Adaptation Strategies In Response Research Articles

Two common, often coexisting grassland plant species differ in their evolutionary potential in response to experimental drought.

For terrestrial plant communities, the increase in frequency and intensity of drought events is considered as one of the most severe consequences of climate change. While single-species studies demonstrate that drought can lead to relatively rapid adaptive genetic changes, the evolutionary potential and constraints to selection need to be assessed in comparative approaches to draw more general conclusions. In a greenhouse experiment, we compare the phenotypic response and evolutionary potential of two co-occurring grassland plant species, Bromus erectus and Trifolium pratense, in two environments differing in water availability. We quantified variation in functional traits and reproductive fitness in response to drought and compared multivariate genetic variance-covariance matrices and predicted evolutionary responses between species. Species showed different drought adaptation strategies, reflected in both their species-specific phenotypic plasticity and predicted responses to selection indicating contrasting evolutionary potential under drought. In T. pratense we found evidence for stronger genetic constraints under drought compared to more favourable conditions, and for some traits plastic and predicted evolutionary responses to drought had opposing directions, likely limiting the potential for adaptive change. Our study contributes to a more detailed understanding of the evolutionary potential of species with different adaptive strategies in response to climate change and may help to inform future scenarios for semi-natural grassland ecosystems.

Is the multi-species variation in leaf anatomical traits along the environmental gradient modulated by herbaceous functional groups?

Grasses are widely distributed in various habitats with significantly different characteristics than non-grass species. However, an understanding of the multi-species differences in leaf anatomical traits variation and adaptive strategies between grass and non-grass species is limited. We measured leaf anatomical traits of 242 species from 10 sampling sites along an environmental gradient on the Loess Plateau (from east to west, environmental temperature, precipitation, and soil nutrients decreased, but radiation increased). Nine leaf anatomical traits were measured, and these traits related to the leaf physiological functions of photosynthesis (mesophyll thickness (MT), palisade tissue thickness (PT), spongy tissue thickness (ST)), defense (epidermal thickness (ET) and leaf thickness (LT)), and transport (xylem conduit diameter (CD) and major vein diameter (MVD)). Subsequently, we calculated the trait ratios, which reflect the proportion of investment in trait construction (epiderm-leaf thickness ratio (ET/LT) and mesophyll-leaf thickness ratio (MT/LT)). The results of linear regression analysis showed that non-grasses living under harsh environmental conditions have thicker leaf tissues responsible for photosynthesis and defense compared to grasses from the same environment. However, grasses and non-grasses living under stressful environmental conditions have higher MT/LT and lower ET/LT compared to species living in environments with a more proper resource supply, which indicated that both preferred to invest less in defense-related traits (e.g., epidermal thickness) while cost more in photosynthesis-related traits (e.g., mesophyll thickness) under the limited resource conditions. These findings highlight that grass and non-grass species have different trait characteristics and adaptive strategies in response to environmental changes. More importantly, a new inspiration is provided for exploring the plants’ general investment rule from the perspective of leaf anatomical trait-ratio values.

Climatic and Fruit Productivity Trends in Solan District, Himachal Pradesh, India

The shortened duration of the winter season in the Himalayan region caused by snow melting has a negative impact on fruit crop growth and productivity. The present study focused on examining the impact of climate change on fruit crops in the Solan district of Himachal Pradesh, India, situated in the Himalayan region. The trend analysis of climatic variables (temperature and rainfall) along with the productivity of fruit crops was investigated. The climate data spanning 30 years (1990–2019), including average temperature (maximum, minimum, and diurnal) and annual rainfall used during crop development stages like pre-flowering, flowering, and fruit-setting stages. To evaluate climatic trends, the Standardized Anomaly Index (SAI) and Mann-Kendall Test for quantification were employed. The Multivariate Linear Regression Analysis was performed to establish a correlation between climatic variables and crop productivity. The findings indicated that during the pre-flowering stage, there was a gradual increase in average maximum temperature at a rate of 0.001°C per year, along with a corresponding rise in diurnal temperature at a rate of 0.036°C per year. However, annual rainfall and average minimum temperature exhibited non-significant decreasing trends, with rates of -0.044°C and -0.033 mm, respectively. During the flowering stage, there was a significant increase in minimum temperature at a rate of 0.151°C per year, while diurnal temperature exhibited a significant decrease of -0.158°C per year. Other variables did not exhibit substantial changes during this stage. In the fruit-setting stage, only the minimum temperature demonstrated a significant decrease over the study period. The response to climate change revealed an overall positive trend for all fruit crops, leading to higher productivity. The correlation study indicated that the phenological stages of each crop were more positively influenced by temperature than rainfall, owing to existing climatic variations. The current climatic conditions in the Solan district were found to be favorable and productive for crop development, as all crops showed increased productivity based on the trend analysis. The study highlights climatic trends and their impact on the productivity of fruit crops in the Himalayan region, which is useful for agricultural planning and adaptation strategies in response to changing climatic conditions.

Climate change perception and adaptation among farmers in coastal communities of Bayelsa State, Nigeria: a photovoice study

PurposeThere is an increasing need for greater awareness and understanding of the risks climate change poses to farming communities so as to inform appropriate adaptive responses. The purpose of this study is to investigate farmers’ climate change impacts, awareness, risk perception and current adaptation strategies adopted to deal with the impacts of climate change on their livelihood.Design/methodology/approachThis research was undertaken with 67 farmers in Bayelsa State, Nigeria. This study used a combination of focus group discussion and quantitative survey to obtain data. Surveyed farmers were invited to an initial workshop and asked to take photos of climate change impacts on their land and the adaptation strategies being adopted. The photos were analysed and discussed with the farmers in a second workshop. Then, in a third workshop, farmers and other stakeholders came together to rank the most important consequences of climate change and shared knowledge on adaptation strategies. The survey and photovoice data were analysed using descriptive and inferential statistics.FindingsThe results of this study showed that a majority of the farmers were knowledgeable of climate change, mostly got climate information through media. Floods and high temperatures were perceived as the most occurring climate change-related disaster risks. Majority of the farmers perceived climate change as high risk and have taken up multiple adaptation strategies in response to it, including changing planting times, mulching their land and digging irrigation pits. Farmers’ responses indicated that they want to do more but are restricted by financial resources.Practical implicationsThis study outcomes provide evidence for a need to consider stakeholders’ participation in planning climate change responses to effectively address the challenges posed by climate change, particularly in coastal agricultural communities. Government and relevant agencies as recommended need to support farmers to undertake needed adaptive strategies to adapt with future flooding, high temperature and drought, providing them with necessary facilities to enhance their adaptive capacities.Originality/valueTo the best of the authors’ knowledge, this was one of the first studies to use photovoice to investigate climate change awareness, impacts and adaptations strategies with majority female farmers in west Africa. This study highlights the importance of participatory approaches to capture grassroots climate adaptation approaches.

Leaf trait Adaptation in Grewia optiva Drummond along Altitudinal Gradient in the North Western Himalayas

The current study was carried out between year 2020-2023 in the Department of Tree Improvement and Genetic Resources, College of Forestry, Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni, Solan (H.P.). This study was carried out in four altitudinal ranges of Himachal Pradesh and Uttarakhand (400 to 800 m (A1), 801-1200 m (A2), 1201-1600 m (A3), and 1601-2000 m (A4) above mean sea level (a m s l). Leaf morphometric traits such as leaf area, leaf length, leaf width and petiole length increased from the A1 (400-800 m) altitudinal zone to the A2 (800-1200 m). These apparent characteristics, however, declined more as the altitudinal range increased from A2 to A4.  Maximum values were reported for A2 (800-1200 m altitudinal range) in relation to average leaf area, length, width, and petiole length. The reason being the as elevation increased, leaves became thicker and water content reduced and leaves size became smaller. Plants can develop adaptive strategies in response to environmental change produced by an elevational gradient as elevation increases, the temperature always drops, limiting leaf area expansion due to heat and energy availability. However, according to our findings, the leaf area steadily increase up to 800-1200 m a m s l (A2 altitudinal zone). This counterintuitive pattern could be explained by the impact of precipitation and temperature fluctuations on LA.

Changes in agricultural scenario of Madhya Pradesh with special reference to soybean in changed climatic scenario: A study on farmers' perception

This study examined soybean growers' perception about climate change and variability, and their adaptation strategies in response to the perceived impacts of climate change. The multi-stage sampling method was employedto select 280 rural farmers in Dewas, Indore and Dhar districts located in Malwa plateau and Nimar valley ofMadhya Pradesh. The results revealed that the crop diversification is lost over a period of time and monocropping ofsoybean became popular in the study area. The introduction ofsoybean was found to be instrumental for enhancement in the cropping intensity ofthe area. Among abiotic weather-related stresses perceived bymajority offarmers were delayed arrival of monsoon, uneven and erratic rainfall, reduced number of rainy days, increased temperature and sunshine hours, and the reduced humidity. Majority of farmers perceived a decrease in annual rainfall. They also perceived that the biotic stresses (weeds, insects and diseases) had increased significantly over a period of time. All thesefactors were responsible for low yields. Survey also indicated that the mechanization increased substantially, and short duration varieties replaced the long duration soybean varieties. To reduce the perceived impacts of climate change, farmers adopted various farm-level adaptation strategies. The results of this study will provide baseline information for local governments, researchers, and policy-makers on farmers' perception of climate change and adaptation strategies.

Microbial mats as model to decipher climate change effect on microbial communities through a mesocosm study.

Marine environments are expected to be one of the most affected ecosystems by climate change, notably with increasing ocean temperature and ocean acidification. In marine environments, microbial communities provide important ecosystem services ensuring biogeochemical cycles. They are threatened by the modification of environmental parameters induced by climate change that, in turn, affect their activities. Microbial mats, ensuring important ecosystem services in coastal areas, are well-organized communities of diverse microorganisms representing accurate microbial models. It is hypothesized that their microbial diversity and metabolic versatility will reveal various adaptation strategies in response to climate change. Thus, understanding how climate change affects microbial mats will provide valuable information on microbial behaviour and functioning in changed environment. Experimental ecology, based on mesocosm approaches, provides the opportunity to control physical-chemical parameters, as close as possible to those observed in the environment. The exposure of microbial mats to physical-chemical conditions mimicking the climate change predictions will help to decipher the modification of the microbial community structure and function in response to it. Here, we present how to expose microbial mats, following a mesocosm approach, to study the impact of climate change on microbial community.

Response-adapted therapy for locally advanced nasopharyngeal carcinoma based on clinical response and circulating Epstein-Barr virus DNA level post induction chemotherapy.

TPS6112 Background: For locally advanced nasopharyngeal carcinoma (NPC), the mainstay treatment is cisplatin-based concurrent chemoradiation (CCRT). Recent phase III clinical trials have demonstrated that induction chemotherapy (ICT) plus CCRT, compared with CCRT alone, further improved progression-free survival (PFS). However, not every patient has good response to ICT. Evidence has accumulated that those with poor response to ICT, or those with detectable Epstein-Barr Virus (EBV) DNA post ICT, correlated with poorer PFS. In addition, real-time monitoring of plasma EBV DNA response adds prognostic information, and has the potential utility for risk-adapted treatment intensification in NPC. The aim of this study is to clarify whether response-adapted strategy based on clinical efficacy and EBV DNA response confers survival benefit to patients with locally advanced NPC. Methods: This is an open-label, 3-arm, phase II study. Patients with pathologically confirmed, locally advanced NPC (III-IVA, excluding T3N0M0, 8th AJCC staging system), with pretreatment detectable plasma EBV DNA level and ECOS PS 0-1 were eligible. Patients will receive one cycle of GP-based ICT. After one cycle of ICT, plasma EBV DNA and head and neck MR are performed. Based on clinical efficacy (evaluated per RECIST 1.1 criteria) and changes of plasma EBV DNA after one cycle, patients will be divided into three arms. Patients with good response (Arm A: Early Responders, undetectable EBV DNA level and CR/PR) will directly receive CCRT. Patients with intermediate response (Arm B: Intermediate Responders, detectable EBV DNA and CR/PR/decreased SD; or undetectable EBV DNA yet without CR/PR) will be randomized to experiment subgroup (GP combined with Toripalimab for two additional cycles then CCRT and maintenance Toripalimab treatment) and standard subgroup (GP for two additional cycles then CCRT). Patients with poor response (Arm C: Treatment Resistant, increased EBV DNA level, or PD/enlarged SD) will be switched to TP regimen combined with Toripalimab, followed by CCRT and maintenance Toripalimab treatment. Sample size calculation is based on 2-year PFS rate for arm B as the primary endpoint (one-sided α = 0.10, power = 0.80). Our target sample size is estimated to be 198-240, among them 168 for arm B. Secondary endpoints include adverse events determined by CTCAE v5.0, ORR at 3 months post-CRT, 2-year locoregional recurrence-free survival (LRFS) rate, 2-year distant metastasis-free survival (DMFS) rate, 2-year overall survival (OS) rate, as well as quality of Life for arm B. Exploratory endpoints include 2-year PFS rate, LRFS rate, DMFS rate, OS rate, ORR at 3 months post-CRT, adverse effects, and quality of life for arm A and arm C. This trial opened to accrual in July 2022 and the recruitment is ongoing. Clinical trial information: NCT05628922 .

Molecular Mechanisms of Lipid-Based Metabolic Adaptation Strategies in Response to Cold.

Temperature changes and periods of detrimental cold occur frequently for many organisms in their natural habitats. Homeothermic animals have evolved metabolic adaptation strategies to increase mitochondrial-based energy expenditure and heat production, largely relying on fat as a fuel source. Alternatively, certain species are able to repress their metabolism during cold periods and enter a state of decreased physiological activity known as torpor. By contrast, poikilotherms, which are unable to maintain their internal temperature, predominantly increase membrane fluidity to diminish cold-related damage from low-temperature stress. However, alterations of molecular pathways and the regulation of lipid-metabolic reprogramming during cold exposure are poorly understood. Here, we review organismal responses that adjust fat metabolism during detrimental cold stress. Cold-related changes in membranes are detected by membrane-bound sensors, which signal to downstream transcriptional effectors, including nuclear hormone receptors of the PPAR (peroxisome proliferator-activated receptor) subfamily. PPARs control lipid metabolic processes, such as fatty acid desaturation, lipid catabolism and mitochondrial-based thermogenesis. Elucidating the underlying molecular mechanisms of cold adaptation may improve beneficial therapeutic cold treatments and could have important implications for medical applications of hypothermia in humans. This includes treatment strategies for hemorrhagic shock, stroke, obesity and cancer.

Evaluation of General Circulation Models CMIP6 Performance and Future Climate Change over the Omo River Basin, Ethiopia

One of the world’s major issues is climate change, which has a significant impact on ecosystems, human beings, agricultural productivity, water resources, and environmental management. The General Circulation Models (GCMs), specially the recently released (coupled model intercomparison project six) CMIP6 are very indispensable to understand and support decision makers to identify adaptation strategies in response to future climate change in a basin. However, proper selection of skillful GCMs and future climate assessment is a prior task to climate impact studies. The objective of the study is an attempt to appraise the climate model’s performance and future climate scenarios of Shared Socioeconomic Pathways (SSPs) in the Omo River Basin. The performance evaluation of 20 GCMs of the CMIP6 was properly performed to reproduce the precipitation and the maximum temperature in the basin. Their performance has been carried out against the best selected mean monthly Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) precipitation and European Community Medium Water Range Weather Forecasts Version 5 (ECMWF-ERA5) maximum temperature. The GCMs of the CMIP6 were selected and ranked using the compromise programming method of multi-criteria decision making. The result shows that ensemble models and NorESM2-MM models have been designated to reproduce the precipitation and maximum temperature in the basin respectively. The Mann–Kendall trend test was executed to appraise the trend of selected CMIP6 models, and subsequently, downscaling and bias correction techniques were conducted. The projected seasonal precipitation of June, July, August, September (JJAS) and March, April, May (MAM) shows an increasing trend with 10.86, 17.66, 38.96 and 11.85, 22.1, and 40.7% under SSP2452031-2060, SSP5852031-2060, and SSP5852071-2100 scenarios respectively. Furthermore, increasing trends were detected in MAM by 12.8% and decreasing trends in JJAS were detected by 15.23% under SSP2452071-2100 scenario. The maximum temperature projection will be increased on average by 0.95, 1.78, 1.4, and 3.88 °C in JJAS and 1.53, 2.24, 1.56, and 3.89 °C in MAM under climate change scenarios of near-future SSP2452031-2060, SSP5852031-2060, far-future SSP2452071-2100, and SSP5852071-2100, respectively. Additionally, the basin has shown temporal-spatial climate fluctuation in terms of precipitation and maximum temperature.

Seasonal Dependence and Variability of Rainfall Extremes in a Tropical River Basin, South Asia

In recent years, rainfall extremes have increased significantly and have threatened the socio-economic development in Sri Lanka. This study investigates the rainfall extremes in the Mahaweli River Basin (MRB) of Sri Lanka with daily station datasets from 1985 to 2015. The extreme rainfall indices recommended by the Expert Team on Climate Change Detection Monitoring Indices (ETCCDMI) have been used in this study. Results showed a strong seasonal variation of rainfall extreme events over the MRB and a significant interdecadal change of extreme rainfall indices between 1985–1999 and 2000–2015 in the wet region of MRB, which is coherent with the decadal shift of southwest monsoon (SWM) rainfall from wet to dry situations since the year 2000. Based on the General Extreme Value distributions, the long-term mean of SWM rainfall in the wet region (814 mm) moved leftward for the 2000–2015 period (704 mm) and rightward for the 1985–2000 period, suggesting that SWM rainfall is decreased in the late period. The observed above-average (below-average) rainfall and associated rainfall extremes during the SWM can be ascribed to strengthening (weakening) moisture flux from the Arabian Sea direction and strong (weak) convergence over the study domain. The results further identified the negative correlation between Dipole Mode Index and SWM rainfall and associated rainfall extremes in the wet region, signifying that the negative Indian Ocean Dipole phase can enhance the SWM rainfall over the MRB. The negative correlation between Nino3.4 and SWM rain and extreme indices suggested that high probability of wet rainfall extremes in the La Nina phase. The findings of this study can be used to understand precipitation extremes in the context of climate change at the river basin scale and benefit policymakers in building local adaptation strategies in response to long-term climate change.

Climate change and maple syrup: Producer observations, perceptions, knowledge, and adaptation strategies

IntroductionClimate change is impacting forest-based agricultural systems with implications for producer decision-making and livelihoods. This article presents a case study on the observations, perceptions, knowledge, and adaptation strategies of maple syrup producers in the United States to climate change.MethodsWe carried out two semi-structured surveys with maple producers on: (1) climate change and its impacts on the maple system (n = 106 participants); and (2) responses to climate adaptation scenarios (n = 98 participants). Additionally, we carried out two focus groups and key informant interviews (n = 70+) to understand barriers and opportunities for climate adaptation. One of these focus groups and follow up key informant interviews was with tribally affiliated community members with the intention to acknowledge Indigenous Peoples’ voices, history, and relationships to the land.ResultsFindings highlight that most of the surveyed producers (89%) have experienced the negative impacts of climate on maple syrup production. While 40% of participants feel concerned regarding the future of the maple system, 39% feel hopeful, with significant differences based on the age of the surveyed producers. The majority of producers have adapted their harvesting practices to climate effects. Producers shared knowledge of multiple adaptation strategies in response to climate scenarios comprised of: (1) stand management practices such as diversification of sap species tapped; (2) harvesting practices such as changing the type and number of taps; (3) sap processing practices focused on the integration of technology such as the use of an evaporator and reverse osmosis; and (4) marketing practices such as innovation of products and marketing different maple syrup characteristics. Responses shared by tribally affiliated producers highlight knowledge of multiple adaptation strategies that focus on long-term ecological management of forests rather than technological solutions.DiscussionOverall, findings emphasize the importance of cooperation and diversification at every level and dimension of the maple system for its long-term resilience.

Comparing Control Intervention Scenarios for Raccoon Rabies in Southern Ontario between 2015 and 2025.

The largest outbreak of raccoon rabies in Canada was first reported in Hamilton, Ontario, in 2015 following a probable translocation event from the United States. We used a spatially-explicit agent-based model to evaluate the effectiveness of provincial control programs in an urban-centric outbreak if control interventions were used until 2025, 2020, or never used. Calibration tests suggested that a seroprevalence of protective rabies antibodies 2.1 times higher than that inferred from seroprevalence in program assessments was required in simulations to replicate observed raccoon rabies cases. Our simulation results showed that if control interventions with an adjusted seroprevalence were used until 2025 or 2020, the probability of rabies elimination due to control intervention use was 49.2% and 42.1%, respectively. However, if controls were never used, the probability that initial rabies cases failed to establish a sustained outbreak was only 18.2%. In simulations where rabies was not successfully eliminated, using control interventions until 2025 resulted in 67% fewer new infections compared to only applying controls until 2020 and in 90% fewer new infections compared to no control intervention use. However, the model likely underestimated rabies elimination rates since we did not adjust for adaptive control strategies in response to changes in rabies distributions and case numbers, as well as extending control interventions past 2025. Our agent-based model offers a cost-effective strategy to evaluate approaches to rabies control applications.

DO ORGANISATIONS REFLECT THEIR UPPER ECHELONS WHILE RESPONDING TO DISRUPTIVE INNOVATION?

Purpose Utilising the upper echelon theory (UET), the purpose of this study is to investigate the impact of dynamic managerial capabilities (i.e., managerial human capital, managerial social capital (MSC), and managerial cognition (MC)) on organisations’ response strategies to disruptive innovation, under the mediating role of unlearning. Design/methodology/approach Following a deductive approach, quantitative methodology and survey strategy, data was collected through an online questionnaire from (491) managers and top executives of PSF operating in Dubai-UAE and analysed using covariance-based structural equation modelling. Findings The findings revealed that dynamic managerial capabilities played mixed role in predicting firms’ response strategies to disruptive innovation. MSC and MC played a significant role with unlearning as a partial mediator, while managerial human capital did not. Practical implications The findings are important to managers, practitioners, and policymakers, shedding light on which dynamic managerial capabilities is of significance if creative economy is being pursued through adaptive response strategies to disruptive innovation.

Adaptation to climate change in the UK wine sector

This research contributes to literature on private sector adaptation, examining business-level adaptation to climate change in the UK wine sector. The research adopts a temporal and relational view of adaptation, through a sector-wide, value chain lens and through considering adaptation to both climate variability and longer-term change. Using the lens of ‘a good year’ and ‘a bad year’ in the sector, we consider the role of extreme events in adaptation decision-making and learning. We focus, unusually, on both opportunities and risks of climate change. Results show businesses increasingly see climate change as an opportunity for the UK wine sector. Yet climate risks remain and propagate along value chains, through supply and demand. This produces winners and losers in ‘good years’ and ‘bad years’, as well as over longer timescales. We find businesses along the value chain take steps to engage in extensive proactive adaptation behaviour, often right from business design and development. Business relationships condition climate risk exposure and adaptive capacity and adaptation decisions within one business can influence risks and opportunities throughout the value chain. Our results also reflect and develop organisational adaptation theories. We find businesses continually refine their adaptation strategies in response to climate variability and extreme events. They enhance adaptation learning by experimenting with new technologies and strategies. Irregular and extreme events can become important focal or tipping points in creative iteration and innovation of adaptation strategies, including for longer-term climate change. Our results stand in contrast to earlier literatures which suggest that businesses consider climate change to be too uncertain, or long-term, to engage in adaptation. Instead, climate change has become a master-narrative within the wine industry, through which sector actors often interpret their experiences and orient their business design and activities. Results indicate a strong dependence on own experience in adaptation decision making, that risks creating adaptation lock-in. We propose a typology of proactive private sector adaptation responses.

Comparison of Seasonally Adaptive Metabolic Response Strategies of Two Acer Species

Acer L. species are well known as ornamental trees due to their colourful leaves in autumn season. Acer pictum subsp. mono (Maxim.) H. Ohashi (APM) and Acer tataricum subsp. ginnala (Maximowicz) Wesmael (ATG) form leaves with completely different colours in autumn, yellow and red, respectively. In response to this phenomenon, we investigated the metabolic regulation of APM and ATG in different seasons by combining metabolomics, ionomics, the antioxidant system and pigment content. The results showed that the process of senescence and discolouration exists in leaves of different Acer species, and the regulatory strategy shows species specificity. Compared with green leaves, the accumulation of primary metabolites in autumn leaves of APM was extensively depleted, chlorophyll content was decreased, and antioxidant enzymes and C6C3C6 type phenolic compounds synergistically enhanced the antioxidant capacity of plants to cope with senescence. Carotenoid content was raised, which together with phenolic compounds (chlorogenic acid, rutin) provides the leaves with a yellow colour. The response of chlorophyll and the antioxidant system in autumn leaves of ATG is consistent with that of APM, while sugar content increases. The increased anthocyanin content in autumn leaves of ATG explains the transition of leaves from green to the red colour, which may be accompanied by the combined effect of elements (Fe, Zn, Mn) and isoflavones. This study provides a reference for the study of colouration mechanism and seasonal adaptation in Acer L. species.

Understanding farmers’ perception of climate change and adaptation practices in the marshlands of South Kivu, Democratic Republic of Congo

Understanding farmers’ perceptions about climate change and adaptation strategies can help support their efforts and develop interventions more suited to the local context. This is particularly important for farmers who exploit fragile ecosystems such as marshlands.Using semi-structured questionnaires and interviews conducted with smallholder farmers in the marshlands of Kabare, this study compares the perception of men and women relating to climate change and uses the chi-square test and logistic regression to examine gendered differences in response to climate change and the determinants of farmers’ choice of sustainable practices. Meteorological data trends for three decades were also compared.Results showed that both men (77 %) and women (73 %) experienced climate change and this was illustrated by changes in temperature and rainfall patterns. Farmers’ climate change perceptions are consistent with the local historical climate data showing a slightly increasing trend of temperature and a decrease in rainfall for the last decade, particularly between 2013 and 2019. Although significant differences were observed between gender and sources of climate information (p < 0.05), 50 % of women farmers favored indigenous knowledge of climate, while 61 % of men farmers stated that experience exchange among fellow farmers helped to read and predict climate trends. The common impacts reported by farmers included the proliferation of pests (90 %), a decrease in soil fertility (75 %), and floods, resulting in crop failure. Farmers used various adaptation strategies in response to the perceived impacts. However, the choice of sustainable practices such as crop diversification, drainage, growing low-maintenance crops, and use of mulch and manure were associated with farmers ‘experience, exchanging information among fellow farmers, livestock ownership, and the perception of climatic threats to crops. The information provided in this paper is valuable for the farmers' resilience-building program.

Long-Term Adaptation to Galactose as a Sole Carbon Source Selects for Mutations Outside the Canonical GAL Pathway.

Galactose is a secondary fermentable sugar that requires specific regulatory and structural genes for its assimilation, which are under catabolite repression by glucose. When glucose is absent, the catabolic repression is attenuated, and the structural GAL genes are fully activated. In Saccharomyces cerevisiae, the GAL pathway is under selection in environments where galactose is present. However, it is unclear the adaptive strategies in response to long-term propagation in galactose as a sole carbon source in laboratory evolution experiments. Here, we performed a 4,000-generation evolution experiment using 48 diploid Saccharomyces cerevisiae populations to study adaptation in galactose. We show that fitness gains were greater in the galactose-evolved population than in identically evolved populations with glucose as a sole carbon source. Whole-genome sequencing of 96 evolved clones revealed recurrent de novo single nucleotide mutations in candidate targets of selection, copy number variations, and ploidy changes. We find that most mutations that improve fitness in galactose lie outside of the canonical GAL pathway. Reconstruction of specific evolved alleles in candidate target of selection, SEC23 and IRA1, showed a significant increase in fitness in galactose compared to glucose. In addition, most of our evolved populations (28/46; 61%) fixed aneuploidies on Chromosome VIII, suggesting a parallel adaptive amplification. Finally, we show greater loss of extrachromosomal elements in our glucose-evolved lineages compared with previous glucose evolution. Broadly, these data further our understanding of the evolutionary pressures that drive adaptation to less-preferred carbon sources.

Efficacy of Short-Duration Alemtuzumab in T-Cell Large Granular Lymphocytic Leukemia: Potential for a Response-Adapted Strategy

Introduction T-cell large granular lymphocytic leukemia (T-LGL) is a chronic incurable malignancy where once refractory to immunosuppressive therapy, few treatment options and no optimal treatment consensus exists. Alemtuzumab, 10 milligrams (mg) intravenously (IV) administered daily for a total of 10 doses, has been shown to be effective for relapsed or refractory (R/R) T-LGL (Dumitriu, et al. Lancet Haematol 2016); however, it can be associated with severe infusion reactions and infections. Given the palliative nature of T-LGL-directed treatments and the increasing potential for toxicity with cumulative alemtuzumab exposure, we conducted a retrospective analysis to describe the efficacy and safety of abbreviated alemtuzumab regimens in R/R T-LGL patients. Methods We identified patients ≥18 years with R/R T-LGL who were treated with short-duration (defined as ≤ 5 doses) alemtuzumab between 2012 and 2022 from the University of Washington lymphoma database. Patients who received prior alemtuzumab were excluded. The primary endpoint was overall hematologic response rate (ORR). Secondary efficacy endpoints included hematologic response rate at 3 and 6 months, rate of transfusion independence, progression-free and overall survival. Safety endpoints included rate of infusion reactions and infections, specifically Epstein-Barr virus (EBV) and cytomegalovirus (CMV) reactivation. Results Nine patients meeting criteria were identified (Table 1). Five patients received alemtuzumab 10 mg IV daily for 5 doses and 4 patients received alemtuzumab 10 mg IV weekly for 4 doses. Median age was 65 (range 34-81) years and the median number of prior regimens was 3 (range 1-5). All (100%) patients were refractory to immunosuppressive therapy. Seven (78%), 1 (11%) and 1 (11%) patients had unilineage, bilineage and trilineage cytopenias, respectively. Five patients (56%) had autoimmune comorbidities and five (56%) required periodic transfusions. No patients had myelodysplasia on bone marrow biopsy. Overall, 6 (67%) patients had a hematologic response with 2 patients achieving a partial response (PR) and 4 patients achieving a complete response (CR). ORR at 3 and 6 months was 56% and 44%, respectively. Two (40%) patients achieved transfusion independence. The 3 patients without a hematologic response were retreated with alemtuzumab 10 mg IV daily for 10 doses with 1 subsequently achieving a CR. At a median follow-up time of 7.2 (range 2.3-36.6) months, 3 out of 6 patients who achieved a response had disease relapse; 8 (89%) patients were alive and 1 had died from COVID-19 pneumonia. Among the 5 patients who received alemtuzumab at 10 mg daily for 5 doses, ORR was 40% with 1 patient achieving PR and 1 patient achieving CR. ORR at 3 and 6 months was 40% and 40%, respectively. One (20%) patient had an infusion reaction. Two patients (40%) had subclinical CMV viremia which resolved with valganciclovir. No cases of EBV viremia were noted. Four patients completed alemtuzumab at 10 mg weekly for 4 doses; ORR was 100% with 1 patient achieving PR and 3 achieving CR. Hematologic response rate at 3 and 6 months was 75% and 50%, respectively. Three (75%) patients relapsed at 3, 4 and 14.2 months, respectively; 2 were retreated 4-6 times with alemtuzumab 10 mg IV weekly for 2 to 6 doses each time, with both achieving hematologic responses with each course of treatment. One (25%) patient experienced an infusion reaction. No cases of CMV or EBV viremia were noted. Conclusions Short-duration alemtuzumab is effective and well tolerated in R/R T-LGL with responses observed in 67% overall and no cases of CMV viremia detected in the weekly dosing group. Alemtuzumab given at 10 mg IV weekly for 4 doses or until a response is noted followed by retreatment upon relapse was particularly effective; this abbreviated, response-adapted alemtuzumab strategy should be prospectively explored in this patient population. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Cell-Free HPV DNA Kinetics Predicted by Radiographic Response in Locoregional Viral-Associated Oropharyngeal Cancer Receiving Response-Adaptive Treatment – Exploratory Analysis of a Prospective Trial

<h3>Purpose/Objective(s)</h3> Human papillomavirus (HPV) associated oropharyngeal cancer (HPV+OPC) has a favorable prognosis. Current response-adapted strategies utilize RECIST to guide therapy. In the present study, we examined the utility of cell-free HPV DNA (cfHPV DNA) kinetic responses as an additional parameter to track therapy efficacy in de-escalation strategies. Here, we report a comparison of cfHPV DNA kinetics by RECIST and tumor volume (TV) from a prospective response-adaptive de-escalation trial. <h3>Materials/Methods</h3> Patients enrolled on the prospective phase II OPTIMA 2 (NCT03107182) de-escalation trial with available cfHPV DNA information were included for analysis. OPTIMA 2 enrolled locoregionally advanced HPV+OPC including low and high risk patients. High risk patients were defined as T4, N2c-N3 (AJCC 7^th edition), > 20 pack year smoking history, or non-HPV16 subtype. Neck CT or MRI as well as cfHPV DNA was obtained at baseline and following induction chemoimmunotherapy. Target lesions were assessed via RECIST 1.1 at baseline and post-induction therapy per protocol; patients with ≥ 50% response by RECIST received de-escalated radiation dose and volume. cfHPV DNA was detected and quantified using a CLIA-certified cfHPV sequencing assay (HPV-SEQ, Sysmex Inostics, Inc.). For this analysis, target lesions were delineated post hoc to obtain TV metrics. Linear regression was used to examine correlation between cfHPV DNA, RECIST, and TV response. Receiver Operating Characteristic (ROC) analysis was used to identify an optimal TV response to predict ≥ 95% cfHPV DNA response. <h3>Results</h3> 39 patients of which 31 had follow up cfHPV DNA information were evaluable. Median RECIST was 4.9 cm at baseline and 2.0 cm at follow up. Median TV was 29 cm³ at baseline and 6 cm³ at follow-up. 39 (100%) patients had detectable cfHPV DNA at baseline, with median 180 [IQR: 15, 966] copy number/mL. Of 31 patients with paired cfHPV DNA information at baseline, 29 (94%) had a ≥ 95% cfHPV DNA reduction. Of those, cfHPV DNA was undetectable in 21 (71%) cases. Baseline TV was associated with cfHPV DNA (p=0.04), and the median cfHPV DNA / TV ratio was 5.5 (copy number / cm³). No differences were observed between low and high-risk cohorts with respect to cfHPV DNA or radiographic metrics. RECIST was not associated with cfHPV DNA metrics. When adjusting for risk, TV response predicted cfHPV DNA response (p = 0.003). ROC analysis identified a TV response of 63% (AUC 0.88) to predict ≥ 95% cfHPV DNA response; 74% of patients had a TV response ≥ 63%. <h3>Conclusion</h3> cfHPV DNA kinetics were more pronounced than radiographic response to systemic therapy in both high and low risk groups. cfHPV DNA was predicted by TV response to chemoimmunotherapy, but was not predicted by traditional RECIST dynamics. We identified potential TV responses to predict cfHPV DNA response. This represents the first direct correlation of circulating tumor DNA levels to tumor volume and has implications for response assessment in the neoadjuvant setting as well as in other solid tumors.