Galectin-3 immunodetection in follicular thyroid neoplasms: a prospective study on fine-needle aspiration samples

Fine-needle aspiration cytology, which is well established to be accurate for the diagnosis of thyroid cancer, may be inconclusive for the follicular thyroid neoplasms. As galectin-3 was suggested to be a marker of malignant thyrocytes, we investigated whether this protein might be helpful in the diagnosis of aspirates classified as undeterminate by cytology. After establishing an easy processing of aspirates for galectin-3 immunodetection, a series of aspirates categorised as benign (n=63), malignant (n=17) or undeterminate (n=34) was prospectively analysed for galectin-3. Only the patients with malignant or undeterminate lesions underwent surgery. Most lesions (86%) diagnosed as malignant by cytology or after surgery were positive for galectin-3. The majority of lesions (94%) classified as benign by cytology or after surgery was negative for galectin-3. The positive and negative predictive values were 83 and 95%, respectively. When focusing on the undeterminate lesions, the sensitivity and specificity were 75 and 90%, respectively, while the positive and negative predictive values were 82 and 87%, respectively. The specificity and the positive predictive value were higher (100%) when considering the percentage of stained cells. Altogether these results show that galectin-3 constitutes a useful marker in the diagnosis of thyroid lesions classified as undeterminate by conventional cytology

A Coupling Scheme for Direct Numerical Simulations with an Acoustic Solver

A code for direct numerical simulations (DNS) has been coupled with an acoustic solver for aeroacoustic applications. The DNS code is intended to compute the noise generation while the acoustic far-field is evaluated using the linearized Euler equations. Both codes run on different computers on which they show their best computational performance. As a test case, we show a pressure pulse emitting from the DNS domain and being propagated by the acoustic solver

Trace element mobility during sub-seafloor alteration of basaltic glass from ODP-Site 953 (off Gran Canaria)

Trace element concentrations of altered basaltic glass shards (layer silicates) and zeolites in volcaniclastic sediments drilled in the volcanic apron northeast of Gran Canaria during Ocean Drilling Program (ODP) leg 157 document variable element mobilities during low-temperature alteration processes in a marine environment. Clay minerals (saponite, montmorillonite, smectite) replacing volcanic glass particles are enriched in transition metals and rare earth elements (REE). The degree of retention of REE within the alteration products of the basaltic glass is correlated with the field strength of the cations. The high field-strength elements are preferentially retained or enriched in the alteration products by sorption through clay minerals. Most trace elements are enriched in a boundary layer close to the interface mineral–altered glass. This boundary layer has a key function for the physico-chemical conditions of the subsequent alteration process by providing a large reactive surface and by lowering the fluid permeability. The release of most elements is buffered by incorporation into secondary precipitates (sodium-rich zeolites, phillipsite, Fe- and Mn-oxides) as shown by calculated distribution coefficients between altered glasses and authigenic minerals. Chemical fluxes change from an open to a closed system behavior during prograde low-temperature alteration of volcaniclastic sediments with no significant trace metal flux from the sediment to the water column

A system design for space-based space surveillance

This paper presents the capabilities of a Space-Based Space Surveillance (SBSS) demonstration mission for Space Surveillance and Tracking (SST) based on a micro- satellite platform. The results have been produced in the frame of ESA’s "As sessment Study for Space Based Space Surveillance Demonstration Mission (Phase A) " performed by the Airbus DS consortium. Space Surveillance and Tracking is part of Space Situational Awareness (SSA) and covers the detection, tracking and cataloguing of spa ce debris and satellites. Derived SST services comprise a catalogue of these man-made objects, collision warning, detection and characterisation of in-orbit fragmentations, sub-catalogue debris characterisation, etc. The assessment of SBSS in an SST system architecture has shown that both an operational SBSS and also already a well - designed space-based demonstrator can provide substantial performance in terms of surveillance and tracking of beyond - LEO objects. Especially the early deployment of a demonstrator, possible by using standard equipment, could boost initial operating capability and create a self-maintained object catalogue. Unlike classical technology demonstration missions, the primary goal is the demonstration and optimisation of the functional elements in a complex end-to-end chain (mission planning, observation strategies, data acquisition, processing and fusion, etc.) until the final products can be offered to the users. The presented SBSS system concept takes the ESA SST System Requirements (derived within the ESA SSA Preparatory Program) into account and aims at fulfilling some of the SST core requirements in a stand-alone manner. The evaluation of the concept has shown that an according solution can be implemented with low technological effort and risk. The paper presents details of the system concept, candidate micro - satellite platforms, the observation strategy and the results of performance simulations for GEO coverage and cataloguing accurac

Space-based space surveillance and tracking demonstrator: mission and system design

This paper presents the capabilities of a Space-Based Space Surveillance (SBSS) demonstration mission for Space Surveillance and Tracking (SST) based on a micro-satellite platform. The results have been produced in the frame of ESA’s "Assessment Study for Space Based Space Surveillance Demonstration Mission" performed by the Airbus Defence and Space consortium. The assessment of SBSS in an SST system architecture has shown that both an operational SBSS and also already a well- designed space-based demonstrator can provide substantial performance in terms of surveillance and tracking of beyond-LEO objects. Especially the early deployment of a demonstrator, possible by using standard equipment, could boost initial operating capability and create a self-maintained object catalogue. Furthermore, unique statistical information about small-size LEO debris (mm size) can be collected in-situ. Unlike classical technology demonstration missions, the primary goal is the demonstration and optimisation of the functional elements in a complex end-to-end chain (mission planning, observation strategies, data acquisition, processing, etc.) until the final products can be offered to the users and with low technological effort and risk. The SBSS system concept takes the ESA SST System Requirements into account and aims at fulfilling SST core requirements in a stand-alone manner. Additionally, requirements for detection and characterisation of small-sizedLEO debris are considered. The paper presents details of the system concept, candidate micro-satellite platforms, the instrument design and the operational modes. Note that the detailed results of performance simulations for space debris coverage and cataloguing accuracy are presented in a separate paper “Capability of a Space-based Space Surveillance System to Detect and Track Objects in GEO, MEO and LEO Orbits” by J. Silha (AIUB) et al., IAC-14, A6, 1.1x25640

Capability of a space-based space surveillance system to detect and track objects in GEO, MEO and LEO orbits

In this paper we present the results from the coverage and the orbit determination accuracy simulations performed within the recently completed ESA study “Assessment Study for Space Based Space Surveillance (SBSS) Demonstration System” (Airbus Defence and Space consortium). This study consisted in investigating the capability of a space based optical sensor (SBSS) orbiting in low Earth orbit (LEO) to detect and track objects in GEO (geosynchronous orbit), MEO (medium Earth orbit) and LEO and to determinate and improve initial orbits from such observations. Space based systems may achieve better observation conditions than ground based sensors in terms of astrometric accuracy, detection coverage, and timeliness. The primary observation mode of the proposed SBSS demonstrator is GEO surveillance, i.e. the systematic search and detection of unknown and known objects. GEO orbits are specific and unique orbits from dynamical point of view. A space-based sensor may scan the whole GEO ring within one sidereal day if the orbit and pointing directions are chosen properly. For an efficient survey, our goal was to develop a leak-proof GEO fence strategy. Collaterally, we show that also MEO, LEO and other (GTO,Molniya, etc.) objects would be possible to observe by the system and for a considerable number of LEO objects to down to size of 1 cm we can obtain meaningful statistical data for improvement and validation of space debris environment model

Radar and optical sensor data fusion for orbital determination of HEO objects

The paper presents the results of a GSTP project led by GMV for ESA/ESOC to define and experimentally analyse orbit determination techniques for the cataloguing of objects in Highly Eccentric Orbits (HEO), such as the Geostationary Transfer Orbits (GTO) and Molniya-type orbits, using a combination, or fusion, of observations acquired by ground-based radars and optical telescopes. An experimental tracking campaign was scheduled and performed to test the evaluated concepts. Additionally, the needs of a future tracking network in terms of topology and sensors characteristics for the coverage of the population of HEO object were assessed and formulated. It is shown that acceptable orbit determination results for objects on eccentric orbits can only be expected when a longer arc of the orbit is covered with observations. As a result, the orbit determination of such objects would highly benefit from the combination of observations from optical telescopes and radars

The Use of Different Architectures and Streak Observations Algorithms to Detect Space Debris.

Modern society depends heavily on satellite infrastructure. However, Space becomes more and more congested by space debris from over 50 years of space activities. This growing threat in orbit must be monitored. The aim of the ESA GSTP activity „Optical In-Situ Monitor“ is to design and test a breadboard of a space-based space debris camera and to develop and test its end-to-end processing chain. The on-board processing functions will focus on the payload image processing in order to reduce the data volume (image segmentation for streak detection). The suitable technologies for the processing units will be described: the HPDP, an ARM-Cortex R5F processor and Microsemi’s RTG4 FPGA. For image processing, several algorithms were tested extensively: the CCSDS 122.0-B-1, the Boundary Tensor and the Differences Method. This paper shows the current state of the project and gives an overview of what activities still need to be tackled before finalisation. The final step of the project will be to decide which combination of processor-algorithm yields the best results