How Big Will Our Farms Get?

The cost economics which come with different sizes of forms aren\u27t the only factors which affect form size. But, coupled with risk and uncertainty, they do have an important influence on changes in farm size

The 1961 Feed-Grain Program - What Did Farmers Think of It?

Why did or didn\u27t Iowa farmers take part in the 1961 Feed-Grain Program? A follow-up survey in 12 north-central and south-central counties reveals reasons and some farmer opinions of the program and of possible changes

Farm size adjustments in Iowa and cost economies in crop production for farms of different sizes

The relation of cost economies to size of farm has been a subject of considerable speculation in Iowa. Farmers are interested in farms of different sizes because cost advantages or disadvantages have an important bearing on farm profits. Other segments of the population have also been interested in size and scale economies in farming. Many people put forth the hypothesis that modern farming methods give very great cost economies to the large acreage. The supposition is: Mechanization results in very low per-acre costs for large units and a danger exists that these cost advantages will give rise to large-scale units which cause the liquidation of family-farm units. Whether or not a threat of this nature actually exists depends on the costs associated with farms of different sizes. Discussion of farm size has gone on with very little knowledge of the cost economies realized in different types of agriculture. Certain aspects of cost are, however, evident: (1) Cost economies are likely greatest in grain and crop farming systems; mechanization has been developed particularly around these enterprises. Important changes have taken place in production of livestock. fruit and vegetable crops. However, the adaptation of mechanization to these enterprises has not been great. (2) If foods and fibers are to be produced efficiently, and farm families are to have favorable incomes, the size of the farm must be great enough to attain some of the efficiencies inherent in mechanization. Farms that are too small will result in low income

Optimum allocation of resources between pasture improvement and other opportunities on southern Iowa farms

Pasture land represents an important portion of the total land in southern Iowa. One opportunity for increasing resource productivity and farm incomes in this part of the state is to invest capital in pasture improvement. Experiments show that capital invested in pasture improvement and renovation, and the livestock to utilize the increased forage production, can greatly increase the value of products produced on land unadapted to continuous cropping; yields of forage and livestock products can be increased as much as threefold. However, the practices of improving and renovating pastures are proceeding at a slow rate. One reason suggested is capital limitations. Most farmers operate with limited funds. Accordingly, if they are to make greatest profits, they must use each dollar, acre and labor hour where it will bring the greatest return. The question is not so much whether pasture improvement and renovation is profitable; but whether it is more profitable than alternative uses of scarce capital and labor. For example, pasture improvement may cost $5 per year and return$8 In the same period. It is profitable in this sense: Each $1 In costs returns$1.60 in sales. However, if the same $1 invested in fertilizer for crops or in hogs returns$1.80, pasture improvement should not be included in the farming plan until these more profitable opportunities have been fully exploited. It should, of course, be included before other investments which return less than $1.60

New procedures in estimating feed substitution rates and in determining economic efficiency in pork production II. Replacement rates of corn and soybean oilmeal in fortified rations for growing-fattening swine on pasture

A previous bulletin reported results from an experiment designed to predict substitution rates and economic optima in corn/soybean oilmeal rations for growing and fattening hogs in drylot.2 Principles and analytical models were included which illustrate that the least-cost ration depends both on (1) the marginal rate of substitution between feeds and (2) the ratio of feed prices. These basic concepts will not be repeated in this bulletin. Since more hogs are farrowed in spring than in fall, the research reported in this study was conducted for growing and fattening hogs raised on pasture. Like the drylot study, the objectives of the pasture experiment were to estimate: (1) the production function, (2) the substitution rate between corn and soybean oilmeal at different points on the production surface, (3) the least-cost ration for different soybean oilmeal/corn price ratios, (4) the relationship between the rate of hog gains and the input of corn and soybean oilmeal and (5) the proportion of the years in which a least-cost feeding system results in greater profits than a least-time feeding system. Substitution between major classes of feed such as corn and soybean oilmeal is possible mainly where the rations are fortified with appropriate quantities of trace minerals (as well as antibiotics in the case of drylot feeding). These fortifying elements have been included in the rations of this study

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

The contribution of X-linked coding variation to severe developmental disorders

Over 130 X-linked genes have been robustly associated with developmental disorders, and X-linked causes have been hypothesised to underlie the higher developmental disorder rates in males. Here, we evaluate the burden of X-linked coding variation in 11,044 developmental disorder patients, and find a similar rate of X-linked causes in males and females (6.0% and 6.9%, respectively), indicating that such variants do not account for the 1.4-fold male bias. We develop an improved strategy to detect X-linked developmental disorders and identify 23 significant genes, all of which were previously known, consistent with our inference that the vast majority of the X-linked burden is in known developmental disorder-associated genes. Importantly, we estimate that, in male probands, only 13% of inherited rare missense variants in known developmental disorder-associated genes are likely to be pathogenic. Our results demonstrate that statistical analysis of large datasets can refine our understanding of modes of inheritance for individual X-linked disorders

Enterobactin-Mediated Delivery of β-Lactam Antibiotics Enhances Antibacterial Activity against Pathogenic Escherichia coli

The design, synthesis, and characterization of enterobactin–antibiotic conjugates, hereafter Ent-Amp/Amx, where the β-lactam antibiotics ampicillin (Amp) and amoxicillin (Amx) are linked to a monofunctionalized enterobactin scaffold via a stable poly(ethylene glycol) linker are reported. Under conditions of iron limitation, these siderophore-modified antibiotics provide enhanced antibacterial activity against Escherichia coli strains, including uropathogenic E. coli CFT073 and UTI89, enterohemorrhagic E. coli O157:H7, and enterotoxigenic E. coli O78:H11, compared to the parent β-lactams. Studies with E. coli K-12 derivatives defective in ferric enterobactin transport reveal that the enhanced antibacterial activity observed for this strain requires the outer membrane ferric enterobactin transporter FepA. A remarkable 1000-fold decrease in minimum inhibitory concentration (MIC) value is observed for uropathogenic E. coli CFT073 relative to Amp/Amx, and time-kill kinetic studies demonstrate that Ent-Amp/Amx kill this strain more rapidly at 10-fold lower concentrations than the parent antibiotics. Moreover, Ent-Amp and Ent-Amx selectively kill E. coli CFT073 co-cultured with other bacterial species such as Staphylococcus aureus, and Ent-Amp exhibits low cytotoxicity against human T84 intestinal cells in both the apo and iron-bound forms. These studies demonstrate that the native enterobactin platform provides a means to effectively deliver antibacterial cargo across the outer membrane permeability barrier of Gram-negative pathogens utilizing enterobactin for iron acquisition.Pacific Southwest Regional Center of Excellence for Biodefense and Emerging Infectious DiseaseKinship Foundation. Searle Scholars ProgramMassachusetts Institute of Technology. Department of Chemistr

Finding Diagnostically Useful Patterns in Quantitative Phenotypic Data.

Trio-based whole-exome sequence (WES) data have established confident genetic diagnoses in ∼40% of previously undiagnosed individuals recruited to the Deciphering Developmental Disorders (DDD) study. Here we aim to use the breadth of phenotypic information recorded in DDD to augment diagnosis and disease variant discovery in probands. Median Euclidean distances (mEuD) were employed as a simple measure of similarity of quantitative phenotypic data within sets of ≥10 individuals with plausibly causative de novo mutations (DNM) in 28 different developmental disorder genes. 13/28 (46.4%) showed significant similarity for growth or developmental milestone metrics, 10/28 (35.7%) showed similarity in HPO term usage, and 12/28 (43%) showed no phenotypic similarity. Pairwise comparisons of individuals with high-impact inherited variants to the 32 individuals with causative DNM in ANKRD11 using only growth z-scores highlighted 5 likely causative inherited variants and two unrecognized DNM resulting in an 18% diagnostic uplift for this gene. Using an independent approach, naive Bayes classification of growth and developmental data produced reasonably discriminative models for the 24 DNM genes with sufficiently complete data. An unsupervised naive Bayes classification of 6,993 probands with WES data and sufficient phenotypic information defined 23 in silico syndromes (ISSs) and was used to test a "phenotype first" approach to the discovery of causative genotypes using WES variants strictly filtered on allele frequency, mutation consequence, and evidence of constraint in humans. This highlighted heterozygous de novo nonsynonymous variants in SPTBN2 as causative in three DDD probands