346 research outputs found
Locating food sovereignty: geographical and sectoral distance in the global food system
This paper seeks to problematize the role of local food systems within the food sovereignty movement and as a counter to the logic of the global industrial food system. It answers the question of how food sovereignty, via its tenet of local food systems, addresses the geographical and sectoral distances in the global food system. In doing this, it utilizes an approach loosely based on Chayanovian thinking and analytical tools provided through food regime analysis, the theory of uneven geographical development and the metabolic rift.
The paper explores six forms of distance in the industrial food system – production from consumption, distant markets, peasants from their land, producers from consumers, the rural-urban divide and agriculture from nature. Then the paper situates local food systems within food sovereignty and food sovereignty within the wider transnational agrarian movements from which it emerged. Next the paper differentiates local food systems by scale, method and character. Finally, it illustrates how and to what extent food sovereignty counters these distances by evaluating the abilities and gaps of food sovereignty in relation to the various forms of distance
Effect of Phosphorus Fertilization on the Selenium Concentration in Alfalfa (Medicago sativa)
A study was conducted to determine the effect of P fertilization
on the Se concentration in alfalfa. Adding P to the soil increased
the Se concentration in alfalfa grown in the greenhouse
on six of 14 soils from the northwestern United States. The Se
concentration increase in alfalfa resulting from P addition was
noted on some alkaline and some acid soils. Phosphorus addition
increased the availability to alfalfa of both native and
applied Se in the Portneuf silt loam. Applying 160 kg P/ha
either as H?PO? or concentrated superphosphate to Gooding
sandy loam in the field increased the Se concentration in alfalfa
from a level marginal for animal requirements to an adequate
level
Selenium Concentrations in Alfalfa from Several Sources Applied to a Low Selenium, Alkaline Soil
Two laboratory-prepared ferric hydroxy bi-selenites and
CuSeO? applied to Portneuf silt ham in the field provided
slowly available Se to alfalfa, resulting in Se concentration adequate
but nontoxic for livestock. These materials have potential
as Se fertilizers at low application rates. The ferric hydroxy
bi-selenites offer little or no advantage over CuSeO?. Se from
BaSeO? alone, BaSeO?—BaSO? mixtures, and CuSeO? was
absorbed by alfalfa in concentrations toxic to livestock. A small
fraction of applied elemental Se was available immediately
after application, providing adequate Se to alfalfa for livestock.
The remaining elemental Se was rather inert, and supplies only
slightly more Se to alfalfa than did the untreated soil the year
following application
Selenium Concentrations in Forage on Some High Northwestern Ranges
Forages produced on some high northwestern ranges were
analyzed for selenium concentration to determine the
hazard of white muscle disease (WMD) in calves and
lambs. The selenium concentration in 94 forage samples
ranged from 0.01 to 0.78 ppm, of which 20 samples contained
more than 0.10 ppm. The remaining 74 samples
contained less than 0.10 ppm and 59 of those contained
Less than 0.05 ppm. Approximately 90% of the summer
ranges studied produce forage containing less than 0.10
ppm selenium. Thus, the hazard of WMD on these northwestern
ranges may be high. Ranchers should work individually
and in groups to ascertain losses from the
disease and minimize them by injecting the animals with
selenium
Whey utilization in furrow irrigation: Effects on aggregate stability and erosion
Improving soil structure often reduces furrow erosion and maintains adequate infiltration. Cottage
cheese whey, the liquid byproduct from cottage cheese manufacture, was utilized to stabilize soil aggregates
and reduce sediment losses from furrow irrigation. We applied either 2.4 or 1.9 L of whey per meter
of furrow (3.15 or 2.49 L m?-2, respectively) by gravity flow without incorporation to two fields of Portneuf
silt loam (Durinodic Xeric Haplocalcid) near Kimberly, ID. Furrows were irrigated with water beginning
four days later. We measured sediment losses with furrow flumes during each irrigation and
measured aggregate stability by wet sieving about 10 days after the last irrigation. Overall, whey significantly
increased aggregate stability 25% at the 0–15 mm depth and 14% at 15–30 mm, compared to controls.
On average, whey reduced sediment losses by 75% from furrows sloped at 2.4%. Whey increased the
aggregate stability of structurally degraded calcareous soil in irrigation furrows
Phosphorus Associated With Sediments in Irrigation and Drainage Waters for Two Large Tracts in Southern Idaho
Phosphorus was measured in irrigation and surface drainage
waters for two large irrigation tracts, and inorganic, water-soluble
PO?-P and total P inputs and outputs were computed. The present
irrigation practices on both irrigation tracts conserve P by removing
more P from the Snake River in irrigation water than is returned in
drainage water. Even greater P conservation could be attained by
implementing new practices. Approximately 90% of the P in
waters diverted to irrigate the Northside Tract remained in the
tract. About 50% of the amount diverted remained in the Twin
Falls Tract. Particle size segregation takes place in some drainage
streams and the finer sediments returning to the river contain higher
total and NaHCO?-extractable P concentrations than the soils
from which they were eroded. The importance of defining sampling
methods and procedures for P analyses is illustrated by comparative
data on irrigation and drainage waters. The PO?-P concentration
in samples filtered through a 0.45 µm membrane filter
was independent of the sediment concentration in waters, whereas
the total P concentration of unfiltered samples was proportional to
the sediment concentration
Extramedullary Hematopoiesis Generates Ly-6C(high) Monocytes That Infiltrate Atherosclerotic Lesions
BACKGROUND: Atherosclerotic lesions are believed to grow via the recruitment of bone marrow-derived monocytes. Among the known murine monocyte subsets, Ly-6C(high) monocytes are inflammatory, accumulate in lesions preferentially, and differentiate. Here we hypothesized that the bone marrow outsources the production of Ly-6C(high) monocytes during atherosclerosis. METHODS AND RESULTS: Using murine models of atherosclerosis and fate-mapping approaches, we show that hematopoietic stem and progenitor cells (HSPC) progressively relocate from the bone marrow to the splenic red pulp where they encounter GM-CSF and IL-3, clonally expand, and differentiate to Ly-6C(high) monocytes. Monocytes born in such extramedullary niches intravasate, circulate, and accumulate abundantly in atheromata. Upon lesional infiltration, Ly-6C(high) monocytes secrete inflammatory cytokines, reactive oxygen species, and proteases. Eventually, they ingest lipids and become foam cells. CONCLUSIONS: Our findings indicate that extramedullary sites supplement the bone marrow’s hematopoietic function by producing circulating inflammatory cells that infiltrate atherosclerotic lesions
Growth, microstructure, and failure of crazes in glassy polymers
We report on an extensive study of craze formation in glassy polymers.
Molecular dynamics simulations of a coarse-grained bead-spring model were
employed to investigate the molecular level processes during craze nucleation,
widening, and breakdown for a wide range of temperature, polymer chain length
, entanglement length and strength of adhesive interactions between
polymer chains. Craze widening proceeds via a fibril-drawing process at
constant drawing stress. The extension ratio is determined by the entanglement
length, and the characteristic length of stretched chain segments in the
polymer craze is . In the craze, tension is mostly carried by the
covalent backbone bonds, and the force distribution develops an exponential
tail at large tensile forces. The failure mode of crazes changes from
disentanglement to scission for , and breakdown through scission
is governed by large stress fluctuations. The simulations also reveal
inconsistencies with previous theoretical models of craze widening that were
based on continuum level hydrodynamics
Simulations of the Static Friction Due to Adsorbed Molecules
The static friction between crystalline surfaces separated by a molecularly
thin layer of adsorbed molecules is calculated using molecular dynamics
simulations. These molecules naturally lead to a finite static friction that is
consistent with macroscopic friction laws. Crystalline alignment, sliding
direction, and the number of adsorbed molecules are not controlled in most
experiments and are shown to have little effect on the friction. Temperature,
molecular geometry and interaction potentials can have larger effects on
friction. The observed trends in friction can be understood in terms of a
simple hard sphere model.Comment: 13 pages, 13 figure
The institutional shaping of management: in the tracks of English individualism
Globalisation raises important questions about the shaping of economic action by cultural factors. This article explores the formation of what is seen by some as a prime influence on the formation of British management: individualism. Drawing on a range of historical sources, it argues for a comparative approach. In this case, the primary comparison drawn is between England and Scotland. The contention is that there is a systemic approach to authority in Scotland that can be contrasted to a personal approach in England. An examination of the careers of a number of Scottish pioneers of management suggests the roots of this systemic approach in practices of church governance. Ultimately this systemic approach was to take a secondary role to the personal approach engendered by institutions like the universities of Oxford and Cambridge, but it found more success in the different institutional context of the USA. The complexities of dealing with historical evidence are stressed, as is the value of taking a comparative approach. In this case this indicates a need to take religious practice as seriously as religious belief as a source of transferable practice. The article suggests that management should not be seen as a simple response to economic imperatives, but as shaped by the social and cultural context from which it emerges
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