529 research outputs found
Happiness and education: troubling students for their own contentment
Currently higher education strategies seem to concentrate on the expedient, developing skills that can secure employment in the world of work. Following Dreyfus and Spinosa (2003), this may have immediate advantages, but in totalising pedagogic practices it may restrict our openness to people and to our own contentment with ourselves. Valuable as this may be as a way to satisfy politico-economic policy imperatives, it strays from education as an edifying process where personal development represents, through the facing up to distress and despair, an unsettling of our developing identity and a negation of our immediate desire satisfaction. Such an unsettling is not intended to give pleasure or satisfaction in the normative way in which the imperative of happiness has been used in student satisfaction surveys or in the wider societal context that this totalisation represents (Ahmed 2010). What I propose for higher education is not a dominant priority to feed the happiness for others but a mission to personal contentment revealed through realising student potentialities to them and so recognising their limitations as part of seeking an attunement to contentment
The contribution of DNA ploidy to radiation sensitivity in human tumour cell lines
The contribution of DNA ploidy to radiation sensitivity was investigated in a group of eight human tumour cell lines. As previous studies suggest, while more aneuploid tumours tend to be more radioresistant, there is no significant relationship between ploidy and radiation sensitivity (SF2). The failure to observe a significant effect of ploidy on radiation sensitivity is due to the complex and multifactorial basis of radiation sensitivity. When we determined the relationship between survival and radiation-induced chromosome aberration frequency, a measure independent of most other modifiers of sensitivity, we observed a direct relationship between ploidy and mean lethal aberration frequency. The mean lethal frequency of aberrations increased from about 1 for diploid cells to about 2 for tetraploid cells. The mean lethal frequency of aberrations was independent of DNA repair variations. These observations demonstrate that changes in DNA ploidy are an important contributor to radiation sensitivity variations in human tumour cell lines. Therefore, any battery of predictive assays should include DNA ploidy measurements. © 1999 Cancer Research Campaig
Determinants of rapid weight gain during infancy: baseline results from the NOURISH randomised controlled trial
Background: Rapid weight gain in infancy is an important predictor of obesity in later childhood. Our aim was to determine which modifiable variables are associated with rapid weight gain in early life.Methods: Subjects were healthy infants enrolled in NOURISH, a randomised, controlled trial evaluating an intervention to promote positive early feeding practices. This analysis used the birth and baseline data for NOURISH. Birthweight was collected from hospital records and infants were also weighed at baseline assessment when they were aged 4-7 months and before randomisation. Infant feeding practices and demographic variables were collected from the mother using a self administered questionnaire. Rapid weight gain was defined as an increase in weight-for-age Z-score (using WHO standards) above 0.67 SD from birth to baseline assessment, which is interpreted clinically as crossing centile lines on a growth chart. Variables associated with rapid weight gain were evaluated using a multivariable logistic regression model.Results: Complete data were available for 612 infants (88% of the total sample recruited) with a mean (SD) age of 4.3 (1.0) months at baseline assessment. After adjusting for mother's age, smoking in pregnancy, BMI, and education and infant birthweight, age, gender and introduction of solid foods, the only two modifiable factors associated with rapid weight gain to attain statistical significance were formula feeding [OR = 1.72 (95%CI 1.01-2.94), P = 0.047] and feeding on schedule [OR = 2.29 (95%CI 1.14-4.61), P = 0.020]. Male gender and lower birthweight were non-modifiable factors associated with rapid weight gain.Conclusions: This analysis supports the contention that there is an association between formula feeding, feeding to schedule and weight gain in the first months of life. Mechanisms may include the actual content of formula milk (e.g. higher protein intake) or differences in feeding styles, such as feeding to schedule, which increase the risk of overfeeding.Trial Registration: Australian Clinical Trials Registry ACTRN12608000056392
Heidegger on creativity: From boredom to re-engagement with the world
Experimental psychologists have discussed whether boredom can help us become more creative. At ïŹrst blush, this would seem to be rather unlikely. When we are bored, we are disengaged; we cannot be bothered and nothing seems worthwhile; we have no interest in the world around us. Such a condition, surely, is not conducive to creativity (Haager et al. 2018). Yet some psychologists disagree (Gasper and Middlewood 2014). Boredom, they explain, breaks down entrenched routines and thought-patterns and provides us with an opportunity to think again and anew. Respondents in âapproach-oriented statesâ such as boredom engage in more âassociative thoughtâ than those in âavoidance-oriented affective states.â This is how boredom comes to encourage âthe quest for meaning and explorationâ (Gasper and Middlewood 2014, pp. 53â55...2-s2.0-8508440789
Radio pulsar populations
The goal of this article is to summarize the current state of play in the
field of radio pulsar statistics. Simply put, from the observed sample of
objects from a variety of surveys with different telescopes, we wish to infer
the properties of the underlying sample and to connect these with other
astrophysical populations (for example supernova remnants or X-ray binaries).
The main problem we need to tackle is the fact that, like many areas of
science, the observed populations are often heavily biased by a variety of
selection effects. After a review of the main effects relevant to radio
pulsars, I discuss techniques to correct for them and summarize some of the
most recent results. Perhaps the main point I would like to make in this
article is that current models to describe the population are far from complete
and often suffer from strong covariances between input parameters. That said,
there are a number of very interesting conclusions that can be made concerning
the evolution of neutron stars based on current data. While the focus of this
review will be on the population of isolated Galactic pulsars, I will also
briefly comment on millisecond and binary pulsars as well as the pulsar content
of globular clusters and the Magellanic Clouds.Comment: 16 pages, 6 figures, to appear in Proceedings of ICREA Workshop on
The High-Energy Emission from Pulsars and their Systems, Sant Cugat, Spain,
2010 April 12-16 (Springer
Observation of the radiative decay mode of the free neutron
The theory of quantum electrodynamics (QED) predicts that beta decay of the neutron into a proton, electron and antineutrino should be accompanied by a continuous spectrum of soft photons. While this inner bremsstrahlung branch has been previously measured in nuclear beta and electron capture decay, it has never been observed in free neutron decay. Recently, the photon energy spectrum and branching ratio for neutron radiative decay have been calculated using two approaches: a standard QED framework(1-3) and heavy baryon chiral perturbation theory(4) (an effective theory of hadrons based on the symmetries of quantum chromodynamics). The QED calculation treats the nucleons as point-like, whereas the latter approach includes the effect of nucleon structure in a systematic way. Here we observe the radiative decay mode of free neutrons, measuring photons in coincidence with both the emitted electron and proton. We determined a branching ratio of (3.13 +/- 0.34) x 10(-3) (68 per cent level of confidence) in the energy region between 15 and 340 keV, where the uncertainty is dominated by systematic effects. The value is consistent with the predictions of both theoretical approaches; the characteristic energy spectrum of the radiated photons, which differs from the uncorrelated background spectrum, is also consistent with the calculated spectrum. This result may provide opportunities for more detailed investigations of the weak interaction processes involved in neutron beta decay.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62639/1/nature05390.pd
Binary and Millisecond Pulsars at the New Millennium
We review the properties and applications of binary and millisecond pulsars.
Our knowledge of these exciting objects has greatly increased in recent years,
mainly due to successful surveys which have brought the known pulsar population
to over 1300. There are now 56 binary and millisecond pulsars in the Galactic
disk and a further 47 in globular clusters. This review is concerned primarily
with the results and spin-offs from these surveys which are of particular
interest to the relativity community.Comment: 59 pages, 26 figures, 5 tables. Accepted for publication in Living
Reviews in Relativity (http://www.livingreviews.org
Massive stars as thermonuclear reactors and their explosions following core collapse
Nuclear reactions transform atomic nuclei inside stars. This is the process
of stellar nucleosynthesis. The basic concepts of determining nuclear reaction
rates inside stars are reviewed. How stars manage to burn their fuel so slowly
most of the time are also considered. Stellar thermonuclear reactions involving
protons in hydrostatic burning are discussed first. Then I discuss triple alpha
reactions in the helium burning stage. Carbon and oxygen survive in red giant
stars because of the nuclear structure of oxygen and neon. Further nuclear
burning of carbon, neon, oxygen and silicon in quiescent conditions are
discussed next. In the subsequent core-collapse phase, neutronization due to
electron capture from the top of the Fermi sea in a degenerate core takes
place. The expected signal of neutrinos from a nearby supernova is calculated.
The supernova often explodes inside a dense circumstellar medium, which is
established due to the progenitor star losing its outermost envelope in a
stellar wind or mass transfer in a binary system. The nature of the
circumstellar medium and the ejecta of the supernova and their dynamics are
revealed by observations in the optical, IR, radio, and X-ray bands, and I
discuss some of these observations and their interpretations.Comment: To be published in " Principles and Perspectives in Cosmochemistry"
Lecture Notes on Kodai School on Synthesis of Elements in Stars; ed. by Aruna
Goswami & Eswar Reddy, Springer Verlag, 2009. Contains 21 figure
Postpartum-specific anxiety as a predictor of infant-feeding outcomes and perceptions of infant-feeding behaviours: new evidence for childbearing specific measures of mood
Studies of pregnancy-specific anxiety suggest that it is a distinct construct which predicts perinatal outcomes more effectively than other general measures of anxiety. In response, a novel measure of postpartum-specific anxiety (PSAS) has been developed and validated, but it is not yet clear whether it possesses the same predictive power as its pregnancy-specific counterparts. The aim of this short-term prospective study was to (a) test the predictive validity of the PSAS in the context of one specific perinatal outcome, infant-feeding, and (b) examine whether the PSAS may be more efficacious at predicting infant-feeding outcomes and behaviours than the more commonly used general measures. Eight hundred mothers of infants aged between 0 and 6 months completed the PSAS alongside general measures of anxiety and depression at baseline. A subsample (n = 261) returned to complete a follow-up questionnaire examining infant-feeding outcomes and behaviours two weeks later. Hierarchical regression models revealed that the PSAS was associated with lower odds of breastfeeding exclusively, and breastfeeding in any quantity in the first 6 months postpartum. PSAS scores were also significantly associated with infant-feeding behaviours including a lower perceived enjoyment of food, and greater perceived food responsiveness and satiety responsiveness in the infant. As hypothesised, the PSAS was a stronger predictor of infant-feeding outcomes and behaviours than general anxiety and depression. The findings provide evidence for the predictive validity of the PSAS and call for the use of childbearing specific measures of mood when attempting to predict perinatal outcomes. Replication of these findings across other indices of maternal and infant health is now necessary
Extrapolation for Time-Series and Cross-Sectional Data
Extrapolation methods are reliable, objective, inexpensive, quick, and easily automated. As a result, they are widely used, especially for inventory and production forecasts, for operational planning for up to two years ahead, and for long-term forecasts in some situations, such as population forecasting. This paper provides principles for selecting and preparing data, making seasonal adjustments, extrapolating, assessing uncertainty, and identifying when to use extrapolation. The principles are based on received wisdom (i.e., expertsâ commonly held opinions) and on empirical studies. Some of the more important principles are:âą In selecting and preparing data, use all relevant data and adjust the data for important events that occurred in the past.âą Make seasonal adjustments only when seasonal effects are expected and only if there is good evidence by which to measure them.âą In extrapolating, use simple functional forms. Weight the most recent data heavily if there are small measurement errors, stable series, and short forecast horizons. Domain knowledge and forecasting expertise can help to select effective extrapolation procedures. When there is uncertainty, be conservative in forecasting trends. Update extrapolation models as new data are received.âą To assess uncertainty, make empirical estimates to establish prediction intervals.âą Use pure extrapolation when many forecasts are required, little is known about the situation, the situation is stable, and expert forecasts might be biased
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