Journal Articles

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    Probing the Phytochemical Composition and Antioxidant Activity of Moringa oleifera under Ideal Germination Conditions
    (MDPI (Basel, Switzerland), 2023-08-21) Bhuker A; Malik A; Punia H; McGill C; Sofkova-Bobcheva S; Mor VS; Singh N; Ahmad A; Mansoor S; Setzer WN
    Moringa oleifera is a rich source of polyphenols whose contents and profile may vary according to environmental conditions, harvest season, and plant tissue. The present study aimed to characterize the profile of phenolic compounds in different tissues of M. oleifera grown under different temperatures (25, 30, and 35 °C), using HPLC/MS, as well as their constituent phytochemicals and in vitro antioxidant activities. The in vitro antioxidant activity of the extracts was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis-3-ethylenebenzothiozoline-6-sulfonicacid (ABTS), and ferric-reducing antioxidant power (FRAP) methods. The polyphenolic compounds were mainly found in the leaves at 30 °C. UPLC/QTOF-MS allowed for the identification of 34 polyphenolic components in seedlings, primarily consisting of glucosides, phenols, flavonoids, and methoxy flavones. At 30 °C, the specific activities of antioxidative enzymes were the highest in leaves, followed by seedlings and then seeds. The leaf and seed extracts also exhibited a greater accumulation of proline, glycine betaine, and antioxidants, such as ascorbic acid, and carotenoids, as measured by the inhibition of ROS production. We found that changes in the expression levels of the validated candidate genes Cu/Zn-SOD, APX, GPP, and TPS lead to significant differences in the germination rate and biochemical changes. These findings demonstrate that M. oleifera plants have high concentrations of phytochemicals and antioxidants, making them an excellent choice for further research to determine their use as health-promoting dietary supplements.
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    Integrating pH into the metabolic theory of ecology to predict bacterial diversity in soil
    (National Academy of Sciences, 2023-01-17) Luan L; Jiang Y; Dini-Andreote F; Crowther TW; Li P; Bahram M; Zheng J; Xu Q; Zhang X-X; Sun B; Brown J
    Microorganisms play essential roles in soil ecosystem functioning and maintenance, but methods are currently lacking for quantitative assessments of the mechanisms underlying microbial diversity patterns observed across disparate systems and scales. Here we established a quantitative model to incorporate pH into metabolic theory to capture and explain some of the unexplained variation in the relationship between temperature and soil bacterial diversity. We then tested and validated our newly developed models across multiple scales of ecological organization. At the species level, we modeled the diversification rate of the model bacterium Pseudomonas fluorescens evolving under laboratory media gradients varying in temperature and pH. At the community level, we modeled patterns of bacterial communities in paddy soils across a continental scale, which included natural gradients of pH and temperature. Last, we further extended our model at a global scale by integrating a meta-analysis comprising 870 soils collected worldwide from a wide range of ecosystems. Our results were robust in consistently predicting the distributional patterns of bacterial diversity across soil temperature and pH gradients-with model variation explaining from 7 to 66% of the variation in bacterial diversity, depending on the scale and system complexity. Together, our study represents a nexus point for the integration of soil bacterial diversity and quantitative models with the potential to be used at distinct spatiotemporal scales. By mechanistically representing pH into metabolic theory, our study enhances our capacity to explain and predict the patterns of bacterial diversity and functioning under current or future climate change scenarios.
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    Possible Consequences of Climate Change on Survival, Productivity and Reproductive Performance, and Welfare of Himalayan Yak (Bos grunniens)
    (MDPI (Basel, Switzerland), 2022-08-22) Sapkota S; Acharya KP; Laven R; Acharya N; Turzillo AM
    Yak are adapted to the extreme cold, low oxygen, and high solar radiation of the Himalaya. Traditionally, they are kept at high altitude pastures during summer, moving lower in the winter. This system is highly susceptible to climate change, which has increased ambient temperatures, altered rainfall patterns and increased the occurrence of natural disasters. Changes in temperature and precipitation reduced the yield and productivity of alpine pastures, principally because the native plant species are being replaced by less useful shrubs and weeds. The impact of climate change on yak is likely to be mediated through heat stress, increased contact with other species, especially domestic cattle, and alterations in feed availability. Yak have a very low temperature humidity index (52 vs. 72 for cattle) and a narrow thermoneutral range (5-13 °C), so climate change has potentially exposed yak to heat stress in summer and winter. Heat stress is likely to affect both reproductive performance and milk production, but we lack the data to quantify such effects. Increased contact with other species, especially domestic cattle, is likely to increase disease risk. This is likely to be exacerbated by other climate-change-associated factors, such as increases in vector-borne disease, because of increases in vector ranges, and overcrowding associated with reduced pasture availability. However, lack of baseline yak disease data means it is difficult to quantify these changes in disease risk and the few papers claiming to have identified such increases do not provide robust evidence of increased diseases. The reduction in feed availability in traditional pastures may be thought to be the most obvious impact of climate change on yak; however, it is clear that such a reduction is not solely due to climate change, with socio-economic factors likely being more important. This review has highlighted the large potential negative impact of climate change on yak, and the lack of data quantifying that impact. More research on the impact of climate change in yak is needed. Attention also needs to be paid to developing mitigating strategies, which may include changes in the traditional system such as providing shelter and supplementary feed and, in marginal areas, increased use of yak-cattle hybrids.
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    Do hotter temperatures increase the incidence of self-harm hospitalisations?
    (Routledge, 2016) Williams MN; Hill SR; Spicer J
    A relationship between air temperature and the incidence of suicide has been established in a number of previous studies. Interestingly, the relationship between geographical variation in temperature and suicide incidence has generally been found to be negative, while the relationship between temporal variation in temperature and suicide incidence has generally been found to be positive. It is less clear, however, how temperature relates to the incidence of self-harm. This topic is of particular importance given the presence of ongoing global warming. This study investigated the relationship between temperature and the incidence of self-harm resulting in hospitalisation in New Zealand. Self-harm hospitalisations by date and district for 1993-2009 were obtained from the Ministry of Health. Meteorological data was obtained from NIWA. Generalised linear mixed models were used to estimate the effects of three different components of variation in temperature: geographical, seasonal and irregular. Irregular (random) daily variation in temperature had a modest positive relationship with the incidence of acts of self-harm resulting in hospitalisation, with about 0.7% extra incidents for every 1 °C increase in temperature. However, there was no strong evidence for a positive effect of either seasonal or geographical variation in temperature. We conclude that temperature does appear to bear some relation to the incidence of self-harm, with irregular daily variation in temperature having a positive effect. However, inconsistencies in the effects of different components of variation in temperature make it challenging to accurately predict how global warming will influence the incidence of self-harm.