University of Missouri

About: University of Missouri is a education organization based out in Columbia, Missouri, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 41427 authors who have published 83598 publications receiving 2911437 citations. The organization is also known as: Mizzou & Missouri-Columbia.

Root growth maintenance during water deficits: physiology to functional genomics

Abstract: Progress in understanding the network of mechanisms involved in maize primary root growth maintenance under water deficits is reviewed. These include the adjustment of growth zone dimensions, turgor maintenance by osmotic adjustment, and enhanced cell wall loosening. The role of the hormone abscisic acid (ABA) in maintaining root growth under water deficits is also addressed. The research has taken advantage of kinematic analysis, i.e. characterization of spatial and temporal patterns of cell expansion within the root growth zone. This approach revealed different growth responses to water deficits and ABA deficiency in distinct regions of the root tip. In the apical 3 mm region, elongation is maintained at well-watered rates under severe water deficit, although only in ABA-sufficient roots, whereas the region from 3-7 mm from the apex exhibits maximum elongation in well-watered roots, but progressive inhibition of elongation in roots under water deficit. This knowledge has greatly facilitated discovery of the mechanisms involved in regulating the responses. The spatial resolution with which this system has been characterized and the physiological knowledge gained to date provide a unique and powerful underpinning for functional genomics studies. Characterization of water deficit-induced changes in transcript populations and cell wall protein profiles within the growth zone of the maize primary root is in progress. Initial results from EST and unigene analyses in the tips of well-watered and water-stressed roots highlight the strength of the kinematic approach to transcript profiling.

Communicating evidence for participatory decision making

Abstract: ContextInformed patients are more likely to actively participate in their care, make wiser decisions, come to a common understanding with their physicians, and adhere more fully to treatment; however, currently there are no evidence-based guidelines for discussing clinical evidence with patients in the process of making medical decisions.ObjectiveTo identify ways to communicate evidence that improve patient understanding, involvement in decisions, and outcomes.Data Sources and Study SelectionSystematic review of MEDLINE for the period 1966-2003 and review of reference lists of retrieved articles to identify original research dealing with communication between clinicians and patients and directly addressing methods of presenting clinical evidence to patients.Data ExtractionTwo investigators and a research assistant screened 367 abstracts and 2 investigators reviewed 51 full-text articles, yielding 8 potentially relevant articles.Data SynthesisMethods for communicating clinical evidence to patients include nonquantitative general terms, numerical translation of clinical evidence, graphical representations, and decision aids. Focus-group data suggest presenting options and/or equipoise before asking patients about preferred decision-making roles or formats for presenting details. Relative risk reductions may be misleading; absolute risk is preferred. Order of information presented and time-frame of outcomes can bias patient understanding. Limited evidence supports use of human stick figure graphics or faces for single probabilities and vertical bar graphs for comparative information. Less-educated and older patients preferred proportions to percentages and did not appreciate confidence intervals. Studies of decision aids rarely addressed patient-physician communication directly. No studies addressed clinical outcomes of discussions of clinical evidence.ConclusionsThere is a paucity of evidence to guide how physicians can most effectively share clinical evidence with patients facing decisions; however, basing our recommendations largely on related studies and expert opinion, we describe means of accomplishing 5 communication tasks to address in framing and communicating clinical evidence: understanding the patient's (and family members') experience and expectations; building partnership; providing evidence, including a balanced discussion of uncertainties; presenting recommendations informed by clinical judgment and patient preferences; and checking for understanding and agreement.

SNP discovery and allele frequency estimation by deep sequencing of reduced representation libraries

Abstract: High-density single-nucleotide polymorphism (SNP) arrays have revolutionized the ability of genome-wide association studies to detect genomic regions harboring sequence variants that affect complex traits. Extensive numbers of validated SNPs with known allele frequencies are essential to construct genotyping assays with broad utility. We describe an economical, efficient, single-step method for SNP discovery, validation and characterization that uses deep sequencing of reduced representation libraries (RRLs) from specified target populations. Using nearly 50 million sequences generated on an Illumina Genome Analyzer from DNA of 66 cattle representing three populations, we identified 62,042 putative SNPs and predicted their allele frequencies. Genotype data for these 66 individuals validated 92% of 23,357 selected genome-wide SNPs, with a genotypic and sequence allele frequency correlation of r = 0.67. This approach for simultaneous de novo discovery of high-quality SNPs and population characterization of allele frequencies may be applied to any species with at least a partially sequenced genome.

Evolution Semigroups in Dynamical Systems and Differential Equations

Abstract: Introduction Semigroups on Banach spaces and evolution semigroups Evolution families and Howland semigroups Characterizations of dichotomy for evolution families Two applications of evolution semigroups Linear skew-product flows and Mather evolution semigroups Characterizations of dichotomy for linear skew-product flows Evolution operators and exact Lyapunov exponents Bibliography List of notations Index.

Development of a passive, in situ, integrative sampler for hydrophilic organic contaminants in aquatic environments.

Abstract: Increasingly it is being realized that a holistic hazard assessment of complex environmental contaminant mixtures requires data on the concentrations of hydrophilic organic contaminants including new generation pesticides, pharmaceuticals, personal care products, and many chemicals associated with household, industrial, and agricultural wastes. To address this issue, we developed a passive in situ sampling device (the polar organic chemical integrative sampler [POCIS]) that integratively concentrates trace levels of complex mixtures of hydrophilic environmental contaminants, enables the determination of their time-weighted average water concentrations, and provides a method of estimating the potential exposure of aquatic organisms to the complex mixture of waterborne contaminants. Using a prototype sampler, linear uptake of selected herbicides and pharmaceuticals with log K(ow)s < 4.0 was observed for up to 56 d. Estimation of the ambient water concentrations of chemicals of interest is achieved by using appropriate uptake models and determination of POCIS sampling rates for appropriate exposure conditions. Use of POCIS in field validation studies targeting the herbicide diuron in the United Kingdom resulted in the detection of the chemical at estimated concentrations of 190 to 600 ng/L. These values are in agreement with reported levels found in traditional grab samples taken concurrently.