Cubesat constellation in LEO for air navigation monitoring

This project’s aim is to design a Matlab simulator capable of representing satellite constellations in Low Earth Orbits with the mission of monitoring air navigation trajectories. The objective is to create a tool capable of visually simulate the distribution of satellites in space along with the communication links between satellites, ground stations and aircraft. The aerospace industry is one of the most technologically and economically powerful in the world. This sector has evolved and grown exponentially in recent years thanks to the many applications it offers. In addition, the arrival of the New Space initiative has brought a new paradigm to the aerospace market, which has promoted the use of cubesats in LEO for telecommunication purposes. Furthermore, air transportation is one of the means of mobility that moves more passengers worldwide. Therefore, it is crucial to have the necessary elements to ensure constant and global coverage of air traffic, with the aim of improving the efficiency and safety of aircraft tracking. For the construction of the constellations, an analysis of the Walker pattern has been carried out. This methodology distributes the satellites symmetrically around a celestial body, providing global coverage. In addition, the effect of the different orbital parameters on the operation of the constellation has been studied. Finally, the structure of the ground segment required for the optimal performance of the mission has also been defined. The simulator designed in this thesis allows the user to create customized satellite configurations and visually represent the connections between the different objects in the defined scenario. The obtained result is able to perform a 3D representation of the orbits of the satellites, the ground stations network and the aircraft’s flight trajectory. Moreover, visibility intervals and communication links between satellites and antennas, and between satellites and aircraft are calculated. In addition, the simulator illustrates the efficiency of the constellation defined by the user taking into account the visibility with the aircraft through the entire flight route

Effect of Stress, Emotional Lability and Depression on the Development of Pregnancy Complications

Chronic stress and other emotional factors may have relevant impacts on pregnancy outcomes because they are related to neuroendocrine changes that lead to alterations in immunomodulation during pregnancy. In this quantitative prospective cross-sectional study, the relationship of emotional lability, depression, and stress during pregnancy and the development of preterm labor, preeclampsia, placental abruption, and low birth weight for gestational age babies was examined. Additionally, social support scores were compared to levels of stress/anxiety, depression, and emotional lability in pregnant women. Two hundred and forty two pregnant women who received prenatal services at the National Institute of Perinatology in Mexico City were evaluated during the 2nd or 3rd trimester of pregnancy and followed until pregnancy termination. Logistic regression analyses showed that being single significantly predicted preeclampsia and preterm birth, and the presence of social support significantly decreased the likelihood of preterm birth development. In the logistic regression model, family income significantly predicted the development of abruptio placentae. MANCOVA results revealed a significant difference among the social support categories on the combined dependent variables (stress/anxiety, depression, and emotional lability). The ANCOVA reported significant differences between social support scores, and stress/anxiety and depression scores. ANCOVA also showed significant differences between the number of pregnancies and stress scores. A 2X2 factorial analysis of variance showed a significant main effect of stress and depression on newborn weight. By promoting awareness of the importance of emotional factors during pregnancy among healthcare workers and pregnant women, this study contributed to positive social change

Arthritis in acute febrile neutrophilic dermatosis (Sweet's Syndrome)

Sir: Acute febrile neutrophilic dermatosis or Sweet's syndrome' is an uncommon condition characterised by fever, polymorphonuclear leucocytosis, painful erythematous cutaneous plaques, and a dense dermal infiltrate of neutrophils without vasculitis at the site of the skin lesions. Although many investigators suggest that acute febrile neutrophilic dermatosis is a hypersensitivity reaction,2 no defmitive cause is known. The role of the neutrophil as a cause or effect in this syndrome has not been clarified. Acute febrile neutrophilic dermatosis is histologically and clinically mimicked by several disorders, and the differential diagnosis with pyoderma gangrenosum3 and with some reactive erythemas such as erythema multiforme2 is usually difficult

Imatinib and dasatinib as salvage therapy for sclerotic chronic graft-vs-host disease.

Aim To assess the toxicity, tolerance, steroid-sparing capacity, effectiveness, and response rate to imatinib and dasatinib for the treatment of severe sclerotic chronic graft-vs-host disease (scGVHD). Methods This retrospective study analyzed 8 consecutive patients with severe refractory scGVHD who received salvage therapy with imatinib. Patients intolerant and/or refractory to imatinib received dasatinib treatment. Results 7 patients discontinued imatinib treatment (1 achieved complete response, 5 were resistant and/or intolerant, and 1 developed grade IV neutropenia) and 1 patient achieved prolonged partial response, but died due to an infectious complication while on treatment 5 patients started dasatinib treatment (3 achieved partial responses and discontinued dasatinib, 1 achieved a durable partial response, but died due to a consecutive rapid pulmonary cGVHD progression and 1 with stable disease discontinued treatment due to gastroenteric intolerance). The response rate (partial and/or complete responses) for severe scGVHD was 25% for imatinib and 60% for dasatinib. Conclusion In our series, dasatinib was better tolerated, safer, steroid-sparing, and had a low incidence of infectious complications, which suggests that it may be a more effective therapeutic alternative for patients with refractory scGVHD than imatinib. Treatment of scGVHD with effective antifibrotic drugs such as TKI, which block the kinase fibrotic pathway, may be a safe and effective therapeutic option, but further studies are needed to confirm our findings

Methylation status of the p15, p16 and MGMT promoter genes in primary cutaneous T-cell lymphomas

p15(INK4b), p16(INK4a) and O(6)-methylguanine DNA methyltransferase (MGMT) gene hypermethylation was studied in 22 patients with primary cutaneous T-cell lymphomas (CTCL). p15(INK4b) and p16(INK4a) inactivation is present in early and advanced disease and seems to be independent of disease stage. MGMT inactivation may play a pathogenetic role in a subset of CTCL

Absence of MALT1 traslocation in primary cutaneous marginal zone B-cell lymphoma

The implication of MALT1 gene in the pathogenesis of primary cutaneous marginal zone B-cell lymphomas (PCMZL) has been a matter of controversy. We examined the presence of MALT1 translocations in a series of 23 PCMZL. FISH assay with a MALT1 dual color break apart translocation probe revealed the absence of MALT1 translocations in all cases

Effects of Conjugated Linoleic Acid and Metformin on Insulin Sensitivity in Obese Children: Randomized Clinical Trial

Context: Insulin resistance precedes metabolic syndrome abnormalities and may promote cardiovascular disease and type 2 diabetes in children with obesity. Results of lifestyle modification programs have been discouraging, and the use of adjuvant strategies has been necessary. Objective: This study aimed to evaluate the effects of metformin and conjugated linoleic acid (CLA) on insulin sensitivity, measured via euglycemic-hyperinsulinemic clamp technique and insulin pathway expression molecules in muscle biopsies of children with obesity. Design: A randomized, double-blinded, placebo-controlled clinical trial was conducted. Setting: Children with obesity were randomly assigned to receive metformin, CLA, or placebo. Results: Intervention had a positive effect in all groups. For insulin sensitivity Rd value (mg/kg/min), there was a statistically significant difference between the CLA vs placebo (6.53 ± 2.54 vs 5.05 ± 1.46, P = 0.035). Insulinemia and homeostatic model assessment of insulin resistance significantly improved in the CLA group (P = 0.045). After analysis of covariance was performed and the influence of body mass index, age, Tanner stage, prescribed diet, and fitness achievement was controlled, a clinically relevant effect size on insulin sensitivity remained evident in the CLA group (37%) and exceeded lifestyle program benefits. Moreover, upregulated expression of the insulin receptor substrate 2 was evident in muscle biopsies of the CLA group. Conclusions: Improvement of insulin sensitivity, measured via euglycemic-hyperinsulinemic clamp and IRS2 upregulation, favored patients treated with CLA. Trial registration: ClinicalTrials.gov NCT02063802

Lymphomatoid papulosis associated with mycosis fungoides. A clinicopathological and molecular study of 12 cases

The association of mycosis fungoides and a primary cutaneous CD30+ lymphoproliferative disorder has been reported and probably represents different clinical aspects of a unique T-cell monoclonal expansion. In this study, 12 patients (6 men and 6 women) presented with lymphomatoid papulosis and mycosis fungoides. A TCRgamma gene rearrangement study was performed by an automated high-resolution PCR fragment analysis method on skin biopsy specimens taken from the different clinical lesions in each patient. An indolent clinical course was observed in the majority of patients. T-cell clonality was identified in 7 of 12 lymphomatoid papulosis lesions (58%) and in 6 skin biopsies of plaque stage mycosis fungoides (50%). In each individual case, where T-cell clonality was detected, both mycosis fungoides and lymphomatoid papulosis specimens exhibited an identical peak pattern by automated high-resolution PCR fragment analysis, confirming a common clonal origin. Only one case showed a clonal TCRgamma rearrangement from the lymphomatoid papulosis lesion, which could not be demonstrated in the mycosis fungoides specimen. The demonstration of an identical clone seems to confirm that both disorders are different clinical manifestations of a unique T-cell monoclonal proliferation. Our results also seem to confirm that the association of mycosis fungoides with a primary cutaneous CD30+ lymphoproliferative disorder usually carries a favourable prognosis