13,501 research outputs found
Analyses of space environment effects on active fiber optic links orbited aboard the LDEF
The results of the 'Preliminary Analysis of WL Experiment no. 701, Space Environment Effects on Operating Fiber Optic Systems,' is correlated with space simulated post retrieval terrestrial studies performed on the M0004 experiment. Temperature cycling measurements were performed on the active optical data links for the purpose of assessing link signal to noise ratio and bit error rate performance some 69 months following the experiment deployment in low Earth orbit. The early results indicate a high correlation between pre-orbit, orbit, and post-orbit functionality of the first known and longest space demonstration of operating fiber optic systems
Sun, sea, sand and silicone: mapping cosmetic surgery tourism
This multi-site, mixed methods project charted the experiences of British, Chinese and Australian patients travelling abroad for cosmetic surgery. Cosmetic surgery tourism is a fast developing industry that incorporates novel forms of labour and organisational structures that cross national boundaries, as well as drawing together pre-existing medical and tourism infrastructure. While medical tourism has often been characterised as wealthy patients from the global south travelling to the global north for high quality medical treatment unavailable at home, cosmetic surgery patients often travel from global north to global south, but these patients are on modest incomes. Despite this they can sometimes access upmarket private hospitals beyond their reach back home, made possible by favourable currency rates, cheap flights and lower labour costs outside the richest countries in the world. UK and Australian patients travelled for surgeries that were popular back home – such as breast augmentation and uplift, ‘tummy tuck’, rhinoplasty and liposuction. Others travel regionally, for example within Europe, often also motivated by cost savings. There are important exceptions to this pattern: Chinese patients travelling to South Korea access more expensive but high quality cosmetic surgery unavailable back home. Here patients from abroad often seek particular types of surgery prevalent amongst South Koreans, for example eye or jawbone surgery, or high tech surgery, such as breast augmentation using the patient’s own fat and stem cells. Patients therefore travel from global north to global south, across regional borders, and many are also ex-patriates. UK patients in Spain were most usually already living in Southern Spain or Gibraltar. Monitoring the movements of cosmetic surgery tourists is important in predicting health tourism in the future. As public healthcare systems are increasingly squeezed, patients become consumers in search of cut price procedures, taking on the risks of the choices they make. This research aimed to broaden understandings of surgical tourist experiences, the organisations involved, and the implications for globalize
European cities in globalization: a comparative analysis based on the location strategies of advanced producer services
Today there is a key question that lurks behind any consideration of Europe and its cities: is this foundation core zone of the modern world-system showing symptoms of dropping out of the contemporary core zone? It certainly appears that in the period of crises since 2008, Europe has been falling behind other major world-regions. Dubbed the “austerity region” of the world, such an interpretation sees Europe as the first part of the world-economy core to be subject to what are effectively structural adjustment programmes, largely self-imposed but still resulting in a process of peripheralization. Although uneven in impact, this is clearly a result of Europe’s states failing to adequately manage and regulate the economic activities within their territories. However it is far too soon to say whether such a monumental global economic shift is happening but we can investigate the current unevenness of economic globalization amongst European states. We compare three of these states that represent different degrees of potential peripheralization: Spain showing the stronger symptoms, Germany with least symptoms, and Britain somewhere in between. Our study is based upon an original analysis of advanced producer services that combines comparisons between countries and relations between cities
Co2+ sorption capacity indicators of La Plata region´s soils. Insights and correlations with soil properties
Notwithstanding soil act as a pollutant sink, its Co sorption capacity presents still controversial results. Here, Co2+ sorption on soil samples from La Plata (Argentina) was analyzed. Four sorption indicators were used: Kdis (estimated from the entire sorption isotherm), KF1 (estimated from the lineal part of the sorption isotherm), Kdx, (solid-solution distribution coefficient) and Kr, a dimensionless parameter recently developed. Pearson correlation coefficients between the parameters and soil properties were calculated. Significant and negative correlations with silt were obtained, while significant and positive correlations were established with clay and smectite content. Soil clay fractions were isolated and Co2+ sorption was evaluated, observing relatively high removal. The correlations with kaolinite, magnetite and Mn and Fe oxides showed debatable results: Kdis could be more sensitive than Kr to magnetite variations while Kr seems to be more sensitive to Mn changes. KF1 presented similar behavior to Kr. The studied soils presented a high Co2+ sorption capacity, making them an effective barrier of this pollutant, avoiding its passage to groundwater and crops.Fil: Montes, María Luciana. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Fernandez M. A. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; ArgentinaFil: Brendle, J. Université Haute-alsace. Institut de Science Des Matériaux de Mulhouse.; FranciaFil: Michelin, L.. Université Haute-alsace. Institut de Science Des Matériaux de Mulhouse.; FranciaFil: Taylor, Marcela Andrea. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Torres Sanchez, Rosa Maria. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentin
Galaxy And Mass Assembly (GAMA): a deeper view of the mass, metallicity and SFR relationships
A full appreciation of the role played by gas metallicity (Z), star formation rate (SFR) and stellar mass (M*) is fundamental to understanding how galaxies form and evolve. The connections between these three parameters at different redshifts significantly affect galaxy evolution, and thus provide important constraints for galaxy evolution models. Using data from the Sloan Digital Sky Survey–Data Release 7 (SDSS–DR7) and the Galaxy and Mass Assembly (GAMA) surveys, we study the relationships and dependences between SFR, Z and M*, as well as the Fundamental Plane for star-forming galaxies. We combine both surveys using volume-limited samples up to a redshift of z ≈ 0.36. The GAMA and SDSS surveys complement each other when analysing the relationships between SFR, M* and Z. We present evidence for SFR and metallicity evolution to z ∼ 0.2. We study the dependences between SFR, M*, Z and specific SFR (SSFR) on the M*–Z, M*–SFR, M*–SSFR, Z–SFR and Z–SSFR relations, finding strong correlations between all. Based on those dependences, we propose a simple model that allows us to explain the different behaviour observed between low- and high-mass galaxies. Finally, our analysis allows us to confirm the existence of a Fundamental Plane, for which M* = f(Z, SFR) in star-forming galaxies
A Non-Natural Nucleotide Uses a Specific Pocket to Selectively Inhibit Telomerase Activity
Telomerase, a unique reverse transcriptase that specifically extends the ends of linear chromosomes, is up-regulated in the vast majority of cancer cells. Here, we show that an indole nucleotide analog, 5-methylcarboxyl-indolyl-2′-deoxyriboside 5′-triphosphate (5-MeCITP), functions as an inhibitor of telomerase activity. The crystal structure of 5-MeCITP bound to the Tribolium castaneum telomerase reverse transcriptase reveals an atypical interaction, in which the nucleobase is flipped in the active site. In this orientation, the methoxy group of 5-MeCITP extends out of the canonical active site to interact with a telomerase-specific hydrophobic pocket formed by motifs 1 and 2 in the fingers domain and T-motif in the RNA-binding domain of the telomerase reverse transcriptase. In vitro data show that 5-MeCITP inhibits telomerase with a similar potency as the clinically administered nucleoside analog reverse transcriptase inhibitor azidothymidine (AZT). In addition, cell-based studies show that treatment with the cell-permeable nucleoside counterpart of 5-MeCITP leads to telomere shortening in telomerase-positive cancer cells, while resulting in significantly lower cytotoxic effects in telomerase-negative cell lines when compared with AZT treatment
A Non-Natural Nucleotide Uses a Specific Pocket to Selectively Inhibit Telomerase Activity
Telomerase, a unique reverse transcriptase that specifically extends the ends of linear chromosomes, is up-regulated in the vast majority of cancer cells. Here, we show that an indole nucleotide analog, 5-methylcarboxyl-indolyl-2′-deoxyriboside 5′-triphosphate (5-MeCITP), functions as an inhibitor of telomerase activity. The crystal structure of 5-MeCITP bound to the Tribolium castaneum telomerase reverse transcriptase reveals an atypical interaction, in which the nucleobase is flipped in the active site. In this orientation, the methoxy group of 5-MeCITP extends out of the canonical active site to interact with a telomerase-specific hydrophobic pocket formed by motifs 1 and 2 in the fingers domain and T-motif in the RNA-binding domain of the telomerase reverse transcriptase. In vitro data show that 5-MeCITP inhibits telomerase with a similar potency as the clinically administered nucleoside analog reverse transcriptase inhibitor azidothymidine (AZT). In addition, cell-based studies show that treatment with the cell-permeable nucleoside counterpart of 5-MeCITP leads to telomere shortening in telomerase-positive cancer cells, while resulting in significantly lower cytotoxic effects in telomerase-negative cell lines when compared with AZT treatment
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Criticality issues with highly enriched fuels in a repository environment
This paper presents preliminary analysis of a volcanic tuff repository containing a combination of low enrichment commercial spent nuclear fuels (SNF) and DOE-owned SNF packages. These SNFs were analyzed with respect to their criticality risks. Disposal of SNF packages containing significant fissile mass within a geologic repository must comply with current regulations relative to criticality safety during transportation and handling within operational facilities. However, once the repository is closed, the double contingency credits for criticality safety are subject to unremediable degradation, (e.g., water intrusion, continued presence of neutron absorbers in proximity to fissile material, and fissile material reconfiguration). The work presented in this paper focused on two attributes of criticality in a volcanic tuff repository for near-field and far-field scenarios: (1) scenario conditions necessary to have a criticality, and (2) consequences of a nuclear excursion that are components of risk. All criticality consequences are dependent upon eventual water intrusion into the repository and subsequent breach of the disposal package. Key criticality parameters necessary for a critical assembly are: (1) adequate thermal fissile mass, (2) adequate concentration of fissile material, (3) separation of neutron poison from fissile materials, and (4) sufficient neutron moderation (expressed in units of moderator to fissile atom ratios). Key results from this study indicated that the total energies released during a single excursion are minimal (comparable to those released in previous solution accidents), and the maximum frequency of occurrence is bounded by the saturation and temperature recycle times, thus resulting in small criticality risks
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