An Edge Computing Application of Fundamental Frequency Extraction for Ocean Currents and Waves.

This paper describes the design and optimization of a smart algorithm based on artificial intelligence to increase the accuracy of an ocean water current meter. The main purpose of water current meters is to obtain the fundamental frequency of the ocean waves and currents. The limiting factor in those underwater applications is power consumption and that is the reason to use only ultra-low power microcontrollers. On the other hand, nowadays extraction algorithms assume that the processed signal is defined in a fixed bandwidth. In our approach, belonging to the edge computing research area, we use a deep neural network to determine the narrow bandwidth for filtering the fundamental frequency of the ocean waves and currents on board instruments. The proposed solution is implemented on an 8 MHz ARM Cortex-M0+ microcontroller without a floating point unit requiring only 9.54 ms in the worst case based on a deep neural network solution. Compared to a greedy algorithm in terms of computational effort, our worst-case approach is 1.81 times faster than a fast Fourier transform with a length of 32 samples. The proposed solution is 2.33 times better when an artificial neural network approach is adopted.

Integer Arithmetic Algorithm for Fundamental Frequency Identification of Oceanic Currents.

Underwater sensor networks play a crucial role in collecting valuable data to monitor offshore aquaculture infrastructures. The number of deployed devices not only impacts the bandwidth for a highly constrained communication environment, but also the cost of the sensor network. On the other hand, industrial and literature current meters work as raw data loggers, and most of the calculations to determine the fundamental frequencies are performed offline on a desktop computer or in the cloud. Belonging to the edge computing research area, this paper presents an algorithm to extract the fundamental frequencies of water currents in an underwater sensor network deployed in offshore aquaculture infrastructures. The target sensor node is based on a commercial ultra-low-power microcontroller. The proposed fundamental frequency identification algorithm only requires the use of an integer arithmetic unit. Our approach exploits the mathematical properties of the finite impulse response (FIR) filtering in the integer domain. The design and implementation of the presented algorithm are discussed in detail in terms of FIR tuning/coefficient selection, memory usage and variable domain for its mathematical formulation aimed at reducing the computational effort required. The approach is validated using a shallow water current model and real-world raw data from an offshore aquaculture infrastructure. The extracted frequencies have a maximum error below a 4%.

High Gain, Low Noise and Power Transimpedance Amplifier Based on Second Generation Voltage Conveyor in 65 nm CMOS Technology.

A transimpedance amplifier (TIA) based on a voltage conveyor structure designed for high gain, low noise, low distortion, and low power consumption is presented in this work. Following a second-generation voltage conveyor topology, the current and voltage blocks are a regulated cascode amplifier and a down converter buffer, respectively. The proposed voltage buffer is designed for low distortion and low power consumption, whereas the regulated cascode is designed for low noise and high gain. The resulting TIA was fabricated in 65 nm CMOS technology for logic and mixed-mode designs, using low-threshold voltage transistors and a supply voltage of ±1.2 V. It exhibited a 52 dBΩ transimpedance gain and a 1.1 GHz bandwidth, consuming 55.3 mW using a ±1.2 V supply. Our preamplifier stage, based on a regulated cascode, was designed considering detector capacitance, bonding wire, and packaging capacitance. The voltage buffer was designed for low-power consumption and low distortion. The measured input-referred noise of the TIA was 22 pA/√Hz. The obtained total harmonic distortion of the TIA was close to 5%. In addition, the group delay is constant for the considered bandwidth. Comparisons against published results in terms of area (A), power consumption (P), bandwidth (BW), transimpedance gain (G), and noise (N) are were performed. Both figures of merit FoMs-the ratio √ (G × BW) and P × A-and FoM/N values demostrated the advantages of the proposed approach.

Novel Deep-Water Tidal Meter for Offshore Aquaculture Infrastructures.

This paper presents a tidal current meter that is based on the inertial acceleration principle for offshore infrastructures in deep water. Focusing on the marine installations of the aquaculture industry, we studied the forces of tides at a depth of 15 m by measuring the acceleration. In addition, we used a commercial MEMS triaxial accelerometer to record the acceleration values. A prototype of the tidal measurement unit was developed and tested at a real offshore aquaculture infrastructure in Gran Canaria, which is one of the Canary Islands in the Atlantic Ocean. The proposed tidal measurement unit was used as a recorder to assess the complexity of measuring the frequency of tidal currents in the short (10 min), medium (one day) and long term (one week). The acquired data were studied in detail, in both the time and frequency domains, to determine the frequency of the forces that were involved. Finally, the complexity of the frequency measurements from the captured data was analyzed in terms of sampling ratio and recording duration, from the point of view of using our proposed measurement unit as an ultra-low-power embedded system. The proposed device was tested for more than 180 days using a lithium-ion battery. This working period was three times greater than the best alternative in the literature because of the ultra-low-power design of the on-board embedded system. The measurement accuracy error was lower than 1% and the resolution was 0.01 cm/s for the 0.8 m/s velocity scale. This performance was similar to the best Doppler solution that was found in the literature.

A Novel Miniaturized Biosensor for Monitoring Atlantic Salmon Swimming Activity and Respiratory Frequency.

The advanced development of sensor technologies has led to the emergence of fish biosensors that are currently used for research and commercial purposes. AEFishBIT is a miniaturized biosensor attached to fish operculum that measures physical activity and respiration frequencies. In this study, we determined the effect of the tagging method and evaluated the use of this biosensor to monitor post-smolt Atlantic salmon in a tank-based system. The use of piercing fish tag had a negative impact on the gills and operculum, unlike the identical protocols used in gilthead sea bream and European sea bass. In contrast, a surgical thread did not show any apparent tissue damage. Two data recording schedules were considered to monitor immediate early reaction to fish handling and light regime changes (records every 15 min over 2 days) or adaptation to new light conditions (records every 30 min over 4 days). Data showed stabilization of physical activity 8 h post-tagging, with different steady states for the activity/respiratory ratio after changes in light intensity that reflected a different time course adaptation to new light conditions. High correlations were observed between AEFishBIT and video recording data. These findings supported the use of AEFishBIT as a promising tool for smart sensing of Atlantic salmon.

Application of NSGA-II to Obtain the Charging Current-Time Tradeoff Curve in Battery Based Underwater Wireless Sensor Nodes.

In this paper, a novel application of the Nondominated Sorting Genetic Algorithm II (NSGA II) is presented for obtaining the charging current-time tradeoff curve in battery based underwater wireless sensor nodes. The selection of the optimal charging current and times is a common optimization problem. A high charging current ensures a fast charging time. However, it increases the maximum power consumption and also the cost and complexity of the power supply sources. This research studies the tradeoff curve between charging currents and times in detail. The design exploration methodology is based on a two nested loop search strategy. The external loop determines the optimal design solutions which fulfill the designers' requirements using parameters like the sensor node measurement period, power consumption, and battery voltages. The inner loop executes a local search within working ranges using an evolutionary multi-objective strategy. The experiments proposed are used to obtain the charging current-time tradeoff curve and to exhibit the accuracy of the optimal design solutions. The exploration methodology presented is compared with a bisection search strategy. From the results, it can be concluded that our approach is at least four times better in terms of computational effort than a bisection search strategy. In terms of power consumption, the presented methodology reduced the required power at least 3.3 dB in worst case scenarios tested.

A New Method for Gaining the Control of Standalone Underwater Sensor Nodes Based on Power Supply Sensing.

In this paper, a new method for gaining the control of standalone underwater sensor nodes based on sensing the power supply evolution is presented. Underwater sensor networks are designed to support multiple extreme scenarios such as network disconnections. In those cases, the sensor nodes involved should go into standalone, and its wired and wireless communications should be disabled. This paper presents how to exit from the standalone status and enter into debugging mode following a practical ultra-low power design methodology. In addition, the discharge and regeneration effects are analyzed and modeled to minimize the error using the sensor node self measurements. Once the method is presented, its implementation details are discussed including other solutions like wake up wireless modules or a pin interruption solution. Its advantages and disadvantages are discussed. The method proposed is evaluated with several simulations and laboratory experiments using a real aquaculture sensor node. Finally, all the results obtained demonstrate the usefulness of our new method to gain the control of a standalone sensor node. The proposal is better than other approaches when the hibernation time is longer than 167.45 µs. Finally, our approach requires two orders of magnitude less energy than the best practical solution.

A Novel Charging Method for Underwater Batteryless Sensor Node Networks.

In this paper, we present a novel charging method for underwater batteryless sensor node networks. The target application is a practical underwater sensor network for oceanic fish farms. The underwater sections of the network use a wireless power transfer system based on the ISO 11784/11785 HDX standard for supplying energy to the batteryless sensor nodes. Each sensor has an accumulator capacitor, which is charged for voltage supplying to the sensor node. A new distributed charging scheme is proposed and discussed in detail to reduce the required time to charge all sensor nodes of the underwater sections. One important key is its decentralized control of the charging process. The proposal is based on the self disconnection ability of each sensor node from the charging network. The second important key is that the hardware implementation of this new feature is quite simple and only requires to include a minimal circuitry in parallel to the current sensor node antenna while the rest of the sensor network remains unaltered. The proposed charging scheme is evaluated using real corner cases from practical oceanic fish farms sensor networks. The results from experiments demonstrate that it is possible to charge up to 10 sensor nodes which is the double charging capability than previous research presented. In the same conditions as the approach found in the literature, it represents reaching an ocean depth of 60 m. In terms of energy, in case of an underwater network with 5 sensors to reach 30 m deep, the proposed charging scheme requires only a 25% of the power required using the traditional approach.

Design of a Practical Underwater Sensor Network for Offshore Fish Farm Cages.

In this paper, we present the design of a practical underwater sensor network for offshore fish farm cages. An overview of the current structure of an offshore fish farm, applied sensor network solutions, and their weaknesses are given. A mixed wireless-wired approach is proposed to mitigate the problem of wire breakage in underwater wired sensor networks. The approach is based on the serial arrangement of identical sections with wired and wireless interconnections areas. Wireless section alleviates underwater maintenance operations when cages are damaged. The analytical model of the proposed solution is studied in terms of maximum power transfer efficiency and the general formulas of the current in their transmitting antennas and sensor nodes are provided. Subsequently, based on simulations, the effects of parasitic resistance across the network are evaluated. A practical underwater sensor network to reach the 30 m depth with sensor nodes distanced 6 m is used to determine the proposal compliance with the ISO 11784/11785 HDX standard in its normal operation. Taking into account the cable breakage scenario, the results from experiments demonstrate the robustness of the proposed approach to keep running the sensor nodes that are located before the short circuit. Sensor node run time is reduced only 4.07% at most using standard values when a cable breakage occurs at the second deepest section.

Ultra-Low Power Sensor Devices for Monitoring Physical Activity and Respiratory Frequency in Farmed Fish.

Integration of technological solutions aims to improve accuracy, precision and repeatability in farming operations, and biosensor devices are increasingly used for understanding basic biology during livestock production. The aim of this study was to design and validate a miniaturized tri-axial accelerometer for non-invasive monitoring of farmed fish with re-programmable schedule protocols. The current device (AE-FishBIT v.1s) is a small (14 mm × 7 mm × 7 mm), stand-alone system with a total mass of 600 mg, which allows monitoring animals from 30 to 35 g onwards. The device was attached to the operculum of gilthead sea bream (Sparus aurata) and European sea bass (Dicentrarchus labrax) juveniles for monitoring their physical activity by measurements of movement accelerations in x- and y-axes, while records of operculum beats (z-axis) served as a measurement of respiratory frequency. Data post-processing of exercised fish in swimming test chambers revealed an exponential increase of fish accelerations with the increase of fish speed from 1 body-length to 4 body-lengths per second, while a close relationship between oxygen consumption (MO2) and opercular frequency was consistently found. Preliminary tests in free-swimming fish kept in rearing tanks also showed that device data recording was able to detect changes in daily fish activity. The usefulness of low computational load for data pre-processing with on-board algorithms was verified from low to submaximal exercise, increasing this procedure the autonomy of the system up to 6 h of data recording with different programmable schedules. Visual observations regarding tissue damage, feeding behavior and circulating levels of stress markers (cortisol, glucose, and lactate) did not reveal at short term a negative impact of device tagging. Reduced plasma levels of triglycerides revealed a transient inhibition of feed intake in small fish (sea bream 50-90 g, sea bass 100-200 g), but this disturbance was not detected in larger fish. All this considered together is the proof of concept that miniaturized devices are suitable for non-invasive and reliable metabolic phenotyping of farmed fish to improve their overall performance and welfare. Further work is underway for improving the attachment procedure and the full device packaging.

Linfoma primario de pulmón tipo malt: presentación de caso clínico / Primary lung lymphoma MALT Type: Clinical case presentation

Antecedentes:Background: Los Linfomas Pulmonares constituyen menos del 15 % de todos los linfomas. Los linfomas primarios en pulmón son una entidad de poca frecuencia, más aún el subtipo llamado MALT (linfoma de tejido linfoide asociado a mucosas) estos representan apenas al 1 % de todos los linfomas y 0,5 % de todos los tumores pulmonares. Se caracterizan por proli-feración clonal linfoide que afecta a los bronquios o al parénquima pulmonar de forma unilateral o bilateral sin que exista evidencia de afectación extra torácica al momento de su diagnóstico. Caso Clinico: paciente de 33 años atendido en servicio de Neumología del Instituto Nacional Cardiopulmonar de Tegucigalpa, Honduras por historia de dolor pleurítico en hemitórax derecho, tos con expecto-ración hemoptoica de 3 semanas de evolución acompañado de estertores crepitantes en hemitórax anterior derecho con diagnóstico histológico e inmunohistoquimico mediante biopsia de linfoma pulmonar de tipo Malt. Discusión: Es importante tener en cuenta a este tipo de tumores, dado que los síntomas, signos clínicos y los estudios de imágenes son inespecíficos. (5) teniendo en cuenta los diagnósticos diferenciales de causas no infecciosas, como la enfermedad metastásica, la granulomatosis de Wegener, los linfomas, las leucemias, las neumonías criptogénicas, la enfermedad tromboembólica y las enfermedades del colágeno...(AU)

Vigilancia molecular de la malaria en potenciales reservorios silvestres que viven en una región históricamente endémica de Paraguay / Molecular surveillance of malaria in potential wild reservoirs that live in a historically endemic region of Paraguay

En Paraguay, no se han registrado casos autóctonos de malaria desde el 2011. Se realizó un estudio descriptivo observacional transversal en 6 monos y 23 aves que vivían en una región históricamente endémica de Paraguay para buscar presencia de reservorios silvestres de parásitos plasmodios causantes de la malaria. El ADN se extrajo por el método de Chelex a partir de una gota de sangre en un papel de filtro, y la detección del parásito se realizó mediante la PCR múltiple semianidada. Por este método, no se detectaron parásitos en ninguna de las 29 muestras. Se evaluó el riesgo potencial de circulación selvática de los parásitos que causan la malaria. Teniendo en cuenta la presencia de mosquitos anofelinos vectores en la zona, el hecho de que no se hayan observado casos positivos es un buen indicador teniendo en cuenta que nuestro país fue declarado recientemente como país libre de malaria por la OMS(AU)

In Paraguay, autochthonous cases of malaria have not been recorded since 2011. A cross-sectional observational descriptive study was conducted in 6 monkeys and 23 birds living in a historically endemic region of Paraguay to identify wild reservoirs of plasmodium parasites that cause malaria. DNA was extracted by the Chelex method from a blood drop in a filter paper, and parasite detection was performed by the seminested multiplex PCR. By this method, parasites were not detected in any of the 29 samples. The risk of potential sylvatic circulation of the parasites causing malaria was evaluated. Considering the presence of anopheline mosquitoes in the area, the fact that we did not find any positive cases is a good indicator as our country was recently certified as a malaria-free country by the WHO(AU)

Lesiones dentales no cariosas en pacientes atendidos en la Clínica Estomatológica Siboney / Non-carious dental lesions in patients treated at the Siboney Stomatology Clinic

Introducción: El desgaste dental es un proceso insidioso y acumulativo que lleva a la destrucción del esmalte y la dentina; conocido como lesiones dentales no cariosas y son: Atrición, Abrasión, Abfracción y Erosión. En Cuba estas lesiones han sido poco estudiadas. Objetivo: Identificar las lesiones dentales no cariosas y sus formas clínicas en pacientes atendidos en la Clínica Estomatológica Siboney. Métodos: Se estudiaron 876 pacientes escogidos al azar de la población que fue atendida durante un período de 10 meses en dicha clínica estomatológica. A los mismos se les realizó un examen estomatológico para determinar si eran portadores o no de tales lesiones y cuál o cuáles variedades de las mismas presentaban. Resultados: Se comprobó que 102 de los 876 pacientes examinados eran portadores de lesiones dentales no cariosas para un 11,43 por ciento; de los cuales el 42,15 por ciento presentaron un solo tipo de lesión; 50 pacientes mostraron dos tipos de lesiones, para un 49,01 por ciento, en todas las combinaciones posibles, siendo la combinación más frecuente Atrición y Abfracción seguida por la Atrición y la Abrasión. Por último, nueve pacientes presentaron tres tipos de lesiones, para un 8,82 por ciento; en este caso la combinación más frecuente fue Atrición, Abfracción y Erosión. Conclusiones: El porcentaje de pacientes con lesiones dentales no cariosas fue relativamente elevado; pudiendo presentarse una lesión aislada o combinaciones de dos o tres; siendo las formas clínicas más frecuentes: Abfracción, en el caso de una lesión; Atrición y Abfracción en el de dos y Atrición, Abrasión y Erosión, en el de tres(AU)

Introduction: Dental wear is an insidious and cumulative process that leads to the destruction of enamel and dentin; Known as non-carious dental injuries and are: Attrition, Abrasion, Abrasion and Erosion. In Cuba these injuries have been little studied. Objective: To identify non-carious dental lesions and their clinical forms in patients treated at the Siboney Stomatology Clinic. Methods: We studied 876 patients chosen at random from the population that was attended during a period of 10 months in said stomatological clinic. They underwent a stomatological examination to determine if they were carriers or not of such injuries and which one or which varieties of them they presented. Results: It was verified that 102 of the 876 patients examined were carriers of non-carious dental lesions for 11.43 percent; of which 42.15 percent presented a single type of injury; 50 patients showed two types of injuries, for 49.01 percent, in all possible combinations, with the most frequent combination being Attrition and Abfraction followed by Attrition and Abrasion. Finally, nine patients presented three types of injuries, for 8.82 percent; in this case the most frequent combination was Attrition, Abrasion and Erosion. Conclusions: The percentage of patients with non-carious dental lesions was relatively high; being able to present an isolated lesion or combinations of two or three; the most frequent clinical forms being: Abfraction, in the case of an injury; Attrition and Abrasion in the two and Attrition, Abrasion and Erosion, in the three(AU)

Identificación molecular del sexo en 9 especies de aves del Centro de Investigación en Animales Silvestres de la hidroeléctrica de Itaipu, lado paraguayo / Sex identification by molecular methods in 9 species of birds from the wild animal research center of Itaipu dam on the paraguayan side

La importancia de determinar el sexo en especies monomórficas que viven en cautiverio conlleva a estrategias de apareamiento a fin de poder incentivar la reproducción. Existen métodos no moleculares de reconocimiento pero son factibles en edad adulta y mucho más difícil cuando son polluelos. Mediante la técnica molecular de PCR, se amplificó el gen de la Cromo Helicasa de Unión al ADN empleando los cebadores, 2550F/2718R. Por este método molecular se consiguió determinar el sexo en 19 de 23 especies de las cuales 3 son ejemplares de: Amazona aestiva, 1 de Pipile grayi, 1 de Bubo virginianus, 4 de Ara chloropterus, 6 de Crax fasciolata, 2 de Caracara plancus, 3 de Chauna torquata, 1 de Cariama cristata y 2 de Cairina moschata del Centro de Investigación de Animales Silvestres de ITAIPU binacional, del lado paraguayo. Nuestros resultados sugieren que el par de cebadores 2550F/2718R podría ser de utilidad para determinar el sexo en las especies estudiadas en el país.

In monomorphic species living in captivity, determining the sex is important because it may allow choosing mating strategies to enhance reproduction. Sex can be determined either by non-molecular recognition methods, which are only feasible in adult birds, or by molecular techniques, which may allow sexing monomorphic species at young ages. Thus, in this study, we used molecular techniques such PCR to amplifying the CHD gene by using 2550F/2718R primers. This method allowed us to determine the sex in 19 out of 23 bird specimens from the Centro de Investigación de Animales Silvestres (CIASI) of the ITAIPÚ BINACIONAL at Paraguayan side. The specimens belonged to the following species: Amazona aestiva (3), Pipile grayi (1), Bubo virginianus (1), Ara chloropterus (4), Crax fasciolata (6), Caracara plancus (2), Chauna torquata (3), Cariama cristata (1) and Cairina moschata (2). The 2550F/2718R primers were useful for determine the sex of the studied species.

Surgical treatment of right coronary arteries with anomalous origin and slit ostium.

BACKGROUND: Right coronary arteries arising in the left sinus or ectopically in the anterior coronary sinus with slit ostium course inside the aorta. They are subject to variable systolic compression and can cause myocardial ischemia with its sequelae or death. METHODS: From May 1991 to March 2003, we treated 16 patients with anomalous origin of the right coronary artery from the left sinus and 4 whose right coronary artery arose ectopically in the anterior sinus. All patients had a slit ostium and underwent transaortic unroofing of the trunk to modify the proximal portion of the anomalous artery. RESULTS: All patients survived operation, although 1 patient died of unrelated causes. Nineteen patients were followed for a period from 0.2 to 11.8 years (median age, 53 years). One experienced angina 1 year after surgery and underwent percutaneous transluminal coronary angioplasty of a left internal thoracic to left anterior descending coronary artery anastomosis. All patients are New York Heart Association class I, without angina; none has sustained a myocardial infarction or required reoperation. CONCLUSIONS: Right coronary arteries that arise in anomalous fashion with a slit ostium can cause myocardial ischemia or death. Transaortic modification of the anomalous trunk addresses the anatomic and pathophysiologic features of the malformation that cause myocardial ischemia. Excellent results can be achieved with this surgical approach.

Implantation of cryopreserved allograft pulmonary monocusp patch to treat nonthrombotic femoral vein incompetence.

We implanted cryopreserved allograft monocusp patches made from cadaveric pulmonary arteries to correct nonthrombotic valvular insufficiency of the common femoral vein in patients with chronic venous ulcers. Thirty-eight patients with 40 ulcers of longer than 3 years' duration underwent valvular repair of the common femoral vein from September 1995 through November 2001. We studied ulcer healing and competence of the monocusp patches using duplex ultrasonography Three patients with a total of 4 ulcers were lost to follow-up; therefore, 35 patients with 36 ulcers were available for examination. Twenty-four ulcers healed, and 12 did not. Of the 24 healed ulcers, 5 recurred. Four of the 5 ulcers were treated, 3 by monocusp patch replacement and 1 by iliac vein dilation and stenting. All such recurrent ulcers healed. The 5th recurrent ulcer was not treated, because the patient refused therapy Therefore, of the 24 ulcers that healed initially, 23 were healed at the end of the study Of the 12 unhealed ulcers, 4 were treated: 2 by ligation of incompetent perforating veins, 1 by saphenous vein ligation and partial stripping, and 1 by monocusp replacement. All 4 ulcers healed. The other 8 patients, all of whom had severe monocusp insufficiency, refused therapy. Therefore, of the 12 ulcers that did not heal initially, 4 were healed after additional treatment. No implanted monocusp patch developed clots. The ulcers remained healed when the prostheses remained competent. We conclude that monocusp patches can restore valvular competence to the femoral vein in patients who have primary valve insufficiency. In such patients, venous ulcers heal rapidly after prosthesis implantation if the monocusp remains competent and if there is no severe incompetence of the superficial venous system or of perforating veins.