Stoebe vulgaris is a declared indigenous bush encroacher species in South Africa. It has invaded over 11 million ha of grasslands. It is commonly called bankrupt bush due to its ability to outcompete other indigenous forb and grass species, decreasing grazing capacity, biodiversity, and ecosystem functioning, eventually leading to financial ruin for farmers. Landowners are legally required to control the plant. A herbicide trial was set up in a severely encroached camp at Dundee Research Station in KwaZulu-Natal, South Africa, to test the effectiveness of metsulfuron-methyl (50 g active ingredient ha−1) in controlling S. vulgaris. Applying metsulfuron-methyl provided a significant long-term reduction in S. vulgaris cover over six years. However, effective monitoring and management strategies depend on knowledge of the spatial distribution and expansion patterns of invasive species. We evaluated the ability of UAV-based imagery and machine learning, using Picterra, to detect and map S. vulgaris, while determining the optimal parameters to maximise detection accuracy. The best season for image acquisition was late summer when vegetation was at peak growth and maturity, providing the best spectral distinction between species, under light overcast and mild wind conditions. We recommend careful consideration of the flight orientation to the solar angle. We achieved 92% detector accuracy, with multispectral imagery enhancing the discrimination of similarly coloured plants. Plants smaller than 10 cm were not detected by the model. Our approach, using high-resolution drone imagery and AI, is capable of individual plant detection suited to a farm scale. This opens the way for using advances in drone technology for targeted, spot-application of herbicide.
Paraphenylenediamine (PPD), locally known as “Kala Pathar”, has historically been a major agent of suicidal self poisoning in Southern Punjab, Pakistan. In response to escalating morbidity and mortality, the Government of Punjab implemented a policy prohibiting the commercial scale distribution of raw PPD at the end of 2017. This study aimed to quantitatively evaluate the impact of this policy on the incidence of PPD-related suicidal poisoning in Bahawalpur using an interrupted time series design. A quasi-experimental, retrospective interrupted time series (ITS) analysis was conducted using hospital records from the emergency department of Bahawal Victoria Hospital, Bahawalpur, from January 2016 to March 2024. Annual counts of confirmed PPD poisoning cases were analyzed. The intervention point was defined as January 2018. Segmented regression analysis was performed to estimate changes in both the level and the trend following policy implementation. A total of 4455 PPD poisoning cases were recorded during the study period. Prior to the intervention, cases increased from 832 in 2016 to a peak of 1243 in 2017. Following the prohibition, cases declined sharply to 407 in 2019 and further to 155 in 2023. Segmented regression analysis demonstrated a statistically significant immediate reduction in case level after the intervention (β2 < 0, p < 0.05), along with a significant negative change in post intervention trend (β3 < 0, p < 0.05), indicating a sustained decline in PPD poisoning incidence. The majority of cases occurred among males (72%) and individuals aged 21–40 years (48%). The prohibition of commercial scale PPD distribution was associated with a significant and sustained reduction in PPD-related suicidal poisoning in Bahawalpur. These findings support targeted means restriction policies as an effective suicide prevention strategy in resource limited settings.
Salamanders of the genus Ambystoma in the Trans-Mexican Volcanic Belt are experiencing severe population declines due to habitat loss and fragmentation. This study evaluated critical protection gaps for four Critically Endangered microendemic species: A. amblycephalum, A. andersoni, A. dumerilii and A. mexicanum. We compiled and cleaned 89 validated presence records from databases and the literature. Refined areas of occupancy were calculated using minimum convex polygons adjusted with elevation masks, hydrographic network filters, and species-specific buffer zones (50–100 m). Bioclimatic variables (temperature and precipitation-based) were derived from MexHiResClimDB, and overlap with protected areas, and the Ecosystem Integrity Index (EII) was quantified. The resulting areas of occupancy (0.38–108.19 km2) were larger than previous IUCN estimates for A. amblycephalum and A. dumerilii, yet showed null or minimal overlap with protected areas for these two species (4.79% and 0%, respectively). Ecosystem integrity was low across all species (EII 0.05–0.43), indicating severe degradation. Climatic niches were narrow, differentiated, and associated with restricted altitudinal ranges. These results reveal a crisis of effective protection, where expanded distribution knowledge does not translate into improved conservation status, demanding urgent expansion of active conservation strategies to counteract severe habitat degradation caused by urbanization, intensive agriculture, pollution, and invasive species.
Electromagnetic waves are the foundation of modern communication and information transmission which take advantage of strong penetration and fast propagation. To prevent electromagnetic radiation pollution and improve application efficiency, the development of new types of electromagnetic wave absorption and shielding materials that can convert electromagnetic wave energy into thermal energy for absorption and shielding has become increasingly important. Although progress in different electromagnetic wave-absorbing and shielding materials is exciting, there are few reviews of new materials, especially two-dimensional materials. By analyzing the structure and loss mechanism of two-dimensional materials, this review systematically summarizes the current research status and unique advantages of two-dimensional materials in electromagnetic wave absorption and shielding. By extending traditional synthetic two-dimensional materials to natural two-dimensional mineral materials, the potential applications of these materials in future green development havee been explored. Based on different application scenarios, new challenges and future directions for highly efficient electromagnetic wave absorption and shielding materials are presented. The prospects for the development of two-dimensional materials are also clarified from aspects of macroscopic and microscopic structural design and functional integration.
Enantioselective photohydrogenation using semiconductor photocatalysts remains challenging because of the heterogeneity of solid surfaces and the difficulty in controlling adsorption geometries. In this study, we systematically investigated the enantioselective photohydrogenation of aromatic ketones using TiO2 photocatalysts in the presence of chiral co-adsorbents, focusing on the combined effects of co-adsorbent structure and TiO2 crystal morphology. Chiral aromatic amino alcohols, such as 2-amino-1-phenylethanol (PhEA), were identified as effective and relatively photostable co-adsorbents, affording moderate enantioselectivity with reduced inhibition compared with carboxylate-type co-adsorbents. Structural analyses revealed pronounced differences in particle size, lattice distortion, and inferred exposed crystal facets among anatase TiO2 samples. TIO-13, composed of larger particles with relatively well-defined surface structures, exhibited higher and more reproducible enantioselectivity, whereas TIO-7, composed of smaller nanoparticles with more heterogeneous surfaces, showed higher reaction rates but lower enantioselectivity. Consecutive photohydrogenation experiments provided supportive evidence that residual surface-adsorbed chiral co-adsorbent contributes to both asymmetric induction and inhibition of the reaction. Although the present work should be regarded primarily as a fundamental study rather than a practically optimized catalytic methodology, it provides useful insight into the design of chiral semiconductor photocatalysts for heterogeneous asymmetric photocatalysis.
