In Situ Hypoiodite-Catalyzed Oxidative Rearrangement of Chalcones: Scope and Mechanistic Investigation.

It is highly desirable to avoid using rare or toxic metals for oxidative reactions in the synthesis of pharmaceuticals and fine chemicals. Hypervalent iodine compounds are environmentally benign alternatives, but their catalytic use has been quite limited. Herein, the protocol for in situ hypoiodite-catalyzed oxidative rearrangement of chalcones is first realized under mild and metal-free conditions, which provided a nontoxic, environmental-benign, and catalytic alternative to the thallium-based protocol. Also, the applicability and effectiveness of this catalytic protocol got well demonstrated via gram-scale synthesis and product derivatization. What is more, control and NMR tracking experiments were performed to figure out the possible catalytic species and intermediates.

Building climate change resilience by using a versatile toolkit for local governments and communities in rural Himalaya.

With the impacts of climate disruption becoming more evident there has been an increase in the uptake of climate change adaptation "toolkits" to assist local governments build community resilience and adapt to the impacts of climate change. There is increasing attention and call for practitioners to adopt proactive and participatory approaches to help in the adaptive response planning process. One such toolkit is the International Council for Local Environmental Initiatives (ICLEI) Asian Cities Climate Change Resilience Network (ACCRN) Process (IAP). This is a simple but rigorous toolkit developed to help local governments in Asian cities build resilience to the impacts of climate change. This paper outlines the application of the toolkit to determine its versatility in the rural context and was trialled in the Himalayan rural enclave of Ramgad in the Indian state of Uttarakhand. Given the differences between urban and rural environments, the outcomes highlighted the need for further investigation and analysis into the process to ensure that the methodology truly reflects the nature of rural systems and their level of vulnerability and adaptive capacity. Overall, the toolkit proved to be a simple but versatile toolkit to assess the vulnerability and adaptive capacity of communities in rural Himalaya. Over 40 resilience intervention strategies were developed for the Ramgad enclave and these were prioritized according to their technical, political, social and economic feasibility.

Farmers' perceptions of agricultural land use changes in Nepal and their major drivers.

Historical trends show that the total area of agricultural land in Nepal has changed markedly over time, but few studies have addressed the causative drivers underlying this change. Evaluating the perceptions of farmers is an effective tool for addressing this issue because it reflects the full range of drivers associated with changes in land use. This study utilizes historical agricultural area, population, and climate data for 1910-2010, combined with a series of applied household surveys and focus group discussions to assess farmers' perceptions of these changes and identify the major drivers. The paired t-test was employed to measure differences between various groups of drivers. The total area of agricultural land in Nepal has expanded rapidly since 1910, more intensively in the southern (Tarai) and central (Hill) ecological regions of the country, and has decreased slightly near large cities in recent decades. Farmers' perceptions show that socioeconomic variables were considered to be the crucial drivers of changes in agricultural land use. The three other major drivers were grouped as: neighborhood, climate-topography, and policy drivers. In particular, farmers pointed to the high level of population growth (93.96%) as the main factor underlying the changes, and the majority of drivers are associated with this variable. Access to roads (77.36%), urbanization (33.77%), government policies (23.58%), and remittance impact (16.79%) are other notable triggering variables. The paired t-test results equating variables from different groups of drivers and ecological regions indicate varied significance (p-values range from 0.004 to 0.983). Our analysis confirms that the synergy between social and natural observations can be integrated to obtain research findings that identify scientific and social issues. The interplay between the drivers should be emphasized in developing plans for sustainable agricultural land use management.

Influences of landscape pattern on water quality at multiple scales in an agricultural basin of western China.

Determining the associations between landscape pattern and river water quality and quantifying the abrupt change points of landscape metrics are vital to optimize landscape planning and improve basin water quality. This study took an agricultural basin in western China as a case study. River water quality of 61 sub-basin outlets were monitored during wet and dry seasons from 2020 to 2021. Landscape metrics were extracted at 100 m, 300 m, 500 m riparian buffer and sub-basin scales, respectively. Relationships between water quality and landscape pattern at multiple scales were explored by using redundancy analysis (RDA). Results showed that urban-related landscape metrics served as the primary contributor to degrade water quality during both seasons, followed by cropland-related metrics, which might be attributed to the increase of urban land and reduction of agricultural chemical fertilizer use. Landscape metrics could better explain the water quality variations during wet season than dry season. The explanatory abilities of landscape metrics to overall water quality appeared little difference among spatial scales during wet season, whereas landscape metrics within 100 m riparian buffer had much larger explanatory rate than other spatial scales during dry season. Results of abrupt change point analysis revealed that the abrupt change interval values (ACIVs) of percentage of urban land (PLANDurban) and the largest patch index of urban land (LPIurban) differed among COD, TN, and TP. The recommended threshold values of PLANDurban and LPIurban for COD, TN, and TP management were smaller than 11.0%, 2.5%, and 1.0%, respectively. When the PLANDurban or LPIurban exceeded 19.0%, the TN, TP, and COD pollution would all significantly accelerate. Therefore, a limit value of 19% of PLANDurban and LPIurban, respectively is put forward. From dry season to wet season, the ACIVs of PLANDurban and LPIurban for COD concentration increased, whereas they decreased for TN and TP concentrations. Our results can provide scientific insights into sustainable landscape planning and effective water quality protection in agricultural basins.

Wetland Changes and Their Relation to Climate Change in the Pumqu Basin, Tibetan Plateau.

Wetland ecosystems play one of the most crucial roles in the world. Wetlands have the functions of ecological water storage, water supply, and climate regulation, which plays an indispensable role in global environmental security. The Pumqu River Basin (PRB) is located in an area with extremely vulnerable ecological environment, where climate change is obvious. Understanding wetland distribution, changes and causes in the PRB are of great importance to the rational management and protection of wetlands. Using the Landsat series satellite images, wetlands of this area in 2000, 2010, and 2018 were extracted. The results showed that (1) there were obvious regional differences in wetland types and their distribution patterns in the basin. Wetlands were mainly distributed in areas with slopes less than 12° and at elevations between 4000 m and 5500 m. (2) During the past 20 years, the wetland area in the basin decreased, and the changing trend of wetlands was different. Palustrine wetlands decreased tremendously, riverine and lacustrine wetlands first decreased and then increased, while floodplain wetlands first increased and then decreased. Palustrine wetlands were reclaimed to cultivated land, but the proportion of reclamation is small. (3) Climate dominated wetland changes in the PRB. The changes in riverine and lacustrine wetlands were mainly affected by the warm-season average temperature, the change in palustrine wetlands was mainly related to the annual precipitation and the warm-season average temperature, and the change in floodplain wetlands was related to the warm-season precipitation. To achieve sustainable development, the government plays a guiding role and actively formulates and implements wetland protection policies, such as restricting or prohibiting grazing on wetlands, which play an important role in wetland protection and restoration.

[Study of biological characteristics of the IVpi-189 virus derived from persistent influenza A virus-infected cell line].

To investigate biological characteristics of the IVpi-189 progeny virus derived from the culture of influenza A virus as a live-attenuated vaccine candidate. Persistent infection of a cultured cell line with influenza A virus (MDCK-IVpi) was established by incubating continuously influenza virus-infected cells at a lower temperature. The infectious progeny virus derived from MDCK-IVpi cells at the 189rd subculture was designated as the IVpi-189 strain of influenza virus. The cytopathic effect induced by IVpi-189 virus was observed under different temperature conditions. The production of infectious progeny virus was examined at 38 and 32 degrees C by plaque titration of cell-associated and released virus. IVpi-189 virus showed cytopathic effect as strong as that of IVwt in infected cell line of MDCK at 32 degrees C. However, when culture temperature was raised to 38 degrees C, the cytopathic effect induced by IVpi-189 virus was delayed and less pronounced. Virus growth in IVpi-189 virus-infected cells at 38 degrees C was significantly reduced as compared with that of IVwt virus, although both viruses yielded nearly equivalent high titers of cell-associated and released virus at 32 degrees C. The reasons of the decreased proliferative ability of IVpi-189 virus at high culture temperature were unrelated with virus inactivation or the release of progeny virus, but associated with the decreased replication of infectious progeny virus in the infected cells. IVpi-189 virus derived from MDCK cells infected persistently with influenza A virus showed biological characteristics as a potential live-attenuated vaccine candidate.

[Effect of heat treatment on the electrocatalytic activity of SnO2/Ti anode in degradation of p-benzoquinone].

Sb-doped SnO2/Ti anode was prepared in our lab with thermal decomposition method, and in the same time, the effect of heat treatment on the properties of the electrode also was studied. Scanning electron microscopy (SEM) was used to study the surface characterization of the electrodes. X-ray photoelectro-spectroscopy (XPS) measurements were carried out to study the chemical state of elements, Sn and Sb. The potentiodynamic polarization behaviors of the two anodes in different solutions were performed. Galvanostatic electrolyses were carried out at 5 mA/cm2 to study the electrocatalytic activity of the two anodes in removing organic pollutant. SEM showed that the electrodes had the same well-known cracked-mud structure, while the electrode annealed in O2 [SnO2/Ti(O2)] had more larger surface area than the electrode annealed in the air [SnO2/Ti(air)]. XPS measurements showed that the binding energies of both Sn3d(5/2) and Sb3d(5/2) of SnO2/Ti(O2) were 0.15 eV smaller than what of the SnO2/Ti(air) film. Both of the electrochemical measurements and electrolyses results confirmed that SnO2/Ti(O2) was more active in the degradation of organic pollutant. The galvanostatic electrolyses lasted until the solutions were decoloured throughly, 76.3% of total organic carbon (TOC) was removed with SnO2/Ti(O2), compared with 63.3% of SnO2/Ti(air). The similar exponential rules were driven for the variations of residual TOC concentration with two anodes.