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Dynamic spillover effects among green bond, renewable energy stocks and carbon markets during COVID-19 pandemic: Implications for hedging and investments strategies
No full textThis study has been inspired by the emergence of socially responsible investment practices in mainstream investment activity as it examines the transmission of return patterns between green bonds, carbon prices, and renewable energy stocks, using daily data spanning from 4th January 2015 to 22nd September 2020. In this study, our dataset comprises the price indices of S&P Green Bond, Solactive Global Solar, Solactive Global Wind, S&P Global Clean Energy and Carbon. We employ the TVP-VAR approach to investigate the return spillovers and connectedness, and various portfolio techniques including minimum variance portfolio, minimum correlation portfolio and the recently developed minimum connectedness portfolio to test portfolio performance. Additionally, a LASSO dynamic connectedness model is used for robustness purposes. The empirical results from the TVP-VAR indicate that the dynamic total connectedness across the assets is heterogeneous over time and economic event dependent. Moreover, our findings suggest that clean energy dominates all other markets and is seen to be the main net transmitter of shocks in the entire network with Green Bonds and Solactive Global Wind, emerging to be the major recipients of shocks in the system. Based on the hedging effectiveness, we show that bivariate and multivariate portfolios significantly reduce the risk of investing in a single asset except for Green Bonds. Finally, the minimum connectedness portfolio reaches the highest Sharpe ratio implying that information concerning the return transmission process is helpful for portfolio creation. The same pattern has been observed during the COVID-19 pandemic period
Resolving 500 Years of anthropogenic impacts in a mesotrophic lake: Nutrients outweigh other drivers of lake change
No full textInteractions among multiple stressors, legacies of past perturbations, and the lack of historical information make it difficult to determine the influence of individual anthropogenic impacts on lakes and separate them from natural ecosystem variability. In the present study, we coupled paleolimnological approaches, historical data, and ecological experiments to disentangle the impacts of multiple long-term stressors on lake ecosystem structure and function. We found that the lake structure and function remained resistant to the impacts of catchment deforestation and erosion, and the introduction of several exotic fish species. Changes in ecosystem structure and function were consistent, with nutrient enrichment being the primary driver of change. Significant and sustained changes in the lake diatom community structure (and their nutrient requirements), bacterial community function, and paleolimnological proxies of ecosystem function coincided with nitrogen and phosphorus fertilizers in the catchment. The results highlight that the effects of increased nutrient inputs are much stronger than the influence of other, potentially significant, drivers of ecosystem change, and that the degree of nutrient impact can be underestimated by environmental monitoring due to its diffuse and accumulative nature. Delineating the effects of multiple anthropogenic drivers requires long-term records of both impacts and lake ecosystem change across multiple trophic level
Deciphering the molecular signal from past and alive bacterial communities in aquatic sedimentary archives
No full textLake sediments accumulate information on biological communities thus acting asnatural archives. Traditionally paleolimnology has focussed on fossilized remains oforganisms, however, many organisms do not leave fossil evidence, meaning major eco-system components are missing from environmental reconstructions. Many paleolim-nology studies now incorporate molecular methods, including investigating microbialcommunities using environmental DNA (eDNA), but there is uncertainty about thecontribution of living organisms to molecular inventories. In the present study, weobtained DNA and RNA inventories from sediment spanning 700 years to investigatethe contribution of past and active communities to the molecular signal from sedimen-tary archives. Additionally, a droplet digital PCR (ddPCR) targeting the 16S ribosomalRNA (16S rRNA) gene of the photosynthetic cyanobacterial genera Microcystis wasused to explore if RNA signals were from legacy RNA. We posit that the RNA signalis a mixture of legacy RNA, dormant cells, living bacteria and modern-day trace levelcontaminants that were introduced during sampling and preferentially amplified. Thepresence of legacy RNA was confirmed by the detection of Microcystis in sedimentsaged to ~200 years ago. Recent comparisons between 16S rRNA gene metabarcod-ing and traditional paleo proxies showed that past changes in bacterial communitiescan be reconstructed from sedimentary archives. The recovery of RNA in the presentstudy has provided new insights into the origin of these signals. However, caution isrequired during analysis and interpretation of 16S rRNA gene metabarcoding dataespecially in recent sediments were there are potentially active bacteria
Volatility contagion between crude oil and G7 stock markets in the light of trade wars and COVID-19: A TVP-VAR extended joint connectedness approach
No full textWe investigate volatility contagion across G7 stock markets and the market for crude oil for the period between 2007 and 2021. Following the work of Balcilar et al. (2021), we utilise the TVP-VAR extended joint connectedness method and compare results to the standard TVP-VAR method that predicates upon the normalisation approach by Diebold and Yılmaz (2009, 2012, 2014). Both methods provide qualitatively similar results. Overall, findings suggest that connectedness in this network is highly responsive to events that greatly affect international financial markets and assume large values across the sample period. Prominent among our results is that the crude oil market is an important net transmitter of volatility shocks across the network during the 2014 oil collapse period. In addition, the period from the beginning of 2018 and until mid-2019 is a rather turbulent period for stock markets a fact which is reflected upon the net receiving character of the market for crude oil. Finally, we show that the Canadian stock market is a persistent net transmitter of volatility in recent years, following developments in international trade and the outbreak of the COVID-19 crisis
Development of a triplex droplet digital polymerase chain reaction assay for the detection of three New Zealand native freshwater mussels (Echyridella) in environmental samples
No full textThe freshwater mussel Echyridella (also known as kākahi) is the only freshwater mussel found in New Zealand's lakes and rivers and is endemic to the country. They play a crucial role in freshwater ecosystems and have high cultural significance. The three putative species of Echyridella are all classified as at risk. Monitoring is required to enhance knowledge on their distribution and to provide management, but conventional approaches (diving, wading, or swimming and visually looking for mussels) are time-consuming, costly, and require good visibility. The use of environmental DNA (eDNA) in combination with PCR techniques offer advantages over conventional methods. In this study, we developed a triplex droplet digital PCR assay, targeting a region of the mitochondrial cytochrome oxidase subunit 1 gene, that differentiates all three kākahi species. The limits of quantification using gblocks were 0.6 × 10⁻⁰—6 × 10⁻⁰³ fg/µl, yielding 2–8 copies/reaction, and for tissue DNA 10,000–100,000 fg/µl, yielding 9–15 copies/reaction. The method was applied to water samples from 48 lakes, lagoons, or ponds and two samples from streams. A total of 58% of samples from lakes, lagoons, or ponds and all samples from the streams were positive for kākahi. Sediment samples (n = 15) were also tested. Only those collected in close proximity (<1 m) to living kākahi were positive highlighting the patchy distribution of eDNA in sediment. This new assay will assist in determining the current distribution of kākahi at large temporal and spatial scales and has the potential to be used for the assessment of historic distributions as well
Diversity and bioactivity of endophytic actinobacteria associated with grapevines
Get PDFGrapevine trunk diseases (GTDs) are a significant problem for New Zealand viticulture. Endophytic actinobacteria are of interest as potential biocontrol agents due to their ability to inhibit plant pathogens and improve plant growth. However, no studies have investigated the diversity of actinobacteria associated with grapevines in New Zealand vineyards and their bioactivity. Actinobacteria diversity in different ‘Sauvignon blanc’ vine tissues from three vineyards (conventional and organic management, and different vine ages) was assessed using different methods and media. Forty-six endophytic actinobacteria were isolated, with more isolates recovered from roots n = 45) than leaves (n = 1) and shoot internodes (n= 0). More isolates were recovered from the organic (n = 21) than conventional (n = 8) vineyard, mature (25-year old; n = 21) than young (2-year old; n = 2) vines and using a tissue maceration technique (n = 40). Actinomycete Isolation Agar, International Streptomyces Project 2, and Starch Casein media were effective for actinobacteria isolation. Most of the isolates recovered belonged to Streptomyces, with one isolate identified as Mycolicibacterium. Forty isolates were assessed for antifungal activity and plant growth-promoting (PGP) characteristics. Of these, 13 isolates had antifungal activity against test GTD pathogens (Dactylonectria macrodidyma, Eutypa lata, Ilyonectria liriodendri, Neofusicoccum parvum, and N. luteum). Eighteen isolates exhibited more than one PGP trait; 25siderophore production (n = 25), phosphate solubilization (n = 6), and indole acetic acid production (n = 16). Two strains, Streptomyces sp. LUVPK-22 and Streptomyces sp. LUVPK-30, exhibited the best antifungal and PGP properties. This study revealed the diversity of culturable endophytic actinobacteria from grapevines in New Zealand vineyards and their biocontrol potential against GTD pathogens
Effects of tasting and ingredient information statement on acceptability, elicited emotions, and willingness to purchase: A case of pita chips containing edible cricket protein
Get PDFSustainable and nutritious alternatives are needed to feed the ever-increasing world population. The successful incorporation of edible-cricket protein (ECP) into foods needs deeper consumer insights. Treatments (plain, Italian, and Cajun pita chips containing 6.9% w/w ECP) were evaluated by subjects for overall liking (OL), emotions, and purchase intent (PI) in three different moments: (1) before tasting, (2) after tasting/before ECP statement, and (3) after tasting/after ECP statement. Attributes’ liking scores were evaluated only after tasting/before ECP statement. Liking scores (mixed-effects ANOVA), emotions, and PI across moments within treatments/across treatments within moments were evaluated. Emotion-based penalty-lift analyses for OL within moments were assessed using two-sample t-tests (p < 0.05). Random forest model analyzed after-tasting informed PI and variables’ importance. Although formulations’ OL and PI were similar across moments, plain and Italian chips had higher after-tasting (before and after ECP statement) OL than the Cajun chips. Moments indirectly affected OL via emotions elicitation. Valence and activation/arousal emotions discriminated across moments for the plain treatment whereas valence and mostly activation/arousal terms discriminated across moments for the Italian and Cajun treatments, respectively. For either formulation or moment, “interested” and “adventurous” positively affected OL. Before and after-tasting attribute liking, “satisfied,” and “enthusiastic” emotions were critical in predicting after-tasting informed PI
Predictive potential of MALDI-TOF analyses for wine and brewing yeast
Get PDFThe potential of MALDI-TOF profiling for predicting potential applications of yeast strains in the beverage sector was assessed. A panel of 59 commercial yeasts (47 wine and 12 brewing yeasts) was used to validate the concept whereby 2 culture media (YPD agar and YPD broth), as well as two mass ranges m/z 500–4000 and m/z 2000–20,000, were evaluated for the best fit. Three machine learning-based algorithms, PCA, MDS, and UMAP, in addition to a hierarchical clustering method, were employed. Profiles derived from broth cultures yielded more peaks, but these were less well-defined compared with those from agar cultures. Hierarchical clustering more clearly resolved different species and gave a broad overview of potential strain utility, but more nuanced insights were provided by MDS and UMAP analyses. PCA-based displays were less informative. The potential of MALDI-TOF proteomics in predicting the utility of yeast strains of commercial benefit is supported in this study, provided appropriate approaches are used for data generation and analysis
Landscape modelling of a protected cultural landscape: Kura Tāwhiti Conservation Area
Get PDFProtecting culturally significant sites has become an increasingly recognised undertaking as seen with the increase in the number of listed UNESCO World Heritage cultural sites from 563 in 2002 to 897 in 2021. Landscape architects, planners, environmental scientists and other consultants are involved with the management of these resources and creating accurate landscape models of these can contribute to informing decision making. In the Aotearoa, New Zealand context, one of these levels of protection, Tōpuni, is unique and has been designated as such by the indigenous Māori people. This designation has been placed on 14 sites and for this research, Kura Tāwhiti Conservation Area was selected due to its distinct limestone landforms and the risk of negative impact due to increased tourist visitor numbers. An accurate 3D landscape model of the Kura Tāwhiti Conservation Area was created using aerial an UAV survey and land-based 3D laser scanning. The landscape modelling exercise is the first of any tōpuni site and provides a set of tools for decision makers. The benefits of such a landscape model for this culturally significant and protected conservation area include the potential for further analysis by other professionals of the landforms, being used in accurate visualisations for future scenarios, and providing a benchmark for changes over time
Exploring local peoples’ perspectives of online destination images: A case study of the Khumbu region : A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Applied Science at Lincoln University
Get PDFThrough various benefits of tourism, a place is transformed into a destination. These destinations compete with one another for tourists, with promoters creating and promoting the place as a destination, a product. Due to increased access to and use of the internet, promotion and reach have become much easier online, where individuals may obtain destination information with relative ease. These factors can contribute to tourists developing an illusory perception of a place that frequently differs from their experience. Locals are frequently absent from the narratives (both contributing and being a part) of their place which are depicted online. This can result in dissatisfaction among both residents and visitors and has the potential to negatively affect the relationships between them.
While much of the research on locals’ perspectives on place focuses on developed country settings using quantitative approaches, there is a scarcity of literature that focuses on the qualitative nature of locals’ place image and their perceptions in a developing country setting. This research aims to address these gaps by exploring how local people respond to the online images used to promote their places.
The study utilised as its case study site an area that is one of the most famous tourist destinations in Nepal, the Khumbu, the upper region of Solukhmbu which is known as the Everest region. The official Nepalese tourism website was used as the source for the online images analysed. Text and photos were gathered from Nepal's official tourism website and analysed to develop themes for a semi-structured interview with local people about their perspectives on destination image. Semi-structured online interviews were undertaken with 19 Khumbu residents. Their perspectives reveal that they have a strong sense of place based on their ancestral connection. They lacked faith in the official website as the true face of Khumbu. Their responses to the online themes were classified into three categories: acceptance, tolerance and disapproval. It was discovered that all of the participants wanted their community to be promoted and wanted to showcase Khumbu as their contemporary reality, including the stories of the various places and highlighting more of the culture and lifestyle, rather than only focusing on the mountains.
The destination image formation model (Beerli & Martin, 2004) was modified based on the findings, to draw attention to the importance of local people and promoters as key agents in the destination image-making process. It is expected that this research will help inform authorities including official tourism promoters about the perspectives local people have regarding the portrayal of their place online. This will assist promoters in comprehending the destination which includes local people while also identifying opportunities to collaborate which improves the relationship between officials and local people and contribute to a more harmonious tourism system