Computer program determines exact two-sided tolerance limits for normal distributions

Computer program determines by numerical integration the exact statistical two-sided tolerance limits, when the proportion between the limits is at least a specified number. The program is limited to situations in which the underlying probability distribution for the population sampled is the normal distribution with unknown mean and variance

Re-examination of the Effects of Food Abundance on Jaw Plasticity in Purple Sea Urchins

Morphological plasticity is a critical mechanism that animals use to cope with variations in resource availability. During periods of food scarcity, sea urchins demonstrate an increase in jaw length relative to test diameter. This trait is thought to be reversible and adaptive by yielding an increase in feeding efficiency. We directly test the hypotheses that (1) there are reversible shifts in jaw length to test diameter ratios with food abundance in individual urchins, and (2) these shifts alter feeding efficiency. Purple sea urchins, Strongylocentrotus purpuratus, were collected and placed in either high or low food treatments for 3 months, after which treatments were switched for two additional months between February and September, 2015 in La Jolla, CA (32.8674°N, 117.2530°W). Measurements of jaw length to test diameter ratios were significantly higher in low compared to high food urchins, but this was due to test growth in the high food treatments. Ratios of low food urchins did not change following a switch to high food conditions, indicating that this trait is not reversible within the time frame of this study. Relatively longer jaws were also not correlated with increased feeding efficiency. We argue that jaw length plasticity is not adaptive and is simply a consequence of exposure to high food availability, as both jaw and test growth halt when food is scarce

Whitened Geographies and Education Inequalities in Southern Chile

In this paper we draw on critical geographies and sociologies of race and education to explore ways in which the meanings and conducts of whiteness are reproduced in and through Chilean secondary education in an indigenous-majority area. We focus on links between socio-economic, geographical and racial criteria to understand how the privileges of whiteness are naturalised in the region’s educational provision and among Mapuche indigenous pupils. Although socio-economic inequalities are widely recognised to structure inequality between young people in Chile, we highlight the pervasiveness and unmarked nature of whiteness in the educational system in relation to the socio-spatial segregation of Mapuche pupils, secondary teachers’ attitudes, and young peoples’ self-positioning in the nation. These combine to marginalise and disempower Mapuche populations across the landscape of rural secondary schools in the Araucanía region of Chile.This work was supported by the Economic and Social Research Council [grant number RES-062- 23-3168].This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Intercultural Studies on 3 March 2015, available online: http://wwww.tandfonline.com/10.1080/07256868.2015.1008433

Indigenous citizens in the making: civic belonging and racialized schooling in Chile

This paper explores expressions of sociocultural and political subjectivity among indigenous youth located within four secondary boarding schools in the Araucanía Region of Chile. For rural indigenous students, these schools are a primary site in which they come to gain a sense of themselves as members of civil society and as future citizens. Drawing on young peoples’ experiences in boarding facilities and expressions regarding sociopolitical positioning, we analyse the ways Mapuche youth engage with the racially and class-inflected hierarchies of inequality present in the school, the region and beyond. Within these school spaces, little intellectual space afforded young people to consider how civic inclusion can be renegotiated in relation to indigenous identifications. Nevertheless, the young people demonstrate a capacity to engage critically with national discourses from media and schooling. Whilst not widely engaged in politicized youth activism, the pupils demonstrated agency by positioning themselves critically in quotidian and negotiated re-workings of the meaning of citizenship.This work was supported by the Economic and Social Research Council [grant number RES-062-23-3168]This is the accepted manuscript. The final version is available at http://dx.doi.org/10.1080/13562576.2015.105696

Flight and wind-tunnel comparisons of the inlet-airframe interaction of the F-15 airplane

The design of inlets and nozzles and their interactions with the airplane which may account for a large percentage of the total drag of modern high performance aircraft is discussed. The inlet/airframe interactions program and the flight tests conducted is described. Inlet drag and lift data from a 7.5% wind-tunnel model are compared with data from an F-15 airplane with instrumentation to match the model. Pressure coefficient variations with variable cowl angles, capture ratios, examples of flow interactions and angles of attack are for Mach numbers of 0.6, 0.9, 1.2, and 1.5 are presented

Ground-state cooling of a trapped ion Using long-wavelength radiation

We demonstrate ground-state cooling of a trapped ion using radio-frequency (rf) radiation. This is a powerful tool for the implementation of quantum operations, where rf or microwave radiation instead of lasers is used for motional quantum state engineering. We measure a mean phonon number of n¯=0.13(4) after sideband cooling, corresponding to a ground-state occupation probability of 88(7)%. After preparing in the vibrational ground state, we demonstrate motional state engineering by driving Rabi oscillations between the |n=0⟩ and |n=1⟩ Fock states. We also use the ability to ground-state cool to accurately measure the motional heating rate and report a reduction by almost 2 orders of magnitude compared with our previously measured result, which we attribute to carefully eliminating sources of electrical noise in the system

A fourth HI 21-cm absorption system in the sight-line of MG J0414+0534: a record for intervening absorbers

We report the detection of a strong HI 21-cm absorption system at z=0.5344, as well as a candidate system at z=0.3389, in the sight-line towards the z=2.64 quasar MG J0414+0534. This, in addition to the absorption at the host redshift and the other two intervening absorbers, takes the total to four (possibly five). The previous maximum number of 21-cm absorbers detected along a single sight-line is two and so we suspect that this number of gas-rich absorbers is in some way related to the very red colour of the background source. Despite this, no molecular gas (through OH absorption) has yet been detected at any of the 21-cm redshifts, although, from the population of 21-cm absorbers as a whole, there is evidence for a weak correlation between the atomic line strength and the optical--near-infrared colour. In either case, the fact that so many gas-rich galaxies (likely to be damped Lyman-alpha absorption systems) have been found along a single sight-line towards a highly obscured source may have far reaching implications for the population of faint galaxies not detected in optical surveys, a possibility which could be addressed through future wide-field absorption line surveys with the Square Kilometre Array.Comment: Accepted by ApJ Letter