authors: Ding Liwen , Guo Zongxin , Xu Hang , Li Tie , Wang Yuanyuan , Tao Hu
Published: February 2019

Celangulin V (CV) is a compound isolated from Celastrus angulatus Max that has a toxic activity against agricultural insect pests. CV can bind to subunits a, H, and B of the vacuolar ATPase (V-ATPase) in the midgut epithelial cells of insects. However, the mechanism of action of CV is still unclear. In this study, the soluble complex of the V-ATPase A subunit mutant TSCA which avoids the feedback inhibition by the hydrolysate ADP and V-ATPase B subunit were obtained and then purified using affinity chromatography. The H+K+-ATPase activity of the complex and the inhibitory activity of CV on ATP hydrolysis were determined. The results suggest that CV inhibits the ATP hydrolysis, resulting in an insecticidal effect. Additionally, the homology modeling of the AB complex and molecular docking results indicate that CV can competitively bind to the AB complex at the ATP binding site, which inhibits ATP hydrolysis. These findings suggest that the AB subunits complex is one of the potential targets for CV and is important for understanding the mechanism of interaction between CV and V-ATPase.
ANTARES and KM3NeT: The Latest Results of the Neutrino Telescopes in the Mediterranean
Authors: Sanguineti Matteo
Published: February 2019

The measurement of cosmic neutrinos is a new and unique method to observe the Universe. Neutrinos are chargeless, weakly-interacting particles that can provide information about the interior of an astrophysical object for cosmological distances. Indeed, they are a complementary probe with respect to other messengers such as multi-wavelength light and charged cosmic rays, allowing the observation of the far Universe and providing information on the production mechanism. Here, the neutrino telescopes in the Mediterranean Sea that are operating or in progress will be reviewed. The ANTARES (Astronomy with a Neutrino Telescope and Abyss environmental RESearch) detector is the largest neutrino telescope currently in operation in the Mediterranean Sea and the first operating in sea water. Some of the ANTARES results will be summarized, including diffuse, point-like, and multi-messenger source searches. Finally, the future km 3 -scale telescope KM3NeT (Cubic Kilometre Neutrino Telescope) will be described focusing on the expected performances and sensitivities.
Sharing Cities Shaping Cities
Authors: Salvia Giuseppe , Morello Eugenio , Arcidiacono Andrea
Published: February 2019

In recent years, ‘sharing cities’ has spread globally, starting in 2012 when Seoul declared its intent to pursue sharing economy strategies [...]
Development and Characterization of a Sin Nombre Virus Transmission Model in Peromyscus maniculatus
Authors: Warner Bryce M. , Stein Derek R. , Griffin Bryan D. , Tierney Kevin , Leung Anders , Sloan Angela , Kobasa Darwyn , Poliquin Guillaume , Kobinger Gary P. , Safronetz David
Published: February 2019

In North America, Sin Nombre virus (SNV) is the main cause of hantavirus cardiopulmonary syndrome (HCPS), a severe respiratory disease with a fatality rate of 35–40%. SNV is a zoonotic pathogen carried by deer mice (Peromyscus maniculatus), and few studies have been performed examining its transmission in deer mouse populations. Studying SNV and other hantaviruses can be difficult due to the need to propagate the virus in vivo for subsequent experiments. We show that when compared with standard intramuscular infection, the intraperitoneal infection of deer mice can be as effective in producing SNV stocks with a high viral RNA copy number, and this method of infection provides a more reproducible infection model. Furthermore, the age and sex of the infected deer mice have little effect on viral replication and shedding. We also describe a reliable model of direct experimental SNV transmission. We examined the transmission of SNV between deer mice and found that direct contact between deer mice is the main driver of SNV transmission rather than exposure to contaminated excreta/secreta, which is thought to be the main driver of transmission of the virus to humans. Furthermore, increases in heat shock responses or testosterone levels in SNV-infected deer mice do not increase the replication, shedding, or rate of transmission. Here, we have demonstrated a model for the transmission of SNV between deer mice, the natural rodent reservoir for the virus. The use of this model will have important implications for further examining SNV transmission and in developing strategies for the prevention of SNV infection in deer mouse populations.
Host Resistance, Genomics and Population Dynamics in a Salmonella Enteritidis and Phage System
Authors: Holguín Angela Victoria , Cárdenas Pablo , Prada-Peñaranda Catalina , Rabelo Leite Laura , Buitrago Camila , Clavijo Viviana , Oliveira Guilherme , Leekitcharoenphon Pimlapas , Møller Aarestrup Frank , Vives Martha J.
Published: February 2019

Bacteriophages represent an alternative solution to control bacterial infections. When interacting, bacteria and phage can evolve, and this relationship is described as antagonistic coevolution, a pattern that does not fit all models. In this work, the model consisted of a microcosm of Salmonella enterica serovar Enteritidis and φSan23 phage. Samples were taken for 12 days every 48 h. Bacteria and phage samples were collected; and isolated bacteria from each time point were challenged against phages from previous, contemporary, and subsequent time points. The phage plaque tests, with the genomics analyses, showed a mutational asymmetry dynamic in favor of the bacteria instead of antagonistic coevolution. This is important for future phage-therapy applications, so we decided to explore the population dynamics of Salmonella under different conditions: pressure of one phage, a combination of phages, and phages plus an antibiotic. The data from cultures with single and multiple phages, and antibiotics, were used to create a mathematical model exploring population and resistance dynamics of Salmonella under these treatments, suggesting a nonlethal, growth-inhibiting antibiotic may decrease resistance to phage-therapy cocktails. These data provide a deep insight into bacterial dynamics under different conditions and serve as additional criteria to select phages and antibiotics for phage-therapy.
Novel Approaches for The Development of Live Attenuated Influenza Vaccines
Authors: Blanco-Lobo Pilar , Nogales Aitor , Rodríguez Laura , Martínez-Sobrido Luis
Published: February 2019

Influenza virus still represents a considerable threat to global public health, despite the advances in the development and wide use of influenza vaccines. Vaccination with traditional inactivate influenza vaccines (IIV) or live-attenuated influenza vaccines (LAIV) remains the main strategy in the control of annual seasonal epidemics, but it does not offer protection against new influenza viruses with pandemic potential, those that have shifted. Moreover, the continual antigenic drift of seasonal circulating influenza viruses, causing an antigenic mismatch that requires yearly reformulation of seasonal influenza vaccines, seriously compromises vaccine efficacy. Therefore, the quick optimization of vaccine production for seasonal influenza and the development of new vaccine approaches for pandemic viruses is still a challenge for the prevention of influenza infections. Moreover, recent reports have questioned the effectiveness of the current LAIV because of limited protection, mainly against the influenza A virus (IAV) component of the vaccine. Although the reasons for the poor protection efficacy of the LAIV have not yet been elucidated, researchers are encouraged to develop new vaccination approaches that overcome the limitations that are associated with the current LAIV. The discovery and implementation of plasmid-based reverse genetics has been a key advance in the rapid generation of recombinant attenuated influenza viruses that can be used for the development of new and most effective LAIV. In this review, we provide an update regarding the progress that has been made during the last five years in the development of new LAIV and the innovative ways that are being explored as alternatives to the currently licensed LAIV. The safety, immunogenicity, and protection efficacy profile of these new LAIVs reveal their possible implementation in combating influenza infections. However, efforts by vaccine companies and government agencies will be needed for controlled testing and approving, respectively, these new vaccine methodologies for the control of influenza infections.
Metagenomics Response of Anaerobic Ammonium Oxidation (anammox) Bacteria to Bio-Refractory Humic Substances in Wastewater
Authors: Meng Yabing , Huang Li-Nan , Meng Fangang
Published: February 2019

Anammox-based processes have been widely applied for the treatment of wastewater (e.g., wastewater irrigation systems and constructed wetland) which consists of bio-refractory humic substances. Nonetheless, the impacts of bio-refractory humic substances on anammox consortia are rarely reported. In the present study, three identical lab-scale anammox reactors (i.e., HS0, HS1 and HS10), two of which were dosed with humic substances at 1 and 10 mg·L−1, respectively, were operated for nearly one year. The long-term operation of the reactors showed that the presence of humic substances in influent had no significant influence on nitrogen removal rates. Despite this, comparative metagenomics showed changes in anammox microbiota structure during the exposure to humic substance; e.g., the relative abundance of Candidatus Kuenenia was lower in HS10 (18.5%) than that in HS0 (22.8%) and HS1 (21.7%). More specifically, a lower level of humic substances (1 mg·L−1) in influent led to an increase of genes responsible for signal transduction, likely due to the role of humic substances as electron shuttles. In contrast, a high level of humic substances (10 mg·L−1) resulted in a slight decrease of functional genes associated with anammox metabolism. This may partially be due to the biodegradation of the humic substances. In addition, the lower dosage of humic substances (1 mg·L−1) also stimulated the abundance of hzs and hdh, which encode two important enzymes in anammox reaction. Overall, this study indicated that the anammox system could work stably over a long period under humic substances, and that the process was feasible for leachate treatment.
Water Related Properties to Assess Soil Quality in Two Olive Orchards of South Spain under Different Management Strategies
Authors: Guzmán Gema , Perea-Moreno Alberto-Jesus , Gómez José Alfonso , Cabrerizo-Morales Miguel Ángel , Martínez Gonzalo , Giráldez Juan Vicente
Published: February 2019

Soil quality is usually assessed through the measurement of selected soil properties. However, in spite of the diversity of the chosen properties, use of the soil water retention curve, like the pressure head or the specific water capacity at the inflection point, provides relevant information of degradation or improvement of soil. The main aim of this study was to evaluate the methods based on these indices in the evaluation of short-term changes of olive cropped soils under typical Mediterranean agricultural conditions. For this reason, soil properties (bulk density, hydraulic conductivity, aggregates stability, and organic matter content) were measured in a short-term trial settled in two olive orchards under different soil managements: tillage and cover crop. Several sampling areas were also distinguished: (i) along the inter tree row and under the canopies’ projection and (ii) at 0–10 cm and 10–20 cm depth. In addition, water retention curves were determined and fitted using two models (van Genutchen’s and Kosugi’s) in order to obtain the inflection point and therefore the S index. This index is the maximum value of the slope of the soil water retention curve and is related to soil quality. At the two sites, changes in soil management, even after a brief period of two years, had a relatively quick effect, especially in organic matter content along the inter tree row. The use of indices based on soil water retention curves helps to detect soil degradation or improvement changes. Future research, including the inclusion of more soil types and longer time periods, might lead to the development of more refined tools for the assessment of soil health.
Composition and Dynamics of Phytoplankton in the Coastal Bays of Maryland, USA, Revealed by Microscopic Counts and Diagnostic Pigments Analyses
Authors: Oseji Ozuem F. , Fan Chunlei , Chigbu Paulinus
Published: February 2019

Maryland Coastal Bays (MCBs) have undergone changes in water quality in the past two decades due to nutrient enrichment but the composition and dynamics of the phytoplankton community have not been adequately described. Microscopic counts and photosynthetic pigments of samples collected monthly in 2012 at selected sites in MCBs that differed with regard to the degree of anthropogenic impacts were examined. Sixty-three (63) phytoplankton genera were recorded, of which 40 species are being reported for the first time in the Bays. Among the dominant species were Dactyliosolen fragilissimus (Bacillariophyta), Paulinella ovalis (Cercozoa) and Cryptomonas sp. (Cryptophyta). Bloom densities of Heterocapsa rotundata (Miozoa), which previously had not been reported in the Bays, were observed bay-wide in December, particularly at the mouth of St. Martin River. Diatoms dominated (>40%) the phytoplankton community in winter and decreased in spring (<40%), while Cercozoa and microphytoflagellates (MPF) co-dominated in summer (July). From August to October, diatoms dominated with maximum contributions from an unidentified small (<10 µM) centric species and co-dominated the assemblage with cryptophytes in late fall (November). Canonical correspondence analysis indicated that diatoms were favored by high salinity and total dissolved phosphorus (TDP), cercozoans and chlorophytes by total dissolved nitrogen (TDN) and cryptophytes by dissolved organic carbon. The spatial and seasonal differences in the composition of phytoplankton species, coupled with the occurrence of potentially toxic species and bloom densities of H. rotundata suggest that important changes have occurred in the phytoplankton assemblage that likely have affected the food web of these eutrophic bays.
A Fractal Model of Hydraulic Conductivity for Saturated Frozen Soil
Authors: Chen Lei , Li Dongqing , Ming Feng , Shi Xiangyang , Chen Xin
Published: February 2019

In cold regions, hydraulic conductivity is a critical parameter for determining the water flow in frozen soil. Previous studies have shown that hydraulic conductivity hinges on the pore structure, which is often depicted as the pore size and porosity. However, these two parameters do not sufficiently represent the pore structure. To enhance the characterization ability of the pore structure, this study introduced fractal theory to investigate the influence of pore structure on hydraulic conductivity. In this study, the pores were conceptualized as a bundle of tortuous capillaries with different radii and the cumulative pore size distribution of the capillaries was considered to satisfy the fractal law. Using the Hagen-Poiseuille equation, a fractal capillary bundle model of hydraulic conductivity for saturated frozen soil was developed. The model validity was evaluated using experimental data and by comparison with previous models. The results showed that the model performed well for frozen soil. The model showed that hydraulic conductivity was related to the maximum pore size, pore size dimension, porosity and tortuosity. Of all these parameters, pore size played a key role in affecting hydraulic conductivity. The pore size dimension was found to decrease linearly with temperature, the maximum pore size decreased with temperature and the tortuosity increased with temperature. The model could be used to predict the hydraulic conductivity of frozen soil, revealing the mechanism of change in hydraulic conductivity with temperature. In addition, the pore size distribution was approximately estimated using the soil freezing curve, making this method could be an alternative to the mercury intrusion test, which has difficult maneuverability and high costs. Darcy’s law is valid in saturated frozen silt, clayed silt and clay, but may not be valid in saturated frozen sand and unsaturated frozen soil.
Numerical Simulation of Phosphorus Release with Sediment Suspension under Hydrodynamic Condition in Mochou Lake, China
Authors: Bai Yu , Gao Jinhua , Zhang Tianyi
Published: February 2019

Phosphorus is a major cause of lake eutrophication. Understanding the characteristics regarding the release of phosphorus from sediments under hydrodynamic conditions is critical for the regulation of lake water quality. In this work, the effects of sediment suspension on the release characteristics of phosphorus from sediment were investigated under different hydrodynamic conditions. The experimental results showed that in the experimental process, the phosphorus was at first released quickly into the overlying water but then slowed down. Furthermore, the process of dissolved phosphorus (DP) release under hydrodynamic conditions with and without sediment suspension was simulated using a lattice Boltzmann method. The simulation showed satisfying results.
Influence of Pre-Hydrolysis on Sewage Treatment in an Up-Flow Anaerobic Sludge BLANKET (UASB) Reactor: A Review
Authors: Rajagopal Rajinikanth , Choudhury Mahbuboor Rahman , Anwar Nawrin , Goyette Bernard , Rahaman Md. Saifur
Published: February 2019

The up-flow anaerobic sludge blanket (UASB) process has emerged as a promising high-rate anaerobic digestion technology for the treatment of low- to high-strength soluble and complex wastewaters. Sewage, a complex wastewater, contains 30–70% particulate chemical oxygen demand (CODP). These particulate organics degrade at a slower rate than the soluble organics found in sewage. Accumulation of non-degraded suspended solids can lead to a reduction of active biomass in the reactor and hence a deterioration in its performance in terms of acid accumulation and poor biogas production. Hydrolysis of the CODP in sewage prior to UASB reactor will ensure an increased organic loading rate and better UASB performance. While single-stage UASB reactors have been studied extensively, the two-phase full-scale treatment approach (i.e., a hydrolysis unit followed by an UASB reactor) has still not yet been commercialized worldwide. The concept of treating sewage containing particulate organics via a two-phase approach involves first hydrolyzing and acidifying the volatile suspended solids without losing carbon (as methane) in the first reactor and then treating the soluble sewage in the UASB reactor. This work reviews the available literature to outline critical findings related to the treatment of sewage with and without hydrolysis before the UASB reactor.
N–TiO2 Photocatalysts: A Review of Their Characteristics and Capacity for Emerging Contaminants Removal
Authors: Gomes João , Lincho João , Domingues Eva , Quinta-Ferreira Rosa M. , Martins Rui C.
Published: February 2019

Titanium dioxide is the most used photocatalyst in wastewater treatment; its semiconductor capacity allows the indirect production of reactive oxidative species. The main drawback of the application of TiO2 is related to its high band-gap energy. The nonmetal that is most often used as the doping element is nitrogen, which is due to its capacity to reduce the band-gap energy at low preparation costs. There are multiple and assorted methods of preparation. The main advantages and disadvantages of a wide range of preparation methods were discussed in this paper. Different sources of N were also analyzed, and their individual impact on the characteristics of N–TiO2 was assessed. The core of this paper was focused on the large spectrum of analytical techniques to detect modifications in the TiO2 structure from the incorporation of N. The effect of N–TiO2 co-doping was also analyzed, as well as the main characteristics that are relevant to the performance of the catalyst, such as its particle size, surface area, quantum size effect, crystalline phases, and the hydrophilicity of the catalyst surface. Powder is the most used form of N–TiO2, but the economic benefits and applications involving continuous reactors were also analyzed with supported N–TiO2. Moreover, the degradation of contaminants emerging from water and wastewater using N–TiO2 and co-doped TiO2 was also discussed.
Exploring the Influence Mechanism of Meteorological Conditions on the Concentration of Suspended Solids and Chlorophyll-a in Large Estuaries Based on MODIS Imagery
Authors: He Cheng , Yao Youru , Lu Xiaoman , Chen Mingnan , Ma Weichun , Zhou Liguo
Published: February 2019

In estuary areas, meteorological conditions have become unstable under the continuous effects of climate change, and the ecological backgrounds of such areas have strongly been influenced by anthropic activities. Consequently, the water quality of these areas is obviously affected. In this research, we identified periods of fluctuation of the general meteorological conditions in the Yangtze River Estuary using a wavelet analysis. Additionally, we performed a spatiotemporal evaluation of the water quality in the fluctuating period by using remote sensing modeling. Then, we explored how the fluctuating meteorological factors affect the distribution of total suspended solids (TSS) and chlorophyll-a (Chla) concentration. (1) The results show that from 2000 to 2015, temperature did not present significant fluctuations, while wind speed (WS) and precipitation (PR) presented the same fluctuation period from January 2012 to December 2012. (2) Based on the measured water sample data associated with Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, we developed a water quality algorithm and depicted the TSS and Chla concentrations within the WS and PR fluctuating period. (3) We found that the TSS concentration decreased with distance from the shore, while the Chla concentration showed an initially decreasing trend followed by an increasing trend; moreover, these two water quality parameters presented different inter-annual variations. Then, we discussed the correlation between the changes in the TSS and Chla concentrations and the WS and PR variables. The contribution of this research is reflected in two aspects: 1. variations in water quality parameters over a wide range of water bodies can be evaluated based on MODIS data; 2. data from different time periods showed that the fluctuations of meteorological elements had different impacts on water bodies based on the distance from the shore. The results provide new insights for the management of estuary water environments.
Distribution of Pseudomonas fluorescens and Aeromonas hydrophila Bacteria in a Recirculating Aquaculture System during Farming of European Grayling (Thymallus thymallus L.) Broodstock
Authors: Gołaś Iwona , Szmyt Mariusz , Potorski Jacek , Łopata Michał , Gotkowska-Płachta Anna , Glińska-Lewczuk Katarzyna
Published: February 2019

Pseudomonas fluorescens and Aeromonas hydrophila bacteria are opportunistic pathogens that occur naturally in the aquatic environment and in the gut flora of healthy fish. Both species can pose a serious threat for fish that are highly sensitive to water pollution. The aim of this study was to determine the extent to which the amount of administered fish feed and fish biomass affect the distribution and abundance of Ps. fluorescens and A. hydrophila bacteria in a recirculating aquaculture system (RAS) during farming of European grayling (Thymallus thymallus L.) broodstock. A total of 68 water samples from the inflow, two rearing tanks and the outflow as well as 17 feed samples were collected and analyzed separately. Bacterial populations were analyzed by the culture-dependent method and a molecular method (fluorescence in situ hybridization, FISH) to detect culturable strains and viable but non-culturable strains, respectively. Fish biomass, feed and 16 water quality parameters (temperature, pH, concentration of dissolved oxygen, oxygen saturation, five-day biochemical oxygen demand (BOD5), total phosphorus, total organic phosphorus and nitrogen, orthophosphates, total nitrogen, nitrite and nitrate nitrogen, ammonia nitrogen, ammonium nitrogen, total suspended solids, and total organic carbon) were the explanatory factors. Statistically significant differences (RM-ANOVA, p ≤ 0.05) were stated in bacterial abundance in samples from the inflow, rearing tanks and the outflow. Water samples from the RAS were abundantly colonized by non-culturable Ps. fluorescens and A. hydrophila bacteria. Feed was not a source of bacteria, but a redundancy analysis (RDA) revealed that the amount of feed, fish biomass, BOD5, and total suspended solids and total organic carbon were positively correlated in both Ps. fluorescens and A. hydrophila. These parameters also influenced the distribution of both potentially pathogenic bacterial populations and contributed to the bacterial contamination of water in the RAS. Our results are particularly valuable for aquacultures that help to replenish wild stocks and rebuild populations of threatened species in natural aquatic environments.
Spatial and Temporal Variation of Dissolved Heavy Metals in the Mun River, Northeast Thailand
Authors: Liang Bin , Han Guilin , Liu Man , Li Xiaoqiang , Song Chao , Zhang Qian , Yang Kunhua
Published: February 2019

River water samples between August 2017 (wet season) and March 2018 (dry season) from the Mun River Basin in northeast Thailand were collected and their dissolved heavy metals concentrations (Al, Mn, Fe, Cu, Zn, and Ba) were measured. Compared with international drinking water guidelines, Mn was the dominant pollutant in the dry season. The correlation analysis (CA) suggested that similar sources were shown in each element pair of Al-Fe, Mn-Zn, and Fe-Ba in both seasons. The principal component analysis (PCA) results showed that the dominant source of dissolved heavy metals was sedimentary inputs or colloid destabilization in the wet season, while anthropogenic inputs were the main sources in the dry season, such as agricultural runoff, industrial effluents, and domestic discharge. On the basis of water quality index (WQI), water at most sites in the wet and dry seasons can be categorized as excellent water, except for a few sites with substandard values. The river water posed no significant health risks according to the health risk assessment, but Mn, Fe, and Ba needed to be paid more attention due to the relatively high values. Al, Fe, and Ba were the main dissolved heavy metals flowing into the Mekong River, and Cu contributed to the background value in the Mekong river.
A New 60-Year 1940/1999 Monthly-Gridded Rainfall Data Set for Africa
Authors: Dieulin Claudine , Mahé Gil , Paturel Jean-Emmanuel , Ejjiyar Soundouss , Tramblay Yves , Rouché Nathalie , EL Mansouri Bouabid
Published: February 2019

The African continent has a very low density of rain gauge stations, and long time-series for recent years are often limited and poorly available. In the context of global change, it is very important to be able to characterize the spatio-temporal variability of past rainfall, on the basis of datasets issued from observations, to correctly validate simulations. The quality of the rainfall data is for instance of very high importance to improve the efficiency of the hydrological modeling, through calibration/validation experiments. The HydroSciences Montpellier Laboratory (HSM) has a long experience in collecting and managing hydro-climatological data. Thus, HSM had initiated a program to elaborate a reference dataset, in order to build monthly rainfall grids over the African continent, over a period of 60 years (1940/1999). The large quantity of data collected (about 7000 measurement points were used in this project) allowed for interpolation using only observed data, with no statistical use of a reference period. Compared to other databases that are used to build the grids of the Global Historical Climatology Network (GHCN) or the Climatic Research Unit of University of East Anglia, UK (CRU), the number of available observational stations was significantly much higher, including the end of the century when the number of measurement stations dropped dramatically, everywhere. Inverse distance weighed (IDW) was the chosen method to build the 720 monthly grids and a mean annual grid, from rain gauges. The mean annual grid was compared to the CRU grid. The grids were significantly different in many places, especially in North Africa, Sahel, the horn of Africa, and the South Western coast of Africa, with HSM_SIEREM data (database HydroSciences Montpellier_Système d’Information Environnementales pour les Ressources en Eau et leur Modélisation) being closer to the observed rain gauge values. The quality of the grids computed was checked, following two approaches—cross-validation of the two interpolation methods, ordinary kriging and inverse distance weighting, which gave a comparable reliability, with regards to the observed data, long time-series analysis, and analysis of long-term signals over the continent, compared to previous studies. The statistical tests, computed on the observed and gridded data, detected a rupture in the rainfall regime around 1979/1980, on the scale of the whole continent; this was congruent with the results in the literature. At the monthly time-scale, the most widely observed signal over the period of 1940/1999, was a significant decrease of the austral rainy season between March and May, which has not earlier been well-documented. Thus, this would lead to a further detailed climatological study from this HSM_SIEREM database.
AN APPROACH TO THE LEGAL REQUIREMENTS REGARDING RAILWAY TRANSPORT SAFETY MONITORING IN THE EUROPEAN UNION
Authors: Sitarz Marek , Chruzik Katarzyna
Published: February 2019

The targeted liberalisation of the European Union railway market in 1998 could have lead to a decrease in the safety of rail transport. To prevent this, the European Commission developed and implemented new requirements in this area without explicitly deciding on the methods and tools to be used for their implementation. Entities operating in the market faced a new challenge, the development of a systems model approach to safety management. Only a correctly designed process model, along with the appropriate tools for monitoring and managing risk, allows the level of safety to be maintained at current levels or improved. As part of the research, solutions were developed for a systems approach to safety management in railway transport and the risk management and maintenance monitoring of railway vehicles. Safety is an essential criterion for assessing the functioning of a railway system, it determines its efficiency as well as – in a widely understood sense – the quality of its transport services. This paper describes the legal requirements and practical methods of implementation arising from the issue of Directive 2004/49/EC as it concerns the monitoring of railway safety (Chruzik et al. 2014). The directive enforces the gradual introduction of Common Safety Targets (CST) and Common Safety Methods (CSM) to maintain (or increase) the existing high safety levels after the opening up (liberalisation) of the rail market. The introduction of CST and CSM necessitates the development of methods for the evaluation of the level of safety and activity of operators, both at the level of the Member States and also at the level of the European Union. The paper describes the practical solutions developed for railway operators as part of the implementation of maintenance management systems (Sitarz et al. 2013; Chruzik et al. 2014).
TOLLING MOTORWAYS IN THE TIME OF ECONOMIC DOWNTURN: THE CASE OF PORTUGAL
Authors: Amorim Marco , Lobo António , Couto António
Published: February 2019

The recent European debt crisis has led many governments to impose strict measures to alleviate public expenditure and increase revenue, especially in the southern countries. Many public services and infrastructures became more costly for users due to the increase of existing fees or the implementation of new ones. In Portugal, one of the measures adopted by the government consisted in the removal of shadow tolls and the application of the user-pays principle to the entire network of rural motorways. To rapidly implement, this measure, in the context of financial constraints, the Electronic Toll Collection (ETC), materialized by the installation of gantries in selected motorway segments, was the preferred solution over the more time and resource consuming construction of toll plazas. Toll revenue is directly collected by the state, which intends to cover, at least partially, the expenses associated with the contractual payments to private concessionaires for the traffic using these roads. The main objective of this research is to provide a new optimization tool to allocate toll gantries to the segments of an existing motorway with the aim of maximizing toll revenue, based on the case study of Portuguese motorways. A macroscopic decision model that predicts drivers’ decision on using a tolled segment or the fastest alternative route and an optimization model that sets the price and location of toll gantries along a given motorway work together to provide a valuable tool to maximize the revenue. A special focus has been placed on scenarios of economic downturn, characterized by a negative growth of the Gross Domestic Product (GDP); however, the new tool allows making explanatory analyses for situations of economic growth. The results show that the optimal configuration for ETC vary with the macroeconomic scenario, with the number of tolled segments and price per kilometre inducing relevant variations on the revenue and traffic volume. The proposed methodology may be applied in other countries to assist decision makers in the implementation of ETC in motorways under different conditions. The required data is easy to collect from sources at the disposal of the practitioners.
Discovery and Vetting of Exoplanets. I. Benchmarking K2 Vetting Tools
Authors: Kostov Veselin B. , Mullally Susan E. , Quintana Elisa V. , Coughlin Jeffrey L. , Mullally Fergal , Barclay Thomas , Colón Knicole D. , Schlieder Joshua E. , Barentsen Geert , Burke Christopher J.
Published: February 2019

We have adapted the algorithmic tools developed during the Kepler mission to vet the quality of transit-like signals for use on the K2 mission data. Using the four sets of publicly available light curves at MAST, we produced a uniformly vetted catalog of 772 transiting planet candidates from K2 as listed at the NASA Exoplanet Archive in the K2 Table of Candidates. Our analysis marks 676 of these as planet candidates and 96 as false positives. All confirmed planets pass our vetting tests. Sixty of our false positives are new identifications, effectively doubling the overall number of astrophysical signals mimicking planetary transits in K2 data. Most of the targets listed as false positives in our catalog show either prominent secondary eclipses, transit depths suggesting a stellar companion instead of a planet, or significant photocenter shifts during transit. We packaged our tools into the open-source, automated vetting pipeline Discovery and Vetting of Exoplanets (DAVE), designed to streamline follow-up efforts by reducing the time and resources wasted observing targets that are likely false positives. DAVE will also be a valuable tool for analyzing planet candidates from NASA’s TESS mission, where several guest-investigator programs will provide independent light-curve sets—and likely many more from the community. We are currently testing DAVE on recently released TESS planet candidates and will present our results in a follow-up paper.
Review of the ant genus Nesomyrmex Wheeler, 1910 (Hymenoptera, Formicidae, Myrmicinae) from the Arabian Peninsula
Authors: Sharaf Mostafa R. , Akbar Shahid Ali , Aldawood Abdulrahman S. , Hita Garcia Francisco
Published: February 2019

In this study, we review the Arabian species of the ant genus Nesomyrmex Wheeler. We provide species reviews for the two previously known species, N.angulatus (Mayr, 1862) and N.humerosus (Emery, 1896) and describe a new species N.zaherisp. n. from Yemen based on the worker caste. An illustrated key to the Arabian species of the genus and montage photos of all three species are provided.
Taxonomic position of several enigmatic Polyommatus (Agrodiaetus) species (Lepidoptera, Lycaenidae) from Central and Eastern Iran: insights from molecular and chromosomal data
Authors: Lukhtanov Vladimir , Shapoval Nazar , Dantchenko Alexander
Published: February 2019

The species-rich subgenus Polyommatus (Agrodiaetus) has become one of the best studied groups of Palearctic blue butterflies (Lepidoptera, Lycaenidae). However, the identity and phylogenetic position of some rare taxa from Iran have remained unclear. An enigmatic, recently described Central Iranian species Polyommatus (Agrodiaetus) shirkuhensis ten Hagen et Eckweiler, 2001 has been considered as a taxon closely related either to Polyommatus (Agrodiaetus) eckweileri ten Hagen, 1998 or to Polyommatus (Agrodiaetus) baltazardi (de Lesse, 1962). Polyommatus (Agrodiaetus) baltazardi, in its turn, was treated as a taxon close to Iranian-Pakistani Polyommatus (Agrodiaetus) bogra Evans, 1932. Here we used a combination of molecular and chromosomal markers to show that none of these hypotheses was true. Instead, Polyommatus (Agrodiaetus) shirkuhensis was recovered as a member of a species group close to Polyommatus (Agrodiaetus) cyaneus (Staudinger, 1899). From genetically closest species, Polyommatus (Agrodiaetus) kermansis (de Lesse, 1962), Polyommatus (Agrodiaetus) cyaneus and Polyommatus (Agrodiaetus) sennanensis (de Lesse, 1959), it differs by the wing coloration. From morphologically similar Polyommatus (Agrodiaetus) mofidii (de Lesse, 1963) and Polyommatus (Agrodiaetus) sorkhensis Eckweiler, 2003, it differs by its chromosome number, n=21. Polyommatus (Agrodiaetus) bogra and Polyommatus (Agrodiaetus) baltazardi were found to be members of two different species groups and, thus, are not closely related.
Chromosomal complements of some Atlantic Blennioidei and Gobioidei species (Perciformes)
Authors: Galvão Tatiana , Bertollo Luiz , Molina Wagner
Published: February 2019

A remarkable degree of chromosomal conservatism (2n=48, FN=48) has been identified in several families of Perciformes. However, some families exhibit greater karyotypic diversity, although there is still scant information on the Atlantic species. In addition to a review of karyotypic data available for representatives of the suborders Blennioidei and Gobioidei, we have performed chromosomal analyses on Atlantic species of the families Blenniidae, Ophioblennius trinitatis Miranda-Ribeiro, 1919 (2n=46; FN=64) and Scartella cristata (Linnaeus, 1758)(2n=48; FN=50), Labrisomidae, Labrisomus nuchipinnis (Quoy & Gaimard, 1824)(2n=48; FN=50) and Gobiidae, Bathygobius soporator (Valenciennes, 1837)(2n=48; FN=56). Besides variations in chromosome number and karyotype formulas, Ag-NOR sites, albeit unique, were located in different positions and/or chromosome pairs for the species analyzed. On the other hand, the heterochromatic pattern was more conservative, distributed predominantly in the centromeric/pericentromeric regions of the four species. Data already available for Gobiidae, Blenniidae and Labrisomidae show greater intra- and interspecific karyotypic diversification when compared to other groups of Perciformes, where higher uniformity is found for various chromosome characteristics. Evolutionary dynamism displayed by these two families is likely associated with population fractionation resulting from unique biological characteristics, such as lower mobility and/or specific environmental requirements.
Diploid males of Scaptotrigona depilis are able to join reproductive aggregations (Apidae, Meliponini)
Authors: Vollet-Neto Ayrton , Fernando dos Santos Charles , Rodrigues Santiago Leandro , de Araujo Alves Denise , de Figueiredo Júlia Pinheiro , Nanzer Marino , Arias Maria Cristina , Imperatriz-Fonseca Vera Lucia
Published: February 2019

The sex determination system in the eusocial stingless bees (Apidae, Meliponini) is based on the combination of alleles at the complementary sex determination (CSD) locus. In this system, males are haploid and females are diploid. However, diploid males can develop from fertilized eggs when they are homozygous at single or multiple sex loci. The production of such males can negatively affect population viability, since they are usually infertile or inviable. Moreover, when they are viable but infertile, or siring sterile triploid offspring, this could cause another load on the population, leading the fertilized offspring of other females to be only haploid males or triploid sterile daughters. In this context, our aim was to verify whether diploid males of the stingless beeScaptotrigonadepilisdo in fact join reproductive aggregations. We showed that of 360 marked males from two different colonies, five were participating in a reproductive aggregationca.20 meters from their natal colonies. Using microsatellites markers, it was confirmed that three of these five males were diploid. They were captured in the mating aggregations when they were 15 to 20 days old. Further research is necessary to determine the mating success of stingless bee diploid males under natural conditions and to determine their impact on stingless bee population extinction risks.