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Evaluation of Pyrethroid/PBO Adulticide Resistance Frequency and Levels in Culex Quinquefasciatus from Harris County, Texas: KDR Genotyping, Field and Laboratory Bioassays, and Field Pesticide Quantification by GC/MS
No full textCulex quinquefasciatus is one of the key mosquitoes vectoring pathogenic arboviruses and parasites. The fastest way to impede pathogen transmissions is to apply synthetic adulticides, e.g., pyrethroids, to suppress the mosquito population. However, the development of insecticide resistance in populations could impair insecticide efficacy and lead to disease control failure. Therefore, Harris County Public Health in Harris County, TX, conducts field cage tests (FCTs) annually to surveil the efficacy of ULV Permanone�� 31-66 (31% permethrin and 66% piperonyl butoxide, i.e., PBO) against F��� female Cx. quinquefasciatus. However, interpretations of FCTs��� outcomes are limited to resistance frequencies due to a lack of studies analyzing significant factors affecting mosquito mortalities. This dissertation focuses on qualitatively and quantitatively analyzing impactful factors on mosquito control. We first developed a diagnostic PCR to detect the kdr-like mutation (L1014F) in Cx. quinquefasciatus from six operational areas in Harris County, estimating high kdr allele frequencies (99.93%, N = 1021/1028) in females. Results of genotyping and FCTs were statistically analyzed to evaluate the effect of the kdr genotypes, the operational areas of mosquito origin (origin), distances from the pyrethroid spraying source (distance), and pseudo-replicate columns within the same distance (column) on mosquitoes��� survival probabilities. Females��� survival probabilities during FCTs were not influenced by kdr-s (heterozygous resistant) and kdr-kdr (homozygous resistant) genotypes but by ���origin,��� ���distance,��� and ���column.��� The two latter factors were quantitatively analyzed for their influences on female mortalities during FCTs by a newly designed workflow to quantify Permanone�� deposited. Heterogeneously distributed adulticide quantities were positively correlated to field mosquito mortalities. Estimated LC������ field resistance ratios (RRs) ranged from 2.65 to 3.51, falling within the 95% CI of RR������ evaluated by laboratory vial assays, highlighting their translatability. The emergence of moderate permethrin/PBO resistance in field-collected females was observed through vial assays in which some F��� and F��� had RRs >5. LCs of permethrin to mosquitoes higher than LCs of permethrin/PBO indicated the contribution of Cytochrome P450 to permethrin resistance. This study improved the interpretation of FCTs��� outcomes, connected field resistance evaluation with laboratory bioassays, and elucidated mechanisms underlying field permethrin/PBO resistance. Future studies on the effect of Cx. quinquefasciatus areas of origin in Harris County on field mortalities could focus on metabolic resistance
���New Observations on the Architecture of the Gournia Shrine.��� (abstract).
No full textAs the first Postpalatial cult building to be discovered on Crete, the Late Minoan IIIB shrine at Gournia has played an important role in studies of Minoan religion, both as an example of an ���independent bench sanctuary��� of the ���Goddess with Upraised Arms��� and as an architectural precedent for more recently excavated cult buildings in eastern Crete. Factors that challenge a full understanding of the architecture, however, include a lack of stratigraphy due to shallow deposition and bioturbation observed at the time of excavation (1901), the relatively poor preservation of the walls, and mid-20th century consolidation and conservation efforts now partially obscure most wall faces and joins. Based upon a program of architectural study conducted as one part of the Gournia Excavation Project, this paper presents a new plan of the shrine and discusses issues of wall construction and sequencing that provide new insights into the complex building history of this part of the site. For example, our analysis shows that the LM IIIB shrine clearly reuses and modifies several earlier Neopalatial (and perhaps even Protopalatial) walls. The built feature in the southwest corner of the room can be interpreted either as a shallow bench that originally extended along the entire inner face of the south wall or as a wall from an earlier phase whose upper surface was reused as a bench in LM IIIB. The ���buttress��� in the southeast corner may have been constructed to reinforce the pre-existing (Neopalatial?) south wall or functioned as a tall platform. The paper also considers the purpose and meaning of this building within the settlement, including questions of both when and why it was constructed on this location, and discusses the architecture and associated artifacts of the Gournia shrine within the context of other Postpalatial cult buildings on Crete
Galveston Bay Travelog
No full text42 slide Power Point presentation on natural,economic features of Galveston Bay. Includes many aerial photographs and maps. Created 200
Cellular Identification of Genes Regulated by ATFS-1 During Anal Depressor Remodeling in Caenorhabditis elegans
Get PDFThe anal depressor in Caenorhabditis elegans undergoes radical morphological change in males to transform from a defecation muscle to an auxiliary copulation muscle. It is known that the transcription factor ATFS-1, a facilitator of the mitochondrial unfolded protein response, is a key player in this change but its target genes are not fully understood. I sought to determine if any target genes of ATFS-1 contribute to the process of anal depressor remodeling. Using the Timer fluorescent reporter, I characterized the expression profiles of ATFS-1 and a subset of its targets. As a result, I found that ATFS-1 differs in expression in males and hermaphrodites, but none of my selected candidates exhibit the same expression pattern. Therefore, I concluded that none of my candidate genes are major contributors to the process of anal depressor morphological remodeling
Motion Planning with Discrete Geodesics
Get PDFSeveral civil and military applications such as surveillance and reconnaissance require unmanned vehicles to visit targets while being optimized for travel time, fuel, and other communication and kinematic constraints. Unmanned vehicles could also have other limitations set by the size, the design, and the environment. This thesis considers discrete path planning problems for unmanned vehicles.
The shortest continuous path for a constant speed vehicle from any arbitrary initial location and orientation to any arbitrary final location and orientation in the absence of obstacles takes the form of a Dubin���s path. While these paths are continuous and smooth, this thesis explores the case when the paths could be discrete instead. Dubin���s path is always one of the six kinds which could be an LRL. RLR, RSR, LSL, RSL, LSR; were L and R, are left and right turn arc segments respectively, and S is a straight-line segment. This thesis is concerned with similar paths except that the L and R, are left and right turn polygonal arc segments instead. Our work will prove that the discrete paths are shorter than their continuous counterparts. Moreover, the discrete paths are a more general form since they could generate the same results as the continuous counterpart when the polygonal arc chord length limits to zero. This is because a circular arc could be imagined as a polygonal arc with infinite edges.
These paths are particularly relevant when we consider environments to travel with limited communication abilities. In GPS denied or GPS limited environments, performing discrete straight segment maneuvers are more reliable than traversing through circular arc segments especially since we do not have GPS feedback. Every vertex of the polygonal path could be imagined as ���position��� (or ���time��� when traveling in a constant speed) where the GPS location could be pinged for instead of relying on GPS feedback for the entire tour.
The thesis characterizes the Discrete Geodesics with both non-inflection and inflection segments and presents explores algorithms. The work explores a more generic and beneficial version of the Dubin���s paths extended to study traveling salesmen problems
