Morphological changes in eggs and embryos of Aedes aegypti (Diptera: Culicidae) exposed to predicted climatic scenarios for the year 2100 in the Central Amazon

According to the IPCC, by the year 2100, rises in global temperature could reach up to 5 °C above current averages. On a planet-wide scale, this is one of the effects of climate changes that could have repercussions on the biological cycle of Aedes aegypti, the main arbovirus vector in urban environments and a transmitter of the arboviruses that cause dengue, Zika, chikungunya and urban yellow fever. The objective of this study was to evaluate morphological changes in Ae. aegypti eggs and embryos maintained in a climate change simulator. For this, specimens obtained from an insectarium were kept in four chambers that simulated the range of environmental scenarios predicted by the IPCC for the year 2100. The eggs obtained from each room were collected and transported to the laboratory for morphometric and morphological analysis, using confocal and scanning microscopy. Aedes aegypti eggs (n=20) were used to obtain the following variables: total width, total length, length-width ratio and diameter of the micropylar disc. Additionally, 20 embryos were used to obtain the data on head capsule length, width and length-width ratio. The data were subjected to a normality test and the means of each variable were compared using ANOVA and Tukey's post-hoc test, considering (p ≤ 0.05). A significant reduction (p < 0.05) was observed mainly in the mean lengths under the current-extreme scenario (587.5 and 553.6 μm, respectively), as well as in the widths under the current-mild scenario (171 and 158.4 μm, respectively). The length of the cephalic capsule was also affected, showing significant differences in the means under the current-intermediate scenario (189.5 and 208.5 μm, respectively), as well as in the widths between the current-intermediate scenarios (173.7 and 194.9 μm, respectively). The results suggest significant changes in the morphometry of Ae. aegypti eggs and embryos as a result of the climatic influences to which the adults were subjected, which may have an impact on vector population density and, consequently, on arbovirus dynamics in urban environments.

Impact of high temperature and drought stress on the microbial community in wolf spiders

High temperatures and drought present significant abiotic challenges that can limit the survival of many arthropods, including wolf spiders, which are ectothermic and play a crucial role in controlling pest populations. However, the impact of these stress factors on the microbiota of spiders remains poorly understood. In this study, we utilized 16 S rRNA gene sequencing to explore the diversity and composition of bacterial communities within Pardosa pseudoannulata under conditions of high temperature and drought stress. We found that Firmicutes, Bacteroidetes, and Proteobacteria were the predominant bacterial phyla present. Analyses of alpha diversity indicated an increase in bacterial diversity under combined stress conditions, as reflected by various diversity indices such as Ace, Chao1, Shannon, and Simpson. Furthermore, co-occurrence network analysis highlighted intricate interactions among the microbial taxa (e.g., Enterobacter, Chitinophaga, and Eubacterium), revealing the adaptive complexity of the spider's microbiome to environmental stress. Functional prediction analysis suggested that combined stress conditions might enhance key metabolic pathways, particularly those related to oxidative phosphorylation and amino acid metabolism. Using Random Forest analysis, we determined that changes in three heat shock proteins were largely attributed to variations in bacterial communities, with Firmicutes being notably influential. Collectively, this in-depth analysis offers novel insights into the responses of microbial communities within spider microbiomes to combined abiotic stresses, providing valuable information for understanding extreme climate impacts and informing ecological management strategies.

A simultaneous impact of digital economy, environment technology, business activity on environment and economic growth in G7: Moderating role of institutions

This study investigates the simultaneous influence of the digital economy, environmental technologies, business activity, and institutional quality on both the environment and economic growth in G7 economies from 1996 to 2020. The study provides an in-depth analysis to investigate the influence of institutional quality, particularly the regulatory environment, on business activity. Employing a rigorous methodology encompassing correlation analysis, long-term examination using Driscoll and regression estimators, and the utilization of various digital economy indicators such as internet usage and cell subscriptions, we uncover significant insights. The findings underscore the substantial impact of digital economies in mitigating carbon emissions and driving economic growth at an accelerated rate. Moreover, the study reveals that certain regulatory constraints on corporate operations can paradoxically facilitate carbon emission management while also fostering economic expansion. The study validates the presence of an inverted U-shaped Environmental Kuznets Curve (EKC) in G7 economies. This suggests that there is a specific point at which economic activities start to contribute more to carbon emissions. Moreover, the study highlights the importance of achieving a balance between economic growth driven by foreign direct investment and the goals of environmental sustainability. Environmental technology is becoming increasingly important in the regulation of emissions. Significantly, the study highlights the need to enhance the quality of implementing institutional regulations. It suggests that G7 economies can improve both environmental quality and economic growth by adopting superior regulatory methods. These findings are relevant for governments seeking economic growth and environmental protection. They suggest the need for specific policy actions to accomplish sustainable development goals.

Spatiotemporal climate variability and trends in the Upper Gelana Watershed, northeastern highlands of Ethiopia

The aim of this study was to evaluate the performance of CHIRPS and TAMSAT satellite rainfall data over the Upper Gelana watershed, where gauged meteorological data to understand the nature of the climate are scarce. In addition, variability and trends in rainfall and temperature were examined from 1983 to 2021. To evaluate satellite rainfall, categorical and continuous validation statistics were used. Trends were analyzed using Mann-Kendall, Sen's Slope estimator, and innovative trend analysis (ITA) methods. The study also utilized time-series geostatistical analysis techniques. The validation statistics show that TAMSAT performs better on the daily timescale, while the two products have comparable performance on the monthly timescale. TAMSAT was chosen for rainfall analysis because of its higher resolution and performance. The results reveal high inter-annual spatiotemporal variability and strong irregularities in monthly rainfall. The Mann-Kendall test indicates statistically significant positive trends in kiremt and annual rainfall, but belg rainfall exhibits an insignificant negative trend. In the kiremt season, we found a 96.1, 101.6, and 104.8 mm decadal rate of rainfall increment in the lower weina dega (LWD), upper weina dega (UWD), and dega agroecological zones, respectively. In contrast, belg season rainfall declined by 16.4, 16.2, and 14.0 mm per decade in the LWD, UWD, and dega agroecology zones, respectively. The pixel-wise trend analysis also revealed trends and magnitudes of monthly, seasonal, and annual rainfall that vary across the study area. In both LWD and UWD annual minimum and maximum temperatures, respectively, showed significant decreasing and increasing trends, but in dega agroecology the trends were insignificant. The findings of rainfall and temperature trends using the ITA method demonstrated its ability to discover some hidden trends that were not detected by the MK test.

Exploring the relationships between human consumption and environmental pressure: A case study of the Yangtze river economic zone in China

It is crucial to decouple and coordinate human consumption and its environmental pressure for achieving sustainable development. As an important aspect of United Nations Sustainable Development Goal (SDG12), sustainability on material consuming is still in its early stages of research. To address the research gap in sustainable consumption of vegetation net primary productivity (NPP), this study analyzed the spatio-temporal dynamics of human consumption and environmental pressure in the Yangtze River Economic Zone (YREZ) using consumption-based HANPP (cHANPP) and Human Appropriation of Net Primary Production (HANPP) as indicators. Later, we measured their decoupling relationship using Tapio decoupling approach. We found that distribution of HANPP and cHANPP were regionally separated, with the former mainly concentrated in the middle and upper reaches provinces, while the latter concentrated in the lower reach provinces. From 2004 to 2019, the relationship between HANPP and cHANPP changed from strong negative decoupling to weak decoupling in the YREZ. Furthermore, the relationship was differed among different regions. As a whole, developing regions showed a weak decoupling state, experiencing an increase in environmental pressure (i.e., HANPP) alongside increased human consumption (i.e., cHANPP). In contrast, developed regions showed a strong decoupling state, experiencing a decrease in environmental pressure (i.e., HANPP) alongside increased human consumption (i.e., cHANPP). Our study highlights that different countermeasures should be formulated by regions according to their own situation to realize sustainable regional development.

Predicting low carbon pathways on the township level in China: a case study of an island

Carbon prediction on the township level is usually difficult due to a lack of necessary information. To fulfil the research gap, the study focused on a town located in a nearshore island (Lingshan) in China. A questionnaire survey was performed to collect essential information about the future development of the town, followed by validating interviews with the island management committee. The carbon prediction of the town was established by the Low Emissions Analysis Platform (LEAP) model. The baseline scenario reflecting the existing method of carbon management was compared with an alternative low-carbon scenario. The prediction from 2020 to 2060 covers the periods of the planned carbon emissions peak in 2030 and carbon neutrality in 2060. It is found that energy-related activities and electricity consumption are the primary contributors to carbon emissions on the island. The carbon emission of Lingshan Island increases from -1333 tCO2e in 2020 to 2744 tCO2e in 2060, and the carbon peak target cannot be achieved in the baseline scenario. However, the carbon emission of the low-carbon scenario is predicted to have a peak of -850 tCO2e in 2029. The prediction model developed in this study, along with the proposed policy recommendations, can be applied to other towns or regions where data availability is limited to promote carbon reduction.

Microbial diversity characterizations, associated pathogenesis and antimicrobial resistance profiling of Najafgarh drain

The Najafgarh drain plays a significant role in the pollution of the Yamuna River, accounting for 40% of the total pollution. Therefore, it is crucial to investigate and analyze the microbial diversity, metabolic functional capacity, and antibiotic resistance genes (ARGs) present in the Najafgarh drain. Additionally, studying the water quality and its relationship with the proliferation of microorganisms in the drain is of utmost importance. Results obtained confirmed the deteriorated water quality as physico-chemical parameters such as biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), and total suspended solids (TSS) in the range of 125-140, 400-460, 0-0.2, 25-140.4 mg/l respectively violated the standard permissible national and global standards. In addition, the next generation sequencing (NGS) analysis confirm the presence of genus such as Thauera, Arcobacter, Pseudomonas, Geobacter, Dechloromonas, Tolumonas, Sulfurospirullum, Desulfovibrio, Aeromonas, Bacteroides, Prevotella, Cloacibacterium, Bifidobacterium, Clostridium etc. along with 864 ARGs in the wastewater obtained from the Najafgarh drain. Findings confirm that the pathogenic species reported from this dataset possess severe detrimental impact on faunal and human health. Further, Pearson's r correlation analysis indicated that environmental variables, mainly total dissolved solids (TDS) and chemical oxygen demand (COD), play a pivotal role in driving microbial community structure of this heavily polluted drain. Thus, the poor water quality, presence of a microbial nexus, pathogenic markers, and ARGs throughout this drain confirmed that it would be one potential contributor to the dissemination of disease-causing agents (pathogens) to the household and drinking water supplies in the near future.

Research progress and prospects for using biochar to mitigate greenhouse gas emissions during composting: A review

Biochar possesses a unique porous structure and abundant surface functional groups, which can potentially help mitigate greenhouse gas (GHG) emissions from compost. This review summarizes the properties and functions of biochar, and the effects of biochar on common GHGs (methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O)) and ammonia (NH₃, an indirect GHG) during composting. Studies have shown that it is possible to improve the mitigation of GHG emissions during composting by adjusting the biochar amount, type of raw material, pyrolysis temperature, and particle size. Biochar produced from crop residues and woody biomass has a greater effect on mitigating CH₄, N₂O, and NH₃ emissions during composting, and GHG emissions can be reduced significantly by adding about 10% (w/w) biochar. Biochar produced by high temperature pyrolysis (500-900 °C) has a greater effect on mitigating CH₄ and N₂O emissions, whereas biochar generated by low temperature pyrolysis (200-500 °C) is more effective at reducing NH₃ emissions. Interestingly, adding granular biochar is more beneficial for mitigating CH₄ emissions, whereas adding powdered biochar is better at reducing NH₃ emissions. According to the current research status, developing new methods for producing and using biochar (e.g., modified or combined with other additives) should be the focus of future research into mitigating GHG emissions during composting. The findings summarized in this review may provide a reference to allow the establishment of standards for using biochar to mitigate GHG emissions from compost.