Now showing items 4998-5017 of 19641


      Clark, Don; Smith, Robert James; Allen, Paul M.; Barnes, Don; Gose, Ken; Droegemueller, Lee (The University of Arizona., 1986)
      The purpose of this study was to investigate the impact of a teacher/advisor program on early adolescents' perception of self image. A review of the literature revealed much which proclaims the virtues of the teacher/advisor program but at the same time demonstrated an absence of any significant research which verifies that such programs, in fact, accomplish what their proponents claim. Because a notable amount of research supports the inclusion of educational experiences which heighten self image, determining specifically what effects a teacher/advisor program has would satisfy the need to validate the credibility of this concept and aid middle level educators in assessing its value. A pretest-posttest control group design with multiple measures of self image was employed. The sample consisted of 145 seventh grade students from two middle level schools. The experimental group came from a 6-7 school with a total of 73 students participating, 37 male and 36 female. The control group came from a 7-8 school with 72 students participating; both males and females numbered 36. Subjects were administered a questionnaire, which was composed of seven self image or transition research, at the beginning of the fall semester and again nine weeks later. Subjects in the experimental group received a thirty minute per day teacher/advisor program during this time interval. The findings of this study revealed significant group effects for the measures of victimization and perceived self image. For the measures of anonymity, self-consciousness, and the three self-esteem measures, however, group effects were not observable. Furthermore, examination of the results using gender as a variable showed no significant difference in any of the seven self image constructs. The data indicate that participation in a teacher/advisor program tended to suppress perceptions of victimization, which can be construed as a positive effect, and to lower perceived self image, which can also be viewed as beneficial if construed as a more realistic occurrence.
    • Early childhood programs and the Arizona public schools: Promises and practices.

      Desjean-Perrotta, Blanche.; Clark, Donald; Paul, Alice; McCorkle, Mary Belle (The University of Arizona., 1995)
      This study explored the public school system in the state of Arizona as a provider of programs for young children. It specifically addressed the quality of preschool at-risk programs administered by the State Department of Education and compared practices to the promises set forth in the Guidelines for Comprehensive Early Childhood Programs as reported by the Early Childhood Advisory Council to the Arizona State Board of Education (1990). The study examined program quality of twelve preschool programs through the lens of the standards for developmentally appropriate early childhood experiences as outlined in the Guidelines, Section 2, titled "Preschool Program Operation." The study consisted of in-depth case studies designed to provide a picture of the essence of what life is like in a preschool program through the eyes of the child. Three basic instruments were used for data collection on site visits: (1) observations, (2) questionnaires, and (3) recorded interviews. Classroom observations were guided by two previously developed and validated instruments: a Shadow Study Observation Form (SSOF) designed by Lounsbury and Clark (1990) for a national shadow study of middle school students, and the Early Childhood Environment Rating Scale (ECERS) developed by Thelma Harms and Richard Clifford (1980) at the Frank Porter Graham Child Development Center at the University of North Carolina at Chapel Hill. These two instruments complemented each other and provided an extensive description of an early childhood program in operation. The second component of data consisted of a survey of directors and teachers designed to obtain information about directors' and teachers' knowledge, attitudes, and beliefs about preschool education and basic demographic information. The third instrument was a set of interview protocols for program directors and teachers. Collectively, the data offered a comprehensive profile of the nature of the state-administered preschool programs in practice as experienced by the child. It also provided an agenda of recommendations for those concerned with quality early childhood public school programs in the state of Arizona.
    • Early childhood teachers' content and pedagogical knowledge of geometry

      Larson, Carol F.; Maxedon, Sandra Jo (The University of Arizona., 2003)
      This study investigated early childhood teachers' knowledge of the following four components of the professional knowledge base: goals of geometry, child development and geometry, geometry curriculum and curriculum content, and geometric concepts. Eight experienced early childhood teachers in grades kindergarten through two participated in interviews on each of the four knowledge components. Their responses to interview questions and geometric concept activities were electronically recorded and transcribed for analysis of patterns, trends, or themes which emerged for the group. The teachers knew how geometry would benefit students and could elucidate their own goals when teaching geometry. They were more familiar with their district's curriculum and performance objectives for geometry than they were with state or national goals. They had ideas about what constitutes developmentally appropriate practice, both generally and in geometry education. Child development as it relates to geometry was an elusive concept. Their expertise in this area was primarily based on their experiences as teachers and their faith in the district's curriculum. They were somewhat familiar with pedagogical aspects of their grade level curricula, including expectations, materials, and resources, with shape names being their primary focus. They were less familiar with subject matter issues such as the scope and content of the geometry curricula in the grades preceding and following theirs, important geometric concepts for primary students, and the role of spatial visualization in children's development of geometry. When solving geometric problems, they tended to be anxious and uncertain but overall were persistent problem solvers who willingly communicated their thinking. Their problem solving was marked by doubt, self-talk, hand movements, and ambiguity. In general there was evidence of difficulty with class inclusion, deductive reasoning, and conceptual verbalization.
    • Early Confucianism: A Study of the Guodian Confucian Texts

      Wu, Jiang; Harper, Donald; Wong, Kwan Leung; Wu, Jiang; Harper, Donald; Shields, Anna M. (The University of Arizona., 2006)
      A discovery unearthed in Jingmen of Hubei province in 1993 has surprised all the students of ancient China studies. A bundle of bamboo manuscripts, which include Taoist and Confucian texts, provides valuable sources for us to reshape our knowledge of the intellectual background and development in the fourth century B.C.In my research, I chose four Confucian texts, Lu Mugong wen zisi, Qiongda yi shi, Tang yu zhi dao and Zhongxin zhi dao, from these Guodian manuscripts as the objects of my studies. I argue that these four texts each has its individual origin rather than all four texts being from a single tradition. These four texts transcribed on two individual rolls can be divided into two units. Lu Mugong wen zisi and Qiongda yi shi form one unit as the ethical guidance for the tomb occupant; while Tang yu zhi dao and Zhongxin zhi dao form another unit as the tomb owner's personal favorite philosophical writings.It is believed that Tang yu zhi dao was a study derived from remote antiquity and the genealogy of ancient emperors. Zhongxin zhi dao was a learning of Confucius' disciple, Zizhang. Both texts were closely related to the ritual documents of the Warring States period.Using the fresh unearthed evidence and ritual documents from Liji and Dadai liji, my research explores the early Confucianism from the death of Confucius to before Mencius.
    • Early designation of at-riskness: A follow-up study of developmental first-graders.

      Sacken, Donal M.; Callicotte, Nancy Rice; Ames, Wilbur S.; Medina, Marcello (The University of Arizona., 1991)
      This study takes an in-depth look at five children who participated in a developmental first grade program after a year in kindergarten. The characteristics of the students that led to their placement in the developmental program, the program itself, and the school progress of the students in the three years following participation in the developmental program are described. Students included in the sample were selected on the basis of their consecutive attendance in the same school for a period of five years to permit a longitudinal perspective on the schooling experiences of children perceived to be at-risk of school failure in the early years of schooling. Availability of classroom teachers for interviewing was also a consideration in sample selection. Qualitative research methods were used to develop detailed case studies on each of the five children. Interviews were conducted with the students themselves, their parent(s), classroom teachers, special area teachers, and other school personnel having contact with each student. School records, including special education records when applicable, were reviewed. In addition to document analysis and interviews, the children were observed in their third grade classrooms. The study examined the characteristics demonstrated by young children perceived to be at-risk in the traditional school setting, their teachers' perceptions of them in subsequent years, and their school progress through third grade. Several issues emerged from the data. These were discussed along with suggestions for consideration by policy makers to more effectively meet the needs of young children perceived to be at-risk of school failure. Recommendations were made for further research.
    • The Early Detection of Depression from Social Networking Sites

      Mehl, Matthias; Holleran, Shannon; Mehl, Matthias; Greenberg, Jeff; Stone, Jeff (The University of Arizona., 2010)
      Depression has a high prevalence among college students. Because it is a highly private (i.e. experiential) and socially stigmatized mental illness, it often goes undetected in daily life. The basic research question behind this line of research is how students' postings on their social networking websites can be used for the early detection of depression. The current research investigates how well depression can be gauged from MySpace profiles (Study 1) and Facebook profiles (Study 2 & Study 3). Across studies, the results reveal that depression can be assessed with a moderate degree of accuracy. In addition, Study 3 presents evidence that viewing "mini-blogs" allows for similar levels of accuracy compared to viewing an entire profile and the degree to which a person is Extraverted or censors information about themselves (e.g. Impression Management, Public Self-Consciousness) influences the degree of accuracy. Overall, the results speak to the idea that social networking sites can be a cost effective and clinically relevant tool to detecting depression.

      Scofield, Margaret Sisson, 1947- (The University of Arizona., 1973)
    • Early evolution of coal nitrogen in opposed flow combustion configurations.

      Wendt, Jost O.L.; Ghani, Muhammad Usman.; Peterson, Thomas W.; Shadman, Farhang; Perkins, Henry C.; Ramohalli, Kumar N.R. (The University of Arizona., 1990)
      A laminar opposed flow, pulverized coal combustion configuration was used to explore the early evolution of light gaseous nitrogenous and hydrocarbon species into the bulk gas phase. Two coals of different ranks were considered. Effects of pyrolysis environment, particle size and heating rates were investigated. Concentration profiles of HCN, NH₃, NO, CH₄, C₂H₂, C₂H₄ and C₂H₆ were measured, under both oxidizing and reducing environments, for three particle sizes, and at high heating rates provided by the hot flue gases of a CO/O₂/Ar flame. Net rates of formation into the bulk gas phase were calculated from the experimental data after correcting for diffusion and convection effects, and were then related to particle time-temperature histories. Experimental data show that HCN precedes NH₃ and NO for both coals. It is the first light gaseous product of coal nitrogen evolution entering into the bulk gas phase. For low rank coals, either only a small amount of tar nitrogen is released or its subsequent oxidation to light gaseous products is slow. For high rank coals secondary reactions of tars are rapid and lead to substantial levels of nitrogenous species. Nature of nitrogenous species evolving into the bulk gas phase was found to be independent of particle size. Lower heating rates favor increased yields of ammonia. Evolution of hydrocarbon species from high rank coals occurs via low molecular weight species, whereas low rank coals yield high molecular weight species. Evolution of hydrocarbon species was found to be independent of particle size and heating rates. Evolution of hydrogen occurs during late stages of devolatilization indicating that it is a product of secondary pyrolysis reactions. A simple kinetic model is proposed to relate rates of formation of nitrogenous species to coal devolatilization kinetics. The latter are similar for three experiments, with fine particles, involving two coals and can be described by a single rate constant given by 63.8 exp (-5220/RT). Bituminous coal (fines), under oxidizing conditions, shows substantially higher rates, possibly due to energy feedback mechanisms in the vicinity of the particles. Literature values, which originated from solid phase measurements, underpredict the quantities of total XN entering the post flame zone by substantial amounts. Our value, which was derived from gas phase species measurements, yields a better prediction of total nitrogenous species entering the post flame zone, and can be incorporated in engineering models aiming at optimizing of pollutant emissions.
    • Early Field Experience in Choral Methods

      Hamann, Donald L.; Kim, Irene J.; Cooper, Shelly; Draves, Tami J.; Hamann, Donald L. (The University of Arizona., 2013)
      The purpose of this study was to identify the value of early field experience (EFE) in choral methods courses, examine participants' likelihood to include EFE practice in choral methods courses, and determine the rationale for incorporating EFE. The study also explored the participants' preferences for activities related to early field experience, investigated possible relationships between EFE activities and participants' teaching experience or primary responsibility and perceived student outcomes of such participation. A survey instrument was distributed to choral music educators identified through the College Music Society. A total of 100 (after adjustments) responses were collected and analyzed employing descriptive and inferential statistics. The result displayed a high consensus among participants on the value and future implementation of EFE practice in choral methods. Participants declared that educational philosophy, personal experience, and requirements influenced their reason for implementing EFE, with personal experience receiving the highest positive response. The survey listed four categories of EFE activities--teaching, observation, evaluation methods, and other EFE activities. Highest rated activities from each categories were as follows: micro teaching at an elementary, middle, or high school; individual observation at an elementary, middle, or high school; reflection/self-evaluation and instructor feedback; and university choral ensemble participation. The result of Two-Way MANOVA to determine significant relationship between EFE activities and participants' teaching experience or primary responsibility reported no correlation in general with the exception of one activity. A significant difference was observed between attending choral seminars and conferences and participants' primary responsibility (p = .01, p<.05). Expected student outcome was measured through five skill types: personal, content, pedagogical, administrative, and communication skills. Of these, all participants agreed on personal skill (100%) followed by communication (95%), content (94%), and pedagogical skills (94%) as their highest expected EFE student outcome. Early field experience has gained notable recognition among music teacher educators in the past three decades. Numerous studies have verified the benefits of EFE and national organizations have actively supported the practice. The results of this study echoed the results of previous research with an overwhelming percentage of participants displaying a high enthusiasm for EFE practice in choral methods courses.
    • Early field experience: Four perspectives

      Doyle, Walter; Burant, Theresa Jean, 1958- (The University of Arizona., 1998)
      Early field experiences (EFEs) are common in teacher education; yet, there is conflicting evidence regarding their value as educative experiences. As the need for preparing prospective teachers for diversity becomes more urgent, research that attends to the context, content, and experiences of preservice teachers in EFEs in diverse schools is necessary. In this study, qualitative case study methodology was used to understand the experiences of preservice teachers, and the meanings they constructed of these experiences, in a reconceptualized EFE in teacher education. The EFE consisted of a team-taught, integrated combination of a general methods course (with a classroom, school, and community-focused field experience), and a foundations of education course, situated in the context of an urban middle/elementary school with a diverse student population. The sample consisted of four preservice teachers: a Mexican-American woman, an American Indian man, and two White women. Data were collected over a period of five months using participant observation, document analysis, interviews, and focus groups. Constant comparison and analytic induction were used to analyze data. Cases of the experiences of the participants revealed three major themes: (a) participation in varied communities; (b) use of multiple literacies to make sense of experience; and, (c) transformations in practices, understandings, and voice. Implications for teacher education from these cases address curriculum and pedagogy in EFEs, experiences that follow EFEs, admissions criteria, and recruitment of members of under-represented groups into teaching.

      Brendel, Klaus; SILBER, PAUL MICHAEL.; Gandolfi, Jay; Wright, Steve; Halpert, Jim (The University of Arizona., 1987)
      It is well known that a variety of toxicants can cause damage to the renal proximal tubule. However, the early pathogenesis of these deleterious interactions between a toxicant and this region of the nephron remain poorly understood. Thus, the purpose of this research was to attempt to answer three interrelated questions. First, what are the earliest changes in kidney function and structure after administration of tubule toxicants in vivo? Secondly, how do these structural/functional alterations change over time? Finally, are certain indicators of renal "dysfunction" more sensitive then others to the early stages of proximal tubule injury? The basic experimental approach consisted of injecting laboratory animals with a selective proximal tubule toxicant, and then collecting blood and/or urine at several timepoints after dosing; a variety of renal function indicators were evaluated at each of these timepoints. These included blood urea nitrogen (BUN), the glomerular filtration rate (GFR), and the excretion of glucose, protein, salts, glutathione, enzymes, and other endogenous molecules into the urine. At the termination of the exposure period the kidneys were evaluated histopathologically, and were also assayed for levels of specific enzymes and glutathione. Enzyme histochemistry was used to visualize changes in renal enzyme distribution, and protein electrophoretic methods permitted quantification of urinary proteins. These studies showed that specific markers of renal dysfunction were more sensitive to acute proximal tubule injury than other indicators. Specifically, the urinary excretion of proteins and the brush border membrane marker γ-glutamyl transpeptidase (GGT) were the best indicators of proximal tubule injury. Glucosuria, lysozymuria, and glutathionuria were all less sensitive markers, and changes in BUN or GFR were the poorest indicators of acute proximal tubule injury. These results indicated that the brush border membrane is one of the most susceptible regions of the proximal tubule to acute renal injury. Analysis of urinary protein electrophoresis patterns and kidney histopathology confirmed this hypothesis. This research also demonstrated the progression of the toxicant-tubule interaction over time, and showed that both tubule structure and function may be altered within minutes of administering a nephro-toxicant.

      Lapin, Charles Allan, 1950- (The University of Arizona., 1978)
    • Early Intervention Programs: Preemie Parents' Perceptions and Barriers to Participation

      Gephart, Sheila; Garcia, Cristianna; Peek, Gloanna; Phipps, Lorri; Gephart, Sheila (The University of Arizona., 2015)
      Infants born prior to 37 weeks gestation are at risk for countless medical problems and developmental delays. In order to help minimize these delays and improve the child’s potential, the Individuals with Disabilities Education Act, Part C, funds Early Intervention (EI) Services. These services may include speech, physical therapy, occupational therapy, or developmental therapy, among others. Purpose and Objective: While numerous studies show the benefits of EI therapies, little is known about barriers to EI participation, what the parents of these children who participate in EI think, or how to improve EI services. This study attempts to answer these questions. Methods: Surveys regarding EI were posted to three preemie parent organizations social media pages, and 140 surveys were returned. These surveys were analyzed for both quantitative and qualitative answers. Qualitative answers were coded and themes were garnered. Results: A total of 148 participants took the survey, and 76% had children that had participated or currently participate in EI. Of the parents who answered their child did not attend EI, most state there was no EI services near them, their child did not qualify, or the EI services were of poor quality. Of the EI parent surveys, most parents (73%) were happy with their child’s EI and their child’s progress, and would recommend EI to others. Most children had EI therapy at least weekly, and were referred to EI prior to leaving the NICU. Parents felt as though their child benefitted in nearly all domains. In addition to the benefits to their child, EI parents also felt as though therapy helped decrease their stress level, gave them a benchmark to measure their child’s progress and connected them with other professionals for their child. Some parents also provided recommendations to improve EI: decrease eligibility requirements, improve communication with parents, provide continuity of care, and create a bridge program for children three and up until they reach school age. Conclusions: With these suggestions, providers can help improve current EI services. Primary care providers should ensure children who are at risk for delays are referred, and EI services should improve communication with parents and enhance continuity of care.
    • Early Intervention Using Function-Based Planning For Children At-Risk for Emotional or Behavioral Disorders

      Nahgahgwon, Kari Noelle; Umbreit, John; Bergan, John; Perfect, Michell; Liaupsin, Carl (The University of Arizona., 2008)
      The purpose of this study was to contribute to the literature by examining a systematic set of methods to assess and treat the problem behavior of young at-risk children. This study examined the use of the Decision Model (Umbreit, Ferro, Liaupsin, & Lane, 2007) with two kindergarten students and one first grade student who were exhibiting chronic behavior problems despite implementation of interventions through their school's existing support system. The study was conducted across three phases including: Phase I (Descriptive Functional Assessment), Phase II (Intervention Development/Testing) and Phase III (Intervention Implementation). Interventions in Phase III, were systematically introduced to each student using a Multiple Baseline Design. The Decision Model was used to develop interventions that resulted in reductions in each child's disruptive behavior and increases in on-task academic behavior. Social validity was examined using the TARF-R and resulted in high acceptability ratings from each teacher responsible for implementing the intervention for each student. Limitations and directions for future research are discussed.
    • Early Laramide Magmatism in Southern Arizona U-Pb Geochronology of Key Igneous Units and Implications for the Timing of Regional Porphyry Copper Mineralization

      Barton, Mark D.; Mizer, Jason; Seedorff, Eric; Quade, Jay; Metz, Robert (The University of Arizona., 2018)
      Subduction of the Farallon slab under North America during Late Cretaceous time resulted in compressional forces that deformed and uplifted southern Arizona and produced widespread magmatism in several distinct periods. During early Laramide time voluminous eruptions of intermediate volcanic rocks and the emplacement of mostly barren intrusive centers occurred in the region. Subsequent magmatism resulted in the emplacement of numerous productive (porphyry copper) deposits, associated Ag-base metal deposits, and barren intrusive units. The timing of these events has been loosely constrained by early K-Ar ages and cross-cutting field relationships; in many districts early Laramide volcanic rocks host much of the porphyry mineralization, but the genetic relationship between intrusive and extrusive units in multiple districts remains poorly understood. The focus of this work is to investigate the timing of early Laramide magmatic events at several localities in southern Arizona (Silver Bell, Chilito/Christmas, Copper Creek, San Manuel, Cerro Colorado/Oro Blanco districts, Rosemont, Ajo, Texas Canyon/southern Winchester Mts., Dos Cabezas Mts., southwestern Santa Rita Mts., Granite Peak (Whetstone Mts.), and Tombstone), with an emphasis on regional volcanic units proposed by previous researchers to be 1) regionally equivalent in age and 2) genetically associated with the emplacement of porphyry copper mineralization. This investigation presents new U-Pb in zircon ages on key igneous units across southern Arizona to constrain the onset of early Laramide magmatism and to compare the timing of mineralization in several key mining districts with these early events. The objectives of this investigation are accomplished through systematic collection of early Laramide volcanic and intrusive rocks in mineral districts and areas adjacent to or believed to be associated with or known to host porphyry copper. This investigation presents 77 new U-Pb in zircon ages, one new U-Pb in monazite age, one new U-Pb in apatite age, two new Re-Os ages, and two new Ar-Ar age from intrusive and volcanic units across southern Arizona to document timing relationships through geochronology. Special attention was given to areas where intrusive and volcanic rocks are proximal to each other (within ~10 km, taking into account Cenozoic extension), and in districts where Ag-base metal mineralization is prominent and proposed to be associated with porphyry copper systems. The results of this investigation show that there is no single early Laramide volcanic unit that predates porphyry copper mineralization regionally. Geographic exposures of early Laramide volcanic rocks are distinct in age and may predate nearby mineralization by as little as 2 million years, and sometimes as many as 17 million years. These new data suggest that, while Laramide volcanic and intrusive rocks are present locally, they are likely not closely related. These results suggest Laramide magmatism in southern Arizona occurred in at least two phases: 1) early Laramide = large-volume volcanism (dominantly andesitic) ~80 – 71 Ma (possibly as old as 86 Ma), and 2) middle to late Laramide = high volume intrusive, very little volcanism (dominantly intrusive with rarely accompanying volcanism) 71 - ~55 Ma (with outlying intrusive units as young as 46 Ma). The results of this investigation also more tightly constrain the timing of sedimentation, contractional deformation, volcanism and subsequent intrusive events in the region.
    • Early Life Predictors of Allergic Disease

      Wright, Anne L.; Shahar, Eyal; Rothers, Janet; Sherrill, Duane; Pettygrove, Sydney; Wright, Anne L.; Shahar, Eyal (The University of Arizona., 2011)
      BACKGROUND: The prevalence of childhood asthma has been increasing worldwide. Modern societal exposures that have been implicated as possible causes of this increase include more hygienic lifestyles, antibiotic usage, and vitamin D deficiency. While there is much evidence that the origins of allergic disease begin in infancy, the uncertainty of asthma diagnosis in the first few years of life makes it difficult to assess the impact of early environmental exposures in very young children, and intermediate phenotypes that might assist in this assessment are lacking. An additional challenge to allergic disease research is the potential for gene-by-environment interactions, in which specific exposures differentially affect children depending on genotype. The objectives of this study were to assess relations of allergic disease outcomes (total IgE, specific IgE and asthma) with: 1) exposures related to modern lifestyle including day-care, antibiotic use and vitamin D levels; 2) cytokine profiles as a potential intermediate phenotypes; and 3) day-care exposure in the context of a relevant genotype.METHODS: This study utilizes data from a birth cohort. Allergic outcomes were assessed longitudinally through 5 years. Exposure data was collected by interview, or via blood samples in the case of vitamin D, cytokines, and genotype. Relations were assessed using longitudinal analysis techniques.RESULTS: Day-care was associated with decreased total and specific IgE through age 5. Antibiotics use was not associated with any outcome. Vitamin D levels showed 1) a U-shaped association with total and specific IgE, such that both high and low levels conveyed greater risk; and 2) no association with asthma. Cytokine profiles at 3 months of age, but not at birth, were predictive of total IgE and asthma. Finally, a significant gene-by-environment interaction was found between day-care and the TLR2/-16934 gene, such that the protective day-care relation occurred only for children carrying a T-allele.CONCLUSION: This study provides evidence that childhood allergic disease is inversely associated with day-care exposure and has a U-shaped relation with 25(OH)D levels at birth. It demonstrates that cytokine profiles as early as 3 months predict allergic outcomes through age 5 years, and finally, provides an example of a gene-by-environment interaction.
    • Early man in the San Pedro Valley, Arizona

      Hemmings, E. Thomas (The University of Arizona., 1970)

      Hester, James J. (The University of Arizona., 1961)
    • Early nutrition and development of the congeneric parasitoids, Encarsia formosa and Encarsia pergandiella (Hymenoptera: Aphelinidae)

      Hunter, Martha S.; Donnell, David M. (The University of Arizona., 2002)
      The congeneric wasps, Encarsia formosa and E. pergandiella (Hymenoptera: Aphelinidae) are solitary endoparasitoids with an overlapping host range. Despite their similarities these wasps produce eggs that differ markedly in size. This dissertation details research conducted to determine differences in the egg provisioning strategies of these two wasp species and to understand how these differences correlate with differences in their early development. The use of the yolk protein, vitellogenin, was examined in the two wasps. A vitellogenin gene was isolated from E. formosa and the mature gene product observed in ovary extracts. Evidence for the use of vitellogenin was not found in an analysis of ovary extracts from E. pergandiella and a gene for vitellogenin was not detected in the genome of this wasp. Embryonic development times for the two parasitoids were studied in hosts of different ages. The embryonic development time of E. formosa is significantly shorter than that of E. pergandiella regardless of the host stage parasitized. This suggests that the rate of embryonic development of E. pergandiella is much more closely linked to that of the host than the development rate of E. formosa. The quantity and composition of amino acids in the eggs of the two wasps was followed over the course of embryonic development. The quantity of amino acid in the eggs of E. formosa does not increase during embryonic development while the eggs of E. pergandiella absorb more than 30 times the quantity of amino acids from the host hemolymph during embryonic development than is present in the eggs at the time oviposition. Only E. pergandiella appeared capable of absorbing and utilizing [¹⁴C]-labeled lysine in an in vitro system. The capacity of E. pergandiella eggs to absorb host nutrients is correlated with the development of a multinucleate extraembryonic membrane that grows to completely encompass the embryo at a very early stage of development. Evidence was found for pinocytosis of material by the embryo from the space bounded by the extraembryonic membrane. A similarly developed extraembryonic membrane was not observed in the eggs of E. formosa .

      OLSZEWSKI, DEBORAH IRENE.; Jelinek, Arthur J.; Moore, Andrew; Fish, Paul; Thompson, Raymond H. (The University of Arizona., 1984)
      An understanding of the interrelationships between Levantine late Epipaleolithic chipped stone assemblages is essential for an understanding of the cultural developments responsible for early plant and animal domestication. The analysis of the differences and similarities in technological and typological attributes of chipped stone assemblages, in conjunction with site locale, material remains other than chipped stone, and reconstructions of prehistoric environmental and climatic conditions, leads to an increased awareness of the kinds of activities practiced by prehistoric groups in different areas of the Levant at that time. Until recently, a majority of the research on the Levantine late Epipaleolithic was confined to the Palestinian area, and to the Natufian complex that characterizes that region of the Levant. The analyses presented here are concerned with the description and interpretation of a late Epipaleolithic chipped stone assemblage from the northern Levant at Tell Abu Hureyra on the Euphrates River, and the ways in which this assemblage compares and contrasts with those from the Natufian area. This research provides new and important information about prehistoric activities in an area outside of the traditional Natufian core region of Palestine. A complete typological description of the Tell Abu Hureyra chipped stone assemblage is presented. This information is used to compare these materials with the assemblages from other north Syrian sites (Tell Mureybat, Dibsi Faraj East, Nahr el-Homr, el-Kowm, and Aarida 7). Using general tool classes, such as scrapers, burins, and notch/denticulates, the north Syrian assemblages are then compared, by means of distance coefficients, cluster analysis, and principal components analysis, with Natufian assemblages. The lunate, a geometric microlith, is examined in particular. The chronological value of lunate attributes established by certain authors is assessed for lunates from Natufian assemblages and from the Tell Abu Hureyra assemblage. The information derived from these analyses is assessed in conjunction with environmental data, and specific site character (such as open terrace or cave/shelter) to construct a general interpretation of the significance of the variability in the late Epipaleolithic assemblages of the Levant.