bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of Gross Primary Productivity (GPP) Phenology of a Short-Rotation Plantation Using Remotely Sensed Indices Derived from Sentinel-2 Images
Authors: Maleki Maral , Arriga Nicola , Barrios José Miguel , Wieneke Sebastian , Liu Qiang , Peñuelas Josep , Janssens Ivan A. , Balzarolo Manuela
Published: July 2020

This study aimed to understand which vegetation indices (VIs) are an ideal proxy for describing phenology and interannual variability of Gross Primary Productivity (GPP) in short-rotation coppice (SRC) plantations. Canopy structure- and chlorophyll-sensitive VIs derived from Sentinel-2 images were used to estimate the start and end of the growing season (SOS and EOS, respectively) during the period 2016–2018, for an SRC poplar (Populus spp.) plantation in Lochristi (Belgium). Three different filtering methods (Savitzky–Golay (SavGol), polynomial (Polyfit) and Harmonic Analysis of Time Series (HANTS)) and five SOS- and EOS threshold methods (first derivative function, 10% and 20% percentages and 10% and 20% percentiles) were applied to identify the optimal methods for the determination of phenophases. Our results showed that the MEdium Resolution Imaging Spectrometer (MERIS) Terrestrial Chlorophyll Index (MTCI) had the best fit with GPP phenology, as derived from eddy covariance measurements, in identifying SOS- and EOS-dates. For SOS, the performance was only slightly better than for several other indices, whereas for EOS, MTCI performed markedly better. The relationship between SOS/EOS derived from GPP and VIs varied interannually. MTCI described best the seasonal pattern of the SRC plantation’s GPP (R2 = 0.52 when combining all three years). However, during the extreme dry year 2018, the Chlorophyll Red Edge Index performed slightly better in reproducing growing season GPP variability than MTCI (R2 = 0.59; R2 = 0.49, respectively). Regarding smoothing functions, Polyfit and HANTS methods showed the best (and very similar) performances. We further found that defining SOS as the date at which the 10% or 20% percentile occurred, yielded the best agreement between the VIs and the GPP; while for EOS the dates of the 10% percentile threshold came out as the best.
A Sensitivity Study of POD Using Dual-Frequency GPS for CubeSats Data Limitation and Resources
Authors: Wang Kan , Allahvirdi-Zadeh Amir , El-Mowafy Ahmed , Gross Jason N.
Published: July 2020

Making use of dual-frequency (DF) global navigation satellite system (GNSS) observations and good dynamic models, the precise orbit determination (POD) for the satellites on low earth orbits has been intensively investigated in the last decades and has achieved an accuracy of centimeters. With the rapidly increasing number of the CubeSat missions in recent years, the POD of CubeSats were also attempted with combined dynamic models and GNSS DF observations. While comprehensive dynamic models are allowed to be used in the postprocessing mode, strong constraints on the data completeness, continuity, and restricted resources due to the power and size limits of CubeSats still hamper the high-accuracy POD. An analysis of these constraints and their impact on the achievable orbital accuracy thus needs to be considered in the planning phase. In this study, with the focus put on the use of DF GNSS data in postprocessing CubeSat POD, a detailed sensitivity analysis of the orbital accuracy was performed w.r.t. the data continuity, completeness, observation sampling interval, latency requirements, availability of the attitude information, and arc length. It is found that the overlapping of several constraints often causes a relatively large degradation in the orbital accuracy, especially when one of the constraints is related to a low duty-cycle of, e.g., below 40% of time. Assuming that the GNSS data is properly tracked except for the assumed constraints, and using the International GNSS Service (IGS) final products or products from the IGS real-time service, the 3D orbital accuracy for arcs of 6 h to 24 h should generally be within or around 1 dm, provided that the limitation on data is not too severe, i.e., with a duty-cycle not lower than 40% and an observation sampling interval not larger than 60 s.
Does the Intra-Arctic Modification of Long-Range Transported Aerosol Affect the Local Radiative Budget? (A Case Study)
Authors: Nakoudi Konstantina , Ritter Christoph , Böckmann Christine , Kunkel Daniel , Eppers Oliver , Rozanov Vladimir , Mei Linlu , Pefanis Vasileios , Jäkel Evelyn , Herber Andreas , Maturilli Marion , Neuber Roland
Published: July 2020

The impact of aerosol spatio-temporal variability on the Arctic radiative budget is not fully constrained. This case study focuses on the intra-Arctic modification of long-range transported aerosol and its direct aerosol radiative effect (ARE). Different types of air-borne and ground-based remote sensing observations (from Lidar and sun-photometer) revealed a high tropospheric aerosol transport episode over two parts of the European Arctic in April 2018. By incorporating the derived aerosol optical and microphysical properties into a radiative transfer model, we assessed the ARE over the two locations. Our study displayed that even in neighboring Arctic upper tropospheric levels, aged aerosol was transformed due to the interplay of removal processes (nucleation scavenging and dry deposition) and alteration of the aerosol source regions (northeast Asia and north Europe). Along the intra-Arctic transport, the coarse aerosol mode was depleted and the visible wavelength Lidar ratio (LR) increased significantly (from 15 to 64–82 sr). However, the aerosol modifications were not reflected on the ARE. More specifically, the short-wave (SW) atmospheric column ARE amounted to +4.4 - +4.9 W m−2 over the ice-covered Fram Strait and +4.5 W m−2 over the snow-covered Ny-Ålesund. Over both locations, top-of-atmosphere (TOA) warming was accompanied by surface cooling. These similarities can be attributed to the predominant accumulation mode, which drives the SW radiative budget, as well as to the similar layer altitude, solar geometry, and surface albedo conditions over both locations. However, in the context of retreating sea ice, the ARE may change even along individual transport episodes due to the ice albedo feedback.
Spatial and Temporal Changes of Tidal Inlet Using Object-Based Image Analysis of Multibeam Echosounder Measurements: A Case from the Lagoon of Venice, Italy
Authors: Janowski Lukasz , Madricardo Fantina , Fogarin Stefano , Kruss Aleksandra , Molinaroli Emanuela , Kubowicz-Grajewska Agnieszka , Tegowski Jaroslaw
Published: July 2020

Scientific exploration of seabed substrata has significantly progressed in the last few years. Hydroacoustic methods of seafloor investigation, including multibeam echosounder measurements, allow us to map large areas of the seabed with unprecedented precision. Through time-series of hydroacoustic measurements, it was possible to determine areas with distinct characteristics in the inlets of the Lagoon of Venice, Italy. Their temporal variability was investigated. Monitoring the changes was particularly relevant, considering the presence at the channel inlets of mobile barriers of the Experimental Electromechanical Module (MoSE) project installed to protect the historical city of Venice from flooding. The detection of temporal and spatial changes was performed by comparing seafloor maps created using object-based image analysis and supervised classifiers. The analysis included extraction of 25 multibeam echosounder bathymetry and backscatter features. Their importance was estimated using an objective approach with two feature selection methods. Moreover, the study investigated how the accuracy of classification could be affected by the scale of object-based segmentation. The application of the classification method at the proper scale allowed us to observe habitat changes in the tidal inlet of the Venice Lagoon, showing that the sediment substrates located in the Chioggia inlet were subjected to very dynamic changes. In general, during the study period, the area was enriched in mixed and muddy sediments and was depleted in sandy deposits. This study presents a unique methodological approach to predictive seabed sediment composition mapping and change detection in a very shallow marine environment. A consistent, repeatable, logical site-specific workflow was designed, whose main assumptions could be applied to other seabed mapping case studies in both shallow and deep marine environments, all over the world.
RGB-D-Based Framework to Acquire, Visualize and Measure the Human Body for Dietetic Treatments
Authors: Fuster-Guilló Andrés , Azorín-López Jorge , Saval-Calvo Marcelo , Castillo-Zaragoza Juan Miguel , Garcia-D'Urso Nahuel , Fisher Robert B.
Published: July 2020

This research aims to improve dietetic-nutritional treatment using state-of-the-art RGB-D sensors and virtual reality (VR) technology. Recent studies show that adherence to treatment can be improved using multimedia technologies. However, there are few studies using 3D data and VR technologies for this purpose. On the other hand, obtaining 3D measurements of the human body and analyzing them over time (4D) in patients undergoing dietary treatment is a challenging field. The main contribution of the work is to provide a framework to study the effect of 4D body model visualization on adherence to obesity treatment. The system can obtain a complete 3D model of a body using low-cost technology, allowing future straightforward transference with sufficient accuracy and realistic visualization, enabling the analysis of the evolution (4D) of the shape during the treatment of obesity. The 3D body models will be used for studying the effect of visualization on adherence to obesity treatment using 2D and VR devices. Moreover, we will use the acquired 3D models to obtain measurements of the body. An analysis of the accuracy of the proposed methods for obtaining measurements with both synthetic and real objects has been carried out.
Hyperparameter Optimization Method Based on Harmony Search Algorithm to Improve Performance of 1D CNN Human Respiration Pattern Recognition System
Authors: Kim Seong-Hoon , Geem Zong Woo , Han Gi-Tae
Published: July 2020

In this study, we propose a method to find an optimal combination of hyperparameters to improve the accuracy of respiration pattern recognition in a 1D (Dimensional) convolutional neural network (CNN). The proposed method is designed to integrate with a 1D CNN using the harmony search algorithm. In an experiment, we used the depth of the convolutional layer of the 1D CNN, the number and size of kernels in each layer, and the number of neurons in the dense layer as hyperparameters for optimization. The experimental results demonstrate that the proposed method provided a recognition rate for five respiration patterns of approximately 96.7% on average, which is an approximately 2.8% improvement over an existing method. In addition, the number of iterations required to derive the optimal combination of hyperparameters was 2,000,000 in the previous study. In contrast, the proposed method required only 3652 iterations.
Evaluating How ‘Smart’ Brașov, Romania Can Be Virtually via a Mobile Application for Cultural Tourism
Authors: Briciu Arabela , Briciu Victor-Alexandru , Kavoura Androniki
Published: July 2020

Global urbanization brings the urge to identify the most intelligent methods to cope with the challenges arising in the modern society. Sustainable and smart cities are the new target for urban development; their representatives are being forced to identify and develop new strategies to increase their city’s performance and ensure that it endures over time. Information and Communication Technology (ICT) contributes to this purpose. Brașov is one of the cities in Romania for which the process of modernization started years ago, and it is currently developing as a smart city. This paper focuses on the development of the city in terms of cultural tourism solutions by presenting a case study on the use of virtual reality with a mobile application and its evaluation on cultural heritage sites. The original contribution of the paper is to describe and analyze the quality of the mobile application by using a proposed analysis grid to identify the main elements of this app. The main findings suggest that the application may bring authenticity of experience through the lens of heritage preservation for further user engagement and participation in real-time, while suggestions are made for future enhancement. Implications are discussed for a) destination managers, b) for developers to improve the general quality of the mobile application in terms of design and features and to implement changes in the near future, and c) for visitors who engage in real-time and co-create experiences.
Evaluation of Aircraft Boarding Scenarios Considering Reduced Transmissions Risks
Authors: Schultz Michael , Fuchte Jörg
Published: July 2020

Air travel appears as particularly hazardous in a pandemic situation, since infected people can travel worldwide and could cause new breakouts in remote locations. The confined space conditions in the aircraft cabin necessitate a small physical distance between passengers and hence may boost virus transmissions. In our contribution, we implemented a transmission model in a virtual aircraft environment to evaluate the individual interactions between passengers during aircraft boarding and deboarding. Since no data for the transmission is currently available, we reasonably calibrated our model using a sample case from 2003. The simulation results show that standard boarding procedures create a substantial number of possible transmissions if a contagious passenger is present. The introduction of physical distances between passengers decreases the number of possible transmissions by approx. 75% for random boarding sequences, and could further decreased by more strict reduction of hand luggage items (less time for storage, compartment space is always available). If a second door is used for boarding and deboarding, the standard boarding times could be reached. Individual boarding strategies (by seat) could reduce the transmission potential to a minimum, but demand for complex pre-sorting of passengers. Our results also exhibit that deboarding consists of the highest transmission potential and only minor benefits from distance rules and hand luggage regulations.
Working from Home—Who Is Happy? A Survey of Lithuania’s Employees during the COVID-19 Quarantine Period
Authors: Raišienė Agota Giedrė , Rapuano Violeta , Varkulevičiūtė Kristina , Stachová Katarína
Published: July 2020

The virtual way of working is becoming increasingly popular due to its potential for cost savings; it is also a way for an organization to be more agile and adapt to crises such as global pandemics. This innovative way of working brings new challenges to organizations that suddenly have to switch to telework. In fact, telework raises quite a few issues for employees, related to communication, collaboration, and the application of ICT (Information and Communication Technologies). This study examined the evaluation of telework through a questionnaire by different conditional groups of 436 teleworkers in Lithuania. Through a correlation analysis between the study variables, the findings suggest that there are differences in the evaluation of factors affecting telework efficiency and qualities required from a remote worker, depending on gender, age, education, work experience, and experience of telework. The results are discussed in terms of the characteristics of the most satisfied and the most dissatisfied teleworkers.
Cooperative Strategies in Two-Echelon Rescue Delivery Environment with Accessibility Uncertainty
Authors: Zhang Hanpeng , Wu Yuxin , Liao Yi , Gajpal Yuvraj
Published: July 2020

Cooperation between rescue teams is important to improve rescue performance. Vehicles outside of the disaster area usually deliver rescue resources. A two-echelon rescue delivery model is proposed, considering the isolated island of the disaster area where all the roads to the outside are interrupted. This paper first presents a non-cooperation scenario and then a cooperation scenario in an uncertain environment. Furthermore, two types of cooperative strategies to improve rescue performance are provided in the paper. The two cooperative strategies are a reactive cooperative strategy and an anticipatory cooperative strategy. Numerical experiments are used to evaluate the rescue performances of the two cooperation strategies by comparing them with the non-cooperation scenario. The results reveal that the anticipatory cooperative strategy performs the best in different cases varying in size.
Long-Term Orientation as a Resource for Entrepreneurial Orientation in Private Family Firms: The Need for Participative Decision Making
Authors: Schepers Jelle , Voordeckers Wim , Steijvers Tensie , Laveren Eddy
Published: July 2020

Building on the resource-based view (RBV) of the firm, this paper suggests that a family firm’s long-term orientation (LTO) can be an important resource that increases firm-level entrepreneurial orientation (EO). Nevertheless, resource orchestration suggests that managers need to orchestrate their resources in order to realize any potential advantage. Therefore, we hypothesize that a family firm’s LTO entails potential resources to engage in entrepreneurial activities, while a participative decision making (PDM) style serves as coordinating mechanism that helps the firm to manage these resources. Using data from 209 private family firms, the results show a positive association between LTO and EO. Also, PDM was found to positively moderate the LTO-EO relationship, providing empirical support for our central hypothesis.
Competitive Priorities, Employee Management and Development and Sustainable Manufacturing Performance in Asian Organizations
Authors: Adebanjo Dotun , Teh Pei-Lee , Ahmed Pervaiz K , Atay Erhan , Ractham Peter
Published: July 2020

This study investigates the relationships between three dimensions of competitive priorities (customer focus, product innovation and delivery) and how Asian manufacturers manage and develop their employees and the consequent effect on sustainable manufacturing performance. Three dimensions of manufacturing performance are considered in this study—quality performance, production flexibility and operations cost. This study uses 259 datasets collected from manufacturers in four Asian countries. Structural equation modeling and mediation analysis are performed to test the relationships. Results show that there is a significant positive and mediating relationship between the competitive priority of product innovation, employee management and development, quality performance, production flexibility and operation cost. However, such significant relationships do not exist with competitive priorities of customer focus and delivery. Organizations are constantly faced with the problem of determining which competitive priorities to focus on. However, different competitive priorities have different effects on how the employees are managed and developed, and ultimately, on organizational performance and competitiveness. There is a need to focus on innovation-led strategies that relate to sustainable outcomes. This is one of the first studies in Asia to understand the multilateral relationships between different competitive priorities and different performance dimensions when employee management and development intermediate.
A Dual Challenge in China’s Sustainable Total Factor Productivity Growth
Authors: Zhang Shaohua , Chang Tzu-Pu , Liao Li-Chuan
Published: July 2020

Since total factor productivity growth plays an essential role in China’s economic growth, the source of this growth has been a critical issue over the past decades. Hence, this paper applies an input slack-based productivity (ISP) index to investigate the contributors (i.e., labor and capital inputs) to China’s total factor productivity growth. The ISP index, combining the features of the directional distance function and Luenberger productivity index, can calculate the productivity change of each input factor under the total factor framework. According to the decomposition analyses, we find that China is confronting a dual challenge in total factor productivity growth: first, capital productivity growth exhibits a remarkable slowdown after the mid-1990s; second, although labor productivity continually expands, the relative labor efficiency among provinces has deteriorated since the 2000s. The results imply that the government should not only advocate upgrading industrial structure, but also consider balanced regional development policies for China’s sustainable growth.
Face Preference in Infants at Six and Nine Months Old: The Effects of Facial Attractiveness and Observation Experience
Authors: Kuraguchi Kana , Taniguchi Kosuke , Kanari Kei , Itakura Shoji
Published: July 2020

Attractiveness is perceived based on both facial physical features and prior experience for adults. Infants also prefer attractive or familiar faces, but it is unclear whether facial physical features and prior experience affect their preference. In this study, we investigated whether infants’ preference for faces was shaped by both facial physical features and facial looking experience. This experiment comprised two tasks, observation and preference looking. We manipulated fixation durations in the first task (observation experience) to differ between presented faces and measured the preference for faces in the second task right after the observation task. We conducted two experiments: the same faces in the same positions through both tasks in Experiment 1, and the same faces in different positions in Experiment 2, and analyzed the interaction between observation experience and attractiveness of face images in terms of preference. Observation experience and facial attractiveness only affected preference in Experiment 2: Infants generally looked longer at the flickered position but different face, but looked for the attractive face when the face in the flickered position changed from attractive to unattractive. We suggest that observation experience arouses spatial attention, and that facial attractiveness attracts infants’ attention only when they notice changes of faces.
Remarks on Cosmological Bulk Viscosity in Different Epochs
Authors: Brevik Iver , Normann Ben David
Published: July 2020

The intention of this paper is mainly two-fold. First, we point out a striking numerical agreement between the bulk viscosity in the lepton era calculated by Husdal (2016) and our own calculations of the present-day bulk viscosity when the functional form is ζ ∼ ρ . From a phenomenological point of view, we thus seem to have an ansatz for the viscosity, which bridges the infancy of the Universe (∼1 s) with the present. This can also be looked upon as a kind of symmetry between the early-time cosmology and the present-day cosmology: it is quite remarkable that the kinetic theory-based bulk viscosity in the early universe and the experimentally-based bulk viscosity in the present universe can be covered by the same simple analytical formula. Second, we consider the Kasner universe as a typical anisotropic model of Bianchi-Type I, investigating whether this geometrical model is compatible with constant viscosity coefficients in the fluid. Perhaps surprisingly, the existence of a shear viscosity turns out to be incompatible with the Kasner model. By contrast, a bulk viscosity is non-problematic in the isotropic version of the model. In the special case of a Zel’dovich (stiff) fluid, the three equal exponents in the Kasner metric are even determined by the bulk viscosity alone, independent of the value of the fluid energy density. We also give a brief comparison with some other recent approaches to viscous cosmology.
RETRACTED: Hybrid Chemical Enhanced Oil Recovery Techniques: A Simulation Study
Authors: Zhou Haiyan , Davarpanah Afshin
Published: July 2020

Simultaneous utilization of surfactant and preformed particle gel (henceforth; PPG) flooding on the oil recovery enhancement has been widely investigated as a preferable enhanced oil recovery technique after the polymer flooding. In this paper, a numerical model is developed to simulate the profound impact of hybrid chemical enhanced oil recovery methods (PPG/polymer/surfactant) in sandstone reservoirs. Moreover, the gel particle conformance control is considered in the developed model after polymer flooding performances on the oil recovery enhancement. To validate the developed model, two sets of experimental field data from Daqing oil field (PPG conformance control after polymer flooding) and Shengli oil field (PPG-surfactant flooding after polymer flooding) are used to check the reliability of the model. Combination of preformed gel particles, polymers and surfactants due to the deformation, swelling, and physicochemical properties of gel particles can mobilize the trapped oil through the porous media to enhance oil recovery factor by blocking the high permeable channels. As a result, PPG conformance control plays an essential role in oil recovery enhancement. Furthermore, experimental data of PPG/polymer/surfactant flooding in the Shengli field and its comparison with the proposed model indicated that the model and experimental field data are in a good agreement. Consequently, the coupled model of surfactant and PPG flooding after polymer flooding performances has led to more recovery factor rather than the basic chemical recovery techniques.
Heat Transfer Improvement in a Double Backward-Facing Expanding Channel Using Different Working Fluids
Authors: Abdulrazzaq Tuqa , Togun Hussein , Alsulami Hamed , Goodarzi Marjan , Safaei Mohammad
Published: July 2020

This paper reports a numerical study on heat transfer improvement in a double backward-facing expanding channel using different convectional fluids. A finite volume method with the k-ε standard model is used to investigate the effects of step, Reynolds number and type of liquid on heat transfer enhancement. Three types of conventional fluids (water, ammonia liquid and ethylene glycol) with Reynolds numbers varying from 98.5 to 512 and three cases for different step heights at a constant heat flux (q = 2000 W/m2) are examined. The top wall of the passage and the bottom wall of the upstream section are adiabatic, while the walls of both the first and second steps downstream are heated. The results show that the local Nusselt number rises with the augmentation of the Reynolds number, and the critical effects are seen in the entrance area of the first and second steps. The maximum average Nusselt number, which represents the thermal performance, can be seen clearly in case 1 for EG in comparison to water and ammonia. Due to the expanding of the passage, separation flow is generated, which causes a rapid increment in the local skin friction coefficient, especially at the first and second steps of the downstream section for water, ammonia liquid and EG. The maximum skin friction coefficient is detected in case 1 for water with Re = 512. Trends of velocities for positions (X/H1 = 2.01, X/H2 = 2.51) at the first and second steps for all the studied cases with different types of convectional fluids are indicated in this paper. The presented findings also include the contour of velocity, which shows the recirculation zones at the first and second steps to demonstrate the improvement in the thermal performance.
New Bounds for Topological Indices on Trees through Generalized Methods
Authors: Martínez-Pérez Álvaro , Rodríguez José M.
Published: July 2020

Topological indices are useful for predicting the physicochemical behavior of chemical compounds. A main problem in this topic is finding good bounds for the indices, usually when some parameters of the graph are known. The aim of this paper is to use a unified approach in order to obtain several new inequalities for a wide family of topological indices restricted to trees and to characterize the corresponding extremal trees. The main results give upper and lower bounds for a large class of topological indices on trees, fixing or not the maximum degree. This class includes the first variable Zagreb, the Narumi–Katayama, the modified Narumi–Katayama and the Wiener index.
Epitope Selection for Fighting Visceral Leishmaniosis: Not All Peptides Function the Same Way
Authors: Martínez-Rodrigo Abel , Mas Alicia , Álvarez-Campos Daniel , Orden José A. , Domínguez-Bernal Gustavo , Carrión Javier
Published: July 2020

Visceral leishmaniosis (VL) caused by Leishmania infantum is a disease with an increasing prevalence worldwide. Treatments are expensive, toxic, and ineffective. Therefore, vaccination seems to be a promising approach to control VL. Peptide-based vaccination is a useful method due to its stability, absence of local side effects, and ease of scaling up. In this context, bioinformatics seems to facilitate the use of peptides, as this analysis can predict high binding affinity epitopes to MHC class I and II molecules of different species. We have recently reported the use of HisAK70 DNA immunization in mice to induce a resistant phenotype against L. major, L. infantum, and L. amazonensis infections. In the present study, we used bioinformatics tools to select promising multiepitope peptides (HisDTC and AK) from the polyprotein encoded in the HisAK70 DNA to evaluate their immunogenicity in the murine model of VL by L. infantum. Our results revealed that both multiepitope peptides were able to induce the control of VL in mice. Furthermore, HisDTC was able to induce a better cell-mediated immune response in terms of reduced parasite burden, protective cytokine profile, leishmanicidal enzyme modulation, and specific IgG2a isotype production in immunized mice, before and after infectious challenge. Overall, this study indicates that the HisDTC chimera may be considered a satisfactory tool to control VL because it is able to activate a potent CD4+ and CD8+ T-cell protective immune responses.
A Rainfall Intensity Data Rescue Initiative for Central Chile Utilizing a Pluviograph Strip Charts Reader (PSCR)
Authors: Pizarro-Tapia Roberto , González-Leiva Fernando , Valdés-Pineda Rodrigo , Ingram Ben , Sangüesa Claudia , Vallejos Carlos
Published: July 2020

To develop intensity-duration-frequency (IDF) curves, it is necessary to calculate annual maximum rainfall intensities for different durations. Traditionally, these intensities have been calculated from the analysis of traces recorded by rain gauges on pluviograph strip charts (PSCs). For many years, these charts have been recorded and analyzed by the personnel who operate and maintain the pluviograph gauges, thus the reliability of the observational analysis depends exclusively on the professional experience of the person performing the analysis. Traditionally, the analyzed PSCs are physically stored in data repository centers. After storing rainfall data on aging paper for many years, the risk of losing rainfall records is very high. Therefore, the conversion of PSC records to digital format is crucial to preserve and improve the historical instrumental data base of these records. We conducted the first “Data Rescue Initiative” (DRI) for central Chile using a pluviograph strip charts reader (PSCR), a tool that uses a scanner-type device combined with digital image processing techniques to estimate maximum rainfall intensities for different durations for each paper band (>80,000 paper bands). On the paper bands, common irregularities associated with excess ink, annotations, or blemishes can affect the scanning process; this system was designed with a semi-automatic module that allows users to edit the detected trace to improve the recognition of the data from each PSC. The PSCR’s semi-automatic characteristics were designed to read many PSCs in a short period of time. The tool also allows for the calculation of rainfall intensities in durations ranging between 15 min to 1 h. This capability improves the value of the data for water infrastructure design, since intense storms of shorter duration often have greater impacts than longer but less intense storms. In this study, the validation of the PSCR against records obtained from observational analysis showed no significant differences between maximum rainfall intensities for durations of 1 h, 6 h, and 24 h.
Hydrological Drought Risk Assessment Using a Multidimensional Copula Function Approach in Arid Inland Basins, China
Authors: Xiang Yanyun , Wang Yi , Chen Yaning , Bai Yifei , Zhang Leyuan , Zhang Qifei
Published: July 2020

The aim of this research was to use the standardized runoff index (SRI) with a three-month timescale (SRI-3) to analyze hydrological drought risk in two arid river basins characterized by different runoff regimes, Northwest China. Based on SRI-3, hydrological drought levels for different events were defined through run theory. The hydrological drought risk in the two study basins was then comprehensively assessed using a multidimensional copula function that considered the multivariable joint probability of hydrological drought duration, severity, intensity and peak. Results indicate that: (1) the risk of hydrological drought in the two basins between 1961–2018 periodically changed. There was a slight increase in risk within the Yarkant River Basin, while there was a clear decrease in risk within the Kaidu River Basin. The magnitude of drought in the two basins was relatively low; both basins were dominated by mild to moderate hydrological droughts; (2) the drought probabilities of the Yarkant River Basin and Kaidu River Basin from 1961 to 2018 exhibited a falling-rising-falling pattern and a rising-falling trend through time, respectively. These trends were correlated with changes in precipitation and the area of glacial ice, which presumably influenced the amount and source of runoff in the two basins. Hydrological drought risk in the Yarkant River Basin was higher than in the Kaidu River Basin; and (3) the return period of mild, moderate, severe and extreme drought events was 2 yrs, 8 yrs, 20 yrs, and 60 yrs in the Yarkant River Basin, respectively, and 2 yrs, 8 yrs, 23 yrs and 74 yrs in the Kaidu River Basin, respectively.
El “retorno” ruso: cinco claves para entender las relaciones de la Rusia postsoviética con América Latina y el Caribe
Authors: Rouvinski Vladimir
Published: July 2020

En la actualidad, la incidencia de Rusia en América Latina y el Caribe se percibe como una de las evidencias del intento de proyectar el papel internacional de este país como una potencia de alcance global similar a lo que era la Unión Soviética. Sin embargo, sería un error considerar la política exterior rusa hacia la región como una simple réplica del modus operandi soviético. Como se muestra en este documento, en lugar de una nueva Guerra Fría a gran escala, es posible identificar cinco dimensiones clave del compromiso ruso con esta parte del mundo. En primer lugar, se puede caracterizar la presencia rusa en América Latina en términos de reciprocidad simbólica frente a la incidencia estadounidense en los países vecinos de Rusia. Las otras dimensiones se refieren al potencial de la región para expandir la influencia rusa como una superpotencia energética y como una plataforma para sus medios de información. Además, existen oportunidades para obtener ganancias rápidas en el caso de algunas empresas vinculadas al gobierno ruso en el contexto de una amplia incidencia de la diplomacia personal. Desde esta perspectiva, es poco probable que los desafíos actuales que enfrenta el gobierno de Vladimir Putin, incluyendo la reducción de la disponibilidad de los recursos tangibles y la desaparición de algunos de los aliados políticos más importantes de Moscú en la región, cambien el interés de Rusia hacia América Latina y el Caribe a medio y largo plazo dada la permanencia de la mayoría de los factores clave.
Clinical spectrum of paediatric head injury
Authors: Lodha Krishna Govind , Gupta Tarun Kumar , Jaiswal Gaurav , Singh Yogendra
Published: July 2020

Introduction: Traumatic Brain injury is considered as a major health problem which causes frequent deaths and disabilities in paediatric population with special concern to tribal regions of developing countries like India where etiology of traumatic brain injury in the paediatric population fall from height dominant over the road traffic accident as a major.

Aim and objective: The aim is to analyse the epidemiology, mechanism, clinical presentation, severity and outcome of paediatric head injury in the tribal region of northern India that could help to make preventive policies to improve their care.

Material methods: It is a prospective observational study of 345 children of up to 18 years of age admitted under Department of Neurosurgery from October 2017 to April 2019.

Results: The study population comprised of 345 paediatric patients. Mean age was 9.25 years.36.81% patients were in 1-6-year age group and male to female ratio was 2.45. The most common cause for trauma was fall from height in 179(52%) cases followed by RTA in 141(41%) cases. The most common radiological finding was depressed skull fractures in 97(50%) cases. There was 35% mortality in severe head injury patients.

Conclusion: This study through some light on the different scenario of head injury in Tribal regions of Developing country and will help to formulate effective strategies for prevention and better care of the patients.
Coccydynia - a medical condition with multiple causes and different management strategies
Authors: Sabry Amin , Zidan Ashraf S. , Bari Mohemed Abdel , Sobky Hesham El
Published: July 2020

Background: Coccydynia is a common complaint which is usually self-limited and tolerable. Although most of these patients respond dramatically to conservative measures, some patients need more complex plane of treatment. In these conditions, the cause of coccydynia can be complex and multifactorial.

Patients and methods: A total of 8 cases were included in the study. All cases received medical treatment for 9 months before surgery. Complete coccygectomy was performed for all cases. Post-operative outcomes were measured according to the degree of pain relief.

Results: The mean age of the included cases was 43.87 years (range, 39 – 52). A total of 5 females (62.5%) and 3 males (37.5%) were included. The mean preoperative VAS score was 9 (range, 8 – 10), while post-operatively, it decreased significantly down to 2 (range, 1 – 3). Excellent postoperative outcomes were achieved in 6 cases (75%) whereas good outcomes were obtained in the remaining 2 cases (25%).

Conclusion: Although conservative medical measures are effective for treating coccydynia, but surgical excision is still a valid treatment option in resistant cases.
Prognostic factors of ruptured middle cerebral artery aneurysms treated with surgical clipping
Authors: Hoz Samer S. , Albanaa Saja A. , Neamah Ali M. , Abdulmohsin Farah W. , Al-Sharshahi Zahraa
Published: July 2020

Background: Spontaneous subarachnoid haemorrhage is an emergent condition that leads to profound morbidity and mortality. It is mainly caused by a ruptured intracranial aneurysm. Herein we described the relationship of different factors and their impact on the outcome of patients who underwent a surgical clipping exclusively to the ruptured middle cerebral artery aneurysm.

Methods: We retrospectively analyzed the medical records of patients admitted to the Neurosurgery Teaching Hospital (NTH) in Baghdad for the period between January 2017-April 2019 of patients who underwent microsurgical clipping for ruptured middle cerebral artery aneurysm. Demographic, clinical, radiological and surgical data were extracted. A univariate analysis was used to illustrate the relationship between the variables and outcome which was assessed using the five scores of the Glasgow Outcome Scale where patients were dichotomized into two groups; favourable (IV + V) and unfavourable (I, II, III).

Results: Within this cohort, a total of 50 patients were studied and the analysis revealed that 92% (N=46) had a favourable outcome and 8% (N=4) had an unfavourable outcome at discharge. The in-hospital mortality was 6%(N=3). Factors that were significantly associated with poor outcome were giant aneurysms, the presence of other unruptured aneurysms, post-operative clinical vasospasm, presence of contralateral weakness, lower pre/post-operative Glasgow coma scores, higher Hunt and Hess, World Federation of Neurosurgical Societies (WFNS) and modified-WFNS grades.

Conclusion:  The factors with a significant impact on the outcome of patients with surgically clipped ruptured middle cerebral artery aneurysms were GCS, WFNS, m-WFNS, H&H, contralateral muscle weakness, size of the aneurysm, presence of other unruptured aneurysms and clinical vasospasm.
Experience, challenges and lessons learnt from microsurgical clipping of intracranial aneurysms at an emerging neurosurgical centre
Authors: Aggarwal Varun , Maheshwari Chandni , Kavita Divya , Narang Amit
Published: July 2020

Objectives: To share our experience, challenges faced, lessons learnt and analyze the results of surgical management by microsurgical clipping of intracranial aneurysms at an emerging neurosurgical centre at Guru Gobind Singh medical college and hospital (GGSMC&H) Faridkot, Punjab. India.

Material and Methods: This study includes all the patients who presented with the diagnosis of intracranial aneurysm on CT angiography and were treated with the microsurgical clipping,  between March 2017 to April 2019.

Results: There was a total of 23 patients 11female and 12 male. Age range 32 to 85years. On admission 22 patients had SAH on CT scan and one was admitted after incidental detection of the aneurysm without SAH. The time interval between ictus and admission was 0-3 days in 13 patients, 3-14 days in 8 patients and more than 14 days in 1 patient. WFNS grade (gd) I-15 patients, gd II-2, gd III-2, gd IV-3 patients. Fisher gd I-nil, gd II-9, gd III-4, gd IV-9 patients. In 23 patients 27 Aneurysms were clipped. Distribution of location was Anterior Communicating-12, Distal Anterior Cerebral Artery- 4, Middle cerebral artery (MCA) Bifurcation-3, MCA trifurcation-1, Anterior Choroidal-1, Posterior Communicating (P-com) -1, Ophthalmic Internal Carotid Artery (OICA)-4 and three patients had associated multiple aneurysms. Size of aneurysms varied from < 02mm diameter in 2 patients, 2-25mm - 23 and, more than 25mm-2 aneurysms. There was intra op rupture in 2 cases. Post-operatively 2 patients developed hemiparesis, which recovered, nine patients developed vasospasm. Two patients developed chest related complications. One patient developed renal failure.  There were 8 deaths. Patients are on follow up since March 2017 till date.

Conclusions: Intracranial aneurysms are challenging to manage due to their proximity to vital intracranial structures, and difficulty in securing intracranial proximal control. Thorough knowledge of intracranial anatomy of adjacent relations, arachnoid planes and skilful dissection is a key element for a successful outcome. Data collected from GGSMC & Hospital may not be representative of the entire state or country’s population. Therefore, a large-scale data collection is necessary to create our own database to ascertain the risk factors and preventive measures that are exclusive to our state and nation.
Preoperative evaluation of superficial cortical venous drainage
Authors: Singh Surjeet , Kumari Stuti , Sachan Abhijeet , Jain Shashi Kant
Published: July 2020

Objectives and methodology: The preoperative exact localization of superficial intracranial lesions and superficial cortical veins is often necessary for making craniotomy and evaluation of cortical veins. We developed a simple and cheap method for such localization using cod liver oil capsule during the preoperative MRI and MRV brain examination. With the help of MRV brain, 3DCEMRV and 2DTOF images were taken and superficial cortical veins studied in the marked area for comparison between both modalities of MRV and planning of surgery for avoiding venous injury.

Results: Most of the cases were in the age group 16-60 years (91.6%). The most common clinical manifestation was headache (85.4%) and meningioma (60.4%) was found to be the most common pathology. Clear visualization (Grade 3) of the individual superficial cortical vein was observed in 48 cases (100%) in 3DCEMRV as compared to 2DTOF 22 cases (45.8%) P <0.001S. Clear visualization (Grade3) of superior sagittal sinus was observed in 48 cases (100%) in 3DCEMRV as compared to 2DTOF 33 cases (68.6%) P <0.001S.  In post-operative CT Head, we found 4 (8.3%) cases were having venous infarction.  5 patients (10.4%) developed motor weakness postoperatively. In 3 cases, postoperative MRV were done and found no venous injury.

Conclusion: This study showed that preoperative localization and evaluation of the tumoral area and cortical veins with the help of cod liver oil in MRI and MRV brain was very helpful in planning the surgery, making craniotomy and to avoid injury of the veins. This technique is easy to perform and the capsule is easily constructed and inexpensive. 3DCEMRV was found to be better modality than 2DTOF for delineation of veins. Final neurosurgical outcomes were better.
Hypotension intracrânienne spontanée (HIS)
Authors: H. Leklou , M. Djellaoui
Published: July 2020

L’HIS est une céphalée chronique, liée à une fuite de LCR. Son diagnostic est facilité par l’IRM et sa prise est essentiellement médicale. Nous rapportons le cas d’une jeune femme ayant présenté un tableau clinique et signes IRM compatibles avec ce diagnostic et ayant bien évolué sous traitement.
Solitary plasmacytoma of occipital bone
Authors: Misra Rajneesh , Kumar Sushil , Sharma Sandeep , Sinha Rohan
Published: July 2020

We report a case of a 35-year-old male who presented with a pulsatile swelling in the posterior parieto-occipital area. CT and MRI revealed an extra-axial mass. Gross total resection was performed. Histologically it was found to be a plasmacytoma. No recurrence has been noted in the last 48 months of follow up.
Headache, seizures and loss of consciousness in an elderly male following groin hernia surgery
Authors: Agrawal Amit
Published: July 2020

Headache after lumbar puncture is a common occurrence and have a benign course in the majority. In rare cases, it can be a mani­festation of rare but potentially life-threatening intracranial complications. We discuss a case of 65 years male patient who was operated for left inguinal hernia under spinal anaesthesia, had persistent headache partial response to conservative measures developed one episode of seizures and lapsed into altered sensorium. Imaging findings were suggestive of extensive left frontal-temporoparietal acute SDH with mass effect and midline shift. The hematoma was evacuated and the patient recovered well. Prolonged and persistent post-dural puncture headache complicated by atypical neurological deterioration following spinal anaesthesia should prompt the physician to consider the possibility of intracranial complications and to seek immediate radiological investigations.
Phytochemical screening and antimicrobial activity of extracts of Cassia alata L. leaves and seeds
Authors: Le P. T. Q.
Published: July 2020

The aim of the study is to determine the presence of some bioactive compounds in Cassia alata L. leaves and seeds extracts such as tannins, saponins, anthraquinones and flavonoids. Total polyphenol contents (TPC) of leaves and seeds extracts are 59.211 mg GAE/g DW and 1.816 mg GAE/g DW, respectively, while their antioxidant capacities (AC) are 8.14 μmol Fe/g DW and 2.75 μmol Fe/g DW, respectively. The antimicrobial activity is determined by the paper disc diffusion method combined with the minimum inhibitory concentration (MIC). Leaves extract inhibits S. aureus and E. coli at MIC of 400 mg/mL; S. enteritidis and B. subtilis at MIC of 800 mg/mL. Besides, seeds extract also inhibits S. aureus at MIC of 200 mg/mL; E. coli, S. enteritidis and B. subtilis at MIC of 400 mg/mL. However, leaves and seeds extracts of C. alata do not show any inhibitions on the growth of A. niger.

Keywords: Antibacterial activity, Antioxidant, Cassia alata L., Extract, MIC.