Search

The carrier phase received at the receivers of the Global Positioning System (GPS) links is used to detect navigation data and to precisely determine the position, speed and time corresponding to the user's equipment. Therefore, subsystems for carrier phase tracking are crucial parts in all GPS receivers. When the propagation conditions are favorable, the method frequently used for phase tracking is based on Digital Phase-Locked Loop (DPLL)) and implemented through the discrete Costas loop operating under the modulated L1 carrier, in the case of a GPS receiver. This technique is quite simple, well known and very suitable for implementation in low-cost receivers. In this article, we revisit the traditional Costas loop design and point out some issues that affect the phase tracking performance of this loop. In order to overcome these problems, we propose some modifications to the traditional Costas loop. The resulting architecture presents better performance and complexity equivalent to the original loop. Another contribution of this work is the mathematical analysis to evaluate the performance of the new architecture when operating on an Additive White Gaussian Noise (AWGN) channel. Various results from computational simulations carried out with the two architectures, in different operating scenarios, including AWGN, dynamic stress and ionospheric scintillation are presented and discussed. We conclude that the new architecture outperforms the traditional Costas loop in terms of the variance of the estimated phase error, root mean squared error of the estimated phase and robustness to cycle-slip and loss of lock.

Abstract Background Cushing’s syndrome (CS) is associated with an hypercoagulable state and an increased risk of venous thromboembolism (VTE). Evidence-based guidelines on thromboprophylaxis strategies in patients with CS are currently lacking. We aimed to map the current clinical practice for thromboprophylaxis management in patients with CS across reference centers (RCs) of the European Reference Network on Rare Endocrine Conditions (Endo-ERN), which are endorsed specifically for the diagnosis and treatment of CS. Using the EU survey tool, a primary screening survey, and subsequently a secondary, more in-depth survey were developed. Results The majority of the RCs provided thromboprophylaxis to patients with CS (n = 23/25), although only one center had a standardized thromboprophylaxis protocol (n = 1/23). RCs most frequently started thromboprophylaxis from CS diagnosis onwards (n = 11/23), and the majority stopped thromboprophylaxis based on individual patient characteristics, rather than standardized treatment duration (n = 15/23). Factors influencing the initiation of thromboprophylaxis were ‘medical history of VTE’ (n = 15/23) and ‘severity of hypercortisolism’ (n = 15/23). Low-Molecular-Weight-Heparin was selected as the first-choice anticoagulant drug for thromboprophylaxis by all RCs (n = 23/23). Postoperatively, the majority of RCs reported ‘severe immobilization’ as an indication to start thromboprophylaxis in patients with CS (n = 15/25). Most RCs (n = 19/25) did not provide standardized testing for variables of hemostasis in the postoperative care of CS. Furthermore, the majority of the RCs provided preoperative medical treatment to patients with CS (n = 23/25). About half of these RCs (n = 12/23) took a previous VTE into account when starting preoperative medical treatment, and about two-thirds (n = 15/23) included ‘reduction of VTE risk’ as a goal of treatment. Conclusions There is a large practice variation regarding thromboprophylaxis management and perioperative medical treatment in patients with CS, even in Endo-ERN RCs. Randomized controlled trials are needed to establish the optimal prophylactic anticoagulant regimen, carefully balancing the increased risk of (perioperative) bleeding, and the presence of additional risk factors for thrombosis.

AbstractIntroduction It is estimated that 55% to 75% of individuals who experience a stroke have persistent impairment of the affected upper limb (UL) [1,2]. It is needed to identify training strategies allied with interactive systems for retraining motor function of the UL. Virtual reality (VR), using either immersive or nonimmersive technology, seems to be one of those promising strategies. Virtual reality allows patients to have close-to-reality experiences, providing them varied, engaging, and realistic experiences [3]. For the physiotherapist, the use of the interactive technologies is a challenge which can improve treatment adherence, allow new environments adapted to patient needs, abilities and goals, as well as different task options [4]. The objective of this analysis was to systematically review the benefits and limitations of VR towards motor recovery of upper limb in post-stroke population.Materials and methods Randomised controlled trials were researched in Pubmed and PEDro databases, between January 2009 and January 2019, using the following keywords: “Virtual reality”, “video games”, “upper limb” and “stroke”. We included articles that used immersive and nonimmersive technology in upper limb recovery after stroke, and which compared VR with others modalities We excluded all articles in which the patient received home based intervention or community rehabilitation programs. All included clinical trials had level of evidence equal or superior to 6 score, assessed by PEDro scale.Results Fifteen studies met the inclusion criteria. Only three studies considered immersive VR. The training of functional tasks appears to provide the greatest benefits in upper extremity function with improvements in joint range of motion, hand motor function, grip strength, and dexterity. Two studies indicated that long-term improvements persist at follow-up. None of the studies reported any significant adverse effects.Discussion and Conclusions There is moderate to high evidence that supports the beneficial effects of VR on stroke patient upper limb motor recovery. However, more studies are needed to determine what kind of VR systems are the most appropriate, particularly which ones may contribute or affect cortical reorganisation. It is also needed to identify the most adequate frequency, duration and intensity for the sessions.

Abstract Background Collecting data on the localization of users is a key issue for the MASK (Mobile Airways Sentinel networK: the Allergy Diary) App. Data anonymization is a method of sanitization for privacy. The European Commission’s Article 29 Working Party stated that geolocation information is personal data. To assess geolocation using the MASK method and to compare two anonymization methods in the MASK database to find an optimal privacy method. Methods Geolocation was studied for all people who used the Allergy Diary App from December 2015 to November 2017 and who reported medical outcomes. Two different anonymization methods have been evaluated: Noise addition (randomization) and k-anonymity (generalization). Results Ninety-three thousand one hundred and sixteen days of VAS were collected from 8535 users and 54,500 (58.5%) were geolocalized, corresponding to 5428 users. Noise addition was found to be less accurate than k-anonymity using MASK data to protect the users’ life privacy. Discussion k-anonymity is an acceptable method for the anonymization of MASK data and results can be used for other databases.

This systematic review explores the intersection of race, gender, and social class in the context of internationalization of higher education (IHE) research in Brazil. Historically, the development of the Brazilian educational system has responded to the elite's demands and reproduced Western-European values and knowledge. The exponential growth of IHE has led to increased scholarly interest in various interdisciplinary research areas, with a possible move in studies and practices from a neoliberal to a more critical, decolonial, and diverse perspective. This article aims to investigate to what extent Brazilian researchers have investigated the intersectionality of gender, race, and class in IHE. Using two scientific databases, the published between 2015 and 2022. The theoretical framework of intersectionality (Crenshaw, 2002; Collins & Bilge, 2021; Akotirene, 2019) is presented to help recognize the interaction of different social markers of inequalities in IHE. The results pointed to a small number of publications related to this theme and continuous interest in the Science without Borders (SwB) mobility program. A particularly privileged profile of participants in academic mobility programs across various higher education institutions (HEI) in Brazil demonstrated the need for planning and actions to understand the social, historical, and political aspects that perpetuate exclusions. Moreover, this review indicates the importance of addressing colonialism in social dynamics and recognizing the coloniality of power in language policies in IHE. It calls for further investigations that explore the intersections of social markers in IHE processes from a more politically engaged perspective.

Portland cement (OPC) production is one of the most contaminating greenhouse gas producing activities. In order to reduce OPC consumption, several alternatives are being assessed, and the use of pozzolanic material is one of them. This paper presents study on the reactivity of sugarcane bagasse ash (SCBA), a residue from sugarcane industry, as a pozzolanic material. In order to evaluate SCBA reactivity, it was mixed in pastes with hydrated lime and OPC, which were microstructurally characterised. These studies showed that SCBA presents some pozzolanic characteristics. Studies on mortars in which OPC was replaced by SCBA in the range 10–30% were also carried out. Replacement in the range 15–20% yielded the best behaviour in terms of compressive strength. Finally, it can be concluded this ash could be valorised despite its relative low pozzolanic reactivity.

Magnesium ferrite nanoparticles, with diameters around 25 nm, were synthesized by coprecipitation method. The magnetic properties indicate a superparamagnetic behaviour, with a maximum magnetization of 16.2 emu g−1, a coercive field of 22.1 Oe and a blocking temperature of 183.2 K. These MgFe2O4 nanoparticles were used to produce aqueous and solid magnetoliposomes, with sizes below 130 nm. The potential drug curcumin was successfully incorporated in these nanosystems, with high encapsulation efficiencies (above 89%). Interaction by fusion between both types of drug-loaded magnetoliposomes (with or without PEGylation) and models of biological membranes was demonstrated, using FRET or fluorescence quenching assays. These results point to future applications of magnetoliposomes containing MgFe2O4 nanoparticles in cancer therapy, allowing combined magnetic hyperthermia and chemotherapy.

In true social hymenopterans, such as many species of bees, wasps and all species of ants, the main characteristics are the overlapping of generations, the care with the offspring and the division of labor among the members of the colony. The first biological feature means that in a same moment there are groups of individuals, with variable ages, that execute different activities in the colony. In order to study the division of labor among the members of the colony, or to estimate the life span of these insects, or even to analyze any kind of behavior in non-social insects, it is necessary to know the exact age of each individual. For this reason, the insects must be identified soon after emergence. The identification of insects with numbers is an important technological improvement in behavioral studies, mainly in honeybee colonies. The aim of this scientific note is to describe an easy and cheaper technique for marking hymenopterans.