178 research outputs found

    Capture of UAVs through GPS spoofing using low-cost SDR platforms

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    The increased use of unmanned aerial vehicles (UAVs), better known as drones, by civilians has grown exponentially and their autonomous flight control systems have improved significantly, which has resulted in a greater number of accidents and dangerous situations. To help resolve this problem, in this paper, we address the use of low-cost Software Defined Radio (SDR) platforms for simulating a global navigation satellite system (GNSS), more specifically the global positioning system (GPS), in order to transmit false signals and induce a location error on the targeted GPS receiver. Using this approach, a defensive system can be implemented which can divert, or even take control of unauthorized UAVs whose flight path depends on the information obtained by the GPS system.info:eu-repo/semantics/acceptedVersio

    Effective GPS jamming techniques for UAVs using low-cost SDR platforms

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    Lately, a rising number of incidents between unmanned aerial vehicles (UAVs) and airplanes have been reported in airports and airfields. In order to help cope with the problem of unauthorized UAV operations, in this paper we evaluate the use of low cost SDR platforms (software defined radio) for the implementation of a jammer able to generate an effective interfering signal aimed at the GPS navigation system. Using a programmable BladeRF x40 platform from Nuand and the GNU radio software development toolkit, several interference techniques were studied and evaluated, considering the spectral efficiency, energy efficiency and complexity. It was shown that the tested approaches are capable of stopping the reliable reception of the radionavigation signal in real-life scenarios, neutralizing the capacity for autonomous operation of the vehicle.info:eu-repo/semantics/acceptedVersio

    A software defined radio based anti-UAV mobile system with jamming and spoofing capabilities

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    The number of incidents between unmanned aerial vehicles (UAVs) and aircrafts at airports and airfields has been increasing over the last years. To address the problem, in this paper we describe a portable system capable of protecting areas against unauthorized UAVs, which is based on the use of low-cost SDR (software defined radio) platforms. The proposed anti-UAV system supports target localization and integrates effective jamming techniques with the generation of global positioning system (GPS) spoofing signals aimed at the drone. Real-life tests of the implemented prototype have shown that the proposed approach is capable of stopping the reliable reception of radionavigation signals and can also divert or even take control of unauthorized UAVs, whose flight path depends on the information obtained by the GPS system.info:eu-repo/semantics/publishedVersio

    Cloud-based implementation of a SON radio resources planning system for mobile networks and integration in SaaS metric

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    In mobile network deployments of growing size, the optimum and fast planning of radio resources are a key task. Cloud services enable efficient and scalable implementation of procedures and algorithms. In this paper, a proof of concept implementation of a cloud-based network planning work pattern using Amazon Web Services (AWS) is presented, containing new and efficient radio resource planning algorithms for 3G, 4G and 5G systems. It extracts configuration and performance data from the network, enabling to accurately estimate cells coverage, identify neighboring cells and optimally plan scrambling codes (SCs) and physical cell identity (PCI) in 3G and 4G/5G networks, respectively. This implementation was integrated and is available in the commercial Metric Software-as-a-Service (SaaS) monitoring and planning tool. The cloud-based planning system is demonstrated in various canonical and realistic Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE) scenarios, and compared to an algorithm previously used by Metric. For a small LTE realistic scenario consisting of 9 sites and 23 cells, it takes less than 0.6 seconds to perform the planning. For an UMTS realistic scenario with 12 484 unplanned cells, the planning is efficiently achieved, taking less than 8 seconds, and guaranteeing no collisions between first order neighboring cells. The proposed concept is proved, as this system, capable of automatically planning 3/4/5G realistic networks of multi-vendor equipment, makes Metric more attractive to the market.info:eu-repo/semantics/publishedVersio

    Degree of psychological commitment to exercise in young athletes

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    The objective was to analyze the effects of affective, personal and demographic variables in the degree of psychological commitment to exercise (DPCE). 286 athletes aged between 10 and 19 years of both sexes participated in the study. We used the Commitment Exercise Scale, the Body Shape Questionnaire and the "Criterion of Economic Classification Brazil" to assess the DPCE, body dissatisfaction and socioeconomic status, respectively. The results showed significant effects for females (p = .001). These same analyzes for males showed no significant effects. It was concludedthat affective, personal and demographic factors promoted effects in DPCE only in females.El objetivo fue analizar los efectos de los variables afectivos, personales y demográficos en el grado de compromiso psicológico para ejercer (GCPE). 286 atletas de edades comprendidas entre 10 y 19 años de ambos sexos participaron en el estudio. Se utilizó la Commitment Exercise Scale, la Body Shape Questionnaire y el "Criterio de Clasificación Económica Brasil" para evaluar el GCPE, la insatisfacción corporal y nivel socioeconómico, respectivamente. Los resultados mostraron efectos significativos para las mujeres (p = .001). Estos mismos análisis para los machos no mostraron efectos significativos. Se concluyó que la afectiva, factores personales y demográficos promovió efectos en GPCE sólo en las mujeres.O objectivo foi analisar os efeitos das variáveis afectivas, pessoais e demográficas no grau de compromisso psicológico para exercer (GCPE). Participaram no estudo 286 atletas de idades compreendidas entre os 10 e os 19 anos de ambos os géneros. Foi utilizado o Commitment Exercise Scale, o Body Shape Questionnaire e o "Critério de Classificação Económica Brasil" para avaliar o GCPE, a insatisfação corporal e o nível socioeconómico, respetivamente. Os resultados revelaram efeitos significativos para as mulheres (p = .001). Estas mesmas análises não revelaram efeitos significativos nos homens. Conclui-se que a variável afectiva, os factores pessoais e demográficos promoveram efeitos no GCPE apenas nas mulheres

    Probability of At Least One High Arterial Blood Pressure Measurement in Elderly Patients with Healthy Vascular Aging in Two Years of Follow-Up

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    Background/Aims: Elderly patients with normal systemic arterial blood pressure associated with femoral carotid pulse velocity (cf-PWV) less than 7.6 m/s and without associated comorbidities are considered to have good vascular health. The aim of the current study was to verify the probability that elderly patients with good vascular health have at least one blood pressure measurement above the different thresholds for systolic blood pressure (120, 130 and 140 mmHg) during two years of follow–up. Methods: We selected 72 normotensive patients (< 140/90 mmHg) without comorbidities and divided them into group A, with cf-PWV < 7.6 m/s (n = 27; 65 ± 4 years), and group B, with cf-PWV ≥ 7.6 m/s (n = 45; 66± 8 years). These patients were followed for two years and were observed in 3 outpatient visits (0, 12 and 24 months). At each visit, the brachial pressures were indirectly measured in triplicate, and applanation tonometry was performed. Results: When group A and group B were compared, the odds ratio (OR) of having a systolic pressure measurement ≥ 140 mmHg in two years of follow-up was 0.22 (P < 0.0001); ≥ 130 mmHg, the OR was 0.49 (P < 0.0007), and ≥ 120 mmHg, the OR was 0.54 (P < 0.001). Group A and group B showed increased values of cf-PWV during the two years of follow-up (P < 0.05). Changes in the average systolic brachial pressure were not significant during the two years in groups A or B. Conclusion: Vascular health in elderly individuals seems to protect against occasional elevations in systemic arterial pressure

    Riggia cryptocularis (Crustacea: Cymothoidae) parasitizing three fish species in a hydroelectric dam

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    Introduction: Parasites play important roles in ecosystems, but can also create disturbances in the composition of host fauna in anthropogenic environments. Objective: Knowledge about these organisms can contribute to the conservation of diversity and environmental quality and prediction of disease risks. Methods: Parasites were collected from fish hosts in the Doce River (Claro River Basin, Middle Paranaíba) in areas of a small hydropower plant, following specific protocol and identified in the laboratory. Results: This is the first report of Riggia cryptocularis (Crustacea: Cymothoidae) parasitizing Hypostomus ancistroides, Leporinus friderici and Serrasalmus maculatus. Conclusion: The presence of this parasite in three fish species during the same sampling period and the severity of mutilation in the host suggest that the dam may favor a possible outbreak of the parasite R. cryptocularis due to changes introduced in the environment by the establishment of this type of project

    Impairment of Adenosinergic System in Rett syndrome: Novel Therapeutic Target to Boost BDNF Signalling

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    Rett syndrome (RTT; OMIM#312750) is mainly caused by mutations in the X-linked MECP2 gene (methyl-CpG-binding protein 2 gene; OMIM*300005), which leads to impairments in the brain-derived neurotrophic factor (BDNF) signalling. The boost of BDNF mediated effects would be a significant breakthrough but it has been hampered by the difficulty to administer BDNF to the central nervous system. Adenosine, an endogenous neuromodulator, may accomplish that role since through A2AR it potentiates BDNF synaptic actions in healthy animals. We thus characterized several hallmarks of the adenosinergic and BDNF signalling in RTT and explored whether A2AR activation could boost BDNF actions. For this study, the RTT animal model, the Mecp2 knockout (Mecp2-/y) (B6.129P2 (C)-Mecp2tm1.1Bird/J) mouse was used. Whenever possible, parallel data was also obtained from post-mortem brain samples from one RTT patient. Ex vivo extracellular recordings of field excitatory post-synaptic potentials in CA1 hippocampal area were performed to evaluate synaptic transmission and long-term potentiation (LTP). RT-PCR was used to assess mRNA levels and Western Blot or radioligand binding assays were performed to evaluate protein levels. Changes in cortical and hippocampal adenosine content were assessed by liquid chromatography with diode array detection (LC/DAD). Hippocampal ex vivo experiments revealed that the facilitatory actions of BDNF upon LTP is absent in Mecp2-/y mice and that TrkB full-length (TrkB-FL) receptor levels are significantly decreased. Extracts of the hippocampus and cortex of Mecp2-/y mice revealed less adenosine amount as well as less A2AR protein levels when compared to WT littermates, which may partially explain the deficits in adenosinergic tonus in these animals. Remarkably, the lack of BDNF effect on hippocampal LTP in Mecp2-/y mice was overcome by selective activation of A2AR with CGS21680. Overall, in Mecp2-/y mice there is an impairment on adenosinergic system and BDNF signalling. These findings set the stage for adenosine-based pharmacological therapeutic strategies for RTT, highlighting A2AR as a therapeutic target in this devastating pathology.info:eu-repo/semantics/publishedVersio

    Sustained NMDA receptor hypofunction impairs brain-derived neurotropic factor signalling in the PFC, but not in the hippocampus, and disturbs PFC-dependent cognition in mice

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    BACKGROUND: Cognitive deficits profoundly impact on the quality of life of patients with schizophrenia. Alterations in brain derived neurotrophic factor (BDNF) signalling, which regulates synaptic function through the activation of full-length tropomyosin-related kinase B receptors (TrkB-FL), are implicated in the aetiology of schizophrenia, as is N-methyl-D-aspartate receptor (NMDA-R) hypofunction. However, whether NMDA-R hypofunction contributes to the disrupted BDNF signalling seen in patients remains unknown. AIMS: The purpose of this study was to characterise BDNF signalling and function in a preclinical rodent model relevant to schizophrenia induced by prolonged NMDA-R hypofunction. METHODS: Using the subchronic phencyclidine (PCP) model, we performed electrophysiology approaches, molecular characterisation and behavioural analysis. RESULTS: The data showed that prolonged NMDA-R antagonism, induced by subchronic PCP treatment, impairs long-term potentiation (LTP) and the facilitatory effect of BDNF upon LTP in the medial prefrontal cortex (PFC) of adult mice. Additionally, TrkB-FL receptor expression is decreased in the PFC of these animals. By contrast, these changes were not present in the hippocampus of PCP-treated mice. Moreover, BDNF levels were not altered in the hippocampus or PFC of PCP-treated mice. Interestingly, these observations are paralleled by impaired performance in PFC-dependent cognitive tests in mice treated with PCP. CONCLUSIONS: Overall, these data suggest that NMDA-R hypofunction induces dysfunctional BDNF signalling in the PFC, but not in the hippocampus, which may contribute to the PFC-dependent cognitive deficits seen in the subchronic PCP model. Additionally, these data suggest that targeting BDNF signalling may be a mechanism to improve PFC-dependent cognitive dysfunction in schizophrenia
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