19366 research outputs found
Sort by
Thermal adaptation of soil microbial functional responses: Insights from a geothermal gradient in Aotearoa New Zealand
No full textNatural soil temperature gradients provide an excellent proxy to study how soil microbial communities, and their associated activities, will adapt to global warming. The rate at which soil microbes adapt to warming has important implications for biogeochemical cycling and predictions of soil carbon loss. In Aotearoa New Zealand, we take advantage of a decades long geothermal gradient, ranging from 15-42°C mean annual soil temperature, to investigate thermal adaptation of soil microbial respiration (with unlimited substrate), bacterial growth, and extracellular enzyme activities (β-glucosidase, acid phosphatase, and N-acetyl-β-ᴅ-glucosaminidase). We sampled soils from across this gradient and constructed temperature response curves for each soil sample in the lab by incubating them at six or more different temperatures. Using these temperature response curves, we then estimated rates of thermal adaptation for each microbial function and compared how different microbial processes adapt differentially. Despite major changes in microbial community diversity and composition along the gradient, we found only modest shifts in thermal adaptation of the microbial functional responses. The temperature response curves for soil microbial respiration and bacterial growth increased at a rate of approximately 0.2°C per 1°C increase in mean annual temperature. In contrast, we did not find a significant relationship between mean soil temperature and the temperature response of extracellular enzyme activity, suggesting that temperature responses are highly conserved across a variety of soil microbial functions. Nonetheless, it is important to consider how these changes in microbial rates may affect predictions of soil carbon loss with global warming
Heat tolerance in Mashona beef cows in semi-arid rangelands: Does conformation matter?
No full textHigh temperatures and frequent heat waves raise concerns about heat stress in cattle in grass-based systems, especially in arid and semiarid areas. This study analysed the relationship between conformation traits and physiological parameters associated with heat stress in Mashona cattle. A total of 200 records from fifty cows were used to study the relationships between seven conformation traits and physiological parameters associated with heat stress. Body conformation traits were categorised into three principal components related to body capacity (body depth, flank circumference, chest girth), frame size (stature and body length), and loose skin fold (navel height and dewlap size). As the size of abdominopelvic and thoracic cavities increased, respiratory rate, heart rate, and rectal temperature decreased significantly, while blood triiodothyronine concentration increased. Cattle with deeper bodies, larger flanks, and larger chest girths had significantly lower heart rate, respiratory rate, and rectal temperature but higher blood triiodothyronine concentration than cattle with shallower bodies, smaller flanks, and smaller chest girths. Respiratory rate increased with increasing frame size. Large-framed cattle had significantly higher respiratory rate and lower blood thyroxine concentration. Small-framed cattle with larger chest girth, larger dewlap, and navel farther from the ground surface are better adapted to higher ambient temperatures
A potted vine model to facilitate the understanding of Pinot noir yield-quality seesaw according to root growing conditions
No full textPresentation at the inaugural New Zealand Wine Centre Scientific Research Conference on 14 November 2023
Collective computational intelligence in biology – Emergence of memory in somatic tissues
No full textRole of memory in the function of biological tissues, organs and organisms remains unexplored with many unanswered questions. In this study, the emergence of associative memory in somatic (non-neural) tissues and its potential relation to tissue function was explored using a number of biologically plausible network topologies in in silico tissues with computing cells. These topologies were local cooperation; complete system-wide cooperation or inhibition; and local cooperation and short- or long-range inhibition. These were tested with and without self-feedback on two-dimensional (2D) three-dimensional (3D) cell networks, resulting in various forms of fully and partially connected networks. Further, both binary inputs with threshold processing and real-valued inputs with nonlinear processing were considered. Results revealed the emergence of diverse forms of tissue memory. In full cooperation, networks produced one fixed attractor indicating the propensity towards a stable memory pattern which in a real tissue could correspond to an invariable physiological state, such as bioelectric homeostasis. The local neighbourhood cooperation produced both a fixed and a limit cycle attractor that could be beneficial for a tissue to hold few associative memories including circadian rhythms. Most interesting results were found for the local cooperation with short- or long-range inhibition topologies that produced a cluster of fixed and limit cycle attractors offering diverse memories. Fixed attractors could correspond to inactive tissue states and active nonrhythmic functional states and limit cycles could correspond to circadian rhythms such as pumping in heart, kidney or liver in various oscillatory regimes. In all topologies, self-feedback abolished or drastically reduced the limit cycles in favour of fixed stable state. These attractor patterns were found to be largely invariant to scale (2D or 3D) and type of inputs and processing. We also explored the self-optimising ability of the ‘local cooperation with global (short- or long-range) inhibition’ 2D topologies with Hebbian learning with fixed and flexible topologies. The fixed topology learned to self-model to consolidate memory towards fewer more stable attractors. The flexible topology even formed new connections to bring the system to a single fixed state. Thus local cooperation with global inhibition topology can offer greater freedom to create diverse memory pattens that can be tempered by learning, self-feedback, and to some extent continuous processing to simplify and consolidate memory towards manageable forms
Conflicted property rights – balancing the need for seismic safety with heritage conservation : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
No full textTraditionally described as a “bundle of rights” the creation and protection of private property rights is seen as a cornerstone of western democratic societies. However, property rights are not fixed but are a constantly evolving mix of private rights and community rights that ebb and flow with changing community expectations. As a result of the Christchurch earthquakes increased community expectations of seismic safety led to the passing of new legislation imposing mandatory seismic mitigation for buildings considered an unacceptable risk to society. These buildings are defined legally as “earthquake-prone”. The costs of seismic mitigation must be met by the property owner potentially causing significant financial hardship to the individual, but also with the potential to have significant negative impacts on communities. One form of mitigation promoted by the legislation is to demolish the building which puts the owner of an earthquake-prone building with heritage value in conflict with community expectations of heritage conservation. This conflict often leads to litigation with an owner demanding the right to demolish while the community pursues the retention of the heritage building. The results of the litigation are uncertain and often costly. This thesis looks at altering property rights in New Zealand in order to avoid litigation and achieve a more equitable balance between private and public rights and thus achieve a better balance between safety, heritage and property rights. This rebalancing is necessary to protect individuals from financial hardship. It is also necessary to achieve better outcomes for communities by protecting them from the unexpected outcomes of the new legislation and by promoting sustainability by reducing building demolition and instead facilitating heritage-led urban regeneration
Positional distribution of fatty acids in processed Chinook salmon roe lipids determined by ¹³C magnetic resonance spectroscopy (NMR)
No full textRecently, there has been great interest in the lipidomic of marine lipids and their potential health benefits. Processing of seafood products can potentially modify the characteristics and composition of lipids. The present study investigated the effect of processing methods (salting and fermentation) on the positional distribution of fatty acids of Chinook salmon roe using ¹³C nuclear magnetic resonance spectroscopy (NMR). The NMR analysis provided information on the carbonyl atom, double bond/olefinic, glycerol backbone, aliphatic group, and chain ending methyl group regions. The obtained data showed that docosahexaenoic acid (DHA) is the main fatty acid esterified at the sn-2 position of the triacylglycerides (TAGs), while other fatty acids, such as eicosapentaenoic acid (EPA) and stearidonic acid (SDA), were randomly distributed or preferentially esterified at the sn-1 and sn-3 positions. Fermentation of salmon roe was found to enrich the level of DHA at the sn-2 position of the TAG. The processing of roe by both salt drying and fermentation did not appear to affect the proportion of EPA at the sn-2 position. This present study demonstrated that fish roe processing can enhance the proportion of DHA at the sn-2 position and potentially improve its bioavailability
Community-led in-stream habitat creation to protect taonga species
No full textIwi and community groups are at the forefront of river restoration, driving planting and bank restoration initiatives. These efforts are important and can yield significant water quality improvements, however, many aquatic species also suffer from poor structural habitat beneath the water surface. By targeting in-stream habitat (which is often neglected), we hope to facilitate significant improvements in ecological health. This project brings together science, kaupapa Māori, and collective enthusiasm for the rivers of Aotearoa New Zealand to advance restoration practice, using proactive habitat additions which anyone can help build. In-stream habitat structures focussed on fish and invertebrate refuge were collaboratively designed and trialled in Canterbury, New Zealand by Te Taumutu Rūnanga and the Waterways Centre. Inspired by flax wahakura (baby bassinettes), these habitat structures aim to enhance our freshwater taonga (treasured) species, boosting diversity and nurturing mauri (the life force of the river). Importantly, they also provide a storytelling opportunity and analogy in the protection of both babies and young fish, which is an effective tool to inspire and engage. Weaving and restoration wānanga were held at Te Pa o Moki Marae, close to Waikēkēwai Stream. These meetings brought the community together to create and deploy habitat structures, and also facilitated storytelling and sharing of Mātauranga Māori. Ongoing monitoring includes both ecological and cultural assessments, supporting the holistic nature of this project. This collaborative approach holds great promise for ecological health outcomes, and subsequent restoration of mauri will benefit all who interact with the water. Through sharing of knowledge, skills and Mātauranga Māori, we hope to kickstart ongoing, holistic restoration initiatives for years to come, and inspire kaitiakitanga (guardianship) in future generations
Factors influencing pastoral farmers' land-use change decisions in response to environmental regulations in the Selwyn District, Canterbury
No full textHighlights
• Pastoral farmers in Selwyn often feel misunderstood by regulatory authorities regarding the effects of increasing environmental regulations on their farm systems, and subsequent land-use change decisions.
• Financial factors and certainty around policy and practice were the most important factors to farmers when making land-use change decisions.
• Farmers were hesitant to make a sustainable land-use change decision without the confidence that it will remain a financially and strategically viable choice for the longer term.
• To encourage sustainable land-use change, regulatory authorities must give increased thought to understanding farmers’ response to regulations and how this affects creation and implementation of future regulation
Temporal changes in Cd sorption and plant bioavailability in compost-amended soils
No full textThe application of Cd-contaminated phosphate fertiliser has enriched concentrations of this non-essential element in many agricultural soils. Consequently, concentrations of the metal in some agricultural products exceed the Maximum Limit in foods. Composts can reduce the transfer of Cd from soil to plants; however, it is unclear how long this beneficial effect endures. We aimed to determine temporal changes of phytoavailable Cd in two market garden soils (an Allophanic Orthic Granular Soil and a Recent Silt Loam). Soils were amended with either municipal green waste compost or sawdust and animal waste compost at a rate of 2.5% w/w under three incubation regimes: at 19 °C, at 30 °C, and at 30 °C with additional N added as urea at 0.6 g urea/kg soil added over 1 year. Each replicate was sampled after 1, 5, 9, 13, 21, 31, and 49 weeks, and phytoavailable Cd was estimated through 0.05 M Ca(NO₃)₂ extraction. Seed potato (Solanum tuberosum), ‘Nadine’ variety, was grown in the Pukekohe Allophanic Orthic Granular Soil, freshly amended with municipal compost and the same soil aged for one year. The concentration of Cd in all samples was analysed using an ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometer). The C concentration in the soil—compost mixtures decreased over the year, with the greatest decreases occurring in the soils incubated at 30 °C with added N. Unexpectedly, the concentration of Ca(NO₃)₂-extractable Cd in the compost-amended soils did not increase over time and in some cases even decreased. This was confirmed through a pot experiment, which showed the Cd concentration in potato was reduced by 50% in both the freshly amended soil and the amended soil aged for one year. Cadmium immobilisation in soils might be due to both the sorption of Cd by organic matter and the occlusion of sorbed Cd by oxy-hydroxides of iron and aluminium. Over 49 weeks, soluble Cd does not increase as organic matter oxidises. The application of municipal compost to soil will reduce both plant Cd solubility and plant Cd uptake for at least one year in the soils tested
Ovine KRTAP36-2: A new keratin-associated protein gene related to variation in wool yield
No full textKeratin-associated proteins (KAPs) are structural components of wool fibres. High-glycine/tyrosine (HGT)-KAPs are a subset of the KAP family, and their abundance in fibres varies. In this study, we report the discovery of an ovine HGT-KAP gene to which we assigned the name KRTAP36-2. Polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) analyses revealed four variants of this gene in a screening population of 170 sheep from a variety of breeds. The DNA sequencing of the variants revealed four single-nucleotide polymorphisms (SNPs) and a dinucleotide deletion. Three of these SNPs were in the coding region, and one of these was non-synonymous and potentially led to the amino acid substitution p.Cys27Gly near the middle of the protein. The remaining SNP was located near the putative TATA box, and the di-nucleotide deletion was near the putative transcription initiation site. The effect of this variation in KRTAP36-2 was investigated in 274 Southdown × Merino lambs that were the progeny of five sires. Variation was only found to be associated with wool yield, that is, the proportion of the greasy fleece that remained as clean fleece upon scouring (expressed as a percentage). This may have some value in increasing wool production