Momentum Management Tool for Low-Thrust Missions

A momentum management tool was designed for the Dawn low-thrust interplanetary spacecraft en route to the asteroids Vesta and Ceres, in an effort to better understand the early creation of the solar system. Momentum must be managed to ensure the spacecraft has enough control authority to perform necessary turns and hold a fixed inertial attitude against external torques. Along with torques from solar pressure and gravity-gradients, ion-propulsion engines produce a torque about the thrust axis that must be countered by the four reaction wheel assemblies (RWA). MomProf is a ground operations tool built to address these concerns. The momentum management tool was developed during initial checkout and early cruise, and has been refined to accommodate a wide range of momentum-management issues. With every activity or sequence, wheel speeds and momentum state must be checked to avoid undesirable conditions and use of consumables. MomProf was developed to operate in the MATLAB environment. All data are loaded into MATLAB as a structure to provide consistent access to all inputs by individual functions within the tool. Used in its most basic application, the Dawn momentum tool uses the basic principle of angular momentum conservation, computing momentum in the body frame, and RWA wheel speeds, for all given orientations in the input file. MomProf was designed specifically to be able to handle the changing external torques and frequent de - saturations. Incorporating significant external torques adds complexity since there are various external torques that act under different operational modes

Evaluation of MU-MIMO Digital Beamforming Algorithms in B5G/6G LEO Satellite Systems

Satellite Communication (SatCom) systems will be a key component of 5G and 6G networks to achieve the goal of providing unlimited and ubiquitous communications and deploying smart and sustainable networks. To meet the ever-increasing demand for higher throughput in 5G and beyond, aggressive frequency reuse schemes (i.e., full frequency reuse), combined with digital beamforming techniques to cope with the massive co-channel interference, are recognized as a key solution. Aimed at (i) eliminating the joint optimization problem among the beamforming vectors of all users, (ii) splitting it into distinct ones, and (iii) finding a closed-form solution, we propose a beamforming algorithm based on maximizing the users' Signal-to-Leakage-and-Noise Ratio (SLNR) served by a Low Earth Orbit (LEO) satellite. We investigate and assess the performance of several beamforming algorithms, including both those based on Channel State Information (CSI) at the transmitter, i.e., Minimum Mean Square Error (MMSE) and Zero-Forcing (ZF), and those only requiring the users' locations, i.e., Switchable Multi-Beam (MB). Through a detailed numerical analysis, we provide a thorough comparison of the performance in terms of per-user achievable spectral efficiency of the aforementioned beamforming schemes, and we show that the proposed SLNR beamforming technique is able to outperform both MMSE and ZF schemes in the presented SatCom scenario

Evaluation of multi-user multiple-input multiple-output digital beamforming algorithms in B5G/6G low Earth orbit satellite systems

Satellite communication systems will be a key component of 5G and 6G networks to achieve the goal of providing unlimited and ubiquitous communications and deploying smart and sustainable networks. To meet the ever-increasing demand for higher throughput in 5G and beyond, aggressive frequency reuse schemes (i.e., full frequency reuse), combined with digital beamforming techniques to cope with the massive co-channel interference, are recognized as a key solution. Aimed at (i) eliminating the joint optimization problem among the beamforming vectors of all users, (ii) splitting it into distinct ones, and (iii) finding a closed-form solution, we propose a beamforming algorithm based on maximizing the users' signal-to-leakage-and-noise ratio served by a low Earth orbit satellite. We investigate and assess the performance of several beamforming algorithms, including both those based on channel state information at the transmitter, that is, minimum mean square error and zero forcing, and those only requiring the users' locations, that is, switchable multi-beam. Through a detailed numerical analysis, we provide a thorough comparison of the performance in terms of per-user achievable spectral efficiency of the aforementioned beamforming schemes, and we show that the proposed signal to-leakage-plus-noise ratio beamforming technique is able to outperform both minimum mean square error and multi-beam schemes in the presented satellite communication scenario

PEEK versus metal cages in posterior lumbar interbody fusion: a clinical and radiological comparative study

Background: Low back pain and sciatica represent a common disabling condition with a significant impact on the social, working and economic lives of patients. Transforaminal lumbar interbody fusion (TLIF) is a surgical procedure used in degenerative spine conditions. Several types of cages were used in the TLIF procedure. Purpose: To determine whether there is a difference in terms of symptomatology improvement, return to daily activities and fusion rate between metal cages and polyetheretherketone (PEEK) cages. Methods: We have retrospectively reviewed 40 patients who have undergone TLIF from October 2015 to May 2016. All patients were clinically evaluated with questionnaires and were assessed with CT scan and standing X-ray films of the full-length spine. Results: We found no significant functional differences in the two groups. At 1-year follow-up, osteolysis was present in 50% of cases of the PEEK cages and in 10% cases of the metal cages. The degree of fusion at 1 year was evaluated as complete in 40% cases of the metal cages and 15% cases of the PEEK cages. Conclusions: We have found a better fusion rate and prevalence of fusion in the group treated with metal cages, reflecting the well-known osteoinductive properties of titanium and tantalum

Febre Q: uma zoonose de distribuição mundial.

A febre Q é uma zoonose de distribuição mundial causada pelo patógeno Coxiella burnetii, uma bactéria que, além de apresentar resistência e estabilidade ambiental, é um dos agentes mais infecciosos ao ser humano. Sua principal forma de transmissão à população humana ocorre através da inalação de aerossóis contaminados com produtos de animais infectados, principalmente bovinos, caprinos e ovinos. A infecção em humanos apresenta um amplo espectro de manifestações, desde casos assintomáticos até complicações graves e fatais

Q fever: characteristics and reports ofanimportant neglected zoonosisin Brazil.

ABSTRACT - The Q fever is a zoonotic disease neglected in many countries all over the world. This zoonosis is caused by the bacteria Coxiella burnetii, a pathogen that presents stability and environmental resistance with high capacity to cause human infection, which could be fatal. This literature review study aims to describe the general aspects of Q fever, presenting the main cases occurred in Brazil and discussing ways to avoid this zoonosis negligence and underreporting in Brazil. The Q fever is still a disease unknown by the larger part of healthcare professionals in Brazil. In addition, the disease in humans presents a clinical picture similar to that of other acute feverish diseases. Therefore, cases of Q fever cannot be diagnosed and their treatment can be erroneous, which can increase the chances of chronic Q fever occurrence. The inclusion of Q fever as a disease of mandatory notification in humans and the utilization of the "One Health" approach are essential for the confrontation of the disease. Moreover, measures for the control, investigation, and prevention of Q fever will contribribute to avoid the occurrence of outbreaks and possible worsening resulting from this zoonosis. RESUMO - A febre Q é uma doença zoonótica negligenciada em muitos países do mundo. Essa zoonose é causada pela bactéria Coxiella burnetii, um patógeno que apresenta estabilidade e resistência ambiental com alta capacidade de causar infecção em humanos, podendo ser fatal. Este estudo de revisão da literatura tem como objetivo descrever os aspectos gerais da febre Q, apresentar os principais casos ocorridos no Brasil e discutir formas para que essa zoonose deixe de ser negligenciada e subnotificada no Brasil. A febre Q ainda é uma doença desconhecida por grande parte dos profissionais de saúde no Brasil. Aliado a isso, a doença em humanos apresenta um quadro clínico similar ao de outras doenças febris agudas. Dessa forma, casos de febre Q podem não estar sendo diagnosticados e sendo tratados de forma equivocada, o que pode aumentar as chances de ocorrência da febre Q crônica. A inclusão da febre Q como uma doença de notificação compulsória em humanos e a utilização da abordagem "One Health" são fundamentais para o enfrentamento da doença. Ademais, medidas de controle, de investigação e de prevenção da febre Q contribuirão para evitar a ocorrência de surtos e possíveis agravamentos decorrentes dessa zoonose

Impact of an educational intervention in the management of individuals with uncontrolled type 2 diabetes mellitus using insulin therapy.

Objective: To investigate the effects of problematizing intervention in the treatment of individuals with type 2 diabetes mellitus. Methodology: A randomized clinical trial was conducted in 41 patients ages 18 to 64 with type 2 diabetes who were treated with insulin and had glycosylated hemoglobin greater than 7.0%. The mean age of participants was 55.9 (SD = 5.49). A high percentage of patients had comorbidities such as hypertension (92.7%), dyslipidemia (68.3%), overweight (95%), retinopathy (41%), and neuropathy (39%). The patients in the intervention group participated in 6 educational groups using problematization methodology, whereas the patients in the control group attended only routine consultations. Sociodemographic, clinical, behavioral, and lifestyle variables were assessed. Results: After 6 months of follow-up, no statistically significant difference in glycemic control and anthropometric parameters was observed between participants in either study group. The intervention group showed an increase in knowledge about the disease, and an improvement in total cholesterol and uric acid levels. Conclusion: The use of a problematizing intervention provided an improvement in behavioral as well as specific clinical parameters, compared to routine diabetes care. However, longer follow-up time for these patients could bring benefits regarding glycemic control

The other side of recovery: validation of the Portuguese version of the subjective experiences of psychosis scale.

BACKGROUND: The aim of this study was to develop and validate a Portuguese version of The Subjective Experiences of Psychosis Scale (SEPS) for use in Portuguese-speaking populations in order to provide a self-report instrument to assess and monitor dimensions of psychotic experiences, translating patient's perspective and experience in terms of recovery from psychosis. METHODS: The sample consisted of 30 participants with psychotic disorders who had recently experienced delusions or hallucinations. The SEPS was completed along with other observer-based assessments and self-report questionnaires, such as the Brief Psychiatric Rating Scale, the Insight and Treatment Attitudes Questionnaire and the Function Assessment Short Test. RESULTS: Two main factors representing the positive and negative components of each subscale were identified. We obtained good internal consistency and test-retest reliability for the positive and negative components of all subscales. The subscales of SEPS correlated with observer-based assessments and self-report questionnaires. CONCLUSIONS: The Portuguese version of the SEPS is a useful tool in the assessment and monitoring of psychotic symptoms