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Revision of the tribe Serrolecaniini Shinji (Pseudococcidae) with discussion on other "legless" mealybugsHendricks, Harlan Judson 21 October 2005 (has links)
Of the estimated 1100 species of mealybugs, approximately 6% are described as possessing degenerative legs and antennae in the adult female developmental stage or having lost these structures altogether. Fifteen genera composing 63 species are often separated into their own taxonomic group based on these vestigial features (e.g., Sphaerococcinae), and are collectively known as the "legless" mealybugs. A comparative morphological analysis of adult females was undertaken to clarify the taxonomic placement of these species and to determine their relationships. Methods were included on collecting, preserving, slide-mounting, and measuring specimens, and on preparing illustrations. Keys to genera and species of "legless" mealybugs were developed.
Reduction or loss of legs and antennae apparently occurred convergently in response to similar environmental conditions and was not found supportive of homogeneity in the "legless" group as a whole. However, the genera Chaetococcus Maskell, Idiococcus Takahashi & Kanda, Kermicus Newstead, Serrolecanium Shinji, Tangicoccus Kozar & Walter, and a newly established genus share many characteristics and were treated as the tribe Serrolecaniini Shinji. The adult females of 13 species contained in these genera were redescribed, with illustrations produced for 12. A phylogenetic analysis of the tribe showed that converse to simplification in appendages, adaptations in other features (e.g., latero-projecting lobes and a caudally-directed vulva) probably developed to increase reproductive success and survivorship.
The genera Acinococcus Williams, Antonina Signoret, Antoninoides Ferris, Cypericoccus Williams, Nesticoccus Tang, Paludicoccus Ferris, Parapaludicoccus Mamet, Peridiococcus Williams, Pseudantonina Green, and Sphaerococcus Maskell are not closely related to one another or to members of the tribe Serrolecaniini based on adult female morphology. These 10 genera and their type species were redescribed, and illustrations produced for all but Nesticoccus sinensis Tang. Comments or redescriptions are provided for the 21 additional species that comprise these genera; however, the taxonomic placement of 18 additional species erroneously assigned to Pseudantonina and Sphaerococcus is uncertain.
Lectotypes were designated for Antonina crawi Cockerell, A. graminis Parrott, A. phragmitis Marchal, A. purpurea Signoret, A. waterstoni Newstead, Jdiococcus bambusae Takahashi & Kanda, Pseudantonina bambusae Green, Pseudolecanium disticlium Kuwana, and Sphaerococcus ethelae Fuller. A replacement name was proposed for the junior homonym Antoninella Sulc. The species names Antonina anceps Green, Antonina maritima Green, and Jdiococcus maanshanensis Tang & Wu are considered junior synonyms. Two species of Serrolecanium were described, and a new genus was established for the placement of Serrolecanium jiuhuaensis Wu and Serrolecanium sasae (Siraiwa). Six new name combinations are also made. / Ph. D.
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An investigation of the universe and anatomy of workBeruvides, Mario G. 06 June 2008 (has links)
This research study investigated eight specific work characteristics (outputs, inputs, work type, discretion level, work pursuit level, level of endeavor, decision type and maturity level), on three sub-populations of workers (production personnel, office/secretarial personnel, and university engineering professors). Thirty one production personnel from two organizations (the Print Shop and ABC Corporation-pseudonyms) located in southwest Virginia were used for the first group (B group). The second group (W group) comprised five office/secretarial personnel from an engineering department of a southwest Virginia university. The third group (K group) was made up of six engineering professors from three separate universities located in the eastern and midwest United States. The Wand K groups used a self-logging data collection technique (cued by a random beeper) to record information about the work tasks being accomplished when cued. For the B group, a modified work sampling technique was used to gather the same information on work tasks as in the W and K group data collection. This information was compiled by an on-site analyst working from a random time table to cue workers for the required information.
The purpose of this research was to validate a specified work model (BIW/K). The design uses stratified sampling (homogeneity within strata and heterogeneity between strata). A modified chi-squared statistical methodology (contingency table analysis) was used to analyze the data. The work definitions postulated by the BIW IK work model are supported by the research findings of this study. Specifically, four of the eight work characteristics (outputs, inputs, work type, and discretion level) of the work definitions were strongly supported by the results (p value ≪0.001). The remaining four characteristics (pursuit level, endeavors, decision type and maturity level) showed strong results (some p values ≪0.(01), but some aspects of the sub-classifications of the work characteristics are questionable. Along with the eight work characteristics, this study provides detailed data on worker location, product I service, equipment usage, and know ledge data for all three work groups. / Ph. D.
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Identification of the factors impacting immunosorbent performanceSubramanian, Anuradha 06 June 2008 (has links)
Immunoaffinity interactions can play a vital role in the purification of therapeutic proteins. In most cases immunoaffinity chromatography is used as the final clean up step to yield a highly pure product. The customized avidity of the parent antibody for a given antigen or hapten can make immunoaffinity chromatography an indispensable tool in the field of bioseparations. However, the use of immunoaffinity chromatography at a large scale is frequently precluded by the high capital costs of antibody columns. This is in part due to the low functional activity of immobilized antibodies and the high cost of pathogen free antibody.
The objective of this research was to detail the impact of orientation, multipoint attachment and high local density upon the functional activity of immobilized antibodies. Immobilization methods were designed to affect changes in both orientation and local density. Both metal and pH dependent murine monoclonal antibodies against human Protein C were used as model systems. The character of the antigen and antibody were modified to study the impact of orientation, local density and multipoint attachment. For example, modified antigens of various sizes having a single binding epitope were synthesized from polymer-peptide adducts. The lysyl residues of recombinant hPC were chemically modified to reduce chemical reactivity with the matrix while maintaining avidity for the Mab. The synthetic and recombinant antigens were used to mask the antigen binding regions (Fab) of a monoclonal antibody (Mab) prior to covalent immobilization on a porous membrane and beaded supports. In addition, lysyl residues of Mabs against hPC were chemically modified to reduce multipoint covalent attachment.
A 2-step method consisting of permeation and immobilization of antibodies was developed to manipulate local Mab density. Conventional single step immobilization by simultaneous reaction and diffusion produced highly local shell-like density. Immunosorbents made with the 2-Step method at greater than 3 mg Mab / ml gave 2-3 fold higher antigen binding efficiencies and a more uniform distribution of immobilized antibody.
Immunosorbents made from Mabs which were immobilized at low local density having masks consisting of large synthetic or recombinant antigens gave the highest antigen binding efficiency and the most accessible Fab domains to pepsin digest. Mabs at high or low densities containing modified or unmodified lysyl residues gave no difference in antigen binding efficiencies or accessible Fab domains to pepsin digests. In summary, for Mabs immobilized at low densities "orientation" of the antibody on the support was identified as having the most negative impact on immunosorbent performance with multipoint attachment being less important. At high antibody loadings the functional activity of antibodies is also impacted by high local density superimposed with orientation. / Ph. D.
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Simultaneous active control of flexural and extension power flow in thin beamsGibbs, Gary P. 26 October 2005 (has links)
The primary goal of this dissertation consisted of two related parts. The first was to develop an analytical basis for predicting the active control of flexural and extensional power flow in thin semi-infinite and finite beams using piezoelectric actuators and sensors. The second part was to experimentally demonstrate these techniques applied to actual beam systems. In order to maintain total control authority over the system, the control actuators must be able to adequately excite both flexural and extensional motion in the beam. Accurate sensing or estimation of the actual power flow (or variables that can be related to the power flow) in the finite beam in real time is also a requirement. This dictated the development of advanced, new sensing techniques. In order that these overall goals were achieved several tasks were carried out as discussed below.
A theoretical model for the excitation of a thin beam by a single piezoelectric actuator mounted on the surface was developed. The model predicts the simultaneous excitation of flexural and extensional motion by a single actuator whose relative amplitudes are functions of beam and actuator parameters. Further, a single pair of axially co-located, symmetrically bonded, and independently driven piezoelectric actuators can excite flexural and extensional motion of variable complex amplitudes.
A method for the real time filtering of net positive and negative traveling flexural and extensional waves was developed. The theoretical actuator and sensor models were used to study the control of flexural and extensional power.flow in both finite and semi-infinite beams subjected to point force excitation at the free end. These actuator and sensing techniques when combined with an multiple input/output adaptive controller can simultaneously control flexural and extensional power flow in regions of a beam system over a band of frequencies.
The control of flexural and extensional power flow in thin beams was also experimentally investigated for both finite and semi-infinite beams. Power flow attenuations of 30 dB or more downstream of the control actuator location were demonstrated using a single pair of piezoelectric actuators for both resonant and damped beam systems. The experimental and theoretical results demonstrate the effectiveness of piezoelectric actuators and piezoelectric wave vector filters in the control of flexural and extensional power flow in thin beams. / Ph. D.
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Initiating international collaboration: a study of the human genome organizationRumrill, Deborah 12 September 2009 (has links)
The formation of the Human Genome Organization, nicknamed HUGO, in 1988 was a response by scientists to the increasing number of programs designed to examine in detail human genetic material that were developing worldwide in the mid 1980s and the perceived need for initiating international collaboration among the genomic researchers. Despite the expectations of its founders, the Human Genome Organization has not attained immediate acceptance either inside or outside the scientific community, struggling since its inception to gain credibility. Although the organization has been successful as well as unsuccessful in its efforts to initiate international collaboration, there has been little or no analysis of the underlying reasons for these outcomes. This study examines the collaborative activities of the organization, which are new to the biological community in terms of kind and scale, and finds two conditions to be influential in the outcome of the organization’s efforts: 1) the prior existence of a model for the type of collaboration attempted; and 2) the existence or creation of a financial or political incentive to accept a new collaborative activity. / Master of Science
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Numerical simulation of stimulated electromagnetic emissions in the ionosphereCheng, K. T. 05 September 2009 (has links)
One-dimensional electrostatic plasma simulation using the particle-in-cell technique is used to study the spectral features of stimulated electromagnetic emission (SEE). SEE is a potential diagnostic tool to study the ionosphere and its spectrum provides a different view of the heated region from the incoherent scatter radar. At this time, a unified and complete theory which explains the SEE phenomena in detail does not exist. The SEE simulations we discuss are proposed to provide interpretation of many of the past puzzles of the experimental data, as well as to facilitate the design of future SEE experiments and the theoretical development of SEE.
In the numerical simulation, only the upper hybrid layer where the geomagnetic field is essentially perpendicular to the density gradient is modelled. Three of the SEE features, namely the downshifted maximum (DM), upshifted maximum (UM) and broad upshifted maximum (BUM), are suggested to be generated at the upper hybrid layer. We observed these three features which have many similarities in the simulation. It is evident that the DM and UM are generated by the same parametric instability involving lower hybrid waves while the BUM is produced by other different mechanisms. Boundary effects are found important on the generation of all three features in the simulation. Moreover, detailed investigation of the simulation results raises a number of questions concerning detailed generation mechanisms of SEE which have not been considered and answered in the past.
Besides the DM, UM and BUM features, the quenching of DM is also observed in the simulation when the pump frequency is very close to electron cyclotron harmonics. It is concluded that both the cyclotron damping and mode conversion of the upper hybrid wave into electron Bernstein modes are possible causes. Finally, some suggestions for the future SEE simulation are included. / Master of Science
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A critical examination of the phenomenon of claustrophobia: do subtypes exist?Febbraro, Gregorio A. R. 08 June 2010 (has links)
Claustrophobia, a fear of enclosed spaces, is thought of as being a unitary phenomenon. However, different subtypes of claustrophobia may exist. Some claustrophobics may be more similar to individuals with Panic Disorder with Agoraphobia in terms of situations feared, cognitions and symptoms whereas others might be similar to simple phobics with a specific fear of enclosed spaces. The purpose of this study was to investigate whether such subtypes exist. The Claustrophobia Situations Questionnaire (CSQ) and the Claustrophobia General Cognitions Questionnaire (CGCQ) were developed and exploratory factor analyses were performed on these scales. Two-factor solutions for both the anxiety and avoidance ratings on the CSQ were obtained accounting for 40.8% and 33.8% of the variance, respectively. Two subscales were created from each two-factor solution. A three-factor solution was obtained for the CGCQ accounting for 53.6% of the variance from which three subscales were created. Differential validity of the scales and their utility in identifying claustrophobic subtypes was assessed. Self-report measures and physiological response to a hyperventilation challenge were used to validate claustrophobic subtypes. A significant main effect for "Avoidance of Crowds" was found when using heart rate change and post heart rate as dependent measures. Specifically, subjects high on the "Avoidance of Crowds" subscale demonstrated greater heart rate change and post heart rate than subjects low on the "Avoidance of Crowds" subscale. This suggests subjects avoidant of panic-like situations had a greater physiological reaction to the hyperventilation challenge, a task considered to be problematic for panic disordered individuals. Therefore, the results generally suggest the existence of claustrophobic subtypes. The present study was the first to compare subjects differentiated on the basis of claustrophobic subtypes in terms of their physiological response to a hyperventilation challenge. This study both supported and extended past research by developing questionnaires (the CSQ and CGCQ) capable of identifying different claustrophobic situational and cognitive factors. / Master of Science
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Genetic marker frequency differences among strains of goldfish, Carassius auratusBorkholder, Brian D. 12 September 2009 (has links)
Starch gel electrophoresis and DNA fingerprinting were used to assess molecular genetic variation within and between strains of goldfish, Carassius auratus. Genetic variation observed both within and between strains was low using both methods. using isozyme markers, mean heterozygosity (0.0% -
4.4%) and percent polymorphic loci (0.0% - 30.6%) within strains were low compared to other vertebrate species. Analysis of the isozyme data using Chi-square tests against Hardy-Weinberg genotype expectations and wright's (1943, 1951) F statistics indicated modest heterogeneity in genotype frequencies between strains. DNA fingerprint band sharing values were determined both within and between strains of goldfish. Mean band sharing values within strains were high (68.0% -97.6%), comparable to values observed in highly inbred populations of other vertebrates. Levels of band sharing between strains were determined using a DNA mixing procedure. Band sharing values between strains (57.7% - 100%) were higher than those observed between strains of other domesticated species. Analysis of DNA fingerprint data using ANOVA indicated no significant differences between strains, suggesting that the fancy strains did not exhibit significant differentiation as manifested in DNA fingerprint phenotypes. / Master of Science
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Optical method of recording electrical activity in isolated rabbit heartsAmanna, Ashwin E. 31 October 2009 (has links)
A recently developed optical method utilizes a single, implantable, optical fiber to record electrical activity from isolated hearts stained with voltage-sensitive dyes. This optical technique generates recordings of transmembrane potential from excitable myocardial tissue, and remain free from stimulus artifacts that accompany electro stimulation and hinder all standard electrode recording methods during the application of high-voltage electrical shocks. The fiber optic system uses a l00J,lm diameter core fiber which can record from epicardial surface, internal mid-myocardium, or endocardial surfaces. The stained tissue is excited through the fiber and the resulting fluorescence is transmitted through the same fiber to a photomultiplier tube. Changes in fluorescence accompanying normal cardiac action potentials usually range from 1-5%. Substantive motion related signals accompany normal beating hearts, drowning out the actual signal that corresponds to change in membrane potential. When added to the nutrient solution of the heart, an excitation / contraction decoupler restricts motion and reduces the motion related signal making it easier to isolate the true membrane potential signal. / Master of Science
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Simulation of a binary phase shift keyed receiver with an IF correlator for position locationThommana, John Vareed 08 April 2009 (has links)
This thesis conducts a feasibility study of using a binary phase shift keyed receiver with an IF correlator in a position location application. The feasibility study is done using mathematical simulation. Traditionally the correlator, in a binary phase shift keyed receiver, is placed after the data demodulator. It correlates the incoming bitstream with a fixed reference bit sequence (synchronization header) to find the beginning of a data message. For position location applications this correlator is used to record the time of arrival of the signal at the receiver. These correlators can maintain the correlation peaks at best only to 1% of the bit period. At 4800 bits per second, this translates to an inherent range error of 625 meters. This thesis investigates the feasibility of using an additional correlator after the IF bandpass filter which will correlate the IF waveform sample by sample so as to maintain the correlation peaks to better than 1% of the bit period. / Master of Science
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