Energy Performance of LR-FHSS: Analysis and Evaluation.

Long-range frequency hopping spread spectrum (LR-FHSS) is a pivotal advancement in the LoRaWAN protocol that is designed to enhance the network's capacity and robustness, particularly in densely populated environments. Although energy consumption is paramount in LoRaWAN-based end devices, this is the first study in the literature, to our knowledge, that models the impact of this novel mechanism on energy consumption. In this article, we provide a comprehensive energy consumption analytical model of LR-FHSS, focusing on three critical metrics: average current consumption, battery lifetime, and energy efficiency of data transmission. The model is based on measurements performed on real hardware in a fully operational LR-FHSS network. While in our evaluation, LR-FHSS can show worse consumption figures than LoRa, we find that with optimal configuration, the battery lifetime of LR-FHSS end devices can reach 2.5 years for a 50 min notification period. For the most energy-efficient payload size, this lifespan can be extended to a theoretical maximum of up to 16 years with a one-day notification interval using a cell-coin battery.

Archaeological findings show the extent of primitive characteristics of maize in South America.

Scientific research has suggested that maize spread from Mexico and arrived in lowland South America in a state of partial domestication. However, archaeological samples with primitive morphological characteristics that corroborate this finding have not been recorded in the region thus far. Unexpectedly, many samples were identified in the Peruaçu Valley with characteristics never previously observed in South America. These archaeological samples with primitive characteristics, which are the focus of this work, represent the furthest records from the center of origin of the species and the longest duration of the maintenance of such characteristics (between 1010 and 570 years before present). The findings of this study, including archaeological samples, native races, and samples of teosinte, attest to a long history of maize diversification in lowland South America.

Acoustic recognition of predators by mantled howler monkeys (Alouatta palliata): A playback experiment with naïve and experienced subjects.

OBJECTIVES: When the production of antipredator behaviors is costly, prey is expected to stop displaying such behaviors and lose the ability to recognize extirpated predators. However, the loss or maintenance of predator recognition abilities is conditional on the eco-evolutionary context of prey. Here, we examined the behavioral responses of naïve and experienced mantled howler monkeys (Alouatta palliata) to simulated acoustic cues from natural predators. METHODS: We studied experienced individuals in the Uxpanapa Valley and naïve individuals in Los Tuxtlas (Veracruz, México). Jaguars (Panthera onca) and harpy eagles (Harpia harpyja), the main predators of howler monkeys, are extant in the Uxpanapa Valley but have been extirpated in Los Tuxtlas for approximately 70 and 45 years, respectively. We exposed six naïve and six experienced groups to playbacks of acoustic stimuli from the two predators and a non-predator control species (plain chachalacas, Ortalis vetula), and recorded the latency, frequency, and duration of antipredation behaviors (n = 127 trials). RESULTS: In contrast with experienced mantled howler monkeys, naïve subjects did not respond to trials from harpy eagles. However, response patterns were generally similar between naïve and experienced individuals when exposed to jaguar stimuli. DISCUSSION: Our findings suggest that naïve mantled howler monkeys do not recognize harpy eagle calls, but they respond to jaguar calls in a manner consistent with experienced individuals. These results illustrate how different mechanisms for the recognition of extirpated predators operate within a single species according to evolutionary and ecological experience.

Diversity of vegetable landraces in the Pampa biome of Brazil and Uruguay: utilization and conservation strategies.

The historical meeting between originally American people, European colonizers, and slaved peoples from Africa in the biome Pampa in South Brazil and Uruguay involved a cultural syncretism and a great genetic diversity of landraces of cultivated species. Genetic richness evolved by selection and cultural processes in response to different environments, cultural backgrounds, and needs. This review summarized the knowledge on vegetable and maize landraces in South Brazilian and Uruguayan Pampa biome, to design a strategy towards the rediscovery, conservation, and sustainable use. Landraces diversity maintained in situ and ex situ is described, specific case studies are presented, and the main problems and tools towards landraces re-valorization are discussed. We show that traditional family farming systems maintain diverse vegetable species, mainly squashes (Cucurbita spp.), sweet potato (Ipomoea batatas), beans (Phaseolus spp.), onion (Allium cepa), peppers (Capsicum spp.), tomato (Solanum lycopersicum), next to leafy vegetables and maize, among others. We propose the priority of systematic surveys as a basis for monitoring genetic erosion, increasing complementariness between in situ and ex situ conservation, and implementing sustainable conservation and utilization. The case studies highlight genetic diversity within each cultivated species, with different crop physiological responses; disease resistances, different quality traits and associated uses, from animal feeding in maize to a range of culinary uses linked to traditional culture in maize and vegetable species, and ornamental uses of specific Capsicum and Cucurbita. Some landraces were the basis for breeding, where improved cultivars allowed the competitiveness of landrace germplasm in the markets. Renewed industrialized products allowed the competitive and sustainable use of Capsicum landraces in Brazilian farmers communities. Strategies towards in situ conservation improvements and valorization are discussed; emphasizing the role played by agroecology, community seed banks and custodian farmers, participatory plant breeding, promotion of landraces specialties among consumers, and the need of research and capacity building, among others. Farmers' participation in the decisions is a key factor, along with the academia and the public sector. Landraces and associated knowledge are treasures to be used to benefit from farmers to consumers, directing the course of agriculture towards sustainable directions.

Analysis of the Asymmetry between Both Eyes in Early Diagnosis of Glaucoma Combining Features Extracted from Retinal Images and OCTs into Classification Models.

This study aims to analyze the asymmetry between both eyes of the same patient for the early diagnosis of glaucoma. Two imaging modalities, retinal fundus images and optical coherence tomographies (OCTs), have been considered in order to compare their different capabilities for glaucoma detection. From retinal fundus images, the difference between cup/disc ratio and the width of the optic rim has been extracted. Analogously, the thickness of the retinal nerve fiber layer has been measured in spectral-domain optical coherence tomographies. These measurements have been considered as asymmetry characteristics between eyes in the modeling of decision trees and support vector machines for the classification of healthy and glaucoma patients. The main contribution of this work is indeed the use of different classification models with both imaging modalities to jointly exploit the strengths of each of these modalities for the same diagnostic purpose based on the asymmetry characteristics between the eyes of the patient. The results show that the optimized classification models provide better performance with OCT asymmetry features between both eyes (sensitivity 80.9%, specificity 88.2%, precision 66.7%, accuracy 86.5%) than with those extracted from retinographies, although a linear relationship has been found between certain asymmetry features extracted from both imaging modalities. Therefore, the resulting performance of the models based on asymmetry features proves their ability to differentiate healthy from glaucoma patients using those metrics. Models trained from fundus characteristics are a useful option as a glaucoma screening method in the healthy population, although with lower performance than those trained from the thickness of the peripapillary retinal nerve fiber layer. In both imaging modalities, the asymmetry of morphological characteristics can be used as a glaucoma indicator, as detailed in this work.

Decision Trees for Glaucoma Screening Based on the Asymmetry of the Retinal Nerve Fiber Layer in Optical Coherence Tomography.

Purpose: The aim of this study was to analyze the relevance of asymmetry features between both eyes of the same patient for glaucoma screening using optical coherence tomography. Methods: Spectral-domain optical coherence tomography was used to estimate the thickness of the peripapillary retinal nerve fiber layer in both eyes of the patients in the study. These measurements were collected in a dataset from healthy and glaucoma patients. Several metrics for asymmetry in the retinal nerve fiber layer thickness between the two eyes were then proposed. These metrics were evaluated using the dataset by performing a statistical analysis to assess their significance as relevant features in the diagnosis of glaucoma. Finally, the usefulness of these asymmetry features was demonstrated by designing supervised machine learning models that can be used for the early diagnosis of glaucoma. Results: Machine learning models were designed and optimized, specifically decision trees, based on the values of proposed asymmetry metrics. The use of these models on the dataset provided good classification of the patients (accuracy 88%, sensitivity 70%, specificity 93% and precision 75%). Conclusions: The obtained machine learning models based on retinal nerve fiber layer asymmetry are simple but effective methods which offer a good trade-off in classification of patients and simplicity. The fast binary classification relies on a few asymmetry values of the retinal nerve fiber layer thickness, allowing their use in the daily clinical practice for glaucoma screening.

Maize dispersal patterns associated with different types of endosperm and migration of indigenous groups in lowland South America.

BACKGROUND AND AIMS: The lowlands of South America appear to be remarkably important in the evolutionary history of maize, due to new evidence that suggests that maize dispersed from Mexico and arrived in this region in a state of partial domestication. This study aimed to identify dispersal patterns of maize genetic diversity in this part of the continent. METHODS: A total of 170 maize accessions were characterized with 4398 single nucleotide polymorphisms (SNPs) and analysed to determine if maize dispersal was associated with types of endosperm and indigenous language families. KEY RESULTS: Four genetic groups were identified in the discriminant analysis of principal components and five groups in the cluster analysis (neighbour-joining method). The groups were structured according to the predominance of endosperm types (popcorn, floury, flint/semi-flint). Spatial principal component analysis of genetic variation suggests different dispersal patterns for each endosperm type and can be associated with hypotheses of expansions of different indigenous groups. CONCLUSIONS: From a possible origin in Southwestern Amazonia, different maize dispersal routes emerged: (1) towards Northern Amazonia, which continued towards the Caatinga and south-eastern Atlantic Forest (Floury); (2) towards Southern Brazil, passing through the Cerrado and Southern Atlantic Forest reaching the Pampa region (Floury); and (3) along the Atlantic Coast, following Tupi movements originating from two separate expansions: one (Tupinamba) from north to south, and the other (Guarani) in the opposite direction, from south to north (flint, floury and popcorn).

Energy Consumption Model of SCHC Packet Fragmentation over Sigfox LPWAN.

The Internet Engineering Task Force (IETF) has standardized a new framework, called Static Context Header Compression and fragmentation (SCHC), which offers adaptation layer functionality designed to support IPv6 over Low Power Wide Area Networks (LPWANs). The IETF is currently profiling SCHC, and in particular its packet fragmentation and reassembly functionality, for its optimal use over certain LPWAN technologies. Considering the energy constraints of LPWAN devices, it is crucial to determine the energy performance of SCHC packet transfer. In this paper, we present a current and energy consumption model of SCHC packet transfer over Sigfox, a flagship LPWAN technology. The model, which is based on real hardware measurements, allows to determine the impact of several parameters and fragment transmission strategies on the energy performance of SCHC packet transfer over Sigfox. Among other results, we have found that the lifetime of a device powered by a 2000 mAh battery, transmitting packets every 5 days, is 168 days for 2250-byte packets, while it increases to 1464 days for 77-byte packets.

Automatic Segmentation of the Retinal Nerve Fiber Layer by Means of Mathematical Morphology and Deformable Models in 2D Optical Coherence Tomography Imaging.

Glaucoma is a neurodegenerative disease process that leads to progressive damage of the optic nerve to produce visual impairment and blindness. Spectral-domain OCT technology enables peripapillary circular scans of the retina and the measurement of the thickness of the retinal nerve fiber layer (RNFL) for the assessment of the disease status or progression in glaucoma patients. This paper describes a new approach to segment and measure the retinal nerve fiber layer in peripapillary OCT images. The proposed method consists of two stages. In the first one, morphological operators robustly detect the coarse location of the layer boundaries, despite the speckle noise and diverse artifacts in the OCT image. In the second stage, deformable models are initialized with the results of the previous stage to perform a fine segmentation of the boundaries, providing an accurate measurement of the entire RNFL. The results of the RNFL segmentation were qualitatively assessed by ophthalmologists, and the measurements of the thickness of the RNFL were quantitatively compared with those provided by the OCT inbuilt software as well as the state-of-the-art methods.

Alergia al níquel y colocación de endoprótesis aórticas con nitinol / Nickel allergy and placement of aortic endoprostesis with nitinol

Introducción: las alergias al níquel son muy frecuentes. En diversos materiales implantables utilizado en cirugía endovascular, la estructura metálica es de nitinol. Caso clínico: se presenta el caso de un paciente con alergia conocida al níquel y que necesitó una endoprótesis aórtica con ramas en cuya fabricación se sustituyó el níquel por el acero inoxidable. Discusión: a raíz del caso, se recomienda ser estrictos con las instrucciones de uso y se alerta sobre algunas reacciones posoperatorias.(AU)

Introduction: nickel allergies are very common. In various implantable material used in endovascular surgery, the metal structure is made of nitinol. Case report: We present a case of a patient with known nickel allergy who needed an aortic endoprosthesis with branches in which manufacture nickel was replaced with stainless steel. Discussion: as a result of this case it is recommended to be strict with the instructions and to be alert in case of postoperative reactions.(AU)

The SF12 Well in LoRaWAN: Problem and End-Device-Based Solutions.

LoRaWAN has become a popular technology for the Internet of Things (IoT) device connectivity. One of the expected properties of LoRaWAN is high network scalability. However, LoRaWAN network performance may be compromised when even a relatively small number of devices use link-layer reliability. After failed frame delivery, such devices typically tend to reduce their physical layer bit rate by increasing their spreading factor (SF). This reaction increases channel utilization, which may further degrade network performance, even into congestion collapse. When this problem arises, all the devices performing reliable frame transmission end up using SF12 (i.e., the highest SF in LoRaWAN). In this paper, we identify and characterize the described network condition, which we call the SF12 Well, in a range of scenarios and by means of extensive simulations. The results show that by using alternative SF-management techniques it is possible to avoid the problem, while achieving a packet delivery ratio increase of up to a factor of 4.7.

Treadmill and Running Speed Effects on Acceleration Impacts: Curved Non-Motorized Treadmill vs. Conventional Motorized Treadmill.

An increase in the popularity of running can be seen over the last decades, with a large number of injuries on it. Most of the running injuries are related to impact accelerations and are due to overuse. In order to reduce the risk of injury or to improve performance and health new treadmill designs have been created, as it can be the curved non-motorized treadmill. The aim of this study was to analyse impact accelerations, spatio-temporal parameters and perceptual differences while running on curved non-motorized treadmill (cNMT) compared to motorized treadmill (MT) at different speeds. Therefore, 27 recreational runners completed two tests consisting of 10 min warm-up and three bouts of 8 min running at 2.77 m/s, 3.33 m/s and self-selected speed on cNMT and MT, previously randomised. Although the surface did not influence spatio-temporal parameters, a reduction in impact accelerations, head acceleration rate (mean effect size [ES] = 0.86), tibia peak (mean ES = 0.45) and tibia magnitude (mean ES = 0.55), was observed while running on cNMT in comparison with running on MT. Moreover, higher heart rate (HR) (mean ES = 0.51) and rating of perceived effort (RPE) (mean ES = 0.34) were found while running on cNMT. These findings demonstrated that higher intensity training and lower impact accelerations are experimented on cNMT, what can be used by trainers and athletes while planning training sessions.

Justificación y diseño del estudio multicéntrico prospectivo de cohortes para evaluar los resultados del cierre percutáneo en procedimientos de reparación aórtica endovascular. Registro SPAIN / Justification and design of the prospective multicentre cohort study to evaluate the results of percutaneous closure in endovascular aortic repair procedures. SPAIN Registry

Introducción: el cierre percutáneo es una herramienta esencial en el tratamiento endovascular actual. Los procedimientos de patología aórtica precisan abordajes arteriales de gran calibre a nivel inguinal, lo que conlleva mayor posibilidad de complicaciones en el cierre. Es por esto que actualmente continúan conviviendo la técnica quirúrgica abierta y el abordaje percutáneo, siendo también así en el territorio nacional, con resultados a día de hoy no cuantificados. La literatura actual aporta buenos resultados para la técnica de presutura en patología aórtica, sin embargo aún existen dudas respecto a determinados factores de riesgo como la obesidad, calcificación severa o arterias de pequeño calibre. Tampoco existen suficientes datos que estudien cómo afecta este procedimiento a la calidad de vida, lo cual es un punto esencial, especialmente en pacientes mayores. Dado que un alto porcentaje de los pacientes que se someten a estas intervenciones son ancianos con patologías concomitantes (los llamados pacientes frágiles), minimizar la agresión quirúrgica y mejorar su calidad de vida inmediata post-procedimiento puede ser determinante. Objetivos: primarios: estimar la tasa de éxito técnico del procedimiento de cierre percutáneo en intervenciones aórticas, estimación del impacto en la calidad de vida así como encontrar posibles diferencias en la morbimortalidad a 30 días en relación a la puntuación de cada paciente en la escala de fragilidad modificada; secundarios: evaluar el tiempo de presutura, tiempo de hemostasia, complicaciones derivadas del cierre, estancia hospitalaria y el dolor posoperatorio. Material y métodos: el Registro SPAIN es un estudio multicéntrico prospectivo de pacientes sometidos a procedimientos percutáneos sobre la aorta y sus ramas con dispositivos ≥ 10 French (F), en el que serán recogidas variables relacionadas con el cierre de sus accesos inguinales. El periodo de seguimiento será de 30 días...(AU)

Introduction: percutaneous closure is an essential tool in current endovascular treatment. Aortic pathology procedures require large-caliber arterial approaches, leading to a greater possibility of closure complications. For this reason, nowadays, both open surgical and the preclose technique coexist in almost every center worldwide, as it does in Spain with no contrasted results. The current literature provides good results for the pre-closing technique in aortic pathology, however there are still doubts regarding certain risk factors such as obesity, severe calcification or small-caliber arteries. There is not enough data to study how this procedure affects quality of life, an essential point, especially in older patients. Minimizing surgical aggression and improving their immediate post-procedure quality of life can be decisive because most of the patients are elderly with concomitant pathologies (fragile patients). Objetives: primary objectives: to estimate the technical success rate of the percutaneous closure procedure in aortic interventions, estimate the impact on quality of life and find possible differences in morbidity and mortality at 30 days in relation to the score of each patient on the frailty scale; secondary objectives: To evaluate the pre-suture time, hemostasis time, complications derived from closure, hospital stay and post-operative pain. Material and methods: the SPAIN Registry is a prospective multicenter study of patients undergoing percutaneous procedures on the aorta and its branches with ≥ 10 French (F) devices. Variables related to the closure of their inguinal access will be collected. The follow-up period will be 30 days. The duration of the recruitment period will be one year initially. Participants must certify that they have performed the closure of at least 10 large caliber percutaneous approaches (≥ 10 F) in national units of the specialties of Angiology and Vascular Surgery and Cardiology...(AU)

Dolor abdominal secundario a disección espontánea de arteria mesentérica superior complicada / Abdominal pain at complicated spontaneous superior mesenteric artery dissection

La disección espontánea de la arteria mesentérica superior (AMS) es una entidad que se describe como un desgarro o rotura de la íntima y de las capas internas de la media permitiendo el paso de sangre creando una luz falsa en la capa media. El diagnóstico clínico se establece tras la aparición de dolor abdominal súbito en pacientes con factores de riesgo cardiovascular y su manejo puede ser endovascular o mediante cirugía a cielo abierto, dependiendo de diversos factores que mencionaremos. La clasificación se describió en base a los hallazgos por TAC. Se presenta el caso de un paciente de 48 años con disección espontánea de la AMS.(AU)

Spontaneous dissection of the superior mesenteric artery is described as a tear or rupture of the intima and the inner layers of the stocking, allowing the passage of blood creating a false light in the middle layer. The clinical diagnosis is established after the appearance of sudden abdominal pain in patients with cardiovascular risk factors and its management can be endovascular or by open surgery, depending on factors that we will mention. The classification was described based on the CT findings. We present the case of a 48-year-old patient with spontaneous AMS dissection.(AU)

Validity and Reliability of an Instrumented Treadmill with an Accelerometry System for Assessment of Spatio-Temporal Parameters and Impact Transmission.

Running retraining programs focused on concurrent feedback of acceleration impacts have been demonstrated to be a good strategy to reduce running-related injuries (RRI), as well as to improve running economy and reduce acceleration impacts and injury running incidence. Traditionally, impacts have been registered by mean of accelerometers attached directly to the athletes, which is inaccessible to the entire population, because it requires laboratory conditions. This study investigated the validity and reliability of a new device integrated directly into the treadmill, compared to a traditional acceleration impact system. Thirty healthy athletes with no history of RRI were tested on two separate days over the instrumented treadmill (AccTrea) and simultaneously with an acceleration impact system attached to the participant (AccAthl). AccTrea was demonstrated to be a valid and reliable tool for measuring spatio-temporal parameters like step length (validity intraclass correlation coefficient (ICC) = 0.94; reliability ICC = 0.92), step time (validity ICC = 0.95; reliability ICC = 0.96), and step frequency (validity ICC = 0.95; reliability ICC = 0.96) during running. Peak acceleration impact variables showed a high reliability for the left (reliability ICC = 0.88) and right leg (reliability ICC = 0.85), and peak impact asymmetry showed a modest validity (ICC = 0.55). These results indicated that the AccTrea system is a valid and reliable way to assess spatio-temporal variables, and a reliable tool for measuring acceleration impacts during running.

Guías de diagnóstico de la enfermedad cerebrovascular extracraneal / Diagnostic guidelines for extracranial cerebrovascular disease

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A Sigfox Energy Consumption Model.

Sigfox has become one of the main Low-Power Wide Area Network (LPWAN) technologies, as it has attracted the attention of the industry, academy and standards development organizations in recent years. Sigfox devices, such as sensors or actuators, are expected to run on limited energy sources; therefore, it is crucial to investigate the energy consumption of Sigfox. However, the literature has only focused on this topic to a very limited extent. This paper presents an analytical model that characterizes device current consumption, device lifetime and energy cost of data delivery with Sigfox. In order to capture a realistic behavior, the model has been derived from measurements carried out on a real Sigfox hardware module. The model allows quantifying the impact of relevant Sigfox parameters and mechanisms, as well as frame losses, on Sigfox device energy performance. Among others, evaluation results show that the considered Sigfox device, powered by a 2400 mAh battery, can achieve a theoretical lifetime of 1.5 or 2.5 years while sending one message every 10 min at 100 bit/s or 600 bit/s, respectively, and an asymptotic lifetime of 14.6 years as the message transmission rate decreases.

Candida periprosthetic joint infection: A rare and difficult-to-treat infection.

BACKGROUND: Candida periprosthetic joint infection (CPJI) is a rare, difficult-to-treat disease. The purpose of this study was to evaluate the clinical characteristics and outcomes of CPJI treated with various surgical and antifungal strategies. METHODS: We conducted a multicenter retrospective study of all CPJI diagnosed between 2003 and 2015 in 16 Spanish hospitals. RESULTS: Forty-three patients included: median age, 75 years, and median Charlson Comorbidity Index score, 4. Thirty-four (79.1%) patients had ≥1 risk factor for Candida infection. Most common causative species were C. albicans and C. parapsilosis. Thirty-five patients were evaluable for outcome: overall, treatment succeeded in 17 (48.6%) and failed in 18 (51.4%). Success was 13/20 (67%) in patients with prosthesis removal and 4/15 (27%) with debridement and prosthesis retention (p = 0.041). All 3 patients who received an amphotericin B-impregnated cement spacer cured. In the prosthesis removal group, success was 5/6 (83%) with an antibiofilm regimen and 8/13 (62%) with azoles (p = 0.605). In the debridement and prosthesis retention group, success was 3/10 (30%) with azoles and 1/5 (20%) with antibiofilm agents. Therapeutic failure was due to relapse in 9 patients, need for suppressive treatment in 5, persistent infection in 2, and CPJI-related death in 2; overall attributable mortality was 6%. CONCLUSIONS: CPJI is usually a chronic disease in patients with comorbidities and risk factors for Candida infection. Treatment success is low, and prosthesis removal improves outcome. Although there is insufficient evidence that use of antifungals with antibiofilm activity has additional benefits, our experience indicates it may be recommendable.

Modeling the Energy Performance of LoRaWAN.

LoRaWAN is a flagship Low-Power Wide Area Network (LPWAN) technology that has highly attracted much attention from the community in recent years. Many LoRaWAN end-devices, such as sensors or actuators, are expected not to be powered by the electricity grid; therefore, it is crucial to investigate the energy consumption of LoRaWAN. However, published works have only focused on this topic to a limited extent. In this paper, we present analytical models that allow the characterization of LoRaWAN end-device current consumption, lifetime and energy cost of data delivery. The models, which have been derived based on measurements on a currently prevalent LoRaWAN hardware platform, allow us to quantify the impact of relevant physical and Medium Access Control (MAC) layer LoRaWAN parameters and mechanisms, as well as Bit Error Rate (BER) and collisions, on energy performance. Among others, evaluation results show that an appropriately configured LoRaWAN end-device platform powered by a battery of 2400 mAh can achieve a 1-year lifetime while sending one message every 5 min, and an asymptotic theoretical lifetime of 6 years for infrequent communication.