Design of x-ray source for real-time computed tomography

The reduction of motion blur in computed tomography (CT) drives the current research for multisource CT. Due to their compact nature, the current multisource systems utilize stationary angled anodes. Unfortunately, these configurations neither simplify the imaging geometry, nor satisfy the need for managing the high thermal loads demanded by real-time CT (30 acquisition frames per second). To add to the current field of knowledge, two x-ray tube concepts are presented in this dissertation. First, a simulation of transient thermal analysis was performed on a compact transmission-type x-ray tube anode operating in pulse-mode. A correlation was found between deposited beam power and maximum anode temperature for any anode thickness beyond 0.5 mm. A second approach was developed for higher current applications: a rotating cylindrical anode. A modified Oosterkamp equation was developed and used to investigate three beam-sweeping sequences. It was found that although increasing beam sweeping speed increased the maximum power, the deposited energy in the focal spot per acquisition time decreased. Ultimately the step-and shoot sequence was found to be optimal for the cylindrical anode. Next, MCNP was used to find the angular dependence of the fraction of energy that the backscattered electrons carry away from the focal spot for a curved anode. That information was then used in COMSOL to find the electron beam efficiency and maximum power for different incident angles using various focal spot lengths and anode diameters. After that a correlation between maximum deposited power, focal spot length, and rotational surface speed was found. Finally, design considerations are reported based upon a sensitivity analysis of a preliminary design for the cylindrical multisource anode --Abstract, page iii

Clarifying roles in family farm businesses

"This publication reviews four common challenges that farm families face as they navigate family roles and business roles when planning farm transfer. It also lists action steps that families can take to resolve these challenges and move the farm transfer process forward."--Page 1.Written by Mallory Rahe (Assistant Extension Professor, Division of Applied Social Sciences), Wesley Tucker (Field Specialist in Agricultural Business, MU Extension)Includes bibliographical reference

Southern Missouri beef cow-calf planning budget

"Using this planning budget, beef cow-calf farmers may estimate their costs and returns for 2023. Table 1 presents estimates for a cow-calf operation (50-cow herd size and purchased replacements) in Southern Missouri with either a fall or spring calving season. Assumptions were based on price forecasts as of September 2022. Detailed assumptions and feed requirements are summarized in Tables 2, 3 and 4. The production practices used to develop these cost estimates are common in Missouri beef farms. Use the “Your estimate” column to plan your operation’s costs and returns for 2023."--Page 1.Written by Wesley Tucker, Field Specialist, Agricultural Business; Joe Horner, State Specialist, Agricultural Business and Policy Extensio

Beef heifer planning budget

"Using this planning budget, farmers raising beef heifers may estimate their costs and returns for 2023. Table 1 presents estimates for calves purchased and sold later as bred replacement heifers in Missouri. Assumptions were based on price forecasts as of September 2022. Detailed inputs, feed requirements and machinery investments are summarized in Tables 2, 3 and 4. The production practices used to develop these cost estimates are common in Missouri beef farms. Use the 'Your estimate' column to plan your operation's costs and returns for 2023."--Page 1.Written by Wesley Tucker, Field Specialist, Agricultural Business; Joe Horner, State Specialist, Agricultural Business and Policy ExtensionNew 10/2018; Revised 09/202

Three types of farm meetings to strengthen the business and start a farm transition plan

"Families may be inclined to only conduct meetings when they need to make critical decisions. However, regular meetings create a culture of communication and inclusive decision-making. Scheduled communications also create opportunities for the family and the farm to evolve towards more open communications building trust and allowing the family to address areas of potential conflict. Communication allows a family to gather additional information and to acknowledge differences in management approaches when making decisions. This allows the farm business to be more creative and entrepreneurial. Therefore, regularly scheduled meetings increase the likelihood of business success and successful transitioning the farm. This publication discusses three types of meetings family businesses should consider holding to manage different family business needs: farm operating meetings, family business meetings and family council meetings. To assist families as they start these meetings, we also provide example topics for each type of meeting and guidelines for running a successful family meeting."--Page 1.Written by Mallory Rahe (Associate Extension Professor, Division of Applied Social Sciences), Wesley Tucker (Field Specialist in Agricultural Business, MU Extension)New 11/2022Includes bibliographical reference

Five phases of management transition during family farm succession

"This publication outlines a five-phase process for transitioning farm management responsibilities: Phase 1. Successor seeks experience and education away from the farm. Phase 2. Successor works for a trial period on the farm Phase 3. Successor begins taking management and ownership responsibilities Phase 4. Successor accepts advanced management and ownership responsibilities. Phase 5. Successor becomes majority manager and owner."--Page 1.Written by Wesley Tucker (Field Specialist in Agricultural Business, MU Extension), Alice Roach (Senior Research Associate, Division of Applied Social Sciences), Mallory Rahe (Associate Extension Professor, Division of Applied Social Sciences)New 10/2022Includes bibliographical reference

Southern Missouri beef cow-calf planning budget

"This budget presents information useful to beef farmers. Table 1 provides estimates for the 2021 year on a cow-calf operation (50-cow herd size and purchased replacements) in Southern Missouri for a fall and spring calving season. Assumptions were based on price forecasts as of October 2020. Detailed assumptions and feed requirements are summarized in Tables 2, 3 and 4. The production practices used to develop these cost estimates are common for beef farms in Missouri. Farmers are encouraged to modify this budget to fit their operation."--First page.Written by: Wesley Tucker (Field Specialist, Agricultural Business), Eldon Cole (Field Specialist, Livestock), Joe Horner (State Specialist, Agricultural Business and Policy)New 10/18; Revised 10/2

Sampling Balanced Forests of Grids in Polynomial Time

We prove that a polynomial fraction of the set of $k$-component forests in the $m \times n$ grid graph have equal numbers of vertices in each component, for any constant $k$. This resolves a conjecture of Charikar, Liu, Liu, and Vuong, and establishes the first provably polynomial-time algorithm for (exactly or approximately) sampling balanced grid graph partitions according to the spanning tree distribution, which weights each $k$-partition according to the product, across its $k$ pieces, of the number of spanning trees of each piece. Our result follows from a careful analysis of the probability a uniformly random spanning tree of the grid can be cut into balanced pieces. Beyond grids, we show that for a broad family of lattice-like graphs, we achieve balance up to any multiplicative $(1 \pm \varepsilon)$ constant with constant probability, and up to an additive constant with polynomial probability. More generally, we show that, with constant probability, components derived from uniform spanning trees can approximate any given partition of a planar region specified by Jordan curves. These results imply polynomial time algorithms for sampling approximately balanced tree-weighted partitions for lattice-like graphs. Our results have applications to understanding political districtings, where there is an underlying graph of indivisible geographic units that must be partitioned into $k$ population-balanced connected subgraphs. In this setting, tree-weighted partitions have interesting geometric properties, and this has stimulated significant effort to develop methods to sample them

The Effect of a High Fat Meal on Cerebral Vascular Function

It is well known that a single high fat meal (HFM) causes a robust and transient elevation in serum triglycerides (TG). This elevation in serum TG is a primary contributor to the post-prandial attenuation of peripheral vascular endothelial function, as assessed by flow-mediated dilation in the brachial artery. Whether a similar impairment in vascular reactivity can be observed in the cerebral circulation remains unknown, and was the focus of this investigation. PURPOSE: To test the hypothesis that cerebral vascular function is impaired following a HFM. METHODS: End-tidal carbon dioxide partial pressure (PETCO2), middle cerebral artery blood velocity (MCAVmean), calculated cerebral vascular conductance index (CVCI; MCAVmean/mean arterial pressure) and cerebral vasodilator response to rebreathing induced hypercapnia (% increase in CVC from baseline at common maximal ΔPETCO2) were assessed in 6 healthy young men (27 ±5 years). Measures were assessed during fasted baseline and again at 2 and 4 h post meal consumption (HFM day) or at a similar time point in the fasted state (TC day). The two visits were separated by 2-7 days and were conducted in a randomized order. Blood lipids were assessed at baseline and at the 2 h time point into each respective condition. RESULTS: As expected, consumption of the HFM significantly elevated serum TG concentrations relative to TC at 2 h (HFM: 101±38 to 169±77mg/dl, TC: 107±32 to 92±31mg/dl, P=0.007). However, the HFM had no effect of cerebral vasodilator capacity during rebreathing induced hypercapnia. The maximal increase in %CVC achieved at the highest common ΔPETCO2 during all conditions within each subject was unchanged during 2hr and 4hr post HFM or TC (condition x time interaction: P=0.96). Similarly, the slope of the change in %CVC per change in ΔPETCO2 was unaffected by HFM across time (P=0.49). CONCLUSION: Contrary to our hypothesis, and unlike the peripheral vasculature, our preliminary data suggest that the cerebral circulation appears to be protected from the acute negative effects of a high fat meal

Extensive error in the number of genes inferred from draft genome assemblies

Current sequencing methods produce large amounts of data, but genome assemblies based on these data are often woefully incomplete. These incomplete and error-filled assemblies result in many annotation errors, especially in the number of genes present in a genome. In this paper we investigate the magnitude of the problem, both in terms of total gene number and the number of copies of genes in specific families. To do this, we compare multiple draft assemblies against higher-quality versions of the same genomes, using several new assemblies of the chicken genome based on both traditional and next-generation sequencing technologies, as well as published draft assemblies of chimpanzee. We find that upwards of 40% of all gene families are inferred to have the wrong number of genes in draft assemblies, and that these incorrect assemblies both add and subtract genes. Using simulated genome assemblies of Drosophila melanogaster, we find that the major cause of increased gene numbers in draft genomes is the fragmentation of genes onto multiple individual contigs. Finally, we demonstrate the usefulness of RNA-Seq in improving the gene annotation of draft assemblies, largely by connecting genes that have been fragmented in the assembly process