The development and evaluation of computer vision algorithms for the control of an autonomous horticultural vehicle

Economic and environmental pressures have led to a demand for reduced chemical use in crop production. In response to this, precision agriculture techniques have been developed that aim to increase the efficiency of farming operations by more targeted application of chemical treatment. The concept of plant scale husbandry (PSH) has emerged as the logical extreme of precision techniques, where crop and weed plants are treated on an individual basis. To investigate the feasibility of PSH, an autonomous horticultural vehicle has been developed at the Silsoe Research Institute. This thesis describes the development of computer vision algorithms for the experimental vehicle which aim to aid navigation in the field and also allow differential treatment of crop and weed. The algorithm, based upon an extended Kalman filter, exploits the semi-structured nature of the field environment in which the vehicle operates, namely the grid pattern formed by the crop planting. By tracking this grid pattern in the images captured by the vehicles camera as it traverses the field, it is possible to extract information to aid vehicle navigation, such as bearing and offset from the grid of plants. The grid structure can also act as a cue for crop/weed discrimination on the basis of plant position on the ground plane. In addition to tracking the grid pattern, the Kalman filter also estimates the mean distances between the rows of lines and plants in the grid, to cater for variations in the planting procedure. Experiments are described which test the localisation accuracy of the algorithms in offline trials with data captured from the vehicle's camera, and on-line in both a simplified testbed environment and the field. It is found that the algorithms allow safe navigation along the rows of crop. Further experiments demonstrate the crop/weed discrimination performance of the algorithm, both off-line and on-line in a crop treatment experiment performed in the field where all of the crop plants are correctly targeted and no weeds are mistakenly treated

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 3: Support of the design process

The user requirements for computer support of the IPAD design process are identified. The user-system interface, language, equipment, and computational requirements are considered

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 5: Catalog of IPAD technical program elements

The catalog is presented of technical program elements which are required to support the design activities for a subsonic and supersonic commercial transport. Information for each element consists of usage and storage information, ownership, status and an abstract describing the purpose of the element

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 2: The design process

The extent to which IPAD is to support the design process is identified. Case studies of representative aerospace products were developed as models to characterize the design process and to provide design requirements for the IPAD computing system

Hello from the Other Side: Social Studies Faculty Teaching Biography within State History Courses

This paper explores the opinions and interests of pre-service social studies students at two universities enrolled in a state history course taught by a socials studies faculty member. Findings include similar motivation for learning state history and opinions on interactive history lessons, while showcasing different interests in historic figures

Functional Conservation of the Glide/Gcm Regulatory Network Controlling Glia, Hemocyte, and Tendon Cell Differentiation in Drosophila.

High-throughput screens allow us to understand how transcription factors trigger developmental processes, including cell specification. A major challenge is identification of their binding sites because feedback loops and homeostatic interactions may mask the direct impact of those factors in transcriptome analyses. Moreover, this approach dissects the downstream signaling cascades and facilitates identification of conserved transcriptional programs. Here we show the results and the validation of a DNA adenine methyltransferase identification (DamID) genome-wide screen that identifies the direct targets of Glide/Gcm, a potent transcription factor that controls glia, hemocyte, and tendon cell differentiation in Drosophila. The screen identifies many genes that had not been previously associated with Glide/Gcm and highlights three major signaling pathways interacting with Glide/Gcm: Notch, Hedgehog, and JAK/STAT, which all involve feedback loops. Furthermore, the screen identifies effector molecules that are necessary for cell-cell interactions during late developmental processes and/or in ontogeny. Typically, immunoglobulin (Ig) domain-containing proteins control cell adhesion and axonal navigation. This shows that early and transiently expressed fate determinants not only control other transcription factors that, in turn, implement a specific developmental program but also directly affect late developmental events and cell function. Finally, while the mammalian genome contains two orthologous Gcm genes, their function has been demonstrated in vertebrate-specific tissues, placenta, and parathyroid glands, begging questions on the evolutionary conservation of the Gcm cascade in higher organisms. Here we provide the first evidence for the conservation of Gcm direct targets in humans. In sum, this work uncovers novel aspects of cell specification and sets the basis for further understanding of the role of conserved Gcm gene regulatory cascades.We thank the DHSB and the Bloomington Stock Center for reagents and flies as well as J. Veenstra (INCIA UMR 5287 CNRS, France) for the gift of the Anti-DH31 antibody and B. Altenhein (U Mainz, Germany) for fly strains. We thank K. Jamet for initial bioinformatics analyses. We thank C. Diebold, C. Delaporte, and IGBMC facilities for technical assistance. We thank the members of the lab for valuable input and comments on the manuscript. This work was supported by INSERM, CNRS, UDS, Hôpital de Strasbourg, ARC, INCA and ANR grants. A. Popkova and P. Cattenoz were funded by the FRM and by the ANR, respectively. A. Popkova also benefitted from a short Development traveling fellowship to visit the laboratory of A. Brand in Cambridge (UK). The IGBMC was also supported by a French state fund through the ANR labex. T.D.S and A.H.B were funded by Wellcome Trust Programme Grants 068055 and 092545 to A.H.B. A.H.B acknowledges core funding to the Gurdon Institute from the Wellcome Trust (092096) and CRUK (C6946/A14492).This is the final version of the article. It was first available from the American Genetics Society via http://dx.doi.org/10.1534/genetics.115.18215

The crystal structure of mycobacterial epoxide hydrolase A

The human pathogen Mycobacterium tuberculosis is the causative agent of tuberculosis resulting in over 1 million fatalities every year, despite decades of research into the development of new anti-TB compounds. Unlike most other organisms M. tuberculosis has six putative genes for epoxide hydrolases (EH) of the α/β-hydrolase family with little known about their individual substrates, suggesting functional significance for these genes to the organism. Due to their role in detoxification, M. tuberculosis EH’s have been identified as potential drug targets. Here, we demonstrate epoxide hydrolase activity of M. thermoresistibile epoxide hydrolase A (Mth-EphA) and report its crystal structure in complex with the inhibitor 1,3-diphenylurea at 2.0 Å resolution. Mth-EphA displays high sequence similarity to its orthologue from M. tuberculosis and generally high structural similarity to α/β-hydrolase EHs. The structure of the inhibitor bound complex reveals the geometry of the catalytic residues and the conformation of the inhibitor. Comparison to other EHs from mycobacteria allows insight into the active site plasticity with respect to substrate specificity. We speculate that mycobacterial EHs may have a narrow substrate specificity providing a potential explanation for the genetic repertoire of epoxide hydrolase genes in M. tuberculosis