Wide-Field Infrared Survey Telescope and Starshade Formation Flying Dynamics at Sun-Earth L2

The formation flying of an occulter with a telescope at the Sun-Earth L2 (SEL2) Libration Point can be a challenging problem. A good knowledge of the Restricted Three Body Problem dynamics is required to understand how these two spacecraft interact with each other in the SEL2 unstable environment, and how other perturbations such as Solar Radiation Pressure (SRP) affect their mutual trajectories. This paper focuses on the transfer trajectories to achieve specific relative positions between two spacecraft as they fly in formation at SEL2, andanalyzes the relevance of SRP in this formation, using the Wide-Field Infrared Survey Telescope (WFIRST) and the Starshade occulter as an example. Given that WFIRST and Starshade have very different area-to-mass ratios, SRP will affect their motion in different ways, and their relative position can be key to reduce the V cost. In this paper we intend on providing an explanation on how the relative position between both spacecrafts affects the transfer V from one observation to the other using dynamical system theory and Floquet modes

Detección rápida de la adulteración de aceite de argán con aceites de fritura usando espectroscopía de fluorescencia inducida por láser combinada con herramientas quimiométricas

There is a contentious need for robust and rapid methodologies for maintaining the authenticity of foods. The aim of this study was to detect and quantify argan oil adulteration using Laser Induced Fluorescence (LIF) spectroscopy coupled with chemometric methods. Principal Component Analysis (PCA) and Partial Least Squares Regression (PLSR) were used to assess argan oil authenticity; PCA was used to classify samples according to their quality and the PLS model to determine the amount of adulterants in pure argan oil. The correlation coefficient of the obtained model was about 0.99, with Root Mean Square Error of Prediction (RMSEP) and Standard Error of Prediction (SEP) of 2%. This study demonstrated the feasibility of LIF spectroscopy combined with chemometric tools to identify adulterants in pure argan oil from a percentage of adulteration, of 0.35 % without the need to destruct samples.Existe una necesidad de metodologías sólidas y rápidas para determinar la autenticidad de los alimentos. El objetivo de este estudio es detectar y cuantificar la adulteración del aceite de argán mediante espectroscopia de fluorescencia inducida por láser (LIF) junto con métodos quimiométricos. Se utilizaron el análisis de componentes principales (PCA) y la regresión de mínimos cuadrados parciales (PLSR) para evaluar la autenticidad del aceite de argán. Se utilizó PCA para clasificar las muestras según su calidad y el modelo PLS se aprovechó para determinar la cantidad de adulterantes en el aceite de argán puro. El coeficiente de correlación del modelo obtenido fue de alrededor de 0,99, el error cuadrático medio de la predicción (RMSEP) y el error estándar de predicción (SEP) del 2%. Este estudio demostró la viabilidad de la espectroscopia LIF combinada con herramientas quimiométricas que permiten identificar adulterantes en aceite de argán puro, sin necesidad de destruir muestras, a partir de un porcentaje de adulteración del 0,35 %

Stereoselective syntheses of the antihistaminic drug olopatadine and its E-isomer

Practical stereoselective synthetic routes to the antihistaminic drug olopatadine and its E-isomer have been developed, the key steps being a trans stereoselective Wittig olefination using a nonstabilized phosphorus ylide and a stereoselective Heck cyclization. The stereoselectivity of the Wittig reaction depends on both the phosphonium salt anion and the cation present in the base used to generate the ylide

Primary bony non-Hodgkin lymphoma of the cervical spine: a case report

<p>Abstract</p> <p>Introduction</p> <p>Non-Hodgkin lymphoma primarily originating from the bone is exceedingly rare. To our knowledge, this is the first report of primary bone lymphoma presenting with progressive cord compression from an origin in the cervical spine. Herein, we discuss the unusual location in this case, the presenting symptoms, and the management of this disease.</p> <p>Case presentation</p> <p>We report on a 23-year-old Caucasian-American man who presented with two months of night sweats, fatigue, parasthesias, and progressive weakness that had progressed to near quadriplegia. Magnetic resonance (MR) imaging demonstrated significant cord compression seen primarily at C7. Surgical management, with corpectomy and dorsal segmental fusion, in combination with adjuvant chemotherapy and radiation therapy, halted the progression of the primary disease and preserved neurological function. Histological analysis demonstrated an aggressive anaplastic large cell lymphoma.</p> <p>Conclusion</p> <p>Isolated primary bony lymphoma of the spine is exceedingly rare. As in our case, the initial symptoms may be the result of progressive cervical cord compression. Anterior corpectomy with posterolateral decompression and fusion succeeded in preventing progressive neurologic decline and maintaining quality of life. The reader should be aware of the unique presentation of this disease and that surgical management is a successful treatment strategy.</p

Human neutrophils phagocytose and kill Acinetobacter baumanii and A. pittii

Acinetobacter baumannii is a common cause of health care associated infections worldwide. A. pittii is an opportunistic pathogen also frequently isolated from Acinetobacter infections other than those from A. baumannii. Knowledge of Acinetobacter virulence factors and their role in pathogenesis is scarce. Also, there are no detailed published reports on the interactions between A. pittii and human phagocytic cells. Using confocal laser and scanning electron microscopy, immunofluorescence, and live-cell imaging, our study shows that immediately after bacteria-cell contact, neutrophils rapidly and continuously engulf and kill bacteria during at least 4 hours of infection in vitro. After 3 h of infection, neutrophils start to release neutrophil extracellular traps (NETs) against Acinetobacter. DNA in NETs colocalizes well with human histone H3 and with the specific neutrophil elastase. We have observed that human neutrophils use large filopodia as cellular tentacles to sense local environment but also to detect and retain bacteria during phagocytosis. Furthermore, co-cultivation of neutrophils with human differentiated macrophages before infections shows that human neutrophils, but not macrophages, are key immune cells to control Acinetobacter. Although macrophages were largely activated by both bacterial species, they lack the phagocytic activity demonstrated by neutrophils

Solar sail station keeping of high-amplitude vertical Lyapunov orbits in Sun-Earth system

This paper studies the stability and controllability of a solar sail on displaced, high-amplitude vertical Lyapunov orbits in the Sun-Earth system. In previous works, it was found that these orbits could be used for quasi-continuous coverage of the poles of the Earth. However, these orbits are unstable and an active control is required to remain close to them. Here we describe the types of instabilities for various orbits in the vertical Lyapunov family, and then propose two different stationkeeping strategies. One based on a linear quadratic regulator, and the other on the Floquet multipliers. We have selected three orbits, with different characteristics, for this study. It results that both methods manage control the solar sail, in the vicinity of the nominal orbits, and a comparison of the control requirements and performances is presented

Solar sail station keeping of high-amplitude vertical Lyapunov orbits in Sun-Earth system

This paper studies the stability and controllability of a solar sail on displaced, high-amplitude vertical Lyapunov orbits in the Sun-Earth system. In previous works, it was found that these orbits could be used for quasi-continuous coverage of the poles of the Earth. However, these orbits are unstable and an active control is required to remain close to them. Here we describe the types of instabilities for various orbits in the vertical Lyapunov family, and then propose two different stationkeeping strategies. One based on a linear quadratic regulator, and the other on the Floquet multipliers. We have selected three orbits, with different characteristics, for this study. It results that both methods manage control the solar sail, in the vicinity of the nominal orbits, and a comparison of the control requirements and performances is presented

Management of splenic abscess in a critically ill patient

Because of the increased number of immunocompromised patients within the general population, the incidence of splenic abscesses has increased over the last decade. This cohort of immune-deficient patients with splenic abscesses engenders a distinct evolution in the pathogenesis and microbiology of the disease process. Moreover, the morbidity and mortality rates for splenic abscesses are increased in this unique population. Clinically, these patients do not have a characteristic presentation. Diagnostically, computed tomography of the abdomen is the test of choice. Antibiotics and splenectomy remain the standard of care in most clinical settings. However, percutaneous drainage is reported with solitary and unilocular abscesses and in poor operative candidates. An unusual case of a patient with a splenic abscess awaiting heart transplantation is presented. This patient was successfully treated with percutaneous drainage and antibiotics. The literature regarding the presentation, diagnosis, pathogenesis, and treatment of splenic abscesses is reviewed as well