title: Ground Plane Segmentation of Time-of-Flight Images for Asparagus Harvesting

authors: Peebles, Matthew Christopher Scott

subjects: Science & Technology

abstract: A key task in processing time-of-flight images for the detection of asparagus spears is the identification and segmentation of the ground plane. In this paper, we aim to compare the performance of RANSAC with a modified version of an existing deterministic method, namely Hyun’s method. Each method is tested on scenes with varying amounts of field clutter. Additionally, a variety of camera angles are investigated. We find that both RANSAC and the proposed method produce ground plane predictions with a root mean square error of less than 0.05m and execute at a rate of approximately 0.056s per frame. However, RANSAC was shown to be much less reliable in high clutter scenes. The camera mounting angle is found to significantly affect the density and noise of points in time-of-flight images. These factors translate to significantly worse performance for both methods at low camera angles.

text: Ground Plane Segmentation of Time-of-Flight Images for Asparagus Harvesting A key task in processing time-of-flight images for the detection of asparagus spears is the identification and segmentation of the ground plane. In this paper, we aim to compare the performance of RANSAC with a modified version of an existing deterministic method, namely Hyun’s method. Each method is tested on scenes with varying amounts of field clutter. Additionally, a variety of camera angles are investigated. We find that both RANSAC and the proposed method produce ground plane predictions with a root mean square error of less than 0.05m and execute at a rate of approximately 0.056s per frame. However, RANSAC was shown to be much less reliable in high clutter scenes. The camera mounting angle is found to significantly affect the density and noise of points in time-of-flight images. These factors translate to significantly worse performance for both methods at low camera angles.

year: 2018

title: The Biology and Biochemistry of PhoH2 proteins

authors: Andrews, Emma Sophie Vout

subjects: Mycobacteria

abstract: PhoH2 proteins are found in a diverse range of organisms. To date little is known about these proteins and the role they play in the organisms in which they reside. PhoH2 is a PIN PhoH domain fusion, and these proteins are currently annotated as having unknown function and are described as PhoH like. PhoH domains are thought to be ATPases and all characterised PIN domain proteins are RNases. Most efforts have focussed on determining the role of PIN domain proteins that comprise the toxic component (VapC) of VapBC toxin antitoxin systems, in which the PIN domain is coexpressed as part of an operon with an inhibitor (VapB). In the remaining cases where PIN domain proteins can be found such as PIN PhoH domain fusions, these cases remain unexamined. This thesis describes the biological and biochemical characterisation of the PIN PhoH protein, PhoH2 from Mycobacterium tuberculosis and Mycobacterium smegmatis, along with a preliminary structural characterisation of a thermophilic PhoH2 protein homologue. 

The phoH2 gene from both mycobacterial organisms was found to be expressed as part of a long mRNA transcript. Examination of these transcripts revealed possible alternative 5’ start sites out of frame with the phoH2 gene. For protein overexpression, and ‘normal’ growth and colony formation with conditional overexpression, phoH2 from M. tuberculosis required 152 bp of the 5’ sequence directly upstream of the annotated phoH2 gene (annotated here as phoH2alt). PhoH2 proteins: PhoH2alt MTB, PhoH2alt MSMEG and PhoH2MSMEG show ATP/Mg²⁺ dependent, sequence specific RNA unwinding and cleavage. The sequence (A C) (A/U) (A/U) (G/C) U was deduced as a substrate for PhoH2, and PhoH2alt MTB also demonstrated unwinding and cleavage activity on its upstream ~152 base RNA transcript, suggesting a potential autoregulatory mechanism. Structural analysis of a thermophilic PhoH2 protein homologue has provided preliminary crystallographic data which along with electron microscopy suggest a ring like hexameric PhoH2 oligomer.

text: The Biology and Biochemistry of PhoH2 proteins PhoH2 proteins are found in a diverse range of organisms. To date little is known about these proteins and the role they play in the organisms in which they reside. PhoH2 is a PIN PhoH domain fusion, and these proteins are currently annotated as having unknown function and are described as PhoH like. PhoH domains are thought to be ATPases and all characterised PIN domain proteins are RNases. Most efforts have focussed on determining the role of PIN domain proteins that comprise the toxic component (VapC) of VapBC toxin antitoxin systems, in which the PIN domain is coexpressed as part of an operon with an inhibitor (VapB). In the remaining cases where PIN domain proteins can be found such as PIN PhoH domain fusions, these cases remain unexamined. This thesis describes the biological and biochemical characterisation of the PIN PhoH protein, PhoH2 from Mycobacterium tuberculosis and Mycobacterium smegmatis, along with a preliminary structural characterisation of a thermophilic PhoH2 protein homologue. 

The phoH2 gene from both mycobacterial organisms was found to be expressed as part of a long mRNA transcript. Examination of these transcripts revealed possible alternative 5’ start sites out of frame with the phoH2 gene. For protein overexpression, and ‘normal’ growth and colony formation with conditional overexpression, phoH2 from M. tuberculosis required 152 bp of the 5’ sequence directly upstream of the annotated phoH2 gene (annotated here as phoH2alt). PhoH2 proteins: PhoH2alt MTB, PhoH2alt MSMEG and PhoH2MSMEG show ATP/Mg²⁺ dependent, sequence specific RNA unwinding and cleavage. The sequence (A C) (A/U) (A/U) (G/C) U was deduced as a substrate for PhoH2, and PhoH2alt MTB also demonstrated unwinding and cleavage activity on its upstream ~152 base RNA transcript, suggesting a potential autoregulatory mechanism. Structural analysis of a thermophilic PhoH2 protein homologue has provided preliminary crystallographic data which along with electron microscopy suggest a ring like hexameric PhoH2 oligomer.

year: 2013

title: The day ahead

authors: Webber, Warren

abstract: With a professional background in agriculture and veterinary science, and a decade of participation in water quality issues for the Rotorua Lakes catchments, Warren brings an intense personal, but non-vested interest, to issues of nutrient management on the land and in our waterways. Conference management (international and domestic) helps to pay the bills, but voluntary community interests take up much of his time. As an appointee to the Stakeholder Advisory Group (StAG) which considers land management and land use change policy issues on behalf of the Te Arawa Lakes Strategy Group, he is closely involved with the challenges of nutrient allocation and incentives for change.

text: The day ahead With a professional background in agriculture and veterinary science, and a decade of participation in water quality issues for the Rotorua Lakes catchments, Warren brings an intense personal, but non-vested interest, to issues of nutrient management on the land and in our waterways. Conference management (international and domestic) helps to pay the bills, but voluntary community interests take up much of his time. As an appointee to the Stakeholder Advisory Group (StAG) which considers land management and land use change policy issues on behalf of the Te Arawa Lakes Strategy Group, he is closely involved with the challenges of nutrient allocation and incentives for change.

year: 2013