A Performance Analysis of the IRIDIUM Low Earth Orbit Satellite System

This thesis provides a performance evaluation of the IRIDIUM Low Earth Orbit Satellite system. It examines the system\u27s ability to meet real time communications constraints with a degraded satellite constellation. The analysis is conducted via computer simulation. The simulation is run at low, medium, and high loading levels with both uniform and non-uniform traffic distributions. An algorithmic approach is used to select critical satellites to remove from the constellation. Each combination of loading level and traffic distribution is analyzed with zero, three, five and seven non-operational satellites. The measured outputs are end-to-end packet delay and packet rejection rate. In addition to the delay analysis, a user\u27s ability to access the network with a degraded satellite constellation is evaluated. The average number of visible satellites, cumulative outage time, and maximum continuous outage time are analyzed for both an Equatorial city and a North American city. The results demonstrate that the IRIDIUM network is capable of meeting real-time communication requirements with several non-operational satellites. Both the high loading level and the non-uniform traffic distribution have a significant effect on the network\u27s performance. The analysis of both network delay performance and network access provides a good measure of the overall network performance with a degraded satellite constellation

Exercises for word analysis in grade II.

Thesis (Ed.M.)--Boston University N.B.: the following pages are missing: cover page; pages 374-376 at end of text

Mapa geoelafológico vial de la Provincia de Buenos Aires, 1° parte

Este estudio tiene por finalidad el conocimiento integral de las rasantes naturales que cubren la Provincia de Buenos Aires, mediante. la investigación sistemática de las características físicas, mecánicas y mineralógicas de los suelos que se determinan como "tipo", estableciéndose con tales, a aquellos que regionalmente representan las propiedades técnicas derivadas de su génesis sobre determinadas formaciones geológicas. Sobre la base de la distribución de estos suelos tipo se ha construido el mapa correspondiente a asta primera etapa, que comprende como- límite NE la costa Paraná-Río de La Plata, de Campana a Magdalena y una línea que une los pueblos de San Antonio de Are- co, Mercedes, Navarro y General Belgrano, como límite SO. Los correspondientes al NO y SE están dados por las líneas San Antonio de Areco - Campana y Magdalena - General Belgrano respectivamente.The object of this paper is to acknowledge about the nature of sub-grade of the Province of Buenos Aires, through the sistematic investigation of the physical, mechanical and mineralogical properties of the typical soils. These are types of soils which represent the regional variations derived from the genesis over some special geologic formations. The distribution of these types of soils has allowed the construction of a map of the region delimitated by the Parana - Río de La Plata basin between Campana and Magdalena at NE, and a line through San Antonio de Areco, Mercedes, Navarro and General Belgrano at SW. At NW by the line Campana, San Antonio de Areco and at SE by Magdalena - General Belgran

PO-0803: Validation of a pre-treatment delivery quality assurance method for the CyberKnife Synchrony System

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Fossil fuel and the global energy transition: regulation and standardisation as panacea for a more sustainable world energy order / O combustível fóssil e a transição energética global: regulação e normalização como panaceia para uma ordem energética mundial mais sustentável

The transition from fossil fuels to more sustainable sources of energy has become a topical issue that is likely to remain in the front burner of stakeholders as governments and businesses gradually move towards low-carbon economies. This move has been partly accelerated by the need to combat climate change and greenhouse gases (GHG). The move towards more sustainable energy sources has led to an upsurge in the number of international mechanisms such as the 2015 Paris Agreement on Climate Change (COP 15) (and a plethora of regional and domestic initiatives). Regulations and standardisation have been identified as strategic tools that can play critical roles in the drive towards energy transition. Regulation in this context refers to laws or other form of instruments with legal backing and having cohesiveness, while Standardisation entails the voluntary process of developing technical specifications based on consensus among stakeholders. The focus of this paper is how these two strategic tools interact and how they can be used to, enhance creativity, and further accelerate the drive towards energy transition and therefore more sustainable sources of energy.

Second cancer risk and mortality in men treated with radiotherapy for stage I seminoma

BACKGROUND: Patients with stage I testicular seminoma are typically diagnosed at a young age and treatment is associated with low relapse and mortality rates. The long-term risks of adjuvant radiotherapy in this patient group are therefore particularly relevant. METHODS: We identified patients and obtained treatment details from 12 cancer centres (11 United Kingdom, 1 Norway) and ascertained second cancers and mortality through national registries. Data from 2629 seminoma patients treated with radiotherapy between 1960 and 1992 were available, contributing 51,151 person-years of follow-up. RESULTS: Four hundred and sixty-eight second cancers (excluding non-melanoma skin cancers) were identified. The standardised incidence ratio (SIR) was 1.61 (95% confidence interval (CI): 1.47-1.76, P<0.0001). The SIR was 1.53 (95% CI: 1.39-1.68, P<0.0001) when the 32 second testicular cancers were also excluded. This increase was largely due to an excess risk to organs in the radiation field; for pelvic-abdominal sites the SIR was 1.62 (95% CI: 1.43-1.83), with no significant elevated risk of cancers in organs elsewhere. There was no overall increase in mortality with a standardised mortality ratio (SMR) of 1.06 (95% CI: 0.98-1.14), despite an increase in the cancer-specific mortality (excluding testicular cancer deaths) SMR of 1.46 (95% CI: 1.30-1.65, P<0.0001). CONCLUSION: The prognosis of stage I seminoma is excellent and it is important to avoid conferring long-term increased risk of iatrogenic disease such as radiation-associated second cancers

energy demand hourly simulations and energy saving strategies in greenhouses for the mediterranean climate

This research has been devoted to the selection of the most favourable plant solutions for ventilation, heating and cooling, thermo-hygrometric control of a greenhouse, in the framework of the energy saving and the environmental protection. The identified plant solutions include shading of glazing surfaces, natural ventilation by means of controlled opening windows, forced convection of external air and forced convection of air treated by the HVAC system for both heating and cooling. The selected solution combines HVAC system to a Ground Coupled Heat Pump (GCHP), which is an innovative renewable technology applied to greenhouse buildings. The energy demand and thermal loads of the greenhouse to fulfil the requested internal design conditions have been evaluated through an hourly numerical simulation, using the Energy Plus (E-plus) software. The overall heat balance of the greenhouse also includes the latent heat exchange due to crop evapotranspiration, accounted through an original iterative calculation procedure that combines the E-plus dynamic simulations and the FAO Penman-Monteith method. The obtained hourly thermal loads have been used to size the borehole field for the geothermal heat pump by using a dedicated GCHP hourly simulation tool

Combining functional metagenomics and glycoanalytics to identify enzymes that facilitate structural characterization of sulfated N-glycans

Abstract Background Sulfate modification of N-glycans is important for several biological functions such as clearance of pituitary hormones or immunoregulation. Yet, the prevalence of this N-glycan modification and its functions remain largely unexplored. Characterization of N-glycans bearing sulfate modifications is hampered in part by a lack of enzymes that enable site-specific detection of N-glycan sulfation. In this study, we used functional metagenomic screening to identify enzymes that act upon sulfated N-acetylglucosamine (GlcNAc). Using multiplexed capillary gel electrophoresis with laser-induced fluorescence detection (xCGE-LIF) -based glycoanalysis we proved their ability to act upon GlcNAc-6-SO4 on N-glycans. Results Our screen identified a sugar-specific sulfatase that specifically removes sulfate from GlcNAc-6-SO4 when it is in a terminal position on an N-glycan. Additionally, in the absence of calcium, this sulfatase binds to the sulfated glycan but does not remove the sulfate group, suggesting it could be used for selective isolation of sulfated N-glycans. Further, we describe isolation of a sulfate-dependent hexosaminidase that removes intact GlcNAc-6-SO4 (but not asulfated GlcNAc) from a terminal position on N-glycans. Finally, the use of these enzymes to detect the presence of sulfated N-glycans by xCGE-LIF is demonstrated. Conclusion The present study demonstrates the feasibility of using functional metagenomic screening combined with glycoanalytics to discover enzymes that act upon chemical modifications of glycans. The discovered enzymes represent new specificities that can help resolve the presence of GlcNAc-6-SO4 in N-glycan structural analyses

Technical performance and diagnostic utility of the new Elecsys (R) neuron-specific enolase enzyme immunoassay

This international multicenter study was designed to evaluate the technical performance of the new double-monoclonal, single-step Elecsys neuron-specific enolase (NSE) enzyme immunoassay (EIA) and to assess its utility as a sensitive and specific test for the diagnosis of small-cell lung cancer (SCLC). Intra and interassay coefficients of variation, determined in five control or serum specimens in six laboratories, ranged from 0.7 to 5.3 (interlaboratory median: 1.3%) and from 1.3 to 8.5 (interlaboratory median: 3.4%), respectively. Laboratory-to-laboratory comparability was excellent with respect to recovery and interassay coefficients of variation. The test was linear between 0.0 and 320 ng/ml (highest measured concentration). There was a significant correlation between NSE concentrations measured using the Elecsys NSE and the established Cobas Core NSE EIA II in all subjects (n=723) and in patients with lung cancer (n=333). However, NSE concentrations were systematically lower (approximately 9%) with the Elecsys NSE than with the comparison test. Based on a specificity of 95% in comparison with the group suffering from benign lung diseases (n=183), the cutoff value for the discrimination between malignant and benign conditions was set at 21.6 ng/ml. NSE was raised in 73.4% of SCLC patients (n=188) and was significantly higher (p&lt;0.01) in extensive (87.8%) as opposed to limited disease (56.7%). NSE was also elevated in 16.0% of the cases with non-small cell lung cancer (NSCLC, n=374). It is concluded that the Elecsys NSE EIA is a reliable and accurate diagnostic procedure for the measurement of NSE in serum samples. The special merits of this new assay are the wide measuring range (according to manufacturers declaration up to 370 ng/ml) and a short incubation time of 18 min