3,073 research outputs found
Models of Cosmic Order: Physical Expression of Sacred Space Among the Ancient Maya
The archaeological record, as well as written texts, oral traditions, and iconographic representations, express the Maya perception of cosmic order, including the concepts of quadripartite division and layered cosmos. The ritual act of portioning and layering created spatial order and was used to organize everything from the heavens to the layout of altars. These acts were also metaphors for world creation, world order, and establishing the center as a position of power and authority. This article examines the articulations of these concepts from the level of caches to the level of regions from the past and present in an attempt to understand these ancient perceptions. We emphasize that basic organizational notions of the cosmos permeate all societal levels and argue that scholars should expand their focus to include how the sacred landscape and its related ideology were reproduced in the lives of everyday people
Prediction of extreme events in the OFC model on a small world network
We investigate the predictability of extreme events in a dissipative
Olami-Feder-Christensen model on a small world topology. Due to the mechanism
of self-organized criticality, it is impossible to predict the magnitude of the
next event knowing previous ones, if the system has an infinite size. However,
by exploiting the finite size effects, we show that probabilistic predictions
of the occurrence of extreme events in the next time step are possible in a
finite system. In particular, the finiteness of the system unavoidably leads to
repulsive temporal correlations of extreme events. The predictability of those
is higher for larger magnitudes and for larger complex network sizes. Finally,
we show that our prediction analysis is also robust by remarkably reducing the
accessible number of events used to construct the optimal predictor.Comment: 5 pages, 4 figure
Linguistic incompetence: giving an account of researching multilingually
This paper considers the place of linguistic competence and incompetence in the context of researching multilingually. It offers a critique of the concept of competence and explores the performative dimensions of multilingual research and its narration, through the philosophy of Judith Butler, and in particular her study Giving an account of oneself. It explores aspects of risk, justice, narrative limit and a morality of multilingualism in emergent multilingual research frameworks. These theoretical dimensions are explored through consideration of ‘linguistically incompetent’ ethnographic work with refugees and asylum seekers, in contexts of hospitality and in life long learning research in the Gaza Strip, and of early attempts to learn new languages. The paper offers a prospect of a relational approach to researching multilingually and affirms the vulnerability at the heart of linguistic hospitality
Evaluating the effects of bilingual traffic signs on driver performance and safety
Variable Message Signs (VMS) can provide immediate and relevant information to road users and bilingual VMS can provide great flexibility in countries where a significant proportion of the population speak an alternative language to the majority. The study reported here evaluates the effect of various bilingual VMS configurations on driver behaviour and safety. The aim of the study was to determine whether or not the visual distraction associated with bilingual VMS signs of different configurations (length, complexity) impacted on driving performance. A driving simulator was used to allow full control over the scenarios, road environment and sign configuration and both longitudinal and lateral driver performance was assessed. Drivers were able to read one and two-line monolingual signs and two-line bilingual signs without disruption to their driving behaviour. However, drivers significantly reduced their speed in order to read four-line monolingual and four-line bilingual signs, accompanied by an increase in headway to the vehicle in front. This implies that drivers are possibly reading the irrelevant text on the bilingual sign and various methods for reducing this effect are discussed
Examination Free-Flow Speed Distribution on Two-Lane Rural Roads
[EN] Free-flow speed variation of passenger vehicles along a road segment is one of the most used factors in road safety studies, as a surrogate measure to evaluate road design consistency. Free-flow speed may be measured when a road segment is already built but must be estimated during the design phase. Several studies have been carried out to calibrate models to estimate free-flow speed, with geometric features as explanatory variables. Currently, most free-flow speed models focus only on mean speed or speed in particular percentiles, such as the 85th or 95th. Moreover, most studies have assumed normality in the free-flow speed distribution without checking this hypothesis. The main objective of this study was to analyze the free-flow speed distribution on two-lane rural road curves and tangents. The research focused on two main issues: determining whether speed data were normally distributed at a specific site and analyzing the behavior of the mean and standard deviation of speed on curves and tangents. The study was based on continuous operating speed profiles, which were obtained from a database of more than 16,000 vehicles/km. A total of 63 horizontal curves and 78 tangents were analyzed. According to the results, the normal distribution is not the best distribution in most cases for describing free-flow speeds. In 46 of the curves and 64 of the tangents, free-flow speed cannot be assumed to be normally distributed. Therefore, some other distributions should be tested in further research.The study presented in this paper is part of the research project CASEFU-Estudio experimental de la funcionalidad y seguridad de las carreteras convencionales, subsidized by the Spanish Ministry of Economy and Competitiveness and the European Social Fund. In addition, the authors thank the Center for Studies and Experimentation of Public Works of the Spanish Ministry of Public Works for subsidizing the field data collection, and the Infrastructure and Transportation Department of the General Directorate of Public Works of the Valencian Government, the Valencian Provincial Council, and the Ministry of the Interior, especially the General Directorate of Traffic of Spain, for their cooperation in gathering the field data.García Jiménez, ME.; Pérez Zuriaga, AM.; Llopis-Castelló, D.; Camacho Torregrosa, FJ.; García García, A. (2016). Examination Free-Flow Speed Distribution on Two-Lane Rural Roads. Transportation Research Record Journal of the Transportation Research Board. 2556:86-97. https://doi.org/10.3141/2556-09S8697255
Teleology and Realism in Leibniz's Philosophy of Science
This paper argues for an interpretation of Leibniz’s claim that physics requires both mechanical and teleological principles as a view regarding the interpretation of physical theories. Granting that Leibniz’s fundamental ontology remains non-physical, or mentalistic, it argues that teleological principles nevertheless ground a realist commitment about mechanical descriptions of phenomena. The empirical results of the new sciences, according to Leibniz, have genuine truth conditions: there is a fact of the matter about the regularities observed in experience. Taking this stance, however, requires bringing non-empirical reasons to bear upon mechanical causal claims. This paper first evaluates extant interpretations of Leibniz’s thesis that there are two realms in physics as describing parallel, self-sufficient sets of laws. It then examines Leibniz’s use of teleological principles to interpret scientific results in the context of his interventions in debates in seventeenth-century kinematic theory, and in the teaching of Copernicanism. Leibniz’s use of the principle of continuity and the principle of simplicity, for instance, reveal an underlying commitment to the truth-aptness, or approximate truth-aptness, of the new natural sciences. The paper concludes with a brief remark on the relation between metaphysics, theology, and physics in Leibniz
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Weight Loss and Illness Severity in Adolescents With Atypical Anorexia Nervosa.
BACKGROUND:Lower weight has historically been equated with more severe illness in anorexia nervosa (AN). Reliance on admission weight to guide clinical concern is challenged by the rise in patients with atypical anorexia nervosa (AAN) requiring hospitalization at normal weight. METHODS:We examined weight history and illness severity in 12- to 24-year-olds with AN (n = 66) and AAN (n = 50) in a randomized clinical trial, the Study of Refeeding to Optimize Inpatient Gains (www.clinicaltrials.gov; NCT02488109). Amount of weight loss was the difference between the highest historical percentage median BMI and admission; rate was the amount divided by duration (months). Unpaired t tests compared AAN and AN; multiple variable regressions examined associations between weight history variables and markers of illness severity at admission. Stepwise regression examined the explanatory value of weight and menstrual history on selected markers. RESULTS:Participants were 16.5 ± 2.6 years old, and 91% were of female sex. Groups did not differ by weight history or admission heart rate (HR). Eating Disorder Examination Questionnaire global scores were higher in AAN (mean 3.80 [SD 1.66] vs mean 3.00 [SD 1.66]; P = .02). Independent of admission weight, lower HR (β = -0.492 [confidence interval (CI) -0.883 to -0.100]; P = .01) was associated with faster loss; lower serum phosphorus was associated with a greater amount (β = -0.005 [CI -0.010 to 0.000]; P = .04) and longer duration (β = -0.011 [CI -0.017 to 0.005]; P = .001). Weight and menstrual history explained 28% of the variance in HR and 36% of the variance in serum phosphorus. CONCLUSIONS:Weight history was independently associated with markers of malnutrition in inpatients with restrictive eating disorders across a range of body weights and should be considered when assessing illness severity on hospital admission
Middle Preclassic Period Maya Greenstone Triangulates : Forms, Contexts, and Geology of a Unique Mesoamerican Groundstone Artifact Type
Over the past twenty years our understanding of the Middle Preclassic (900–300 BCE) period has become much clearer through archaeological investigations at a number of sites located in the Upper Belize River Valley region of the eastern Maya Lowlands. While the picture of Middle Preclassic Maya life, including their material culture, has sharpened, there are aspects that remain uninvestigated. One artifact type, identified as greenstone triangulates, has been found at several Belize Valley sites and in a variety of contexts. Although a number of these multifaceted, polished groundstone items have been recovered, little research has focused on their distribution and function in the archaeological record. An evaluation of these items from primary contexts provides data for determining how they were used in daily social and/or ritual activities throughout the lowlands. Comparative data from other regions of Mesoamerica are also discussed. A detailed geological and petrographic pilot study of a sample of greenstone triangulates is provided, pointing conclusively to early, long-distance and complex exchange networks in exotic raw materials
Life in a Harsh Environment: The Effects of Age, Sex, Reproductive Condition, and Season on Hair Cortisol Concentration in a Wild Non-Human Primate
Hair cortisol concentration (HCC) provides a long-term retrospective measure of hypothalamic–pituitary–adrenal axis activity, and is increasingly used to assess the life history, health and ecology of wild mammals. Given that sex, age, season and pregnancy influence HCC, and that it may indicate ongoing stress, we examined HCC in common marmosets (Callithrix jacchus) naturally inhabiting a hot and dry semi-desert like habitat, Caatinga, in northeastern Brazil. We trapped, measured, weighed, marked and collected shaved hair from the back of the neck of 61 wild marmosets during the wet and dry seasons. Using enzyme immunoassay, we found that HCC was higher in the dry season compared with the wet season among all age/sex classes. Females had significantly higher HCC than males, juveniles had higher HCC than adults, and reproductively active adult females and non-pregnant/non lactating adult females did not differ in HCC. There were no interaction effects of sex, age, group, or season on HCC. The magnitude of the effect of this extremely hot and dry environment (average yearly rainfall was only 271 mm) on HCC in common marmosets is difficult to ascertain as these animals are also experiencing a variety of other stressors. However, the elevated HCC seen in common marmosets during the 5–8 month dry season, suggests these primates face an extended period of heat, water and possibly nutritional stress, which appears to result in a high rate of juvenile mortality
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