2,177 research outputs found
Rich, Sturmian, and trapezoidal words
No full textIn this paper we explore various interconnections between rich words, Sturmian words, and trapezoidal words. Rich words, first introduced by the second and third authors together with J. Justin and S. Widmer, constitute a new class of finite and infinite words characterized by having the maximal number of palindromic factors. Every finite Sturmian word is rich, but not conversely. Trapezoidal words were first introduced by the first author in studying the behavior of the subword complexity of finite Sturmian words. Unfortunately this property does not characterize finite Sturmian words. In this note we show that the only trapezoidal palindromes are Sturmian. More generally we show that Sturmian palindromes can be characterized either in terms of their subword complexity (the trapezoidal property) or in terms of their palindromic complexity. We also obtain a similar characterization of rich palindromes in terms of a relation between palindromic complexity and subword complexity
The Moral Economy of the Rich
No full textThis article applies the concept of a ‘moral economy’ to the actions of the rich and powerful. The author focuses attention on business owners and provides a case study of a late nineteenth-century provincial businessman and his dismissal of two long-serving employees, an act which caused outrage in his community. The author questions how the morality of employment, job rights and dismissal developed subsequently and sketches developments up to the 1960s. The article then provides a more speculative discussion of the effects of changes in corporate law on corporate behaviour and suggests they have had a tendency to produce a moral irresponsibility in the behaviour of corporate officers
Cosmic dust impacts on the Hubble Space Telescope
No full textExposure of the Hubble Space Telescope to space in low Earth orbit resulted in numerous hypervelocity impacts by cosmic dust (micrometeoroids) and anthropogenic particles (orbital debris) on the solar arrays and the radiator shield of the Wide Field and Planetary Camera 2, both subsequently returned to Earth. Solar cells preserve residues from smaller cosmic dust (and orbital debris) but give less reliable information from larger particles. Here, we present images and analyses from electron, ion and X-ray fluorescence microscopes for larger impact features (millimetre- to centimetre-scale) on the radiator shield. Validated by laboratory experiments, these allow interpretation of composition, probable origin and likely dimensions of the larger impactors. The majority (~90%) of impacts by grains greater than 50 μm in size were made by micrometeoroids, dominated by magnesium- and iron-rich silicates and iron sulfides, metallic iron-nickel and chromium-rich spinel similar to that in ordinary chondrite meteorites of asteroid origin. Our re-evaluation of the largest impact features shows substantially fewer large orbital debris impacts than reported by earlier authors. Mismatch to the NASA ORDEM and ESA MASTER models of particle populations in orbit may be partly due to model overestimation of orbital debris flux and underestimation of larger micrometeoroid numbers. This article is part of the theme issue ‘Dust in the Solar System and beyond’
Q methodology in low-resource settings: Challenges and best practices
No full textReduction of poverty is a main goal in the global development agenda. The most extreme forms of poverty are mainly rooted in the Global South, and even more engrained in its rurality. Such poverty is not only characterized by infimum incomes, but also by the lack of access to many resources and services: health, sanitation, drinking water, education, etc. Eradication of deep poverty therefore demands a holistic understanding of its causes, as well as the wicked interaction of its many variables. International definitions of (deep) poverty, however, keep resorting to income thresholds (e.g. World Bank’s International Poverty Line) to measure it. In consequence, such definitions may overshadow underlying context-dependent complexities: gender dimensions, urban/rural divide, societal power relationships, local economic dynamics.Q methodology is a potentially powerful tool to understand better the different nuances of poverty, thus to enable a more effective tackling of its roots. First, as a participatory method, it offers voices to grassroots participants to express their own priorities and concerns. Second, it encompasses rich qualitative data that go beyond oversimplified quantitative thresholds and analyses. Third, as a reductionist technique, it condenses (virtually) infinite positions into clearly identifiable poverty discourses.At the same time, methodological deployment of Q methodology in low-resource settings, and particularly in rural areas, poses several (underreported) challenges worth to be considered and discussed. These challenges may be exacerbated in light of big shocks, like the current COVID-19 pandemic. Whether related to the concourse development, sorting grid design, P-set sampling, administration, data recording or validation, researchers may encounter a number of concerns/restrictions.In our work, we analyze these challenges along with proposed corresponding best practices. This analysis is the result of both literature review and first-hand Q methodology administration with smallholders in Nepal, Indonesia and Malawi. Best practices notwithstanding, we advocate for the empowerment of local researchers regarding this technique that remains ‘property’ of the western world. By democratizing the knowledge on its application, we expect local stakeholders to explore and prioritize their needs—and its potential solutions—in a more precise manner.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Water ResourcesDesign for Sustainabilit
Proline-rich tyrosine kinase 2 mediates gonadotropin-releasing hormone signaling to a specific extracellularly regulated kinase-sensitive transcriptional locus in the luteinizing hormone beta-subunit gene
No full textG protein-coupled receptor regulation of gene transcription primarily occurs through the phosphorylation of transcription factors by MAPKs. This requires transduction of an activating signal via scaffold proteins that can ultimately determine the outcome by binding signaling kinases and adapter proteins with effects on the target transcription factor and locus of activation. By investigating these mechanisms, we have elucidated how pituitary gonadotrope cells decode an input GnRH signal into coherent transcriptional output from the LH beta-subunit gene promoter. We show that GnRH activates c-Src and multiple members of the MAPK family, c-Jun NH2-terminal kinase 1/2, p38MAPK, and ERK1/2. Using dominant-negative point mutations and chemical inhibitors, we identified that calcium-dependent proline-rich tyrosine kinase 2 specifically acts as a scaffold for a focal adhesion/cytoskeleton-dependent complex comprised of c-Src, Grb2, and mSos that translocates an ERK-activating signal to the nucleus. The locus of action of ERK was specifically mapped to early growth response-1 (Egr-1) DNA binding sites within the LH beta-subunit gene proximal promoter, which was also activated by p38MAPK, but not c-Jun NH2-terminal kinase 1/2. Egr-1 was confirmed as the transcription factor target of ERK and p38MAPK by blockade of protein expression, transcriptional activity, and DNA binding. We have identified a novel GnRH-activated proline-rich tyrosine kinase 2-dependent ERK-mediated signal transduction pathway that specifically regulates Egr-1 activation of the LH beta-subunit proximal gene promoter, and thus provide insight into the molecular mechanisms required for differential regulation of gonadotropin gene expression
Time-lapse seismic attenuation as a tool for monitoring hydrocarbons and CO2 in geological materials
No full textBoth laboratory experiments and theoretical models have shown seismic attenuation to be sensitive to various petrophysical properties of rock and pore fluids, making attenuation a potentially useful time-lapse attribute to measure and interpret through rock physics models. Attenuation is rarely used as an interpretation tool due to the scarcity of reliable measurements and the wide choice of proposed mechanisms potentially responsible for the
energy loss.
Current methodologies for estimating attenuation from seismic data (spectral ratio, centroid frequencies and instantaneous frequencies) have been applied to the specific geometries associated with prestack surface seismic data and vertical seismic profiles, and
adapted where possible for direct comparison of waveforms from two vintages of data. Phenomena that inhibit reliable estimation of Q can be repeatable between vintages of
data allowing the true change in attenuation to be found, even when apparent attenuation is several times larger then intrinsic attenuation. Time-lapse attenuation measurements
are sensitive to other waveform changes. Two examples of this are; errors due to changes in dispersion being introduced through frequency dependent travel-times (up to 40% error on 1/Q) and frequency dependent reflectivity, the latter being particularly sensitive at low frequencies and where polarity of reflections change with angle; band-limited random noise and multiple energy both decrease the estimate of attenuation (by 39% for a signal to multiple ratio of 2:1) but leave the change in attenuation detectable, with band-limited random noise also increasing the uncertainty. Attenuation measurements are then made
on two field data-sets; a time lapse VSP from a pilot CO2 sequestration experiment where 1600 tonnes of CO2 was injected into a thin (10m) aquifer; and a prestack surface seismic data-set from a mature hydrocarbon reservoir undergoing enhanced oil recovery through alternating water and gas injection.
For the VSP, attenuation changes are more detectable when directly comparing waveforms between vintages: however, the realistic synthetic (with a Q change of 100 to 20) indicated
that the true magnitude of attenuation is unlikely to be recovered for such a small injection interval. In the real data, changes in attenuation (�(Q−1)=0.024) and velocity (5%
decrease) are qualitatively interpreted by use of a patchy saturation model as an increase in CO2 saturation of between 10-30%.
Four methodologies are used to calculate attenuation from the surface seismic data-set and show coherent anomalies indicating the robustness of the measurement. The region
adjacent to a water and gas injector shows an increase in Q−1 of � 0.02. Changes in velocity (±5%) and amplitude (up to 150%) are also measured from the data and qualitatively
agree with the attenuation measurements. A new quasi-linear inversion scheme is introduced to take these time-lapse attributes and solve for pressure and saturation
changes using a patchy saturation model, giving 1-10% increases in gas saturation and up to 5MPa pressure changes around three water and gas injectors
DIFFERENT TREATMENT BETWEEN THE POOR AND THE RICH REFLECTED IN NICK CASSAVETE’S JOHN-Q MOVIE (2002): A MARXIST APPROACH
No full textThis study is aimed to show the different treatment between the poor and the rich in John-Q movie by using Marxist approach. It is done by establishing two parts, the first is analyzing the movie based on its structural elements and the second is analyzing the movie based on the Marxist approach. This research is descriptive qualitative research. Type of the data of the study is text and images taken from two data sources: primary and secondary. The primary data source is John-Q movie directed by Nick Cassavetes released in 2002. While the secondary data sources are gained from author biography, essay, comment,
historical information, the other books, and the thesis that are related to the research. The result of the study shows that first, based on the structural analysis of each
elements, it shows that the character and characterization, casting, plot, setting, point of view, theme, cinematography, Mise_en_Scene, sound , editing are related
to each other. Second, based on the Marxist analysis, there is different treatment toward the poor and the rich that were being faced by America society in early twenty first century
Governance and economic growth
No full textBecause protection of property rights cannot be appropriated by any individual, it is widely recognized as being the state's responsibility. Moreover, recent empirical evidence suggests that protection of property rights leads to higher investment levels and faster growth. The extent of property rights protection differs significantly across countries. The author integrates the emergence of property rights within a simple growth framework. Drawing on North (1990), he presents a model where economic performance and enforcement of property rights may reinforce each other.Initial conditions determine the economy's convergence to a high-income or a low-income steady state. Existing empirical evidence offers tentative support for this theory.Judicial System Reform,Labor Policies,Economic Theory&Research,Environmental Economics&Policies,Common Property Resource Development,Economic Theory&Research,Inequality,Common Property Resource Development,Environmental Economics&Policies,Governance Indicators
Public frames in the road pricing debate: A Q-methodology study
No full textA deep understanding of people's support for road pricing may help policymakers to design more practical pricing schemes that are effective in abating congestion but lead to less public opposition. This study adds to the rich body of road pricing acceptability literature by taking a different approach that focuses on the underlying pattern of the arguments, beliefs and attitudes, which largely determine the viewpoint of individuals with respect to road pricing. We apply Q-methodology to find these viewpoints by asking respondents to rank order subjective arguments that are subtracted from the public debate on road pricing and to identify shared viewpoints that are called frames. Analysis revealed four frames: The polluter should pay, Focus on fair alternatives, What's in it for me? and Don't interfere. Only the Polluter should pay frame is positive about road pricing. The other three frames are negative about road pricing, which suggests that there is not just one single block of citizens opposed to road pricing, but that quite different arguments are used in the various frames. We discuss how these frames can be used by policy-makers that intend to implement road pricing, to fine-tune the design, communication and implementation process of road pricing schemes.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Logistic
PM2.5 and gaseous pollutants in New York State during 2005–2016: Spatial variability, temporal trends, and economic influences
No full textOver the past decades, mitigation strategies have been adopted both by federal and state agencies in the United States (US) to improve air quality. Between 2007 and 2009, the US faced a financial/economic crisis that lowered activity and reduced emissions. At the same time, changes in the prices of coal and natural gas drove a shift in fuels used for electricity generation. Seasonal patterns, diel cycles, spatial gradients, and trends in PM2.5 and gaseous pollutants concentrations (NOx, SO2, CO and O3) monitored in New York State (NYS) from 2005 to 2016 were examined. Relationships between ambient concentrations, changes in NYS emissions retrieved from the US EPA trends inventory, and economic indicators were studied. PM2.5 and primary gaseous pollutants concentrations decreased across NYS. By 2016, PM2.5 and SO2 attained relatively homogeneous concentrations across the state. PM2.5 concentrations decreased significantly at all sites. Similarly, SO2 concentrations declined at all sites within this period, with the highest slopes observed at the urban sites. Reductions in NOx emissions likely contributed to summertime average ozone reductions. NOx and VOCs controls reduced O3 peak concentrations at rural and suburban sites as seen in significant relationships between the annual O3 4th-highest daily maximum 8-h concentrations and estimated NOx emissions at rural and suburban sites (r2 ∼ 0.7). Spring maxima were not reduced with most sites showing insignificant slopes or significant positive slopes (e.g., +2.6% y−1 and +2% y−1, at CCNY and PFI, respectively). Increases in autumn and winter ozone concentrations were found (e,g., 6.6 ± 0.4% y−1 on average in New York City). Significant relationships were observed between PM2.5, primary pollutants, and economic indicators. Overall, a decrease in electricity generation with coal, and the simultaneous increase in natural gas consumption for power generation, led to a decrease in PM2.5 and gaseous pollutants concentrations
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