bluuebunny/crossref_metadata_2025 huggingface dataset:
Susceptibility Assessment for Landslide Initiated along Power Transmission Lines
Authors: Liu Shuhao , Yin Kunlong , Zhou Chao , Gui Lei , Liang Xin , Lin Wei , Zhao Binbin
Published: December 2021

The power network has a long transmission span and passes through wide areas with complex topography setting and various human engineering activities. They lead to frequent landslide hazards, which cause serious threats to the safe operation of the power transmission system. Thus, it is of great significance to carry out landslide susceptibility assessment for disaster prevention and mitigation of power network. We, therefore, undertake an extensive analysis and comparison study between different data-driven methods using a case study from China. Several susceptibility mapping results were generated by applying a multivariate statistical method (logistic regression (LR)) and a machine learning technique (random forest (RF)) separately with two different mapping-units and predictor sets of differing configurations. The models’ accuracies, advantages and limitations are summarized and discussed using a range of evaluation criteria, including the confusion matrix, statistical indexes, and the estimation of the area under the receiver operating characteristic curve (AUROC). The outcome showed that machine learning method is well suitable for the landslide susceptibility assessment along transmission network over grid cell units, and the accuracy of susceptibility models is evolving rapidly from statistical-based models toward machine learning techniques. However, the multivariate statistical logistic regression methods perform better when computed over heterogeneous slope terrain units, probably because the number of units is significantly reduced. Besides, the high model predictive performances cannot guarantee a high plausibility and applicability of subsequent landslide susceptibility maps. The selection of mapping unit can produce greater differences on the generated susceptibility maps than that resulting from the selection of modeling methods. The study also provided a practical example for landslide susceptibility assessment along the power transmission network and its potential application in hazard early warning, prevention, and mitigation.
Hydrometeor Classification of Winter Precipitation in Northern China Based on Multi-Platform Radar Observation System
Authors: Chen Yichen , Liu Xiang’e , Bi Kai , Zhao Delong
Published: December 2021

Hydrometeor classification remains a challenge in winter precipitation cloud systems. To address this issue, 42 snowfall events were investigated based on a multi-platform radar observation system (i.e., X-band dual-polarization radar, Ka-band millimeter wave cloud radar, microwave radiometer, airborne equipment, etc.) in the mountainous region of northern China from 2016 to 2020. A fuzzy logic classification method is proposed to identify the particle phases, and the retrieval result was further verified with ground-based radar observation. Moreover, the hydrometeor characteristics were compared with the numerical simulations to clarify the reliability of the proposed hydrometeor classification approach. The results demonstrate that the X-/Ka- band radars are capable of identifying hydrometeor phases in winter precipitation in accordance with both ground observations and numerical simulations. Three particle categories, including snow, graupel and the mixture of snow and graupel are also detected in the winter precipitation cloud system, and there are three vertical layers identified from top to bottom, including the ice crystal layer, snow-graupel mixed layer and snowflake layer. Overall, this study has the potential for improving the understanding of microphysical processes such as freezing, deposition and aggregation of ice crystal particles in the winter precipitation cloud system.
Stereo Vision System for Vision-Based Control of Inspection-Class ROVs
Authors: Hożyń Stanisław , Żak Bogdan
Published: December 2021

The inspection-class Remotely Operated Vehicles (ROVs) are crucial in underwater inspections. Their prime function is to allow the replacing of humans during risky subaquatic operations. These vehicles gather videos from underwater scenes that are sent online to a human operator who provides control. Furthermore, these videos are used for analysis. This demands an RGB camera operating at a close distance to the observed objects. Thus, to obtain a detailed depiction, the vehicle should move with a constant speed and a measured distance from the bottom. As very few inspection-class ROVs possess navigation systems that facilitate these requirements, this study had the objective of designing a vision-based control method to compensate for this limitation. To this end, a stereo vision system and image-feature matching and tracking techniques were employed. As these tasks are challenging in the underwater environment, we carried out analyses aimed at finding fast and reliable image-processing techniques. The analyses, through a sequence of experiments designed to test effectiveness, were carried out in a swimming pool using a VideoRay Pro 4 vehicle. The results indicate that the method under consideration enables automatic control of the vehicle, given that the image features are present in stereo-pair images as well as in consecutive frames captured by the left camera.
Classification of Cracks in Composite Structures Subjected to Low-Velocity Impact Using Distribution-Based Segmentation and Wavelet Analysis of X-ray Tomograms
Authors: Wronkowicz-Katunin Angelika , Katunin Andrzej , Nagode Marko , Klemenc Jernej
Published: December 2021

The problem of characterizing the structural residual life is one of the most challenging issues of the damage tolerance concept currently applied in modern aviation. Considering the complexity of the internal architecture of composite structures widely applied for aircraft components nowadays, as well as the additional complexity related to the appearance of barely visible impact damage, prediction of the structural residual life is a demanding task. In this paper, the authors proposed a method based on detection of structural damage after low-velocity impact loading and its classification with respect to types of acting stress on constituents of composite structures using the developed processing algorithm based on segmentation of 3D X-ray computed tomograms using the rebmix package, real-oriented dual-tree wavelet transform and supporting image processing procedures. The presented algorithm allowed for accurate distinguishing of defined types of damage from X-ray computed tomograms with strong robustness to noise and measurement artifacts. The processing was performed on experimental data obtained from X-ray computed tomography of a composite structure with barely visible impact damage, which allowed better understanding of fracture mechanisms in such conditions. The gained knowledge will allow for a more accurate simulation of structural damage in composite structures, which will provide higher accuracy in predicting structural residual life.
Implementation of Speed-Efficient Key-Scheduling Process of AES for Secure Storage and Transmission of Data
Authors: Kumar Thanikodi Manoj , Balmuri Kavitha Rani , Marchewka Adam , Bidare Divakarachari Parameshachari , Konda Srinivas
Published: December 2021

Nowadays, a large number of digital data are transmitted worldwide using wireless communications. Therefore, data security is a significant task in communication to prevent cybercrimes and avoid information loss. The Advanced Encryption Standard (AES) is a highly efficient secure mechanism that outperforms other symmetric key cryptographic algorithms using message secrecy. However, AES is efficient in terms of software and hardware implementation, and numerous modifications are done in the conventional AES architecture to improve the performance. This research article proposes a significant modification to the AES architecture’s key expansion section to increase the speed of producing subkeys. The fork–join model of key expansion (FJMKE) architecture is developed to improve the speed of the subkey generation process, whereas the hardware resources of AES are minimized by avoiding the frequent computation of secret keys. The AES-FJMKE architecture generates all of the required subkeys in less than half the time required by the conventional architecture. The proposed AES-FJMKE architecture is designed and simulated using the Xilinx ISE 5.1 software. The Field Programmable Gate Arrays (FPGAs) behaviour of the AES-FJMKE architecture is analysed by means of performance count for hardware resources, delay, and operating frequency. The existing AES architectures such as typical AES, AES-PNSG, AES-AT, AES-BE, ISAES, AES-RS, and AES-MPPRM are used to evaluate the efficiency of AES-FJMKE. The AES-FJMKE implemented using Spartan 6 FPGA used fewer slices (i.e., 76) than the AES-RS.
Videogrammetric Verification of Accuracy of Wearable Sensors Used in Kiteboarding
Authors: Marčiš Marián , Fraštia Marek , Hideghéty Andrej , Paulík Peter
Published: December 2021

Owing to the combination of windsurfing, snowboarding, wakeboarding, and paragliding, kiteboarding has gained an enormous number of fans worldwide. Enthusiasts compete to achieve the maximum height and length of jumps, speed, or total distance travelled. Several commercially available systems have been developed to measure these parameters. However, practice shows that the accuracy of the implemented sensors is debatable. In this study, we examined the accuracy of jump heights determined by sensors WOO2 and WOO3, and the Surfr app installed on an Apple iPhone SE 2016, compared to a combination of videogrammetric and geodetic measurements. These measurements were performed using four cameras located on the shore of the Danube River at Šamorín, Slovakia. The videogrammetrically-determined accuracy of jump heights was 0.03–0.09 m. This can be considered a reference for comparing the accuracy of off-the-shelf systems. The results show that all of the systems compared tend to overestimate jump heights, including an increase in error with increasing jump height. For jumps over 5 m, the deviations reached more than 20% of the actual jump height.
Robust Spatiotemporal Estimation of PM Concentrations Using Boosting-Based Ensemble Models
Authors: Park Soyoung , Son Sanghun , Bae Jaegu , Lee Doi , Kim Jae-Jin , Kim Jinsoo
Published: December 2021

Particulate matter (PM) as an air pollutant is harmful to the human body as well as to the ecosystem. It is crucial to understand the spatiotemporal PM distribution in order to effectively implement reduction methods. However, ground-based air quality monitoring sites are limited in providing reliable concentration values owing to their patchy distribution. Here, we aimed to predict daily PM10 concentrations using boosting algorithms such as gradient boosting machine (GBM), extreme gradient boost (XGB), and light gradient boosting machine (LightGBM). The three models performed well in estimating the spatial contrasts and temporal variability in daily PM10 concentrations. In particular, the LightGBM model outperformed the GBM and XGM models, with an adjusted R2 of 0.84, a root mean squared error of 12.108 μg/m2, a mean absolute error of 8.543 μg/m2, and a mean absolute percentage error of 16%. Despite having high performance, the LightGBM model showed low spatial prediction accuracy near the southwest part of the study area. Additionally, temporal differences were found between the observed and predicted values at high concentrations. These outcomes indicate that such methods can provide intuitive and reliable PM10 concentration values for the management, prevention, and mitigation of air pollution. In the future, performance accuracy could be improved through consideration of different variables related to spatial and seasonal characteristics.
Sustainability of Industrial Building SSMR through Experimental and Analytical Study under Wind Uplift Load
Authors: Choi Hyok Chu , Ji Koochul , Kwon Kyungrok , Kong Jung Sik
Published: December 2021

Standing Seam Metal Roofs (SSMRs) are widely used in the construction of industrial buildings, and their structural characteristics are rapidly being changed in order to improve the parameters of heat insulation and waterproofness. However, newly employed SSMRs did not account for a potential structural instability under strong winds by considering the multi-function of SSMRs. In this study, three different types of new SSMRs were chosen as specimens and were used in full-scale experiments, which were performed using the cyclic wind uplift method based on ASTM E1592 regulations. In contrast to a previous study in which the ultimate failure of the roof under wind pressure corresponded to seam line failure due to panel deflection, in this study, the experimental results show that seam separation was induced by a mid-clip rupture. It is verified that the behavior of the mid-clip plays a significant role in the overall performance of SSMRs under wind uplift loading. The objectives of this study were to (i) understand the structural performance and failure mode of new SSMRs under wind uplift pressure, as this condition is closest to reality, and to (ii) quantify the structural sustainability, which can be applied to risk-management practices through the established performance evaluation. It is expected that the present research results may provide future directions for improving the test standards, design guidelines, and risk-management practices.
Multi-UAV Cooperative Task Assignment Based on Half Random Q-Learning
Authors: Zhu Pengxing , Fang Xi
Published: December 2021

Unmanned aerial vehicle (UAV) clusters usually face problems such as complex environments, heterogeneous combat subjects, and realistic interference factors in the course of mission assignment. In order to reduce resource consumption and improve the task execution rate, it is very important to develop a reasonable allocation plan for the tasks. Therefore, this paper constructs a heterogeneous UAV multitask assignment model based on several realistic constraints and proposes an improved half-random Q-learning (HR Q-learning) algorithm. The algorithm is based on the Q-learning algorithm under reinforcement learning, and by changing the way the Q-learning algorithm selects the next action in the process of random exploration, the probability of obtaining an invalid action in the random case is reduced, and the exploration efficiency is improved, thus increasing the possibility of obtaining a better assignment scheme, this also ensures symmetry and synergy in the distribution process of the drones. Simulation experiments show that compared with Q-learning algorithm and other heuristic algorithms, HR Q-learning algorithm can improve the performance of task execution, including the ability to improve the rationality of task assignment, increasing the value of gains by 12.12%, this is equivalent to an average of one drone per mission saved, and higher success rate of task execution. This improvement provides a meaningful attempt for UAV task assignment.
Calculating Beamforming Vectors for 5G System Applications
Authors: Dmitriyev Edgar , Rogozhnikov Eugeniy , Duplishcheva Natalia , Novichkov Serafim
Published: December 2021

The growing demand for broadband Internet services is forcing scientists around the world to seek and develop new telecommunication technologies. With the transition from the fourth generation to the fifth generation wireless communication systems, one of these technologies is beamforming. The need for this technology was caused by the use of millimeter waves in data transmission. This frequency range is characterized by heavy path loss. The beamforming technology could compensate for this significant drawback. This paper discusses basic beamforming schemes and proposes a model implemented on the basis of QuaDRiGa. The model implements a MIMO channel using symmetrical antenna arrays. In addition, the methods for calculating the antenna weight coefficients based on the channel matrix are compared. The first well-known method is based on the addition of cluster responses to calculate the coefficients. The proposed one uses the singular value decomposition of the channel matrix into clusters to take into account the most correlated information between all clusters when calculating the antenna coefficients. According to the research results, the proposed method for calculating the antenna coefficients allows an increase in the SNR/SINR level by 8–10 dB on the receiving side in the case of analog beamforming with a known channel matrix.
Nonthermal Radiation of the Extreme TeV Blazar 1ES 0229+200 from Electromagnetic Cascades on Infrared Photon Field
Authors: Dzhatdoev Timur , Galkin Vladimir , Podlesnyi Egor
Published: December 2021

Extreme TeV blazars (ETBs) are active galactic nuclei with jets presumably pointing towards the observer having their intrinsic (compensated for the effect of γ-ray absorption on extragalactic background light photons) spectral energy distributions (SEDs) peaked at an energy in excess of 1 TeV. These sources typically reveal relatively weak and slow variability as well as higher frequency of the low-energy SED peak compared to other classes of blazars. It proved to be exceedingly hard to incorporate all these peculiar properties of ETBs into the framework of conventional γ-ray emission models. ETB physics have recently attracted great attention in the astrophysical community, underlying the importance of the development of self-consistent ETB emission model(s). We propose a new scenario for the formation of X-ray and γ-ray spectra of ETBs assuming that electromagnetic cascades develop in the infrared photon field surrounding the central blazar engine. This scenario does not invoke compact fast-moving sources of radiation (so-called “blobs”), in agreement with the apparent absence of fast and strong variability of ETBs. For the case of the extreme TeV blazar 1ES 0229+200 we propose a specific emission model in the framework of the considered scenario. We demonstrate that this model allows to obtain a good fit to the measured SED of 1ES 0229+200.
Idiopathic Chronic Diarrhea in Rhesus Macaques Is Not Associated with Enteric Viral Infections
Authors: Delwart Eric , Tisza Michael J. , Altan Eda , Li Yanpeng , Deng Xutao , Hartigan-O’Connor Dennis J. , Ardeshir Amir
Published: December 2021

While recent changes in treatment have reduced the lethality of idiopathic chronic diarrhea (ICD), this condition remains one of the most common causes of rhesus macaque deaths in non-human primate research centers. We compared the viromes in fecal swabs from 52 animals with late stage ICD and 41 healthy animals. Viral metagenomics targeting virus-like particles was used to identify viruses fecally shed by each animal. Five viruses belonging to the Picornaviridae, one to the Caliciviridae, one to the Parvoviridae, and one to the Adenoviridae families were identified. The fraction of reads matching each viral species was then used to estimate and compare viral loads in ICD cases versus healthy controls. None of the viruses detected in fecal swabs were strongly associated with ICD.
Simulated Flock-Level Shedding Characteristics of Turkeys in Ten Thousand Bird Houses Infected with H7 Low Pathogenicity Avian Influenza Virus Strains
Authors: Bonney Peter J. , Malladi Sasidhar , Ssematimba Amos , St. Charles Kaitlyn M. , Walz Emily , Culhane Marie R. , Halvorson David A. , Cardona Carol J.
Published: December 2021

Understanding the amount of virus shed at the flock level by birds infected with low pathogenicity avian influenza virus (LPAIV) over time can help inform the type and timing of activities performed in response to a confirmed LPAIV-positive premises. To this end, we developed a mathematical model which allows us to estimate viral shedding by 10,000 turkey toms raised in commercial turkey production in the United States, and infected by H7 LPAIV strains. We simulated the amount of virus shed orally and from the cloaca over time, as well as the amount of virus in manure. In addition, we simulated the threshold cycle value (Ct) of pooled oropharyngeal swabs from birds in the infected flock tested by real-time reverse transcription polymerase chain reaction. The simulation model predicted that little to no shedding would occur once the highest threshold of seroconversion was reached. Substantial amounts of virus in manure (median 1.5×108 and 5.8×109; 50% egg infectious dose) were predicted at the peak. Lastly, the model results suggested that higher Ct values, indicating less viral shedding, are more likely to be observed later in the infection process as the flock approaches recovery.
Role of Q675H Mutation in Improving SARS-CoV-2 Spike Interaction with the Furin Binding Pocket
Authors: Bertelli Anna , D’Ursi Pasqualina , Campisi Giovanni , Messali Serena , Milanesi Maria , Giovanetti Marta , Ciccozzi Massimo , Caccuri Francesca , Caruso Arnaldo
Published: December 2021

Genotype screening was implemented in Italy and showed a significant prevalence of new SARS-CoV-2 mutants carrying Q675H mutation, near the furin cleavage site of spike protein. Currently, this mutation, which is expressed on different SARS-CoV-2 lineages circulating worldwide, has not been thoughtfully investigated. Therefore, we performed phylogenetic and biocomputational analysis to better understand SARS-CoV-2 Q675H mutants’ evolutionary relationships with other circulating lineages and Q675H function in its molecular context. Our studies reveal that Q675H spike mutation is the result of parallel evolution because it arose independently in separate evolutionary clades. In silico data show that the Q675H mutation gives rise to a hydrogen-bonds network in the spike polar region. This results in an optimized directionality of arginine residues involved in interaction of spike with the furin binding pocket, thus improving proteolytic exposure of the viral protein. Furin was predicted to have a greater affinity for Q675H than Q675 substrate conformations. As a consequence, Q675H mutation could confer a fitness advantage to SARS-CoV-2 by promoting a more efficient viral entry. Interestingly, here we have shown that Q675H spike mutation is documented in all the VOCs. This finding highlights that VOCs are still evolving to enhance viral fitness and to adapt to the human host. At the same time, it may suggest Q675H spike mutation involvement in SARS-CoV-2 evolution.
Why the HIV Reservoir Never Runs Dry: Clonal Expansion and the Characteristics of HIV-Infected Cells Challenge Strategies to Cure and Control HIV Infection
Authors: Lau Chuen-Yen , Adan Matthew , Maldarelli Frank
Published: December 2021

Antiretroviral therapy (ART) effectively reduces cycles of viral replication but does not target proviral populations in cells that persist for prolonged periods and that can undergo clonal expansion. Consequently, chronic human immunodeficiency virus (HIV) infection is sustained during ART by a reservoir of long-lived latently infected cells and their progeny. This proviral landscape undergoes change over time on ART. One of the forces driving change in the landscape is the clonal expansion of infected CD4 T cells, which presents a key obstacle to HIV eradication. Potential mechanisms of clonal expansion include general immune activation, antigenic stimulation, homeostatic proliferation, and provirus-driven clonal expansion, each of which likely contributes in varying, and largely unmeasured, amounts to maintaining the reservoir. The role of clinical events, such as infections or neoplasms, in driving these mechanisms remains uncertain, but characterizing these forces may shed light on approaches to effectively eradicate HIV. A limited number of individuals have been cured of HIV infection in the setting of bone marrow transplant; information from these and other studies may identify the means to eradicate or control the virus without ART. In this review, we describe the mechanisms of HIV-1 persistence and clonal expansion, along with the attempts to modify these factors as part of reservoir reduction and cure strategies.
COVID-19 in Low- and Middle-Income Countries (LMICs): A Narrative Review from Prevention to Vaccination Strategy
Authors: Pasquale Sansone , Gregorio Giaccari Luca , Caterina Aurilio , Francesco Coppolino , Beatrice Passavanti Maria , Vincenzo Pota , Caterina Pace Maria
Published: December 2021

The management of the COVID-19 pandemic represents a challenging process, especially for low- and middle-income countries (LMICs) due to the serious economic and health resource problems it generates. In this article, we assess COVID-19 situation in LMICs and outline emerging problems and possible solutions. The prevention and control of COVID-19 would be based on focused tests exploiting those systems (e.g., GeneXpert®) already used in other scenarios. This would be less stressful for the healthcare system in LMICs. Avoiding close contact with people suffering from acute respiratory infections, frequent handwashing, and avoiding unprotected contact with farm or wild animals are recommended infection control interventions. The appropriate use of personal protective equipment (PPE) is required, despite its procurement being especially difficult in LMICs. Patients’ triage should be based on a simple and rapid logarithm to decide who requires isolation and targeted testing for SARS-CoV-2. Being able to estimate which patients will develop severe disease would allow hospitals to better utilize the already limited resources more effectively. In LMICs, laboratories are often in the capital cities; therefore, early diagnosis and isolation become difficult. The number of ICU beds is often insufficient, and the equipment is often old and poorly serviced. LMICs will need access to COVID-19 treatments at minimal prices to ensure that all who need them can be treated. Year-to-date, different vaccines have been approved and are currently available. The main obstacle to accessing them is the limited ability of LMICs to purchase significant quantities of the vaccine.
Construction of Recombinant Lactococcus lactis Strain Expressing VP1 Fusion Protein of Duck Hepatitis A Virus Type 1 and Evaluation of Its Immune Effect
Authors: Zhang Xiaoting , Zhang Ruihua , Wang Jingyu , Sui Nana , Xu Guige , Yan Hui , Zhu Yanli , Xie Zhijing , Jiang Shijin
Published: December 2021

With the continuous development of duck farming and the increasing breeding density, the incidence of duck hepatitis A virus type 1 (DHAV-1) has been on the rise, seriously endangering the development of duck farming. To reduce the use of antibiotics in duck breeding, susceptibility risks and mortality, and avoid virulence recovery and immune failure risk, this study aims to develop a new type of mucosal immune probiotics and make full use of molecular biology techniques, on the level of genetic engineering, to modify Lactococcus lactis (L. lactis). In this study, a secretory recombinant L. lactis named MG1363-VP1 with an enhanced Green Fluorescent Protein (eGFP) and translation enhancer T7g10L was constructed, which could express the VP1-eGFP fusion protein of DHAV-1. The animal experiment in ducklings was performed to detect the immune response and protection effect of oral microecologics by recombinant L. lactis. The results showed that oral L. lactis MG1363-VP1 significantly induced the body’s humoral immune system and mucosal immune system to produce specific anti-VP1 IgG antibodies and mucosal secretory immunoglobulin A (sIgA) for DHAV-1 in ducklings, and cytokines including interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-10 (IL-10), and interferon gamma (IFN-γ). The mortality rate was monitored simultaneously by the natural infestation in the process of production and breeding; notably, the ducklings vaccinated with L. lactis MG1363-VP1 were effectively protected against the nature infection of DHAV-1. The recombinant L. lactis MG1363-VP1 constructed in this study provides a new means of preventing and controlling DHAV-1 infection in the future.
Experimental study of the possibility of topical application of polyvinylpyrrolidone for epistaxis
Authors: Bykova Viktoriya Valentinovna , Chubka Svetlana Aleksandrovna
Published: December 2021

Nasal packing is widely used in patients with epistaxis, especially in cases where it is impossible to electrocoagulate the bleeding vessel. The disadvantages of gauze packing are well known. First of all, this is the risk of recurrent bleeding after removing the tampons from the nose. The cause of recurrent epistaxis is the activation of local fibrinolysis during prolonged stay of the tampon in the nasal cavity. To overcome this drawback, we have proposed the topical application of polyvinylpyrrolidone (PVP). In an experiment on animals, the absence of a damaging effect of PVP on mucociliary transport was proved.
Are 45 years of reproductive isolation enough to prevent the amplification of mitochondrial genes in the Pacific oyster?
Authors: Reynaga Franco Felipe , Grijalva Chon José Manuel , Chávez Villalba Jorge Eduardo , Castro Longoria Reina , Arreola Lizárraga José Alfredo , Barraza Guardado Ramón Héctor
Published: December 2021

The Pacific oyster culture in Mexico began 45 years ago, first with spat imported from the USA and now with spat produced in several local hatcheries. Oyster farmers do not know the parameters that define the quality of the spat they buy, among them the level of genetic variability available in the lots offered. In order to evaluate and compare the genetic variability in spat produced by four Mexican hatcheries, an attempt was made to amplify and sequence the non-coding region and the ND5 gene of the oyster mitochondrial DNA with oligos reported in the scientific literature. The amplification of the non-coding region was not possible due to the bad design of the oligos. Despite the integrity of the extracted oyster DNA, the ND5 gene was not able to be amplified possibly due to the modification of the oligo recognition site in the gene. The generational separation of the oyster cultivated in Mexico from its original source population makes it necessary to obtain new mitochondrial sequences in order to design new oligos suitable for the populations established in Mexico.
Bioseguridad en el cultivo de camarones penaeidos: una revisión
Authors: Figueredo Arnaldo , Fuentes José Luis , Cabrera Tomás , León Jesús , Patti José , Silva José , Ron Ernesto , Pichardo Orlando , Marcano Nelson
Published: December 2021

La camaronicultura ha venido creciendo significativamente en las últimas décadas,  particularmente  en  el  sudeste  asiático,  India  y  Ecuador.  Paralelamente,  la bioseguridad  se  ha  presentado  como  una  necesidad  del  aparato  productivo  debido  a  la frecuencia,  magnitud  y  naturaleza  de  las  enfermedades  que  afectan  a  los  camarones penaeidos.  En  este  artículo  se  revisan  las  estrategias  que  han  sido  incluidas  en  este concepto y las que pudieran serlo en el futuro, para asegurar la sustentabilidad del sector productivo. Entre los aspectos más conocidos, pero no necesariamente aplicados, pueden citarse  la  definición  precisa  y  constante  de  la  condición  sanitaria  de  los  camarones cultivados,  la  concepción  de  planes  de  bioseguridad,  la  utilización  de  cepas  libres  de patógenos  específicos  (Specific  Pathogen  Free  o  SPF),  el  fortalecimiento  de  las capacidades diagnósticas en sus tres niveles (signos clínicos, presuntivo y avanzado), la incorporación de análisis de los riesgos sanitarios, la regulación del ingreso de personas a los centros productivos, el establecimiento de protocolos de buenas prácticas de cultivo y la  completa  restricción  de  la  fauna  silvestre  o  doméstica  dentro de  las  instalaciones de cultivo.  Algunos  paradigmas  no  son  tan  ampliamente  manejados,  aunque  revisten  gran importancia, como el involucramiento de múltiples niveles de acción, la implementación del mapeo sanitario, la formulación de planes de contingencia y simulacros, la definición de planes de compensación, la masificación del conocimiento sobre patobiología de los camarones  penaeidos  y  bioseguridad  entre  los  participantes  del  ciclo  productivo,  la sustitución de alimentación fresca, el mayor control del entorno, la apropiada disposición de  residuos  orgánicos,  la  aplicación  de  probióticos  y  manejo  de  microbiomas,  y  el fomento de investigación aplicada. La bioseguridad ha venido adquiriendo relevancia y actualmente es imprescindible para el mantenimiento del cultivo de camarones penaeidos como actividad productiva rentable y sostenible.
Evaluación de dietas microalgales para pre-semillas de la ostra de mangle Crassostrea rhizophorae (Güilding, 1828) y su crecimiento en condiciones exteriores
Authors: Glem María E. , Freites Luis Felipe , Guevara Miguel , Márquez Adrián , Lodeiros César
Published: December 2021

Con el fin de garantizar un nivel adecuado de las macromoleculas energéticas, que permitan su transferencia exitosa al ambiente natural, se estudió la supervivencia, el crecimiento y la composición bioquímica (carbohidratos, lípidos y proteínas) de pre-semillas (“spat”) (talla inicial 3.77 ± 0.64 mm) de ostra de mangle Crassostrea rhizophorae, alimentada con tres microalgas tropicales: Chaetoceros sp. Cepa Araya (Ch-A), Isochrysis galbana (Ig) y Tetraselmis chui (Tc), ofertadas como dietas unialgales o mezcladas en dietas bialgales y trialgales. La composición bioquímica de las diferentes cepas de microalgas fue también determinada. En el bioensayo bajo condiciones de laboratorio (hatchery), se utilizaron tres acuarios (réplicas con 21 semillas) para cada una de las dietas. Adicionalmente tres réplicas se confinaron en el medio ambiente (control). Después de 36 días, se analizó sus contenidos bioquímicos y registraron las variables biométricas, y los juveniles se transfirieron al ambiente exterior (tres réplicas) y se cultivaron en suspensión durante 30 días. Al final del cultivo en el medioambiente se obtuvieron de nuevo sus variables bioquímicas y biométricas. Sin embargo, debido a una alta mortalidad ocurrida en las réplicas de control (≈80%), no fue posible obtener más datos de estas últimas, después de 36 días. Durante el cultivo en el medio ambiente, se tomaron muestras semanales de las variables ambientales. En general, en el cultivo en el laboratorio, los mayores valores biométricos y bioquímicos se obtuvieron en los organismos alimentados con la dieta monoalgal (Ch-A), dietas bialgales (Ch-A + Tc y Ch-A + Ig) y la trialgal (Ch-A+Ig+Tc), una tendencia que se mantuvo en el cultivo en el medio ambiente. Lo anterior se atribuyó a la contribución equilibrada de las biomoléculas ofrecidas anteriormente por estas dietas. Estos resultados evidenciaron el uso de la energía contenida en carbohidratos y lípidos, por parte de las ostras juveniles, una vez que fueron transferidas al medio ambiente, donde estas fuentes de energía probablemente fueron catabolizadas para compensar la escasa disponibilidad de alimentos (baja Clorofila a y materia orgánica) observada en el sitio de cultivo en el medio ambiente.
Nuevos índices para evaluar distintos tipos de luz LED y fluorescente en el cultivo de fitoplancton utilizados en criaderos de moluscos bivalvos
Authors: Lastres Miguel , Da Costa Fix , Maeda-Martínez Alfonso N. , Figueira Isabel , Casais Elena
Published: December 2021

Para facilitar la toma de decisiones en cultivos de organismos fotoautótrofos, se proponen distintos índices que permiten evaluar, de modo efectivo la productividad de los sistemas al emplear diferentes tipos de luz. El coste lumínico por célula producida, se obtiene mediante el indicador Consumo Lumínico Celular (CLC). El rendimiento de cada fuente luminosa, con la Densidad Máxima por Potencia Instalada (DMPI). El Factor de Comparación de Producción (FCP) calcula las células obtenidas con cada tipo de iluminación, teniendo en cuenta la potencia instalada y el tiempo requerido de cultivo. El Factor de Elección de Luz (FEL) expresa el coste celular por W empleado, teniendo en cuenta la productividad celular obtenida, así como la vida útil y el precio de adquisición de cada lámpara. Se ensayaron 3 modelos de luminarias comerciales, (2 LED, y una fluorescente) en el cultivo de 4 especies de microalgas (Tetraselmis suecica, Isochrysis galbana, Diacronema lutheri, y Skeletonema costatum), utilizadas con frecuencia en criaderos de moluscos bivalvos. Los resultados mostraron que con recuentos celulares y aplicando los índices presentados en esta publicación se puede llegar a determinar la eficiencia del tipo de luz empleada en instalaciones industriales donde se realice la producción de fitoplancton con iluminación artificial.
Patrón de expresión tisular de los genes elovl4 en Sparus aurata y Solea senegalensis: de larva a adulto
Authors: Torres-Rodríguez Miguel , Hontoria Danés Francisco , Monroig Marzá Óscar , Varó Vaello Inmaculada , Navarro Tárrega Juan Carlos
Published: December 2021

Very long-chain (˃ C24) fatty acids (VLC-FA) play critical roles during early development of vertebrates, since these compounds are accumulated in the rapidly forming neural tissues, ensuring their normal function. The functionality of VLC-FA has aroused scientific interest, focusing on the study of elongases protein 4 of very long chain fatty acid (Elovl4), which are responsible for their biosynthesis from shorter fatty acids (precursors). For a better understanding of the metabolism and the potential tissue-specific requirements of VLC-FA in marine teleosts, the present study aimed to determine the tissue-expression pattern of the genes that encode for Elovl4 isoforms, i.e. elovl4a and elovl4b, in different windows of development (larval and adult stages) of Gilthead seabream Sparus aurata and Senegalese sole Solea senegalensis. The results indicated that in S. aurata larvae, elovl4a is widely expressed in the head, while elovl4b is strongly focused in the eyes. Interestingly, in S. senegalensis larvae an opposite tissue-expression pattern was observed for both elovl4 isoforms. In adults of both fish, although elovl4 transcripts were detected in most tissues analyzed, elovl4a and elovl4b genes were strongly expressed in brain and eyes, respectively. Importantly, the differential tissue-expression pattern of both elovl4 isoforms associated to the pre- and post-metamorphic stage of S. senegalensis could be indicative of the VLC-FA particular needs linked to neural tissues functionality in each development stage. These findings can contribute to a better understanding of the species-specific VLC-FA metabolism in marine teleosts.
Fitodepuración mixotrófica en sistemas de recirculación acuícola (RAS) para el manejo sustentable de nutrientes contaminantes
Authors: Silva-Acosta Jorge , Canales Valenzuela Christian , Rodríguez Leal Sergio
Published: December 2021

La acuicultura industrial ha crecido rápidamente debido al aumento en la demanda mundial de pescados y mariscos, lo que ha estimulado el desarrollo de sistemas acuícolas de cultivo de especies marinas. La necesidad de mantener altos niveles de productividad los convierte en sistemas complejos e inestables, propensos a sufrir perturbaciones con riesgo potencial de causar problemas de contaminación del ambiente natural. En las operaciones de acuicultura intensiva se estima que en los procesos de transformación para el desarrollo y crecimiento de la biomasa, aproximadamente el 75% del alimento es liberado en forma de nitrógeno y fósforo. Durante las últimas décadas se han realizado esfuerzos para el desarrollo de procesos de eliminación de estos nutrientes-contaminantes, que de otra manera serían liberados a los cuerpos de agua natural, causando eutrofización. El sistema de acuicultura con recirculación (RAS) es el sistema convencional de cultivo; incluye una etapa de remoción de nutrientes con biofiltros de bacterias aerobias que favorecen el proceso de nitrificación, aunque la tecnología de biofiltros tiene dificultades operacionales tales como la disminución en la concentración de oxígeno, acumulación de materia orgánica y dificultad de retroenjuague, entre otras. Así, han surgido opciones basadas en la actividad de organismos fotoautotróficos aprovechando la capacidad de plantas acuáticas, macro y microalgas, de eliminar con eficacia nutrientes-contaminantes (fitodepuración), consumiendo además de carbono y nitrógeno, también el fosforo, este último sin capacidad de ser removido con biofiltros nitrificantes. Sin embargo, esta estrategia de tratamiento no se ha utilizado en acuicultura intensiva debido a la alta disponibilidad de superficie demandada y que supera la requerida por los compactos equipos de para biofiltración nitrificante. La fitodepuración mixotrófica, que corresponde a la integración de dos tecnologías de tratamiento terciario de aguas residuales (biofiltración-autotrófica y fitodepuración), podrían ser una respuesta eficiente para el tratamiento de aguas residuales acuícolas, dada la interacción entre los organismos involucrados. Por ello, esta revisión se enfoca al potencial uso de los cultivos mixotróficos para el control de nutrientes-contaminantes en “RAS” o aguas residuales acuícolas, además de aportar al desarrollo de economía circular.
Efecto de la alimentación natural con organismos del meiobentos marino y biofloc sobre los parámetros de producción en el cultivo de camarón Penaeus vannamei
Authors: Ibarra-Mayorga Teresa Eulalia , Jijón-Vergara Ariana Solange , Proaño-Morales Jonathan Josue , Cobeña-Veliz Víctor Alfonso
Published: December 2021

Con el crecimiento demográfico, el consumo de camarón aumenta exponencialmente, por lo cual es imprescindible la búsqueda de nuevas tecnologías que disminuyan costos y optimicen la producción. Los sistemas biofloc compuestos por bacterias, algas, protozoos y metazoos han sido considerados una alternativa eficiente como suplemento alimentario en el cultivo de camarón. Además, el suministro de meiofauna en los cultivos tiene efectos positivos en el crecimiento del camarón debido a su alto contenido proteico y de ácidos grasos poliinsaturados. Se evaluó el efecto de la alimentación natural con organismos del meiobentos marino y biofloc sobre los paramentos de producción en el cultivo de Penaeus vannamei. El ensayo se realizó en temporada de verano y se analizaron parámetros de calidad del agua e indicadores productivos. La densidad inicial de cultivo fue 40 postlarvas por 0,18 m2. Se utilizó un diseño experimental completamente aleatorizado conformado por cuatro tratamientos con tres réplicas. En el tratamiento 1 (B), se utilizó la tecnología convencional para cultivo de camarón, con alimento balanceado y agua de mar.  En el tratamiento 2 (S) se colocó una capa de cinco centímetros de sustrato arenoso fino y alimento balanceado. En el tratamiento 3 (S-Bf) se añadió sustrato, biofloc y alimento balanceado. En el tratamiento 4 (B-Bf) se aplicó biofloc y alimento balanceado. Los valores de temperatura, pH, salinidad, oxígeno disuelto, sólidos suspendidos, nitrito, nitrato y amoniaco se mantuvieron dentro de los parámetros óptimos para la especie. El tratamiento que tuvo el mayor peso final fue S-Bf (1,17 g) y el tratamiento que reportó menor peso fue el B con 0,76 g. Los resultados sugieren que la combinación de los flóculos bacterianos del biofloc más los micro invertebrados meiobentónicos pueden constituir una estrategia para mejorar la productividad del cultivo y mantener los parámetros ambientales en intervalos óptimos.
Efecto del kéfir de agua sobre la concentración de vibrios en juveniles de Penaeus vannamei Boone, 1931
Authors: Torres Troya Marco Geovanny , Rodríguez Delgado Irán , Sorroza Ochoa Lita
Published: December 2021

El uso de bacterias benéficas contribuye a mejorar la salud de los camarones. El kéfir es un conglomerado probiótico conformado por un grupo de microorganismos que conviven en simbiosis, principalmente bacterias ácido-lácticas y levaduras. El objetivo del trabajo fue evaluar el efecto del kéfir de agua en la reducción de vibrios presentes en el cultivo de Penaeus vannamei. Se utilizó un total de ocho contenedores con 30 L de agua de mar, en los que se mantuvieron 15 juveniles con un peso promedio de 1,39 ± 0,03 g por tratamiento, con 6% de recambio diario del agua. Se prepararon cuatro dietas elaboradas con 75% kéfir y 25% productos extracelulares (T1); 50% kéfir y 50% productos extracelulares (T2); 50% kéfir deshidratado y 25% productos extracelulares (T3), y una dieta control solamente con alimento balanceado de 36% proteínas (TC). Se alimentó los camarones con los tratamientos antes mencionados por 10 d. Los resultados del efecto inhibitorio sobre los vibrios indicaron que los tres tratamientos fueron significativamente diferentes en relación al control. En cuanto a la salud de los camarones, los tratamientos con kéfir y sus productos extracelulares presentaron hepatopáncreas con grado 1 en contenido de lípido y mejor formación de túbulos con respecto al control (grado 3). Asimismo, en branquias los tratamientos mostraron grado 2 en formaciones necróticas mientras el control presentó grado 3. Se recomienda el uso de kéfir como un aditivo dietético para disminuir la carga bacteriana, particularmente de tipo vibrios en el cultivo de juveniles de P. vannamei.
Occurrence of two abdominal neurofibromas in a specimen of Betta splendens
Authors: Romano Luis Alberto , Silva Oliveira Fernando Pablo , Fonseca Pedrosa Vírginia
Published: December 2021

En este trabajo describimos dos neurofibromas en Betta splendens estudiados con microscopía óptica, inmunohistoquímica y microscopía electrónica. El espécimen estudiado, que pertenecía a un criador privado, presentaba marcada distensión abdominal, fue trasladado para diagnóstico al Laboratorio de Inmunología y Patología de Organismos Acuáticos de la Universidade Federal do Rio Grande – FURG. Fue diagnosticado como neurofibroma, positivo para el anticuerpo contra proteína S-100. Con microscopia electrónica, mostraba signos de degeneración en algunas células y contenía mastocitos distribuidos regularmente en la masa neoplásica. Con inmunohistoquímica confirmamos la histogénesis de la neoplasia, en la que existen dos neurofibromas, y con microscopía electrónica confirmamos que las células granulares que se encuentran entre el tejido neoplásico son MC.
Influence of seasons on heart rate variability during cognitive activity in students with different types of daily activity
Authors: Pavlenko S.I. , Vedyasova O.A.
Published: December 2021

It is shown that changes of heart rate variability (HRV) in students with morning, afternoon and evening chronotypes under cognitive load are characterized by seasonal dependence. A more pronounced seasonal modulation of HRV is characteristic of "pigeons", whose background values of HRV parameters and responses to load during the school day are greater in the autumn-winter period than in the spring-summer period. In" larks", HRV changes in the conditions of cognitive activity dominate in the spring-summer season, and in "owls" – in the autumn-winter season, but the observed reactions are weaker than in "pigeons". The observed differences in HRV may be caused by seasonal features of mechanisms of the heart adaptation in different chronotypes.
Keywords: heart rate variability, seasons of the year, chronotypes, cognitive load.
Development of motor abilities in girls with scoliosis of 1-2 degrees by means of recreational aerobics and therapeutic physical culture
Authors: Podlubnaya A.A. , Balashova V.F.
Published: December 2021

In the specialized literature, you can find data from a number of authors indicating that children with scoliosis have a lag in the level of physical development and physical fitness. The article presents the results of a study indicating the positive effect of recreational aerobics and therapeutic physical culture on the development of motor abilities in primary school-age girls with 1-2-degree scoliosis.

Key words: health, posture, scoliosis, aerobics, therapeutic physical education, development.