Passive Synthetic Aperture Radar Imaging Using Commercial OFDM Communication Networks

Modern communication systems provide myriad opportunities for passive radar applications. OFDM is a popular waveform used widely in wireless communication networks today. Understanding the structure of these networks becomes critical in future passive radar systems design and concept development. This research develops collection and signal processing models to produce passive SAR ground images using OFDM communication networks. The OFDM-based WiMAX network is selected as a relevant example and is evaluated as a viable source for radar ground imaging. The monostatic and bistatic phase history models for OFDM are derived and validated with experimental single dimensional data. An airborne passive collection model is defined and signal processing approaches are proposed providing practical solutions to passive SAR imaging scenarios. Finally, experimental SAR images using general OFDM and WiMAX waveforms are shown to validate the overarching signal processing concept

Peritoneal carcinomatosis from a small bowel carcinoid tumour

BACKGROUND: Peritoneal carcinomatosis from a gastrointestinal carcinoid tumour is rare and the long-term management and prognosis have not been clearly defined. The natural history is different from gastrointestinal adenocarcinoma, although its capacity to invade regional lymph nodes and generate distal metastasis can make the management more complex. Whilst the development of carcinomatosis is uncommonly reported, it may be higher than expected. CASE PRESENTATION: A 63 years-old woman underwent emergency surgery in 1993 for right iliac fossa pain and a mass that was found to be an ileal carcinoid tumour. Over the next ten years, further surgery was required for disseminated disease with peritoneal carcinomatosis and liver metastasis. Systemic chemotherapy had little effect, although Somatostatin was used effectively to relieve symptoms caused by the disseminated disease (flushing and diarrhoea). CONCLUSION: Peritoneal carcinomatosis from carcinoid tumours is not well documented in the literature. Aggressive surgery must be performed in order to control the disease since chemotherapy has not been reported to be effective. With repeated surgery long-term survival can be achieved in these patients

Modelling the balance of care:Impact of an evidence-informed policy on a mental health ecosystem

Major efforts worldwide have been made to provide balanced Mental Health (MH) care. Any integrated MH ecosystem includes hospital and community-based care, highlighting the role of outpatient care in reducing relapses and readmissions. This study aimed (i) to identify potential expert-based causal relationships between inpatient and outpatient care variables, (ii) to assess them by using statistical procedures, and finally (iii) to assess the potential impact of a specific policy enhancing the MH care balance on real ecosystem performance. Causal relationships (Bayesian network) between inpatient and outpatient care variables were defined by expert knowledge and confirmed by using multivariate linear regression (generalized least squares). Based on the Bayesian network and regression results, a decision support system that combines data envelopment analysis, Monte Carlo simulation and fuzzy inference was used to assess the potential impact of the designed policy. As expected, there were strong statistical relationships between outpatient and inpatient care variables, which preliminarily confirmed their potential and a priori causal nature. The global impact of the proposed policy on the ecosystem was positive in terms of efficiency assessment, stability and entropy. To the best of our knowledge, this is the first study that formalized expert-based causal relationships between inpatient and outpatient care variables. These relationships, structured by a Bayesian network, can be used for designing evidence-informed policies trying to balance MH care provision. By integrating causal models and statistical analysis, decision support systems are useful tools to support evidence-informed planning and decision making, as they allow us to predict the potential impact of specific policies on the ecosystem prior to its real application, reducing the risk and considering the population’s needs and scientific findings

Geometry-Based Statistical Modeling of Non-WSSUS Mobile-to-Mobile Rayleigh Fading Channels

In this paper, we present a novel geometry-based statistical model for small-scale non-wide-sense stationary uncorrelated scattering (non-WSSUS) mobile-to-mobile (M2M) Rayleigh fading channels. The proposed model builds on the principles of plane wave propagation to capture the temporal evolution of the propagation delay and Doppler shift of the received multipath signal. This is different from existing non-WSSUS geometry-based statistical channel models, which are based on a spherical wave propagation approach, that in spite of being more realistic is more mathematically intricate. By considering an arbitrary geometrical configuration of the propagation area, we derive general expressions for the most important statistical quantities of nonstationary channels, such as the first-order probability density functions of the envelope and phase, the four-dimensional (4-D) time-frequency correlation function (TF-CF), local scattering function (LSF), and time-frequency-dependent delay and Doppler profiles. We also present an approximate closed-form expression of the channel's 4-D TF-CF for the particular case of the geometrical one-ring scattering model. The obtained results provide new theoretical insights into the correlation and spectral properties of non-WSSUS M2M Rayleigh fading channels.acceptedVersionnivå

Association of cortisol serum levels as a prognostic factor in threat of pre-term birth

Background: Prematurity is one of the leading causes of death in children. In Mexico there is a frequency of 12% of preterm birth and this leads to significant maternal-fetal complications comprising 31.5% of neonatal morbidity and mortality. The patient who receives obstetric care in the gynecology service at the naval medical center requires prevention, diagnosis and treatment of threat of preterm birth to reduce perinatal and neonatal complications. Serum cortisol levels was determined as a prognostic factor for the threat of preterm birth in patients with obstetric care at the Naval Medical Center, it is a relatively easy parameter to obtain and would support a timely treatment.Methods: We used a quantitative, non-experimental, retrospective descriptive study of 30 patients with risk factors to develop preterm birth threats in gynecology service of the naval medical center from January to December 2018, which were taken 3 milliliters of peripheral blood to measure serum cortisol concentrations for later analysis. For statistical analysis of the present study, it was used Shapiro Wilk test. Likewise, Pearson's test was performed to measure the degree of association between the dependent and independent variable. Student's t-test was implemented to compare cortisol levels of pregnant women.Results: A total of 30 patients of these were analyzed, the mean age was 30.4 years (SD±5.184). The gestation weeks the average value was 30.63 weeks (SD±4.781). A student t test was performed where the cortisol values of pregnant women were compared with an average value of 2,586 (95% CI 0.45-472) and a t value=2,476 and a p=0.019 lower value of the significance value of 0.05 rejecting the null hypothesis. Which indicates that cortisol levels can be used as a predictive marker of the threat of preterm birth, considering it as an independent factor for this situation to occur in pregnant patients. The variables of the cortisol level and the weeks of gestation Pearson=-0.061 and a significance of p=0.747 were correlated (there being no strong enough relationship between the study variables). Regarding the triggers, it is observed that the highest factor was for urinary tract infection 40% n=12, abnormal uterine activity 20% n=6, followed by premature membrane rupture 16.7% n=5.Conclusions: The risk factors associated with the threat of preterm birth can be multiple, encompassing them in three important areas such as socioeconomic, psycho-emotional and clinicopathological, of the latter, nine of which are most frequent in our population are urinary infection, abnormal uterine activity and premature rupture of membranes. Regarding the association of cortisol levels as a prognostic factor for the threat of preterm birth taking it into account as an independent factor, it can be concluded that it is not statistically significant, however, according to what is reported in the literature, It should be considered as one of the multiple risk factors, considering this timely premise to boost the development of new research in the field

Association between IL-18 gene polymorphisms and biopsy-proven giant cell arteritis

7 pages, 1 figure, 1 table.-- Research article.[Introduction] The objective was to investigate the potential implication of the IL18 gene promoter polymorphisms in the susceptibility to giant-cell arteritis (GCA).[Methods] In total, 212 patients diagnosed with biopsy-proven GCA were included in this study. DNA from patients and matched controls was obtained from peripheral blood. Samples were genotyped for the IL18-137 G>C (rs187238), the IL18-607 C>A (rs1946518), and the IL18-1297 T>C (rs360719) gene polymorphisms with polymerase chain reaction, by using a predesigned TaqMan allele discrimination assay.[Results] No significant association between the IL18-137 G>C polymorphism and GCA was found. However, the IL18 -607 allele A was significantly increased in GCA patients compared with controls (47.8% versus 40.9% in patients and controls respectively; P = 0.02; OR, 1.32; 95% CI, 1.04 to 1.69). It was due to an increased frequency of homozygosity for the IL18 -607 A/A genotype in patients with GCA (20.4%) compared with controls (13.4%) (IL18 -607 A/A versus IL18 -607 A/C plus IL18 -607 C/C genotypes: P = 0.04; OR, 1.59; 95% CI, 1.02 to 2.46). Also, the IL18-1297 allele C was significantly increased in GCA patients (30.7%) compared with controls (23.0%) (P = 0.003; OR, 1.48; 95% CI, 1.13 to 1.95). In this regard, an increased susceptibility to GCA was observed in individuals carrying the IL18-1297 C/C or the IL18-1297 C/T genotypes compared with those carrying the IL18-1297 T/T genotype (IL18-1297 C/C plus IL18-1297 T/C versus IL18-1297 T/T genotype in GCA patients compared with controls: P = 0.005; OR, 1.61; 95% CI, 1.15 to 2.25). We also found an additive effect of the IL18 -1297 and -607 polymorphisms with TLR4 Asp299Gly polymorphism. The OR for GCA was 1.95 for combinations of genotypes with one or two risk alleles, whereas carriers of three or more risk alleles have an OR of 3.7.[Conclusions] Our results show for the first time an implication of IL18 gene-promoter polymorphisms in the susceptibility to biopsy-proven GCA. In addition, an additive effect between the associated IL18 and TLR4 genetic variants was observed.This study was supported by a grant from Fondo de Investigaciones Sanitarias PI06-0024 (Spain) and in part by Junta de Andalucía, grupo CTS-180 (Spain). This work was partially supported by the RETICS Program, RD08/0075 (RIER), from Instituto de Salud Carlos III (ISCIII).Peer reviewe

A decision support system for assessing management interventions in a mental health ecosystem: The case of Bizkaia (Basque Country, Spain)

Evidence-informed strategic planning is a top priority in Mental Health (MH) due to the burden associated with this group of disorders and its societal costs. However, MH systems are highly complex, and decision support tools should follow a systems thinking approach that incorporates expert knowledge. The aim of this paper is to introduce a new Decision Support System (DSS) to improve knowledge on the health ecosystem, resource allocation and management in regional MH planning. The Efficient Decision Support-Mental Health (EDeS-MH) is a DSS that integrates an operational model to assess the Relative Technical Efficiency (RTE) of small health areas, a Monte-Carlo simulation engine (that carries out the Monte-Carlo simulation technique), a fuzzy inference engine prototype and basic statistics as well as system stability and entropy indicators. The stability indicator assesses the sensitivity of the model results due to data variations (derived from structural changes). The entropy indicator assesses the inner uncertainty of the results. RTE is multidimensional, that is, it was evaluated by using 15 variable combinations called scenarios. Each scenario, designed by experts in MH planning, has its own meaning based on different types of care. Three management interventions on the MH system in Bizkaia were analysed using key performance indicators of the service availability, placement capacity in day care, health care workforce capacity, and resource utilisation data of hospital and community care. The potential impact of these interventions has been assessed at both local and system levels. The system reacts positively to the proposals by a slight increase in its efficiency and stability (and its corresponding decrease in the entropy). However, depending on the analysed scenario, RTE, stability and entropy statistics can have a positive, neutral or negative behaviour. Using this information, decision makers can design new specific interventions/policies. EDeS-MH has been tested and face-validated in a real management situation in the Bizkaia MH system.The present research study is frameworked in the REFINEMENT Spain project (Project PI15/01986), funded by the Carlos III Health Institute (http://www.isciii.es/)

All Chronic Rhinosinusitis Endotype Clusters Demonstrate Improvement in Patient Reported and Clinical Outcome Measures after Endoscopic Sinus Surgery

Background It is unclear if chronic rhinosinusitis (CRS) endotypes show differential response to endoscopic sinus surgery (ESS). We explored mucus inflammatory cytokine expression in a cohort with CRS and associations with both patient-reported and clinically measured postoperative outcome measures. Methods Patients with CRS were prospectively recruited between 2016-2021 into a multi-center observational study. Mucus was collected from the olfactory cleft preoperatively and evaluated for 26 biomarkers using cluster analysis. Patient reported outcome measures included the Sino-Nasal Outcome Test (SNOT-22) and Questionnaire of Olfactory Dysfunction (QOD). Additional clinical measures of disease severity included Threshold, Discrimination, and Identification (TDI) scores using Sniffin’ Stick testing and Lund-Kennedy endoscopic scores (LKES). Results A total of 115 patients were clustered into type 2 inflammatory, non-type 2 inflammatory, non-inflammatory, and 2 indeterminate clusters based upon individual protein levels. Overall, the type 2 inflammatory cluster was found to report the highest mean improvement in both SNOT-22 (-28.3 [SD±16.2]) and TDI (6.5 [SD±7.9]) scores 6 months after ESS. However, all endotype clusters demonstrated improvement in all outcome measures after ESS on average, without statistically significant between-group differences in SNOT-22 (p = 0.738), QOD (p = 0.306), TDI (p = 0.358), or LKES (p = 0.514) measures. Conclusions All CRS endotype clusters respond favorably to surgery and show improvement in patient reported and objective outcome measures. Thus, ESS should be considered a more generalized CRS therapy, and benefits appear to not be limited to specific endotypes