Family Context and Weight Status among 18-Month-Old Infants in Southern Appalachia: The Role of Temperament, Parenting Style, and Maternal Feeding Practices.

Pediatric obesity is a major public health crisis in the United States, and is particularly prevalent in the Southeast. Recent research has shifted the focus toward identifying obesity risk factors earlier in the lifespan, as 9.7% of infants and toddlers are at high weight-for-length (\u3e95th percentile). Family context variables have been found to be related to infant and child weight status. A better understanding of these early contributors may facilitate the continued development of interventions for infants and toddlers at risk for obesity. The purpose of the current study was to examine infant weight as it relates to parent-report of temperament, parenting style, and maternal feeding practices, in a sample of 18-month old children (n = 58) residing in Southern Appalachia. Mothers completed three surveys at infant age 18 months: the Early Childhood Behavior Questionnaire (ECBQ), the Parental Authority Questionnaire (PAQ), and the Infant Feeding Questionnaire (IFQ). Anthropometric data was obtained for parents and infants and contributed to body mass index (BMI) and standardized weight-for-length scores, respectively. Maternal BMI and percentile scores were obtained from the Centers for Disease Control and Prevention (CDC). Weight-for-length scores and percentiles were derived from infant weight and recumbent length measures using the 2006 World Health Organization (WHO) Growth Standards. Results of bivariate correlations showed authoritarian parenting style was negatively associated with infant weight status, r(51) = -.34, p \u3c .05. In contrast to previous findings related to early childhood, infants of authoritarian parents were found to be of lower weight status. This novel finding suggests that the role of parenting style in infancy may differ from early childhood. Further longitudinal research beginning in infancy is warranted to examine the role of these concurrent factors on later development

Quantum control via a genetic algorithm of the field ionization pathway of a Rydberg electron

Quantum control of the pathway along which a Rydberg electron field ionizes is experimentally and computationally demonstrated. Selective field ionization is typically done with a slowly rising electric field pulse. The $(1/n^*)^4$ scaling of the classical ionization threshold leads to a rough mapping between arrival time of the electron signal and principal quantum number of the Rydberg electron. This is complicated by the many avoided level crossings that the electron must traverse on the way to ionization, which in general leads to broadening of the time-resolved field ionization signal. In order to control the ionization pathway, thus directing the signal to the desired arrival time, a perturbing electric field produced by an arbitrary waveform generator is added to a slowly rising electric field. A genetic algorithm evolves the perturbing field in an effort to achieve the target time-resolved field ionization signal.Comment: Corrected minor typographic errors and changed the titl

I. Development of novel silicon precursors for rapid and efficient radiofluorination reactions: synthesis and biological evaluation of a 18f-labelled estrogen dendrimer conjugate II. Other studies on 18f-labelled estrogens

Molecular imaging (MI) has revolutionized the visualization of complex biochemical processes in normal physiology and diseased states. Although still in its infancy, the data generated from MI studies aids in identifying sites of pathological involvement and provides key insight into the mechanisms that lead to the onset and progression of disease. Consequently, these techniques hold tremendous potential in the areas of diagnostics, therapy assessment, and drug development in the coming years. Amongst MI techniques, Positron Emission Tomography (PET) separates itself from the rest of the field with its exceptional sensitivity, near limitless depth of penetration and its ability to quantify metabolic processes in living patients. With the ability to visualize and quantify on an individualized basis, PET imaging has received considerable attention recently because of its potential for contributing to personalized medicine. Through better diagnosis, rational selection of targeted therapies, and individualization of therapy regimens for each patient, personalized medicine holds the promise of greatly improving patient outcomes as well as safeguarding against the use of unnecessary, harmful medical procedures. Given the current status of the PET field and the impact it has on many fields, significant effort is being made to expand the existing repertoire of imaging agents capable of further detailing pathophysiological processes beyond the most commonly used PET tracer, [18F]fluorodeoxyglucose, including the use of large, sensitive biomolecules such as peptides and antibodies, which may be of considerable clinical importance. However, the available methodology associated with PET isotope incorporation, specifically fluorine-18, involves rather harsh conditions that are incompatible with sensitive substrates, which restricts the availability of these agents and their subsequent clinical evaluation. Thus, there remains a tremendous need for rapid, mild and efficient methodology that can be used to label these previously inaccessible substrates in a direct, late-stage fashion. Chapter 1 presents a brief introduction into molecular imaging and the techniques available for use in the preclinical and clinical setting as well as in drug development. Additionally, the basics of PET principles and radiochemistry are introduced, with a significant focus on the synthetic difficulties involved in working with the most commonly used PET isotope, fluorine-18, and why there is a need for improved methodology for its incorporation into new radiopharmaceutical agents, especially sensitive ones. Chapter 2 details the development of methodology that targets the shortcomings of C-18F strategies through Si-18F bond formation approaches. We have developed a simple and straightforward strategy in radiofluorinating complex substrates at a late stage, at room temperature, or in an aqueous environment in high radiochemical yields and specific activities through a reactive silyl acetate moiety. The utility and versatility of the approach is showcased in three main areas of research: small adaptor molecules, small molecules, and peptides. We have applied this Si-18F labeling strategy (Chapter 3) to prepare a fluorine-18 labeled version of 17α-ethynylestradiol conjugated PAMAM dendrimer that can be used for in vivo distribution studies of this novel hormone-polymer conjugate. Through biodistribution studies, we have found that the EDC, a dendrimer-bound estrogen that provides selective cardiovascular protection without classical stimulation of uterus and mammary tissues, also shows selective, ER-mediated uptake and retention by the vascular target tissues, heart and aorta, but not the classical target, the uterus. These findings suggest that the selective cardiovascular protective effect of EDC is the result of two factors, one mechanistic (selective stimulation of the extra-nuclear pathway of ER action) and one pharmacokinetic (selective accumulation of EDC in vascular targets). This points to a new dimension for extending the selective, potentially beneficial actions of estrogens. Chapter 4 details the synthetic approaches towards the radiosynthesis a promising ER imaging agent, 2-[18F]fluoroestradiol, and illustrates the most well-known difficulty encountered in fluorine-18 chemistry, specifically the radiofluorination of electron-rich aromatic rings. Efforts have focused on the use of diaryliodonium salts which has afforded synthetically useful radiochemical yields of the desired compound and is currently being scaled up, in terms of radioactivity, for evaluation in animal studies

On the impact of variability and assembly on turbine blade cooling flow and oxidation life

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.Includes bibliographical references (leaves 77-79).The life of a turbine blade is dependent on the quantity and temperature of the cooling flow sup- plied to the blade. The focus of this thesis is the impact of variability on blade cooling flow and, subsequently, its impact on oxidation life. A probabilistic analysis is performed on a commercial jet engine to quantify the variability in blade flow and oxidation life due to variability in ambient conditions, main gaspath conditions, the cooling air delivery system, and the flow capability of the blade internal cooling passages. The probabilistic analysis is used to demonstrate that every blade in a turbine row must be individually modeled in order to accurately estimate the distribution of blade-row oxidation life for a population of jet engines. In particular, since the oxidation life of a blade row is limited by the highest temperature (and therefore lowest-flowing) blades, every blade must be individually represented to correctly model (1) the probability of observing (within a row) a blade with a low coolant flow capability, and (2) the flow rate (and therefore the metal temperature and life) of these passages. A simplified flow network model of the cooling air supply system and a row of blades is proposed which agrees qualitatively and quantitatively with the more complex flow network model of the entire jet engine. Using this simplified model, the controlling parameters which affect the distribution of cooling flow in a blade row are identified. Finally, a selective assembly method is proposed to decrease the impact of blade passage manufacturing variability on blade flow. The method classifies blades into groups based on passage flow capability and assembles rows from within the groups. As a result, the flow and the(cont.) oxidation life improve for the majority of blade rows, while segregating low-flow blades into sets that are no worse than random assembly. Alternatively, selective assembly can be used to allow blades to withstand increased turbine inlet temperature while maintaining the maximum blade metal temperature at random-assembly levels.by Carroll Vincent Sidwell.Ph.D

Constitutive expression of Yes-associated protein (Yap) in adult skeletal muscle fibres induces muscle atrophy and myopathy

Peer reviewedPublisher PD

Separating the influences of prereading skills on early word and nonword reading

The essential first step for a beginning reader is to learn to match printed forms to phonological representations. For a new word, this is an effortful process where each grapheme must be translated individually (serial decoding). The role of phonological awareness in developing a decoding strategy is well known. We examined whether beginning readers recruit different skills depending on the nature of the words being read (familiar words vs. nonwords). Print knowledge, phoneme and rhyme awareness, rapid automatized naming (RAN), phonological short-term memory (STM), nonverbal reasoning, vocabulary, auditory skills, and visual attention were measured in 392 prereaders 4 and 5 years of age. Word and nonword reading were measured 9 months later. We used structural equation modeling to examine the skills–reading relationship and modeled correlations between our two reading outcomes and among all prereading skills. We found that a broad range of skills were associated with reading outcomes: early print knowledge, phonological STM, phoneme awareness and RAN. Whereas all of these skills were directly predictive of nonword reading, early print knowledge was the only direct predictor of word reading. Our findings suggest that beginning readers draw most heavily on their existing print knowledge to read familiar words

Solvatochromic probes for detecting hydrogen-bond-donating solvents

Hydrogen bonding heavily influences conformations, rate of reactions, and chemical equilibria. The development of a method to monitor hydrogen bonding interactions independent of polarity is challenging as both are linked. We have developed two solvatochromic dyes that detect hydrogen-bond-donating solvents. The unique solvatochromism of the triazine architecture has allowed the development of probes that monitor hydrogen-bond-donating species including water