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Assessment of visual landscape quality of urban green spaces using image-based metrics derived from perceived sensory dimensions
No full textUrban green spaces (UGS) have been extensively studied for their psychological benefits to people. However, accurately assessing the quality of UGS, which is closely linked to human perception, remains challenging due to the complexity of this attribute. To address this gap, this study proposed a novel approach that uses comprehensive image-based metrics to evaluate multiple aspects of visual landscape quality (VLQ). These metrics were developed based on a theoretical framework of perceived sensory dimensions (PSD). We presented the meanings and calculation methods of metrics based on panoramic images. Additionally, we conducted an online survey to demonstrate the significant correlation between these metrics and the subjective perception of PSD. This study also proposed a new spatial mapping method to represent VLQ using these metrics, illustrated through a case study of the Singapore Botanic Gardens (SBG). We used analysis of variance to compare the distinctions between metrics naturalness, wildness, and GVI by selecting a few green spaces within the SBG. The approaches provide an innovative way to evaluate UGS visual quality using photographic imagery data, contributing to a more comprehensive understanding of the visual quality assessment of UGS
Nanoencapsulation of antimicrobial agents and antimicrobial effect of silver nanoparticles
No full textNanotechnology is an advanced field that stretches out over a wide scope of various scientific areas. In food science and technology, nanomaterials and nanoparticles are used to enhance food quality and also used as antimicrobial agents, and packaging materials to enhance food safety. One of the major concerns related to food processing is the microbial activity leading to food spoilage. Other than traditional encapsulation systems, nanoparticles can result in efficient encapsulation known as nanoencapsulation. Antimicrobial food agents can be protected using nanoencapsulation which helps in the controlled delivery to specific sites for improving cellular absorption resulting in high antimicrobial activity. Spray drying, high-pressure valve homogenization, microfluidization, ultrasonication, and hot and cold homogenization are some methods used to prepare nanoencapsulation. Biopolymer-based nanoparticles can be delivered into food formulations by nanocarriers such as nanoliposome, lipid nanocarriers, nanoemulsions, and nanofibers. Recently, the metal nanoparticle has been commonly used in food industries; especially, silver nanoparticles (AgNP) is extensively used due to its antimicrobial property. This chapter discusses the nanoencapsulation of antimicrobial agents and their preparing methods, types of nanoencapsulation systems, and the antimicrobial effect of AgNP nanoparticles
Evaluating the in vitro efficacy of Abamectin and Fluopyram, alongside hot water treatments against Meloidogyne incognita and Globodera rostochiensis : A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Applied Science at Lincoln University
No full textPlant germplasm importation into Aotearoa/New Zealand poses a risk of introducing unwanted organisms. Current biosecurity measures for plant nematodes on imported nursery stock are under review. This study aimed to investigate alternative chemicals that could replace fenamiphos, the current border treatment. Abamectin and fluopyram were chosen for assays based on their demonstrated nematocidal activity and availablity. Hot water submersion was also tested as a non- chemical alternative. Pratylenchus sp. were extracted from field samples and identified using morphology and molecular methods. Cultures of Meloidogyne incognita and extraction of Globodera rostochiensis cysts were successful, but Pratylenchus sp. cultures could not be established.
Preliminary experiments tested the field rates of abamectin (0.009 g/L a.i) and fluopyram (0.3 g/L a.i.) individually and in combination, along with two fenamiphos concentrations (2 g/L and 40 g/L). Abamectin and fluopyram resulted in paralysis rates of ≥ 66.7% in M. incognita J2s, while fenamiphos exhibited no significant differences from the negative control. All treatments produced reversible effects on J2 immobility, indicating a nematistatic effect. Hot water experiments at 44°C for 3 hours caused complete and irreversible paralysis in M. incognita J2s. Further experiments using varying concentrations of abamectin and fluopyram on M. incognita J2s, indicating the highest paralysis rate with abamectin (0.09 g/L a.i.) was 75.2%, while concentrations of fluopyram ≥ 0.6 g/L resulted in 100% paralysis. All combined concentrations of abamectin and fluopyram resulted in 100% paralysis, as did hot water treatments for 1 and 2 hours at 44 and 50°C.
In preliminary experiments, no chemical treatments achieved complete mortality in G. rostochiensis juveniles, and no significant differences were observed in the proportion of immobile juveniles compared to the negative control. Hot water treatments at 44°C for 3 hours, in combination with abamectin, fluopyram, abamectin and fluopyram together, and 40 g/L fenamiphos, completely immobilized G. rostochiensis juveniles 48 hours after treatment. Retrospective analysis found the G. rostochiensis experiment results inconclusive due to assessing viability based on movement rather than more precise methods. A preliminary trial using Meldola blue stain revealed that live G. rostochiensis juveniles remained unstained, while dead juveniles stained when exposed to 0.05% Meldola blue for 3, 5, and 7 days. This method was incorporated into further G. rostochiensis experiments. Further chemical experiments on cysts showed no differences compared to the negative control of RO water based on the proportions of juveniles stained with Meldola blue. Hot water treatments at 44°C and 50°C for 1 and 2 hours caused a lower percentage of deceased juveniles compared with the negative control of 24°C.
Further experimentation using in planta bioassays are recommended to assess how the chemicals affects nematodes contained within plant tissues as well as plant viability. Expanding the research to encompass a broader range of nematode species is also recommended. Overall, the study demonstrated the potential of abamectin, fluopyram and hot water submersion which provided the complete mortality required in biosecurity situations as alternatives to fenamiphos for biosecurity measures in Aotearoa/New Zealand
Iturin A strongly inhibits the growth and T-2 toxin synthesis of Fusarium oxysporum: A morphological, cellular, and transcriptomics study
No full textFusarium oxysporum (F. oxysporum) is a common contaminant of dried fish, and the T-2 synthesis by this organism in dried fish products poses a serious public health risk. In this study, we investigated the effects of iturin A, a cyclic lipopeptide produced by Bacillus subtilis, on the growth and synthesis of the T-2 toxin of F. oxysporum, and transcriptomics was conducted. Results showed that the inhibitory effect of iturin A on F. oxysporum was significantly enhanced with an increase in iturin A concentrations. More specifically, compared with the control group, all indexes in the iturin A treatment group with 50 μg/mL were decreased to 24.84 mm, 0.33 x 10⁶ cfu/mL, and 5.86 ng/mL for the colony diameter, number of spores, and concentration of T-2 toxin, respectively. Furthermore, iturin A was proven to destroy the integrity of cell membranes and cause a significant increase in ROS at 25 μg/mL or 50 μg/mL. Transcriptomic analysis revealed that with the treatment of iturin A, the genes of the oxidation-reduction process were up-regulated, while the gene expression of mycelial growth, cell integrity, transmembrane transport, energy metabolism, and others were down-regulated. More importantly, the Tri5 gene cluster was significantly inhibited. This study provided new insights into the mechanism for the inhibitory effect of iturin A on the growth and T-2 toxin synthesis of F. oxysporum and theoretical guidance for the application of iturin A in the preservation of dried aquatic products
Types of biopesticides
No full textBiopesticides are generally regarded as biologically based pesticides. The specific definition however has depended on the researchers, and the term has been used broadly to encompass all biologically derived pesticides or, more often, specifically for certain groups, such as microbial biopesticides. The general aim of using the term biopesticide is to suggest a biological rather than a synthetic origin of the active agent, and implicit is a level of environmental and mammalian safety resulting from the use of naturally derived actives. Various subgroups of biopesticides that could be included under a broad definition comprise packaged pesticides based on live microbes, nematodes, microbial and plant extracts, genetically modified plants, semiochemicals, endophytes, invertebrates used inundatively, and other compounds derived from animals or minerals. The term biopesticide implies some form of packaging and active application, without the expectation of long-term persistence, and often has an element of formulation. The market for biopesticides is increasing rapidly around the world, but regulators in many countries are struggling with providing registration procedures appropriate for these pesticides
Biofilm formation, sodium hypochlorite susceptibility and genetic diversity of Vibrio parahaemolyticus
No full textVibrio parahaemolyticus is a marine oriented pathogen; and biofilm formation enables its survival and persistence on seafood processing plant, complicating the hygienic practice. The objectives of this study are to assess the ability of V. parahaemolyticus isolated from seafood related environments to form biofilms, to determine the effective sodium hypochlorite concentrations required to inactivate planktonic and biofilm cells, and to evaluate the genetic diversity required for strong biofilm formation. Among nine isolates, PFR30J09 and PFR34B02 isolates were identified as strong biofilm forming strains, with biofilm cell counts of 7.20, 7.08 log₁₀ CFU/cm², respectively, on stainless steel coupons after incubation at 25 °C. Free available chlorine of 1176 mg/L and 4704 mg/L was required to eliminate biofilm cells of 1.74–2.28 log₁₀ CFU/cm² and > 7 log₁₀ CFU/cm², respectively, whereas 63 mg/L for planktonic cells, indicating the ineffectiveness of sodium hypochlorite in eliminating V. parahaemolyticus biofilm cells at recommended concentration in the food industry. These strong biofilm-forming isolates produced more polysaccharides and were less susceptible to sodium hypochlorite, implying a possible correlation between polysaccharide production and sodium hypochlorite susceptibility. Genetic diversity in mshA, mshC and mshD contributed to the observed variation in biofilm formation between isolates. This study identified strong biofilm-forming V. parahaemolyticus strains of new multilocus sequence typing (MLST) types, showed a relationship between polysaccharide production and sodium hypochlorite resistance
Nitrate as an alternative electron acceptor destabilizes the mineral associated organic carbon in moisturized deep soil depths
No full textNumerous studies have investigated the effects of nitrogen (N) addition on soil organic carbon (SOC) decomposition. However, most studies have focused on the shallow top soils 1.0 m deep (deep soil) are rare. Here, we investigated the effects and the underlying mechanisms of nitrate addition on SOC stability in soil depths deeper than 1.0 m. The results showed that nitrate addition promoted deep soil respiration if the stoichiometric mole ratio of nitrate to O₂ exceeded the threshold of 6:1, at which nitrate can be used as an alternative acceptor to O₂ for microbial respiration. In addition, the mole ratio of the produced CO₂ to N₂O was 2.57:1, which is close to the theoretical ratio of 2:1 expected when nitrate is used as an electron acceptor for microbial respiration. These results demonstrated that nitrate, as an alternative acceptor to O₂, promoted microbial carbon decomposition in deep soil. Furthermore, our results showed that nitrate addition increased the abundance of SOC decomposers and the expressions of their functional genes, and concurrently decreased MAOC, and the ratio of MAOC/SOC decreased from 20% before incubation to 4% at the end of incubation. Thus, nitrate can destabilize the MAOC in deep soils by stimulating microbial utilization of MAOC. Our results imply a new mechanism on how above-ground anthropogenic N inputs affect MAOC stability in deep soil. Mitigation of nitrate leaching is expected to benefit the conservation of MAOC in deep soil depths
‘Who walked against time’: Nineteenth century intersections of pedestrianism and medicine
No full textDuring the nineteenth century, both medicine and sport were transitioning into recognizably modern identities but no formal relationship between the two existed. It has been suggested that the medical profession had little engagement with sport during this period. One sport that was particularly popular during the nineteenth century was pedestrianism in which athletes performed a range of endurance walking challenges for money and fame. While it has previously been recognized that some medical practitioners were involved in the support of pedestrian athletes, to date there has been no formal evaluation of the magnitude or nature of that involvement. Hence there is a potential that the contribution of medicine to aspects of sport in the nineteenth century may have been under-recognized. Using predominantly contemporaneous reports, this paper investigates the medical support utilized by nineteenth century professional pedestrians. It illustrates that during a period in which medicine underwent a seismic paradigm shift, some doctors were actively involved in both the clinical support and scientific assessment of pedestrians. In so doing, the role that nineteenth century medical practitioners played in supporting endurance pedestrians is clarified and a gap in the literature addressed pertaining to the nineteenth century interactions of medicine and sport
Fungal endophytes of grapevine trunks: community structure and implication for grapevine trunk diseases : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
No full textThe grapevine trunk is colonized by a diverse community of fungi, collectively referred to as the endophytic mycota. These communities are shaped by different factors, both biotic and abiotic, including diseases status. Pathogens and beneficial fungi play important roles in grapevines, and these endophytes are considered key players that enhance plant growth, reduce plant disease and can improve the ability to adapt to stress. Some pathogenic fungi are known to be the causal agents of grapevine trunk disease (GTD) and are considered latent pathogens. Studying variation in their disease expression in response to the endomycobiome can guide the identification of disease suppressive microbial antagonists against (or that interact with) GTDs pathogens. Understanding of the processes by which these endophytic fungi initiate, maintain, or modulate trunk diseases is lacking.
This thesis focused on characterising the taxonomic diversity and the composition of the trunk endophytic mycota (endomycobiome) colonizing symptomatic and asymptomatic trunk tissues of old and young vines from different management systems, by using both culture- dependent and high-resolution culture-independent approaches. Samples were taken from nine vineyards in the Marlborough region. The samples encompassed 60 mature vines (>10 years old) and 30 young vines (<9 years old), with each age group consisting of equal numbers of apparently healthy and symptomatic vines. A culture collection of 2116 fungal isolates from 90 vines (270 tissue samples) were created. As some endophytic fungi are uncultured, this work was complemented by amplicon sequencing to characterise both the unculturable and culturable endophytes. This approach generated a total of 10 M reads. These were divided into 1892 distinct operational taxonomic units (OTUs). The results from both approaches demonstrated a complex community that was dominated by Ascomycetes species. The community analysis revealed that health, tissue age, and type of management were major drivers of the trunk endophytic community structure. The same fungal genera from culturome were identified as the most abundant using metabarcoding.
Consequently, the key indicator fungal isolates recovered from trunk tissues were evaluated for their co-occurrence and interaction with GTD pathogens. Isolates of Botrytis cinerea recovered from symptomatic and asymptomatic woody tissues were pathogenic on grapevine stems. The interaction between Botrytis cinerea and two common botryosphaeriaceous species (N. parvum and D. seriata) on the expression of symptoms in young grapevine plants were explored using detached and attached assays. The co-inoculation on detached material did not show any evidence of synergism. However, co inoculation onto attached shoots on potted plants produced contrasting results. Inhibition of N. parvum lesion development by B. cinerea was observed. Next, in detached and attached grapevine assays the interaction between A. pullulans and the grapevine trunk pathogens and their effect on symptom expression demonstrated that A. pullulans could reduce the disease expression/colonisation by both N. parvum and D. seriata indicating possible antagonistic activity against these pathogens by this fungal species.
The interactions between Seimatosporium spp. and the grapevine trunk pathogens N. parvum and D. seriata in detached and attached grapevine shoots showed that Seimatosporium spp. were effective in reducing the colonisation of shoot tissues by D. seriata in detached experiments, but had no significant effect in attached shoot tissues. Additionally, both S. vitis and S. sp. nov were effective in reducing lesion length caused by N. parvum in detached shoots, while S. vitis also showed a reduction in lesion length in attached shoots of potted vines.
The overall results of this thesis showed that culturome and NGS metabarcoding complement each other and can be applied to gain knowledge about microbial dynamics inside the grapevine trunk. This is the first study investigating the combined effect of three factors on the endomycobiome. The findings of this study provide valuable insights into the complex interactions between pathogens associated with GTD and other fungal species isolated as endophytes from the same grapevine woody tissues
Body composition estimation in breeding ewes using live weight and body parameters utilising image analysis : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
Get PDFFarmers are continually looking for new reliable, objective and non-invasive methods for estimating ewe body condition. Live weight (LW) in combination with body condition score (BCS) are used by farmers as a basis to determine the condition of the animal. Where LW is a crucial indicator of body composition, body condition can be evaluated by determining the amount of fat in the animal. This amount plays a key role in ewes’ health condition and animal productivity. The body condition score is used to monitor animals to ensure the best condition and is a measure between 1 (low condition) and 5 (high condition). If an ewe has a condition below 2 this is considered poor, whereas above 3 is regarded as good condition and ready for breeding. The current method is subjective (relies on professional judgment from farm handlers) as such it can introduce an element of error when estimating the fat, which makes it difficult to monitor the animal condition.
A quick, objective, and accurate method of body composition estimation is required to improve farm management. If such a method could be devised, many farmers around the world would utilize it to assist in managing sheep farms. In addition, image processing and body measurements have not been used before to estimate body composition for ewes during the production cycle using a comprehensive, repeatable, non-invasive method.
Image processing and body parameter measurements have been widely used to estimate ewe body size and weight. The objective of this thesis was to establish a relationship between body parameters of body length, width, depth and height as independent variables and body fat, lean, bone and carcass (total weight of body fat, lean and bone) as dependent variables. The aim was to use these easily obtained body parameters to predict body composition. Two full experiments at weaning and pre-mating were conducted to establish the relationship between body composition and body parameters using measurements automatically determined by an image processing application at Lincoln University sheep farm for 88 Coopworth ewes. Computerised Tomography (CT) technology was used as a benchmark to validate the predicted body composition. A trial run, wool test, uncertainty test, repeat test and carcass test were also conducted to minimise uncertainty and test the experiment setup. The image processing application used techniques from OpenCV library such as image extraction, convert to HSV colour, erode, dilate and smooth filter to remove the ewe’s head, legs (for side image) and extract the body to calculate the body parameters in an automated method.
Multivariate linear regression (MLR), artificial neural network (ANNs) and regression tree (RT) statistical analysis methods were used to analyse the relationship between independent and dependent variables to predict body fat, lean, bone and carcass. The artificial neural network method was found to be the best method to show how much variance of the dependent variables is explained by a set of independent variables. The result showed a correlation between fat, lean, bone and carcass weight determined by CT and the fat, lean, bone, carcass weight and percentage of fat–carcass weight estimated by live weight and body parameters calculated in an automated method using the image processing application with R2 values of 0.88, 0.85, 0.72, 0.97 and 0.94, respectively for the training data of 138 ewes with a root mean square error (RMSE) less than 2.5. A new set test data of was used to test the accuracy of the results of multivariate linear regression, neural networks and regression tree. The neural networks model provided the highest R2 for total fat prediction with R2=0.90 and RMSE=1.01 with a maximum difference of 2.7 kg and a minimum difference of 0.018 kg between the predicted value and the actual value, lean prediction with an R2 of 0.72 and RMSE=1.03, bone prediction with an R2 of 0.50 and RMSE=1.21, carcass prediction with an R2 of 0.95 and RMSE=1.31 and percentage of fat – carcass weight with an R2 of 0.90 and RMSE=1.30, respectively. ANNs also showed the lowest RMSE for fat with a value of 1.01 and for carcass with a value of 1.31. The image processing application calculations showed an uncertainty of -9.43 to 9.22 mm for chest width. The result also showed that many ewes had the same body condition score but different fat and chest widths, which confirmed that the body condition score may not provide an accurate indication of fat. The results showed an optimal fat of 9.37% of LW for ewes during the production cycle. If the percentage of fat is less than or more than 9.37%, farmers must take action to improve the conditions of the animals to ensure the best performance during weaning and ewe and lamb survival during the next lambing.
The new method can be used to determine body composition on sheep farms as an alternative to BCS since it showed more accurate results. This method can also lead to the use of new image analysis technologies and more research on using image processing on-farms. The accuracy of the new method is slightly less than CT but it takes less time and cost than the CT. It can be used on-farm at any stage during ewe production cycle and can be applied on animals with wool or after shearing the wool