9,571 research outputs found
Effect of 2-Substitution on the Rearrangement of 1-Cyclopropylvinyl Cations
2-Substitution in 1-cyclopropylvinyl cations
produces a steric effect on cation generation and solvent
trapping, but an electronic charge-stabilizing effect
on cyclopropyl-to-cyclobutyl rearrangement
Investigation of smooth specimen scc test procedures; variations in environment, specimen size, stressing frame, and stress state
The variables studied in the stress-corrosion cracking performance of high strength aluminum alloys were: (1) corrosiveness of the environment, (2) specimen size and stiffness of the stressing system, (3) interpretation of transgranular cracking, and (4) interaction of the state of stress and specimen orientation in a product with an anisotropic grain structure. It was shown that the probability of failure and time to fracture for a specimen loaded in direct tension are influenced by corrosion pattern, the stressing assembly stiffness, and the notch tensile strength of the alloy. Results demonstrate that the combination of a normal tension stress and a shear stress acting on the plane of maximum susceptibility in a product with a highly directional grain cause the greatest tendency for stress-corrosion cracking
The Impact of See the Sound Visual Phonics Has on Beginning Readers
This paper takes a deeper look at the impact that See the Sound: Visual Phonics has for beginning reading instruction and early intervention instruction for young students. See the Sound: Visual Phonics is a strategy that incorporates hand cues and written symbols into every sound and letter in the English Language. This paper will compare the growth rates that students, who received the intervention and students who did not receive the intervention, made identifying letter names, letter sounds, and onset sounds. Throughout this paper research completed by Goldin-Meadow (2004) supporting the significance hand gestures have in development and student learning, as well as research by Dave Krupke (2008), a lead researcher and trainer in See the Sound: Visual Phonics discussing why this type of visual phonics has a greater impact than others will be considered. Other research completed by Cihon, Gardner, and Morrison (2008) will examine how this specific intervention increases literacy skills for young students who are at-risk readers
ECOPHYSIOLOGICAL RESPONSES OF TROPICAL WOODY SPECIES TO AMBIENT AND ELEVATED TEMPERATURES
Tropical forests cycle one third of Earth’s carbon, yet we are still unsure how tropical vegetation will respond to climate warming. Tropical biomes experience a smaller temperature margin compared to other systems, possibly making them less capable of thermal adjustments. In addition, thermal responses of vegetation have been identified as one of the areas of greatest uncertainty for global carbon models. This dissertation works to quantify tropical forest photosynthetic responses to temperature as well as assessing physiological thermal acclimation of four tropical species. In Chapter, 2 we conducted a meta-analysis to investigate global tropical photosynthetic responses to temperature. We presented algorithms that quantify how instantaneous temperature responses vary for different climate regimes within the tropics. We found that mean annual temperature was the single variable that best predicted most temperature response variables. Stepwise regression showed that including light in net photosynthetic models improved predictive power but, overall, we need better representations of tropical responses to different growth types and conditions. We implemented two in situ warming experiments in a Puerto Rican rainforest to assess physiological thermal acclimation. One experiment was implemented in the understory (Chapter 3) and one in the canopy (Chapter 4). Our understory warming experiment found evidence for net photosynthetic acclimation; however, acclimation did not systematically occur across both warming studies. Some species showed evidence of acclimation of the optimum temperature for photosynthesis (Topt) or both Topt and the photosynthetic rate; while, neither of our canopy species photosynthetically acclimated. Contrary to common hypotheses surrounding plant respiration, only one of the four species showed evidence of respiratory acclimation. Our understory vegetation temperature responses were more strongly controlled by soil moisture than temperature itself. Specifically, the photosynthetic rate declined as soils dried, a response that coincided with stomatal conductance. Surprisingly, Topt decreased with increasing height for our canopy species, and this response was likely, in part, due to higher thermal sensitivity of stomatal conductance in the mid and upper canopies. Additionally, our canopy species were found to be operating right at or above their Topt. The results of this dissertation better quantify tropical physiological responses to temperature, as well as assesses the potential of tropical plants to physiologically acclimate
Exploring Provider-Patient Interactions with Young Children in the Dental Setting
A key element that must be addressed when striving for good overall health is positive oral health practices that begin early in life (AAPD; 2013, 2014). Unfortunately, two major difficulties are commonly faced by dental providers who try to implement these positive oral health practices in young children: dental fear and behavior management problems. The current study aimed to examine how the natural interactions that occur between a dental provider and child patient may be related to child dental fear and behavior. Dental appointments for 36 children under the age of six years old were examined, and verbal and behavioral interactions between the dental provider and child were coded. Analyses were then run to compare these behavioral codes to the Children’s Fear Survey Schedule-Dental Subscale (CFSS-DS; Cuthbert & Melamed, 1982) and the Frankl Behavior Rating Scale (Frankl; Frankl, Shiere, & Fogels, 1962). Interestingly, a significant correlation was found between the CFSS-DS and the Frankl, indicating a strong association between the participants who were dentally fearful and those who displayed challenging behaviors during their appointment. Additionally, significant differences in the use of four behavioral codes existed between dentists and dental hygienists. However, no significant relationships were found between the behavioral codes and the Frankl. These findings suggest that future efforts should be aimed at reducing both child dental fear and behavioral management problems, due to their interconnected nature, in order to improve the early dental experiences, and overall well-being, of children
Health Management and Policy Capstone: A Case Study in Program Evaluation
Program evaluation of a hypothetical comprehensive hypertension self-management program as directed by the CDC Framework for Program Evaluation in Public Health
Current needs and response to suicidal behavior at the elementary school level: A survey of Virginia school psychologists
While minimal information on suicidal behavior at the elementary school level is available, a review of the existing literature demonstrates the erroneous belief that children lack the developmental maturity to understand the concept of death and suicide. To better understand prevalence rates of suicidal behavior in elementary school-aged children, interventions offered to those children, reported levels of practitioner competence, and overall preparedness of elementary school personnel in appropriately addressing suicidal behavior demonstrated by their students, the researcher surveyed 155 Virginia school psychologists. Results from the online survey revealed that while suicidal behavior in elementary school-aged students is rare, school-based professionals do believe that these students are at-risk for experiencing or demonstrating such behavior. Furthermore, school psychologists largely depend on school counselors to lead intervention efforts and communicate valuable information with them. While there are many needs in elementary schools, Virginia school psychologists have expressed the need for additional training opportunities in addition to establishing strong crisis response plans to respond to concerns as soon as possible
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