Climate change impacts crop production worldwide, and coastal regions are particularly vulnerable to its adverse effects. Given the projected rise in temperature and shifting precipitation patterns, ...it is crucial to examine the current challenges faced by farmers in coastal Bangladesh. Using Focus Group Discussions (FGDs) and Key Informant Interviews (KIIs), we assessed the perceptions and experiences of farmers and stakeholders regarding the existing agricultural practices, the challenges they face in crop cultivation, and the adoption of climate-adaptive practices in 2 sub-districts in the southeastern coastal region of Bangladesh. Moreover, using the Standardized Precipitation Evapotranspiration Index (SPEI) and the Standardized Terrestrial Water Storage Index (STI), we assessed the frequency and intensity of different climatic conditions in these two sub-districts. Results show that 100% of the respondents reported an increase in dry climatic conditions, the occurrence of untimely precipitation, and a decline in irrigation water during the cropping season. All the respondents in the FGDs expressed a loss of crop production because of these climate-induced disturbances. Despite these challenges, farmers have been implementing several climate-adaptive practices. Among the 9 mentioned climate-adaptive practices, 50% of FGD respondents utilize organic fertilizers, 42% cultivate heat- and drought-resilient crop varieties, use improved irrigation and harvest rainwater, and 25% cultivate integrated crops. The results of quantitative analysis of 3- and 6-month SPEI and STI values show that this region experienced frequent and intense dry climatic conditions during the growing-season, which supports the farmers’ and stakeholders’ concern about the increasing occurrence of droughts during crop growing periods. The results suggest that despite adopting climate-resilient practices under increasing growing-season droughts, farmers require support from the government and NGOs in capacity-building training and input support (e.g., stress-resilient seeds). This study holds practical implications for government, NGOs, and policymakers for ensuring sustainable agricultural productivity in the coastal region of Bangladesh.
The growing season normalized difference vegetation index (NDVIGS) of vegetation and their responses to climate extremes are critical in assessing the resistance and resilience of the terrestrial ...ecosystem. Using satellite-derived NDVIGS and widely used Standardized Precipitation and Evapotranspiration Index (SPEI) datasets of 18 sites in cold steppe, humid temperate and temperate dry steppe ecoregions for the period of 1982–2012, the NDVIGS response, resistance, and resilience to climate extreme intensity were assessed. The results showed that the mean NDVIGS varied significantly across ecoregions, where higher mean NDVIGS was observed in humid temperate and lower was in temperate dry steppe. The NDVIGS at most sites in three ecoregions showed significantly positive correlations with increasing SPEI. The responses of NDVIGS to climate extreme intensity revealed that moderate and extreme dry events decreased NDVIGS, while moderate and extreme wet events increased NDVIGS in all ecoregions. The results showed that vegetation resistance and resilience were highly dependent on climate extreme intensity. Resistance and resilience to moderate wet, extreme wet, moderate dry and extreme dry events in all ecoregions varied significantly, where vegetation in cold steppe and humid temperate ecoregions showed lower resistance but higher resilience to moderate and extreme dry events, and higher resistance but lower resilience to moderate and extreme wet events. Vegetation in temperate dry steppe showed higher resistance to moderate dry and higher resilience to moderate wet events. The study results suggest that more productive ecosystems (i.e. higher NDVIGS in cold steppe and humid temperate ecoregions) generally provide a lower (higher) resistance but higher (lower) resilience to dry (wet) events. Knowledge from this study also implies that less productive ecosystem (i.e. lower NDVIGS in temperate dry steppe) provides higher resistance to moderate dry and higher resilience after moderate wet events. This study highlights the impacts of climate extremes on NDVIGS, and improves our understanding of the resistance and resilience of vegetation to climate extreme intensity, which is of importance in the face of climate change.
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•Mean NDVIGS was highest in humid temperate and lowest in temperate dry steppe.•Growing-season climate was the better predictor of NDVIGS than the annual climate.•Across ecoregions, significant loss (gain) of NDVIGS resulted from extreme dry (wet) events.•Productive ecosystems showed lower (higher) resistance but higher (lower) resilience to dry (wet) events.•In temperate dry steppe, vegetation showed higher resistance (resilience) to moderate dry (wet) events.
The rising temperature, altering precipitation, and increasing extreme events under climate warming affect the stability and sustainability of grassland ecosystems. The dynamics of above-ground ...biomass (AGB), below-ground biomass (BGB), and biomass partitioning (BGB:AGB ratio) of grasslands are of fundamental importance to understand their feedback to climate change. In this study, we used grassland productivity data extracted from the Oak Ridge National Laboratory Distributed Active Archive Center, Tennessee, USA, in which the AGB was collected within a 1.0 m × 0.25 m quadrat and the BGB was sampled within the center of the quadrat. Using multiple pairwise tests and Pearson’s correlation analysis, we assessed the variations of grassland productivity and examined the response of single-harvest and annual biomass partitioning of C3- and C4-dominated grasslands to the growing-season and annual climatic variability and climate extremes in seven sites belonging to four ecoregions (i.e. cold steppe, humid temperate, humid savanna, and savanna). The results show that the annual and single-harvest BGB:AGB ratio varied significantly across the plant types and ecoregions. Overall, the C3-dominated grasslands exhibited a higher BGB:AGB ratio than that of C4-dominated grasslands. Growing-season temperatures (GSTs) were found to be the key determinants in explaining the single-harvest BGB:AGB ratio rather than growing-season precipitation. For instance, the single-harvest BGB:AGB ratio of C4-dominated grasslands increased, while that of C3-dominated grasslands decreased with elevated GSTs. The growing-season extreme dry climates significantly increased the single-harvest BGB:AGB ratio of C4 plants by a large reduction of AGB, potentially affecting the ecosystem functioning and stability. The C3-dominated grasslands in the cold steppe ecoregion are at great threat of drought-induced stress, as we observed that growing-season extreme dry climates reduced, albeit insignificantly, both the single-harvest AGB and BGB. This study provides key insights into factors influencing the biomass partitioning of C3- and C4-dominated grasslands and has important implications for assessing the grassland functioning and stability under increasing climate extremes.
Abstract
Improved water, sanitation and hygiene (WASH) facilities in water-scarce areas is one of the most important barriers to improving the standards of people's life, which is even worse in a ...locality with forcibly displaced people (e.g., nearly 1 million Rohingya refugees in Bangladesh). In attempting to understand the extent of vulnerability and risks of WASH facilities, their impacts, and adaptive practices in the communities, an exploratory study has been carried out in five selected camps (13, 15, 16, 24 and 27) in Cox's Bazar, Bangladesh. Examination of water facilities shows that households in camps 13, 15 and 16 suffered from an adequate supply of water during summer as there is no direct access to surface water from adjacent water reservoirs, while camps 24 and 27 have such facilities. The frequency of water shortage for drinking purposes in camps 13, 15 and 16 was not so severe as in camps 24 and 27. Drinking water collectors had to spend 3–5 h in queues. All latrines were communal/shared latrines, which made users feel uncomfortable and vulnerable. This study implies that WASH facilities need to be reinforced, and community sensitization on WASH behavior needs to be strengthened to reduce WASH-related health hazards.
Pd(0)-Catalyzed formal carbene insertion into Si-H bonds has been achieved as an efficient method for C(sp3)-Si bond formation. The reaction, which uses readily available N-tosylhydrazones as the ...diazo precursors, is highly efficient and shows a wide substrate scope. Rh(ii) and Cu(i) salts, which are the widely used catalysts for carbene insertion reactions, have been proved to be ineffective for the current reaction. A Pd(ii) carbene migratory insertion/reductive elimination mechanism is proposed.
Abstract
Assessing the dynamics of grassland functioning is critical for gaining an understanding of their feedback on rising aridity. In attempting to understand the response of grassland ecosystem ...functioning to aridity, the (i) relationships between biomass productivity (above- and belowground biomass: AGB and BGB, and their partitioning: BGB:AGB) and seasonal and annual aridity, and (ii) biomass allocation pattern between the AGB and BGB of C3- and C4-dominated grasslands in humid temperate, humid savanna, cold steppe, and savanna ecoregions were assessed. Results reveal that biomass productivity and its partitioning responded significantly to differences in growing season aridity, but the response patterns were not consistent for ecoregions. The decreased annual and seasonal biomass partitioning in humid savanna and cold steppe was associated with increased AGB and decreased BGB with accelerated aridity. There was a significant positive correlation in the biomass allocation pattern between the AGB and BGB of plants in three ecoregions, which supports the optimal partitioning theory. This study reveals that growing season aridity, rather than annual aridity, is the primary factor of biomass productivity and partitioning in the studied grasslands. These findings have significant repercussions for predicting ecosystem functioning and stability, restoring degraded ecosystems, and ensuring the sustainable management of grassland biodiversity.
The degree to which grassland aboveground biomass responds to climatic variability (e.g. annual and growing season precipitation and temperature) as well as management practices (e.g. harvest ...frequency) has attracted considerable interest in ecological studies. This understanding is important for maintaining ecosystem stability and sustainable delivery of ecosystem services under climate change. Here, we analyzed grassland biomass observations in 31 study sites in 5 ecoregions (i.e. cold steppe, humid savanna, humid temperate, savanna, and temperate dry steppe) to examine the effects of growing season and annual climatic variability and harvest frequency on aboveground biomass productivity. Annual aboveground biomass productivity showed significant increasing trends in humid temperate and savanna, but the changes of annual biomass in cold steppe, humid savanna, and temperate dry steppe ecoregions were insignificant. Single harvest aboveground biomass in cold steppe, humid savanna and humid temperate ecoregions increased with higher growing season precipitation and temperature. Although annual precipitation had positive effects on annual biomass, we found growing season precipitation sum was a more important determinant in all ecoregions. Impacts of mean annual and growing season temperature on annual biomass in humid temperate were significantly positive, while significant adverse impacts of mean growing season temperature and mean annual temperature were found in savanna and temperate dry steppe ecoregions, respectively. Irrespective of climatic variability, annual biomass consistently increased with increasing harvest frequency across ecoregions. Our study found significant gains in grassland aboveground biomass across ecoregions with increased precipitation and harvest frequency, and significant loses of biomass in savanna and temperate ecoregions with increased temperature. Our results help improve the understanding of the differences in the responses of grassland productivity to climate variability and harvest frequency across various ecoregions, which is of importance to achieve sustainable grassland management in different geographical regions.
Children bear a large burden of typhoid fever caused by Salmonella enterica serotype Typhi (S. Typhi) in endemic areas. However, immune responses and clinical findings in children are not well ...defined. Here, we describe clinical and immunological characteristics of young children with S. Typhi bacteremia, and antimicrobial susceptibility patterns of isolated strains.
As a marker of recent infection, we have previously characterized antibody-in-lymphocyte secretion (TPTest) during acute typhoid fever in adults. We similarly assessed membrane preparation (MP) IgA responses in young children at clinical presentation, and then 7-10 days and 21-28 days later. We also assessed plasma IgA, IgG and IgM responses and T cell proliferation responses to MP at these time points. We compared responses in young children (1-5 years) with those seen in older children (6-17 years), adults (18-59 years), and age-matched healthy controls.
We found that, compared to age-matched controls patients in all age cohorts had significantly more MP-IgA responses in lymphocyte secretion at clinical presentation, and the values fell in all groups by late convalescence. Similarly, plasma IgA responses in patients were elevated at presentation compared to controls, with acute and convalescent IgA and IgG responses being highest in adults. T cell proliferative responses increased in all age cohorts by late convalescence. Clinical characteristics were similar in all age cohorts, although younger children were more likely to present with loss of appetite, less likely to complain of headache compared to older cohorts, and adults were more likely to have ingested antibiotics. Multi-drug resistant strains were present in approximately 15% of each age cohort, and 97% strains had resistance to nalidixic acid.
This study demonstrates that S. Typhi bacteremia is associated with comparable clinical courses, immunologic responses in various age cohorts, including in young children, and that TPTest can be used as marker of recent typhoid fever, even in young children.
CMISR: Circular medical image super-resolution Li, Honggui; Lokman Hossain, Nahid Md; Trocan, Maria ...
Engineering applications of artificial intelligence,
July 2024, 2024-07-00, Volume:
133
Journal Article
Peer reviewed
Open access
Classical methods of medical image super-resolution (MISR) utilize open-loop architecture with implicit under-resolution (UR) unit and explicit super-resolution (SR) unit. The UR unit can always be ...given, assumed, or estimated, while the SR unit is elaborately designed according to various SR algorithms. The closed-loop feedback mechanism is widely employed in current MISR approaches and can efficiently improve their performance. The feedback mechanism may be divided into two categories: local feedback and global feedback. Therefore, this paper proposes a global feedback-based closed-cycle framework, circular MISR (CMISR), with unambiguous UR and advanced SR elements. Mathematical model and closed-loop equation of CMISR are built. Mathematical proof with Taylor-series approximation indicates that CMISR has zero recovery error in steady-state. In addition, CMISR holds plug-and-play characteristic that fuses model-based and learning-based approaches and can be established on any existing MISR algorithms. Five CMISR algorithms are respectively proposed based on the state-of-the-art open-loop MISR algorithms. Experimental results with three scale factors and on three open medical image datasets show that CMISR is superior to MISR in reconstruction performance and is particularly suited to medical images with strong edges or intense contrast.
Methylglyoxal (MGO) is considered to be one of the vital components responsible for the anti-bacterial activity of
spp. (Manuka) honey. While many studies have demonstrated a dose-dependent ...antibacterial activity for MGO in vitro, from a therapeutic viewpoint, it is also important to confirm its release from Manuka honey and also from Manuka honey-based formulations. This study is the first to report on the release profile of MGO from five commercial products containing Manuka honey using a Franz diffusion cell and High-Performance Liquid Chromatography (HPLC) analysis. The release of MGO expressed as percentage release of MGO content at baseline was monitored over a 12 h period and found to be 99.49 and 98.05% from an artificial honey matrix and NZ Manuka honey, respectively. For the investigated formulations, a time-dependent % MGO release between 85% and 97.18% was noted over the 12 h study period.
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