1,525 research outputs found
The Seasonal Nutrient Density of Country Food Harvested in Makkovik, Labrador
The contribution of country food to the diets of residents of Makkovik, Labrador, reflects the seasonal availability of different species on the northern Labrador coast. The nutrient density of the wild food component of the food supply varies from season to season according to the relative contribution of the various species harvested. In the summer, the level of calcium is somewhat higher than in most other seasons, reflecting the large contribution of fish. In early fall, the nutrient density for iron is the lowest for all seasons, and the level of calcium decreases to about half of that of summer. In late fall, the nutrient density of the country food harvested for household use has the highest density of thiamin, reflecting the contribution from the migratory birds, and the second highest density of iron, reflecting the increase in percentage contribution of seals. In winter the iron density is approximately twice that of other seasons. The level of calcium increases, reflecting the contribution from partridge and ptarmigan. In early spring the large contribution of caribou provides a high protein content, while for riboflavin it is the highest of any season. In late spring the nutrient density reflects the large percentage of fish. Dietary patterns of a population depending on country food for much of its food supply change from one season to another, and nutrient intakes also vary from season to season. These factors must be considered when evaluating dietary intakes and making nutritional inferences.Key words: country food, nutrient density, nutrition, Subarctic, LabradorMot clés: denrées locales, composition nutritive, nutrition, subarctique, Labrado
Gravitation Physics at BGPL
We report progress on a program of gravitational physics experiments using
cryogenic torsion pendula undergoing large-amplitude torsion oscillation. This
program includes tests of the gravitational inverse square law and of the weak
equivalence principle. Here we describe our ongoing search for
inverse-square-law violation at a strength down to of standard
gravity. The low-vibration environment provided by the Battelle Gravitation
Physics Laboratory (BGPL) is uniquely suited to this study.Comment: To be published in The Proceedings of the Francesco Melchiorri
Memorial Conference as a special issue of New Astronomy Review
Back by popular demand: the benefits of traditional vegetables: One community's story
Agricultural biodiversity - the varieties of plants, animals and microorganisms used to benefit people - is critical for improving the nutrition and health of the urban and rural poor. The lack of micronutrients, including certain vitamins, minerals and other components needed for a healthy diet, is a pervasive and growing threat throughout the world. One result of this 'hidden hunger' has been a spectacular rise in obesity, heart disease, type II diabetes and various cancers, especially in developing countries, where many people have adopted an oversimplified diet based on the cheapest refined carbohydrates and fats. So-called neglected or underused crops are often an important source of nutrition as well as being adapted to the marginal environments in which they grow. And yet, a lack of scientific research and development has limited the appreciation of their benefits. Over time, local communities have tended to replace these plants with more prestigious introduced crops that are often less nutritious and less suited to local climate and soils. For example, communities in the high Andean mountains of South America have traditionally consumed several types of Andean grains. The most popular include quinoa, cañihua, amaranth and chocho (also known as tarwi). Like most traditional species, Andean grains are extremely nutritious and hardier than many commercial crops. They are rich in protein and essential amino acids. The leaves contain high levels of protein and iron, which is easily absorbed thanks to the high level of vitamin C that is also present. Andean grains are also easily digested, making them particularly suitable for babies, children and elderly people. Nevertheless, these grains have suffered a decline in status, especially in urban areas, where they have been replaced with cheaper, less nutritious foods such as pasta and rice. Like Andean grains, the minor millets of South Asia are very nutritious and well suited to marginal lands. Yet they too suffer from low status, which makes it difficult to sell them to modern consumers.African leafy vegetables have suffered the same decline in status as these and other traditional crops. About 900 species of leafy vegetables grow in sub-Saharan Africa. These plants were once a key part of people's diets and culture. Women grew the vegetables in their gardens, providing yearround supplies of nutritious foods to supplement the family diet. Then foreign crops such as cabbage and carrots were introduced. Because of their exotic origins, these new crops acquired a special status and came to symbolize modernity. Communities gradually stopped growing traditional leafy vegetables in their gardens, and began to grow the lucrative - though less nutritious - 'modern' crops instead. This booklet describes how reintroducing traditional leafy vegetables had an impact on the lives of people in a community near Nairobi, Kenya, thanks largely to the inspiration of one farmer
Transport coefficients, spectral functions and the lattice
Transport coefficients are determined by the slope of spectral functions of
composite operators at zero frequency. We study the spectral function relevant
for the shear viscosity for arbitrary frequencies in weakly-coupled scalar and
nonabelian gauge theories at high temperature and compute the corresponding
correlator in euclidean time. We discuss whether nonperturbative values of
transport coefficients can be extracted from euclidean lattice simulations.Comment: 25 pages with 7 eps figures, discussion improved, acknowledgement
added; to appear in JHE
Universal neural field computation
Turing machines and G\"odel numbers are important pillars of the theory of
computation. Thus, any computational architecture needs to show how it could
relate to Turing machines and how stable implementations of Turing computation
are possible. In this chapter, we implement universal Turing computation in a
neural field environment. To this end, we employ the canonical symbologram
representation of a Turing machine obtained from a G\"odel encoding of its
symbolic repertoire and generalized shifts. The resulting nonlinear dynamical
automaton (NDA) is a piecewise affine-linear map acting on the unit square that
is partitioned into rectangular domains. Instead of looking at point dynamics
in phase space, we then consider functional dynamics of probability
distributions functions (p.d.f.s) over phase space. This is generally described
by a Frobenius-Perron integral transformation that can be regarded as a neural
field equation over the unit square as feature space of a dynamic field theory
(DFT). Solving the Frobenius-Perron equation yields that uniform p.d.f.s with
rectangular support are mapped onto uniform p.d.f.s with rectangular support,
again. We call the resulting representation \emph{dynamic field automaton}.Comment: 21 pages; 6 figures. arXiv admin note: text overlap with
arXiv:1204.546
Sex differences in brain plasticity: a new hypothesis for sex ratio bias in autism.
Several observations support the hypothesis that differences in synaptic and regional cerebral plasticity between the sexes account for the high ratio of males to females in autism. First, males are more susceptible than females to perturbations in genes involved in synaptic plasticity. Second, sex-related differences in non-autistic brain structure and function are observed in highly variable regions, namely, the heteromodal associative cortices, and overlap with structural particularities and enhanced activity of perceptual associative regions in autistic individuals. Finally, functional cortical reallocations following brain lesions in non-autistic adults (for example, traumatic brain injury, multiple sclerosis) are sex-dependent. Interactions between genetic sex and hormones may therefore result in higher synaptic and consecutively regional plasticity in perceptual brain areas in males than in females. The onset of autism may largely involve mutations altering synaptic plasticity that create a plastic reaction affecting the most variable and sexually dimorphic brain regions. The sex ratio bias in autism may arise because males have a lower threshold than females for the development of this plastic reaction following a genetic or environmental event
Management practices for the amelioration of urban stormwater
AbstractUrban runoff has been identified as a non-point source (NPS) contributor. The most effective mechanism for controlling urban NPS pollution is to reduce the amount of runoff through infiltration and storage on the landscape. Traditional infiltration best management practices (BMPs) have lacked long-term effectiveness because of clogging. The addition of vegetation to the system enhances the longevity of infiltration BMPs by enhancing soil structure. In order to better understand the design and function of vegetated, infiltration-based BMPs, Kansas State University is monitoring several sites in Kansas. Results indicate that vegetation enhances the ability of stormwater systems to store water and reduce down channel erosion and flooding
Censoring for loss to follow-up in time-to-event analyses of composite outcomes or in the presence of competing risks
Background: In time-to-event analyses, there is limited guidance on when persons who are lost to follow-up (LTFU) should be censored. Methods: We simulated bias in risk estimates for: (1) a composite event of measured (outcome only observable in a patient encounter) and captured events (outcome observable outside a patient encounter); and a (2) measured or (3) captured event in the presence of a competing event of the other type, under three censoring strategies: (i) censor at the last study encounter; (ii) censor when LTFU definition is met; and (iii) a new, hybrid censoring strategy. We demonstrate the real-world impact of this decision by estimating: (1) time to acquired immune deficiency syndrome (AIDS) diagnosis or death, (2) time to initiation of antiretroviral therapy (ART), and (3) time to death before ART initiation among adults engaged in HIV care. Results: For (1) our hybrid censoring strategy was least biased. In our example, 5-year risk of AIDS or death was overestimated using last-encounter censoring (25%) and under-estimated using LTFU-definition censoring (21%), compared with results from our hybrid approach (24%). Last-encounter censoring was least biased for (2). When estimating 5-year risk of ART initiation, LTFU-definition censoring underestimated risk (80% vs. 85% using last-encounter censoring). LTFU-definition censoring was least biased for (3). When estimating 5-year risk of death before ART initiation, last-encounter censoring overestimated risk (5.2% vs. 4.7% using LTFU-definition censoring). Conclusions: The least biased censoring strategy for time-to-event analyses in the presence of LTFU depends on the event and estimand of interest
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