3,117 research outputs found
The Fate of Local Food Systems in the Global Industrialization Market: Food and Social Justice in the Rural South
This paper investigates the connection between local food systems, health disparities, and social justice in the rural South. It begins with the relationship between food insecurity and health disparities that disproportionately affect racial and ethnic minority populations, and non-minority women and children. First, we discuss the concept of health disparities within the context of bioethics and public health ethics in order to explore the link between the food system and health as a social justice issue. Second, we define health disparities and discuss how they have historically plagued and disadvantaged racial minority populations. Third, we examine these disparities within the context of the structure of the food system and the related social justice issues. We conclude that food insecurity in the rural south is ethically unacceptable because it harms the disadvantaged populations living in these areas. It worsens their vulnerability, truncates their flourishing, and makes their optimal health a mirage
Personality and the collective: Exploratory homing pigeons occupy higher leadership ranks in flocks
While collective movement is ecologically widespread and conveys numerous benefits on individuals, it also poses a coordination problem: who controls the group's movements? The role that animal ‘personalities’ play in this question has recently become a focus of research interest. Although many animal groups have distributed leadership (i.e. multiple individuals influence collective decisions), studies linking personality and leadership have focused predominantly on the group's single most influential individual. In this study, we investigate the relationship between personality and the influence of multiple leaders on collective movement using homing pigeons, Columba livia, a species known to display complex multilevel leadership hierarchies during flock flights. Our results show that more exploratory (i.e. ‘bold’) birds are more likely to occupy higher ranks in the leadership hierarchy and thus have more influence on the direction of collective movement than less exploratory (i.e. ‘shy’) birds during both free flights around their lofts and homing flights from a distant site. Our data also show that bold pigeons fly faster than shy birds during solo flights. We discuss our results in light of theories about the evolution of personality, with specific reference to the adaptive value of heterogeneity in animal groups
Thermal tides in the Martian middle atmosphere as seen by the Mars Climate Sounder
The first systematic observations of the middle atmosphere of Mars (35–80km) with the Mars Climate Sounder (MCS) show dramatic patterns of diurnal thermal variation, evident in retrievals of temperature and water ice opacity. At the time of writing, the data set of MCS limb retrievals is sufficient for spectral analysis within a limited range of latitudes and seasons. This analysis shows that these thermal variations are almost exclusively associated with a diurnal thermal tide. Using a Martian general circulation model to extend our analysis, we show that the diurnal thermal tide dominates these patterns for all latitudes and all seasons
Are fluoride levels in drinking water associated with hypothyroidism prevalence in England? A large observational study of GP practice data and fluoride levels in drinking water
Background
While previous research has suggested that there is an association between fluoride ingestion and the incidence of hypothyroidism, few population level studies have been undertaken. In England,
approximately 10% of the population live in areas with community fluoridation schemes and hypothyroidism prevalence can be assessed from general practice data. This observational study examines the association between levels of fluoride in water supplies with practice level hypothyroidism prevalence.
Methods
We used a cross-sectional study design using secondary data to develop binary logistic regression models of predictive factors for hypothyroidism prevalence at practice level using 2012 data on fluoride levels in drinking water, 2012/2013 Quality and Outcomes Framework (QOF) diagnosed hypothyroidism prevalence data, 2013 General Practitioner registered patient numbers and 2012 practice level Index of Multiple Deprivation scores.
Findings
We found that higher levels of fluoride in drinking water provide a useful contribution for predicting prevalence of hypothyroidism. We found that practices located in the West Midlands (a wholly fluoridated area) are nearly twice as likely to report high hypothyroidism prevalence in comparison to Greater Manchester (non-fluoridated area). Interpretation In many areas of the world, hypothyroidism is a major health concern and in addition to other factors—such as iodine deficiency—fluoride exposure should be considered as a contributing factor. The findings of the study raise particular concerns about the validity of community fluoridation as a safe public health measure
BRYNTRN: A baryon transport model
The development of an interaction data base and a numerical solution to the transport of baryons through an arbitrary shield material based on a straight ahead approximation of the Boltzmann equation are described. The code is most accurate for continuous energy boundary values, but gives reasonable results for discrete spectra at the boundary using even a relatively coarse energy grid (30 points) and large spatial increments (1 cm in H2O). The resulting computer code is self-contained, efficient and ready to use. The code requires only a very small fraction of the computer resources required for Monte Carlo codes
Spin-Charge Coupling in lightly doped NdCeCuO
We use neutron scattering to study the influence of a magnetic field on spin
structures of NdCuO. On cooling from room temperature, NdCuO
goes through a series of antiferromagnetic (AF) phase transitions with
different noncollinear spin structures. While a c-axis aligned magnetic field
does not alter the basic zero-field noncollinear spin structures, a field
parallel to the CuO plane can transform the noncollinear structure to a
collinear one ("spin-flop" transition), induce magnetic disorder along the
c-axis, and cause hysteresis in the AF phase transitions. By comparing these
results directly to the magnetoresistance (MR) measurements of
NdCeCuO, which has essentially the same AF structures
as NdCuO, we find that a magnetic-field-induced spin-flop transition,
AF phase hysteresis, and spin c-axis disorder all affect the transport
properties of the material. Our results thus provide direct evidence for the
existence of a strong spin-charge coupling in electron-doped copper oxides.Comment: 12 pages, 12 figure
Luminous Infrared Galaxies with the Submillimeter Array: I. Survey Overview and the Central Gas to Dust Ratio
We present new data obtained with the Submillimeter Array for a sample of
fourteen nearby luminous and ultraluminous infrared galaxies. The galaxies were
selected to have luminosity distances D < 200 Mpc and far-infrared luminosities
log(L_FIR) > 11.4. The galaxies were observed with spatial resolutions of order
1 kpc in the CO J=3-2, CO J=2-1, 13CO J=2-1, and HCO+ J=4-3 lines as well as
the continuum at 880 microns and 1.3 mm. We have combined our CO and continuum
data to measure an average gas-to-dust mass ratio of 120 +/- 28 (rms deviation
109) in the central regions of these galaxies, very similar to the value of 150
determined for the Milky Way. This similarity is interesting given the more
intense heating from the starburst and possibly accretion activity in the
luminous infrared galaxies compared to the Milky Way. We find that the peak H_2
surface density correlates with the far-infrared luminosity, which suggests
that galaxies with higher gas surface densities inside the central kiloparsec
have a higher star formation rate. The lack of a significant correlation
between total H_2 mass and far-infrared luminosity in our sample suggests that
the increased star formation rate is due to the increased availability of
molecular gas as fuel for star formation in the central regions. In contrast to
previous analyses by other authors, we do not find a significant correlation
between central gas surface density and the star formation efficiency, as trace
by the ratio of far-infrared luminosity to nuclear gas mass. Our data show that
it is the star formation rate, not the star formation efficiency, that
increases with increasing central gas surface density in these galaxies.Comment: 66 pages, 39 figures, aastex preprint format; to be published in ApJ
Supplements. Version of paper with full resolution figures available at
http://www.physics.mcmaster.ca/~wilson/www_xfer/ULIRGS_publi
- …