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Mechanisms underlying the health benefits of intermittent hypoxia conditioning
No full textIntermittent hypoxia (IH) is commonly associated with pathological conditions, particularly obstructive sleep apnoea. However, IH is also increasingly used to enhance health and performance and is emerging as a potent non-pharmacological intervention against numerous diseases. Whether IH is detrimental or beneficial for health is largely determined by the intensity, duration, number and frequency of the hypoxic exposures and by the specific responses they engender. Adaptive responses to hypoxia protect from future hypoxic or ischaemic insults, improve cellular resilience and functions, and boost mental and physical performance. The cellular and systemic mechanisms producing these benefits are highly complex, and the failure of different components can shift long-term adaptation to maladaptation and the development of pathologies. Rather than discussing in detail the well-characterized individual responses and adaptations to IH, we here aim to summarize and integrate hypoxia-activated mechanisms into a holistic picture of the body's adaptive responses to hypoxia and specifically IH, and demonstrate how these mechanisms might be mobilized for their health benefits while minimizing the risks of hypoxia exposure
Role of existing industrial land in providing supplemental flood mitigation for low-lying coastal cities in a context of climate change : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
No full textFlooding in low-lying coastal cities is projected to worsen with climate change. Planners are concerned about the inadequacy of their current flood protection capacity and the risks associated with under- or over-investment in expensive grey infrastructures under climate change uncertainty. Implementing green stormwater infrastructure (GSI) on strategically located developed land, particularly industrial land, maybe a lower-risk alternative; however, little is known about its potential for providing substantial catchment flood mitigation over time. In addition, there is no effective methodology for determining its potential in the context of climate change.
In this research, a novel Hydrology-based Land Capability Assessment and Classification (HLCA+C) methodology is proposed and used to evaluate the flood mitigation capability (FMC) of strategic land use, having large properties over the long term (80 to 100-year period) with climate change. The methodology was then applied to a case study (the City of Christchurch) to determine the potential of industrial land for providing substantial flood mitigation. The results indicated industrial land has substantial flood mitigation capability in four of its six catchments, capturing both on-site and off-site runoff volumes. While their increased runoff volumes associated with climate change in two catchments can be reduced to a manageable level within the mid-term period (2031-2050), industrial land in the other two catchments had this capability up to the long-term period (2081-2100) and under much larger storm events, though not for all climate change scenarios. The methodology was also applied to one Christchurch catchment to evaluate the FMC of individual industrial properties further. The highly capable properties within the catchment were prioritised to be included in adaptative flood mitigation pathways. Considering the most appropriate implementation approach associated with properties’ FMC and timing for implementation (whether through a retrofit only, retrofit and transfer, redesign or relocation), their flood mitigation capabilities can be maximised in response to increased climate change impacts through time. This would result in flood mitigation just shy of that associated with the high emission scenario up to the end of this century. The findings of this research indicated that the size of drainage area controlled by GSI networks is dominantly responsible for enhancing FMC in the long term if the high groundwater level of industrial land was deeper than 2 m below the surface. Therefore, policies encouraging off-site runoff collection in large private properties, where capable, are deemed necessary to utilise the maximum GSI capability.
The research demonstrates the effectiveness of this novel methodology over existing methods for helping planners develop adaptive flood mitigation plans through time with climate change. These outputs can facilitate planners in developing flood mitigation policies and strategies for the long-term protection of their communities. The findings from the application of this methodology demonstrate that implementing such GSI networks on capable industrial land can provide effective low-risk supplemental flood mitigation to ensure communities in low-lying cities are protected from climate change–induced flooding in the long term. It will also allow costly investments in flood mitigation structures, such as barriers and levees, to be safely delayed until their cost-effectiveness has been confirmed under increased climate certainty. To maximise the FMC of existing industrial land, the research recommends that planners designate strategic stormwater management zones in city plans. These can be used in support of implementing policies to encourage on-site and off-site runoff collection and the establishment of new governing bodies to regulate the uses of land for implementing GSI networks and ensure long-term flood mitigation
Migration of nanocolloid-carrying antibiotics in paddy red soil during the organic fertilization process
No full textSoil nanocolloids are highly mobile and can act as carriers for the transport of antibiotics to a wider and deeper range of soils; however, the inherent behavior and mechanism of nanocolloid-carrying antibiotics in soil remain unclear. In this study, we conducted a comprehensive investigation of the migration of antibiotics in paddy red soil during the organic fertilization process using four common soil nanocolloids: kaolin (KL), montmorillonite (MT), hematite (HT), and humic acid (HA). The results showed that nanocolloid carriers promoted the intra-medium (from soil surface to the bottom) and inter-medium transfer (from organic fertilizers to soil) of antibiotics. The migration mechanisms of antibiotics carried by the nanocolloids differed: the phenolic hydroxyl and carboxyl groups of HA esterified with the carboxyl groups of quinolones and phenolic hydroxyl groups of tetracyclines, respectively, while the oxygen atoms of HT formed stabilizing complexes with the soil, which could further adsorb antibiotics using their functional group-rich complexes. Smaller antibiotic compounds were adsorbed in the metal oxide interlayer of MT via cation exchange, whereas KL adsorbed antibiotics on its metal oxide surface layer in the same way but were susceptible to desorption. Additionally, nanocolloids changed the adsorption capacity of soil for antibiotics and influenced the enrichment of dominant/functional bacteria (e.g., Burkholderiaceae) and thus varied the vertical distribution of antibiotics in soil. These findings enhance our understanding of the migration behavior and mechanism of nanocolloid-carrying antibiotics in red paddy soil and provide a theoretical foundation for preventing and controlling antibiotic pollution in arable systems
Validity and reliability of the VXSport (Omni) device on basketball movement parameters
No full textThe use of inertial devices in sport have become increasingly common. The aim of this study was to examine the within-day validity and reliability of a relatively new inertial measurement unit at measuring basketball movement parameters. Eighteen well-trained basketball players completed several individual performance tests including linear running and change of directions, acceleration, and decelerations, jumping and impacts to measure the validity and reliability of the microtechnology. The players also completed a specific test called the Basketball Exercise Simulation Test (BEST) to investigate whether the microtechnology could accurately detect more dynamic movements. Pearsons’s correlations were determined linking assessments of the practical measures taken from the inertial measurement unit to criterion measures. Testing revealed good validity between the microtechnology and criterion measures with the 20 m run test at various velocities (6 km.h-¹, 12 km.h-¹, 18 km.h-¹, 24 km.h-¹, maximal speed km.h-¹ (mean bias 10%). Total distance, number of sprints, number of sprints >15 km.h-¹, number of decelerations >3m.s-², number of accelerations and decelerations showed very large to nearly perfect reliability (ICC = 0.88 – 0.99). Whereas, relative distance (m.min-1), maximal speed (km.h-¹), total number of accelerations (>3 m.s-²), total number of jumps, average heart rate showed high reliability (ICC 0.77 – 0.87). These results demonstrate the units were able to accurately detect most basketball movement patterns correctly with good repeatability
Tannin – starch interplay: Investigating the impact of grape tannins on the properties of various starches : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Food Innovation at Lincoln University
No full textStarch is a vital macronutrient found in different concentrations across various foods. The structure and physicochemical properties of starch can vary from one source to other, directly or indirectly influencing how it interacts with other bio-macromolecules in the food systems. Interaction of starch with bio-molecules such as tannins can significantly enhance the overall textural-cum-nutritional properties of starch. Tannins, a rich source of phenolic compounds and exhibits antioxidants activity, can interact with various molecules, including starch and proteins in foods, thereby enhancing the nutritional profile of foods. The interaction between starch and tannin molecules in foods has enhanced properties like texture, gelatinization, retro-gradation and breakdown of starch into smaller sugars. This improvement has enabled food scientists to produce foods with a lower glycemic index. This study aimed to develop starch - tannin complexes using starches from three different botanical sources and grape tannins derived from both skin and seeds. All the three normal starches (5% w/v), with amylose content nearly 30%, were cooked with grape skin and grape seed tannins (10 % by
starch weight). Various characterizations were carried out to analyze the effect of tannins on starch properties. The quantity of bound and unbound tannins was quantified through methyl cellulose precipitation method, which revealed nearly 95% of tannins were bound to starch molecules in the solution. Furthermore, to detect the phenolic compounds in tannins and starch – tannin complexes, HPLC was performed. A decrease in the proportion of phenolic compounds present in grape skin and grape seed tannins occurred after complexation with starch, indicating development of possible molecular interactions among starch and tannins. Starch-iodine complexes were developed to further elucidate the mechanism of interaction between starch and tannins. A decrease in the absorbance values near 500-540 nm and 540-660 nm gave an idea regarding tannin interaction with amylose and amylopectin chains. In case of pea starch-tannin complexes, a decrease in the absorbance values within spectral range of 540-660nm proved the binding of tannins with amylose chains. Particle size distribution also supported the development of molecular interactions between these two
biomolecules. For pea starch-tannin complexes, the particle size was constrained to the range within 40-70 µm in contrast to pea starch control samples, for which the particle size distribution ranged within 20-200 µm. It reveals that the particle size of complexes formed during conjugation of tannins with starch molecules was ranging within 40-70 µm. Back extrusion textural properties were analyzed to notice the effect of tannins on the starch properties such as firmness, consistency, cohesiveness and index of viscosity. For corn and pea starch-tannin complexes, a decrease in the firmness and consistency and an increase in the other two properties were observed while an opposite trend was noticed for wheat starch-tannin complexes in contrast to the starch control samples. These properties provide an insight about the textural properties of starch, which can further help in improving the sensory profile of foods containing starch-tannin complexes. Tannins exhibit antioxidant properties and foods rich with antioxidants are believed to boast nutritional profile of such foods. In FRAP assay, starch bound tannin molecules were able to reduce the Fe3+ ions before and after four hours of incubation at 37°C, thus, highlighting the potential contribution of starch-tannin complexes to the antioxidant ability in foods. In-vitro starch digestion revealed the capability of tannins to prevent the digestion of starch molecules among all the three starches. A significant RDS, SDS and TDS decrease was observed in starch-tannin complexes, which promises the potential of these tannins to improve the overall sensory-cum-nutritional profile of starchy foods
Priestia megaterium ASC-1 Isolated from pickled cabbage ameliorates hyperuricemia by degrading uric acid in rats
No full textPickled cabbage, a traditional fermented food rich in functional microorganisms, can effectively control hyperuricemia and gout. In this study, a Priestia megaterium ASC-1 strain with strong uric acid (UA) degradation ability was isolated from pickled cabbage. After oral administration for 15 days, ASC-1 was stably colonized in the rats in this study. ASC-1 significantly reduced UA levels (67.24%) in hyperuricemic rats. Additionally, ASC-1 alleviated hyperuricemia-related inflammatory response, oxidative stress, and blood urea nitrogen. Intestinal microbial diversity results showed that ASC-1 restored intestinal injury and gut flora dysbiosis caused by hyperuricemia. These findings suggest that P. megaterium ASC-1 may be used as a therapeutic adjuvant for the treatment of hyperuricemia
Quantifying soil microbial thermal adaptation
No full textThermal adaptation of soil microbial respiration has the potential to greatly alter carbon cycle-climate feedbacks through acceleration or reduction of soil microbial respiration as the climate warms. However despite its importance, the relationship between warming and soil microbial activity remains poorly constrained. Part of this uncertainty stems from persistent methodological issues and difficulties isolating the interacting effects of changes in microbial community responses from changes in soil carbon availability. To address these challenges, we sampled nearly 50 soils from around New Zealand, including from a long-term geothermal gradient, with mean annual temperatures ranging from 11-35°C. For each of these soils we constructed temperature response curves of microbial respiration given unlimited substrate and estimated a temperature optima (Topt) and inflection point (Tinf). We found that thermal adaptation of microbial respiration occurred at a rate of 0.29°C ± 0.04 1SE for Topt and 0.27°C ± 0.05 1SE for Tinf per degree of warming, demonstrating that thermal adaptation is considerably offset from warming. These relatively small changes occurred despite large structural shifts in microbial community composition and diversity. We also quantitatively assessed how thermal adaptation may alter potential respiration rates under future warming scenarios by consolidating all of the temperature response curves. Depending on the specific mean and instantaneous soil temperatures, we found that thermal adaptation of microbial respiration could both limit and accelerate soil carbon losses. This work highlights the importance of considering the entire temperature response curve when making predictions about how thermal adaptation of soil microbial respiration will influence soil carbon losses
Ryegrass endophyte mixtures for improved animal health : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
No full textIn New Zealand, perennial ryegrass (Lolium perenne) with endophyte (Epichloë festucae var. lolii) is a
standard ingredient of pastures where insect pests challenge the persistence of the ryegrass. Farmers
currently have multiple ryegrass cultivar x endophyte strain combinations from which to choose the
best match for their requirements. However, no single cultivar x strain combination provides both
the highest insect protection and lowest occurrence of ryegrass staggers and heat stress in animals
grazing pasture with endophyte. Furthermore, the current industry protocol for testing the safety of
animals grazing a grass x endophyte combination involves exposing the animals to a simulated worst-
case scenario and needs reassessment. This research aimed to examine the effects of endophyte
diversity in perennial ryegrass on the health and performance of sheep using a modelling approach
so that an animal response of any mixture could be predicted as a function of the mixture’s
endophyte proportions, thus minimising the need for animal testing in the future.
At Barenbrug Plant Breeding Station, Courtenay, Canterbury, eight pasture treatments of Maxsyn
perennial ryegrass – seven that varied widely in sown proportions of three endophyte strains – nea3,
nea12, and standard endophyte (SE) – and an endophyte-free control (nil), were tested over four
experimental runs from February 2020 to December 2021. There were three monocultures (100% of
each strain), three binary mixtures (50% of each of two strains) and one ternary mixture (33.3% of
each strain) of endophyte based on a simplex centroid design. The eight treatments were
randomised in three blocks of 0.156-ha plots. The animal responses of interest were ryegrass
staggers, liveweight gain, heat stress, and diet selection of grazing sheep.
The first experiment run was a test for ryegrass staggers in February 2020. Endophyte toxicity in late
summer is typically near its annual maximum in Canterbury, so the timing of this run created a
‘worst-case scenario’ for ryegrass staggers. The pastures were managed in the previous spring so as
to accumulate a large herbage dry matter (DM) mass (about 3700 kg DM/ha above a cutting height
of 40–50 mm) of low nutritive quality feed (metabolisable energy (ME) = 8.7 MJ/kg DM and crude
protein (CP) = 4.9%). The pasture available (kg DM/ha) was high enough for lambs to remain in the
same plots for a 4-week testing period at a stocking rate of 64.1 lambs/ha. Ryegrass staggers was
severe (score 4–5) in the lambs grazing the SE pasture after 8 days and in all other endophyte
monocultures and mixtures after 22 days. Mixture models fitted to the staggers response data
predicted the staggers score for any combination of sown endophyte proportions and identified an
optimum of 65% nea3 and 35% nea12 which delayed severe staggers by 1 week. Ryegrass staggers
was associated with tremorgenic alkaloids in the herbage above 40–50 mm: epoxy-janthitrem I of
nea12 (1 ppm), paxilline and terpendole C of nea3 (0.1 and 1.2 ppm), and lolitrem B, paxilline and
terpendole C of SE (2.2, 0.2, and 1.1 ppm).
The second experimental run was a study of liveweight gain and ryegrass staggers under low toxicity
conditions from September to December 2020. The spring pastures provided optimal conditions for
liveweight gain and the stocking rate was kept consistent at 44.9 hoggets/ha. Pre-grazing pasture
mass was ca. 1600 kg DM/ha, ME was 12 MJ/kg DM and CP was 20% above 40–50 mm. The average
daily gain for all mixtures was 271 g/day over the first 4 weeks, and 20 g/day for weeks 4–8. The
mixture models fitted to the liveweight gain data identified the optimum endophyte formulation that
maximised liveweight gain to be a monoculture of nea12 so that the responses were equal to the
monoculture performance in the first and second 4 weeks of grazing (292 and 25 g/day). Ergovaline,
the alkaloid linked to suppressed liveweight, was present in nea3 and SE pastures at 0.32 and 0.16
ppm. Staggers scoring at the onset of symptoms after 10 weeks of grazing revealed mild staggers
(score <2) in SE that persisted until the experiment ended at 12 weeks. The model analysis showed
that any mixture containing at least 60% nea3 and up to 40% nea12 and/or SE would result in no
staggers (score 0). Alkaloids associated with staggers were in lower concentrations compared to the
summer test: 0.8 ppm of epoxy-janthitrem I was present in nea12 pastures while lolitrem B, paxilline,
and Terpendole C were present in SE pastures at 1, 0.1, and 0.3 ppm.
The third experimental run tested the assumption that endophyte strain proportions in the diet were
equal to the sown proportions. Plot fences within replicates were removed, 51–56 hoggets were
allocated to each replicate (40.9–44.9 hoggets/ha), and sward height decrease was measured 15 times
between 15 February and 16 March 2021. Herbage mass, ME, and CP values at the beginning of grazing
were circa 1400 kg DM/ha, 11.5 MJ/kg DM, and 11%. Analysis of variance showed no differences
(P>0.05) in sward height decrease between sown treatments, including nil, over the whole grazing
period. Mixture models of each measurement date and the average of all dates only showed
differences (P<0.05) between linear terms (monocultures) on day 2 and further analysis confirmed the
sward height decrease of SE was greater than nea12 (P<0.05), but not nea3. Quadratic terms (binary
mixtures) were not different on any date. The mixture model analysis for the whole period predicted
that a mixture containing 39% nea3 and 61% SE would maximise sward height decline despite lolitrem
B concentrations of SE pastures being sufficient to cause ryegrass staggers (1.4 ppm) and ergovaline
levels in nea3 pastures of 0.37 ppm. The lack of deterrence to these alkaloids indicates that animals
were unable to differentiate between endophyte strains.
The fourth experimental run was a repeat liveweight gain test followed by a heat stress study from
October to December 2021. Pasture conditions were similar to the previous liveweight gain test at
the start of grazing (ca. 2400 kg DM/ha, 12 MJ ME/kg DM, 15% CP). The same number of hoggets
were used as in the previous liveweight gain study, but a higher starting liveweight and greater pre-
grazing pasture mass resulted in greater liveweight gain across mixtures in the first and second 4
weeks (397 and 67 g/day) compared to the previous spring. The model analysis predicted an
optimum mixture containing 16% nea3, 65% nea12, and 20% SE would result in maximum liveweight
gains of 402 and 85 g/day in the first and second 4 weeks of the test. Data loggers attached to
controlled internal drug release (CIDR) devices recorded vaginal temperatures in selected mixtures
(nea3, nea12, nea3–nea12, and nil) during the final 8 days of the 8-week grazing period. Average
temperature for the three mixtures was 39.07°C compared to 38.96°C in the nil endophyte control.
Hoggets grazing nea12 had the lowest temperature of the three mixtures (38.94°C; P<0.05).
Consequently, the mixture model predicted the optimum mixture would only contain nea12.
Ergovaline concentrations were 0.7 and 0.5 ppm in nea3 and SE.
An endophyte diversity model that included ryegrass staggers and liveweight gain responses from
experimental runs 1, 2, and 4 as multivariates, predicted a mixture containing 77% nea12 and 23%
nea3 would give the best overall combination of responses. Although temperature was not included
in the model, the vaginal temperature response of this optimal mixture was predicted to be 39.02°C,
just 0.06°C higher than the nil endophyte control.
This thesis showed that endophyte mixtures can improve the health of grazing sheep and provides
the industry with a new option for mitigating health issues associated with endophyte without
searching for novel strains. Such mixtures would be best suited to scenarios where insect pest
pressure requires the use of endophyte strains that can increase the risk of ryegrass staggers and/or
suppressed liveweight gain. The endophyte diversity modelling approach can predict responses to
sown strain proportions beyond those included in the experiment, reducing the number of animal
entries required for testing
Citizen science is a vital partnership for invasive alien species management and research
No full textInvasive alien species (IAS) adversely impact biodiversity, ecosystem functions, and socio-economics. Citizen science can be an effective tool for IAS surveillance, management, and research, providing large datasets over wide spatial extents and long time periods, with public participants generating knowledge that supports action. We demonstrate how citizen science has contributed knowledge across the biological invasion process, especially for early detection and distribution mapping. However, we recommend that citizen science could be used more for assessing impacts and evaluating the success of IAS management. Citizen science does have limitations, and we explore solutions to two key challenges: ensuring data accuracy and dealing with uneven spatial coverage of potential recorders (which limits the dataset's “fit for purpose”). Greater co-development of citizen science with public stakeholders will help us better realize its potential across the biological invasion process and across ecosystems globally while meeting the needs of participants, local communities, scientists, and decision-makers
Corporate digitalization and green innovation: Evidence from textual analysis of firm annual reports and corporate green patent data in China
No full textWe investigate the effect of corporate digitalization capabilities on green innovation among Chinese-listed firms. Using a panel dataset of 2908 companies from 2011 to 2020, we use textual analysis and entropy weighting on corporate annual reports to construct a yearly corporate digitalization index. Our findings show that corporate digitalization promotes green innovation, as evidenced by patent applications and grants. This relationship is stronger for firms with fewer financial constraints and in provinces with strong intellectual property protection. We also find the national digital policy of the “Internet Plus” strategy has a stronger positive effect on corporate green innovation for corporations with a higher degree of digitalization. Our results are robust to various alternative measures, econometric models, and different samples