689 research outputs found
Looking Ahead in Soybean Processing
War and immediate post-war demands for soybeans have been strong. Farmers in Iowa and throughout the Corn Belt have responded to these demands by greatly expanding their output of soybeans. Soybean production in Iowa in 1945 was more than triple 1940 production. About 43 million bushels of beans were harvested from the 1945 crop. And approximately 35 million bushels are expected from the 1946 crop
Effects of crop acreage control features of AAA on feed production in 11 Midwest states
This bulletin is the product of studies in the appraisal of governmental agricultural programs in progress at Iowa State College. The statistics upon which most of the conclusions relative to the effect of the AAA upon the production of feedstuffs are based are the estimates of feed production in the 3-year period, 1938-40, without crop acreage control. The manner in which the various estimates have been derived is explained in some detail in a series of fairly elaborate footnotes appended to tables 5 to 15, inclusive. The basic assumptions underlying these estimates are given in these footnotes. Available, relevant, empirical data are considered, and the appraisal and criticism of other research workers are taken into account.2 The quantification of these assumptions into estimates of feed production without crop acreage control are in the last analysis those of the authors, and, as all estimates, are subject to error. They are, it is believed, the best approximation that it is possible to make with the evidence now available of what the feed production would have been in the various parts of the Midwest had there been no AAA
Molecular Hydrogen Formation on Porous Dust Grains
Recent laboratory experiments on interstellar dust analogues have shown that
H_2 formation on dust grain surfaces is efficient in a range of grain
temperatures below 20 K. These results indicate that surface processes may
account for the observed H_2 abundance in cold diffuse and dense clouds.
However, high abundances of H_2 have also been observed in warmer clouds,
including photon-dominated regions (PDRs), where grain temperatures may reach
50 K, making the surface processes extremely inefficient. It was suggested that
this apparent discrepancy can be resolved by chemisorption sites. However,
recent experiments indicate that chemisorption processes may not be efficient
at PDR temperatures. Here we consider the effect of grain porosity on H_2
formation. It is found that porosity extends the efficiency of the
recombination process to higher temperatures. This is because H atoms that
desorb from the internal surfaces of the pores may re-adsorb many times and
thus stay longer on the surface. However, this porosity-driven extension may
enable efficient H_2 formation in PDRs only if porosity also contributes to
significant cooling of the grains, compared to non-porous grains.Comment: 17 pages, 4 figures. Minor changes. Accepted for publication in MNRA
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Arabidopsis annexin1 mediates the radical-activated plasma membrane Ca2+ - and K+ -permeable conductance in root cells
Plant cell growth and stress signaling require Ca2+ influx through plasma membrane transport proteins that are regulated by
reactive oxygen species. In root cell growth, adaptation to salinity stress, and stomatal closure, such proteins operate
downstream of the plasma membrane NADPH oxidases that produce extracellular superoxide anion, a reactive oxygen
species that is readily converted to extracellular hydrogen peroxide and hydroxyl radicals, OH_. In root cells, extracellular OH_ activates a plasma membrane Ca2+-permeable conductance that permits Ca2+ influx. In Arabidopsis thaliana, distribution of
this conductance resembles that of annexin1 (ANN1). Annexins are membrane binding proteins that can form Ca2+-permeable
conductances in vitro. Here, the Arabidopsis loss-of-function mutant for annexin1 (Atann1) was found to lack the root hair and
epidermal OH_-activated Ca2+- and K+-permeable conductance. This manifests in both impaired root cell growth and ability to
elevate root cell cytosolic free Ca2+ in response to OH_. An OH_-activated Ca2+ conductance is reconstituted by recombinant
ANN1 in planar lipid bilayers. ANN1 therefore presents as a novel Ca2+-permeable transporter providing a molecular link
between reactive oxygen species and cytosolic Ca2+ in plants
Longitudinal assessment of multiple sclerosis with the brain-age paradigm
OBJECTIVE: During the natural course of MS, the brain is exposed to ageing as well as disease effects. Brain ageing can be modelled statistically; the so-called 'brain-age' paradigm. Here, we evaluated whether brain-predicted age difference (brain-PAD) was sensitive to the presence of MS, clinical progression and future outcomes. METHODS: In a longitudinal, multi-centre sample of 3,565 MRI scans, in 1,204 MS and clinically-isolated syndrome (CIS) patients and 150 healthy controls (mean follow-up time: patients 3.41 years, healthy controls 1.97 years), we measured 'brain-predicted age' using T1-weighted MRI. We compared brain-PAD between MS and CIS patients and healthy controls, and between disease subtypes. Relationships between brain-PAD and Expanded Disability Status Scale (EDSS) were explored. RESULTS: MS patients had markedly higher brain-PAD than healthy controls (mean brain-PAD +10.3 years [95% CI 8.5, 12.1] versus 4.3 years [-2.1, 6.4], p < 0.001). The highest brain-PADs were in secondary-progressive MS (+19.4 years [17.1, 21.9]). Brain-PAD at study entry predicted time-to-disability progression (hazard ratio 1.02 [1.01, 1.03], p < 0.001); though normalised brain volume was a stronger predictor. Greater annualised brain-PAD increases were associated with greater annualised EDSS score (r = 0.26, p < 0.001). INTERPRETATION: The brain-age paradigm is sensitive to MS-related atrophy and clinical progression. A higher brain-PAD at baseline was associated with more rapid disability progression and the rate of change in brain-PAD related to worsening disability. Potentially, 'brain-age' could be used as a prognostic biomarker in early-stage MS, to track disease progression or stratify patients for clinical trial enrolment. This article is protected by copyright. All rights reserved
Mitochondrial Networking Protects β-Cells From Nutrient-Induced Apoptosis
OBJECTIVE: Previous studies have reported that β-cell mitochondria exist as discrete organelles that exhibit heterogeneous bioenergetic capacity. To date, networking activity, and its role in mediating β-cell mitochondrial morphology and function, remains unclear. In this article, we investigate β-cell mitochondrial fusion and fission in detail and report alterations in response to various combinations of nutrients. RESEARCH DESIGN AND METHODS: Using matrix-targeted photoactivatable green fluorescent protein, mitochondria were tagged and tracked in β-cells within intact islets, as isolated cells and as cell lines, revealing frequent fusion and fission events. Manipulations of key mitochondrial dynamics proteins OPA1, DRP1, and Fis1 were tested for their role in β-cell mitochondrial morphology. The combined effects of free fatty acid and glucose on β-cell survival, function, and mitochondrial morphology were explored with relation to alterations in fusion and fission capacity. RESULTS: β-Cell mitochondria are constantly involved in fusion and fission activity that underlies the overall morphology of the organelle. We find that networking activity among mitochondria is capable of distributing a localized green fluorescent protein signal throughout an isolated β-cell, a β-cell within an islet, and an INS1 cell. Under noxious conditions, we find that β-cell mitochondria become fragmented and lose their ability to undergo fusion. Interestingly, manipulations that shift the dynamic balance to favor fusion are able to prevent mitochondrial fragmentation, maintain mitochondrial dynamics, and prevent apoptosis. CONCLUSIONS: These data suggest that alterations in mitochondrial fusion and fission play a critical role in nutrient-induced β-cell apoptosis and may be involved in the pathophysiology of type 2 diabetes.National Institutes of Health (R01HL071629-03, R01DK074778, 5T32DK007201
Deep gray matter volume loss drives disability worsening in multiple sclerosis
Objective: Gray matter (GM) atrophy occurs in all multiple sclerosis (MS) phenotypes. We investigated whether there is a spatiotemporal pattern of GM atrophy that is associated with faster disability accumulation in MS. Methods: We analyzed 3,604 brain high-resolution T1-weighted magnetic resonance imaging scans from 1,417 participants: 1,214 MS patients (253 clinically isolated syndrome [CIS], 708 relapsing-remitting [RRMS], 128 secondary-progressive [SPMS], and 125 primary-progressive [PPMS]), over an average follow-up of 2.41 years (standard deviation [SD] = 1.97), and 203 healthy controls (HCs; average follow-up = 1.83 year; SD = 1.77), attending seven European centers. Disability was assessed with the Expanded Disability Status Scale (EDSS). We obtained volumes of the deep GM (DGM), temporal, frontal, parietal, occipital and cerebellar GM, brainstem, and cerebral white matter. Hierarchical mixed models assessed annual percentage rate of regional tissue loss and identified regional volumes associated with time-to-EDSS progression. Results: SPMS showed the lowest baseline volumes of cortical GM and DGM. Of all baseline regional volumes, only that of the DGM predicted time-to-EDSS progression (hazard ratio = 0.73; 95% confidence interval, 0.65, 0.82; p < 0.001): for every standard deviation decrease in baseline DGM volume, the risk of presenting a shorter time to EDSS worsening during follow-up increased by 27%. Of all longitudinal measures, DGM showed the fastest annual rate of atrophy, which was faster in SPMS (–1.45%), PPMS (–1.66%), and RRMS (–1.34%) than CIS (–0.88%) and HCs (–0.94%; p < 0.01). The rate of temporal GM atrophy in SPMS (–1.21%) was significantly faster than RRMS (–0.76%), CIS (–0.75%), and HCs (–0.51%). Similarly, the rate of parietal GM atrophy in SPMS (–1.24-%) was faster than CIS (–0.63%) and HCs (–0.23%; all p values <0.05). Only the atrophy rate in DGM in patients was significantly associated with disability accumulation (beta = 0.04; p < 0.001). Interpretation: This large, multicenter and longitudinal study shows that DGM volume loss drives disability accumulation in MS, and that temporal cortical GM shows accelerated atrophy in SPMS than RRMS. The difference in regional GM atrophy development between phenotypes needs to be taken into account when evaluating treatment effect of therapeutic interventions. Ann Neurol 2018;83:210–222
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