Net Effect Research Articles

Forest tree community ecology and plant–soil feedback: Theory and evidence

AbstractMounting evidence suggests that reciprocal interactions between plants and the soil microbiota can be a primary force that generates key macroscopic patterns of plant communities (coexistence, dominance, and succession) in forest ecosystems. The aim of this article is to review empirical and theoretical perspectives of plant–soil feedback research in the context of forest community ecology. I first use a simple theoretical model to get insights into an array of the dynamics generated by plant–soil feedback: negative plant–soil feedback maintains plant species diversity and reduces plant growth, while positive plant–soil feedback drives plant growth of certain species and hence their dominance. I then describe how ecologists have unveiled the enormously complex plant‐microbiota interaction (i.e., the soil conditioning experiment) and review the linkage of plant–soil feedback with three key plant community patterns: (i) dominance, (ii) spatial structure and (iii) succession. I highlight one belowground plant trait (mycorrhizal type) that can mediate these linkages: arbuscular mycorrhizal species tend to exhibit negative plant–soil feedback while ectomycorrhizal species tend to exhibit positive plant–soil feedback. Although mycorrhizal plant–soil feedback potentially explains the patterns of tree diversity from local to global scales, many questions remain. Future studies should expand plant–soil feedback theory to incorporate numerous other feedback mechanisms and test how mycorrhizal types mediate the net feedback effects that could propagate to shape large‐scale forest structures and dynamics.

The Role of Shared Resilience in Building Employment Pathways with People with a Disability

For workers living with a disability, pathways to sustainable employment in the open labour market are inhibited by barriers operating at different structural and societal levels. The culture of Australia’s government employment services has applied a ‘work-first’ approach that emphasises finding people employment rather than supporting the acquisition of skills and education. The net effect of this approach is the preferencing of short-term employment solutions, with a focus on individual behaviour or so-called resilience and an emphasis on personal responsibility instead of addressing structural issues. In this paper, we explore how people with disability can be supported in finding employment through a shared resilience approach offered by a Work Integration Social Enterprise (WISE). We suggest that WISEs can provide the conditions for shared resilience by developing and sustaining networks needed to generate hybrid pathways to work and by role modelling inclusive work conditions in the open labour market.

Radiative effect of thin cirrus clouds in the extratropical lowermost stratosphere and tropopause region

Abstract. Cirrus clouds play an important role in the radiation budget of the Earth; nonetheless, the radiative effect of ultra-thin cirrus clouds in the tropopause region and in the lowermost stratosphere remains poorly constrained. These clouds have a small vertical extent and optical depth and are frequently neither observed even by sensitive sensors nor considered in climate model simulations. In addition, their short-wave (cooling) and long-wave (warming) radiative effects are often in approximate balance, and their net effect strongly depends on the shape and size of the cirrus particles. However, the CRyogenic Infrared Spectrometers and Telescopes for the Atmosphere instrument (CRISTA-2) allows ultra-thin cirrus clouds to be detected. Here we use CRISTA-2 observations in summer 1997 in the Northern Hemisphere midlatitudes together with the Suite Of Community RAdiative Transfer codes based on Edwards and Slingo (SOCRATES) radiative transfer model to calculate the radiative effect of observed ultra-thin cirrus. Using sensitivity simulations with different ice effective particle size and shape, we provide an estimate of the uncertainty in the radiative effect of ultra-thin cirrus in the extratropical lowermost stratosphere and tropopause region during summer and – by extrapolation of the summer results – for winter. Cloud top height and ice water content are based on CRISTA-2 measurements, while the cloud vertical thickness was predefined to be 0.5 or 2 km. Our results indicate that if the ice crystals of these thin cirrus clouds are assumed to be spherical, their net cloud radiative effect is generally positive (warming). In contrast, assuming aggregates or a hexagonal shape, their net radiative effect is generally negative (cooling) during summer months and very likely positive (warming) during winter. The radiative effect is in the order of ±(0.1–0.01) W m−2 for a realistic global cloud coverage of 10 %, similar to the magnitude of the contrail cirrus radiative forcing (of ∼ 0.1 W m−2). The radiative effect is also dependent on the cloud vertical extent and consequently the optically thickness and effective radius of the particle size distribution (e.g. effective radius increase from 5 to 30 µm results in a factor ∼ 6 smaller long- and short-wave effects, respectively). The properties of ultra-thin cirrus clouds in the lowermost stratosphere and tropopause region need to be better observed, and ultra-thin cirrus clouds need to be evaluated in climate model simulations.

Movement-Related Modulation in Mouse Auditory Cortex Is Widespread Yet Locally Diverse.

Neurons in the mouse auditory cortex are strongly influenced by behavior, including both suppression and enhancement of sound-evoked responses during movement. The mouse auditory cortex comprises multiple fields with different roles in sound processing and distinct connectivity to movement-related centers of the brain. Here, we asked whether movement-related modulation in male mice might differ across auditory cortical fields, thereby contributing to the heterogeneity of movement-related modulation at the single-cell level. We used wide-field calcium imaging to identify distinct cortical fields and cellular-resolution two-photon calcium imaging to visualize the activity of layer 2/3 excitatory neurons within each field. We measured each neuron's responses to three sound categories (pure tones, chirps, and amplitude-modulated white noise) as mice rested and ran on a non-motorized treadmill. We found that individual neurons in each cortical field typically respond to just one sound category. Some neurons are only active during rest and others during locomotion, and those that are responsive across conditions retain their sound-category tuning. The effects of locomotion on sound-evoked responses vary at the single-cell level, with both suppression and enhancement of neural responses, and the net modulatory effect of locomotion is largely conserved across cortical fields. Movement-related modulation in auditory cortex also reflects more complex behavioral patterns, including instantaneous running speed and nonlocomotor movements such as grooming and postural adjustments, with similar patterns seen across all auditory cortical fields. Our findings underscore the complexity of movement-related modulation throughout the mouse auditory cortex and indicate that movement-related modulation is a widespread phenomenon.

Liming effects on microbial carbon use efficiency and its potential consequences for soil organic carbon stocks

Climate-smart agriculture aims amongst others at protecting and increasing soil organic carbon (SOC) stocks. The allocation of metabolised carbon (C) between soil microbial growth and respiration, i.e. C use efficiency (CUE) is crucial for SOC dynamics. We hypothesised that raising soil pH would alleviate CUE-limiting conditions and that liming could thus increase CUE, thereby supporting SOC accrual. This study investigated whether CUE can be manipulated by liming and how this might contribute to SOC stock changes. The effects of liming on CUE, microbial biomass C, abundance of microbial domains, SOC stocks and OC inputs were assessed for soils from three European long-term field experiments. Field control soils were additionally limed in the laboratory to assess immediate effects. The shift in soil pHH2O from 4.5 to 7.3 with long-term liming reduced CUE by 40 %, whereas the shift from 5.5 to 8.6 and from 6.5 to 7.8 was associated with increases in CUE by 16 % and 24 %, respectively. The overall relationship between CUE and soil pH followed a U-shaped (i.e. quadratic) curve, implying that in agricultural soils CUE may be lowest at pHH2O = 6.4. The immediate CUE response to liming followed the same trends. Changes in CUE with long-term liming contributed to the net effect of liming on SOC stocks. Our study confirms the value of liming as a management practice for climate-smart agriculture, but demonstrates that it remains difficult to predict the impact on SOC stocks due its complex effects on the C cycle.

Effect of Nurse-Led PMTCT Health Education on HIV Disclosure among HIV-Positive Women in Mombasa County: A quasi-experimental study

Background: This study investigated the impact of nurse-led PMTCT (Prevention of Mother-toChild Transmission) health education on enhancing HIV status disclosure among HIVpositive women in Mombasa County, Kenya. HIV status disclosure is crucial for the prevention of mother-to-child transmission and the overall well-being of affected individuals and their families.
 Methods: A quasi-experimental design was employed, with participants divided into an intervention group of 107 receiving nurse-led PMTCT health education and a control group of 107 receiving standard care. Demographic information, knowledge, attitudes, and practices related to HIV status disclosure were collected at baseline and post-intervention phases. Descriptive statistics were computed and a chi-square test was used to compare the level of self-disclosure of HIV status to sexual partners across the groups. Difference in differences (DID) analysis was used to evaluate the effectiveness of the intervention. Results: The study initially found that at baseline, 60.4% of HIV-positive women in the control group did not disclose their status to sexual partners, compared to 55.4% in the intervention group. However, there was no significant difference between the two groups at this stage. In the end-line survey, the control group had 64% non-disclosure, while the intervention group showed a significant improvement, with only 20% not disclosing. Chi-square analysis revealed a substantial difference (p < 0.001) in disclosure rates between the intervention and control groups. Additionally, a Difference-in-Differences (DID) analysis indicated a significant improvement in self-disclosure (23.1% net intervention effect, p < 0.0001). Overall, the nurse-led health education intervention notably increased HIV status disclosure among HIV-positive women in selected Mombasa County health facilities.
 Conclusion: Nurse-led PMTCT education enhances HIV disclosure in Mombasa County, improving PMTCT outcomes and curbing mother-to-child transmission. Tailored interventions are vital in addressing HIV challenges in diverse contexts.

Urbanization, civil conflict, and the severity of food insecurity in Africa

AbstractThe objective of this article is to examine the impact of urbanization and civil conflicts on the severity of food insecurity for a panel of 43 African countries over the period 2000–2020. Subsequently, the heterogeneous choice models approach was used for the estimations. The results show that urbanization and civil conflict increase food insecurity. The parallel line probability hypothesis results specifically show that a one‐unit increase in urban growth rate increases the probability of belonging to a high‐risk food insecurity category by more than .6 times. Furthermore, the results show that the impacts of urbanization on food insecurity are modulated by civil conflicts in Africa leading to the net effect of .692. This corresponds to the policy threshold of 2.315 when the net positive effect is canceled out. Therefore, this study strongly recommends the need for African economies to develop urban agriculture while controlling the pace of urbanization in order to reduce food insecurity and avoid possible civil wars.Related ArticlesAsare‐Nuamah, Peter, Anthony Amoah, and Simplice A. Asongu. 2023. “Achieving Food Security in Ghana: Does Governance Matter?” Politics & Policy 51(4): 614–35. https://doi.org/10.1111/polp.12540.Ayanoore, Ishmael, and Sam Hickey. 2022. “Reframing the Politics of Natural Resource Governance in Africa: Insights from the Local Content Legislation Process in Ghana.” Politics & Policy 50(1): 119–36. https://doi.org/10.1111/polp.12449.Oehmke, James F., Sera L. Young, Godfrey Bahiigwa, Boaz Blackie Keizire, and Lori Ann Post. 2018. “The Behavioral‐Economics Basis of Mutual Accountability to Achieve Food Security.” Politics & Policy 46(1): 32–57. https://doi.org/10.1111/polp.12244.

Facilitation and competition deconstructed: a mechanistic modelling approach to the stress gradient hypothesis applied to drylands

Facilitative interactions among species are key in plant communities. While experimental tests support the Stress Gradient Hypothesis (SGH) as an association between facilitation and stress, whether the shape of net effects along stress gradients can be predicted is controversial, with no available mathematical modelling approaches. We proposed a novel test, using a modification of the R* model to study how negative and positive partial effects of plant interactions in drylands combine along two common stress gradients. We modelled different interactions: competition for water and light, amelioration of soil infiltration and/or grazing protection, obtaining that intensity and importance of facilitation did not generally increase along stress gradients, being dependent on the interaction type. While along the water stress gradient net interactions became more positive, reaching a maximum and then waning again, various outcomes were observed along the grazing gradient. Shape variety was mainly driven by the various shapes of the partial positive effects. Under resource stress, additive interaction effects can be expected, whereas when including grazing, the effects were non-additive. In the context of the SGH, deconstructing the effect of positive and negative interaction in a pairwise mechanistic models of drylands does not show a unique shape along stress gradients.

P099 Neutrophil extracellular traps enhance profibrotic activity of intestinal fibroblasts in Crohn's disease through TLR2/NF-kB pathway

Abstract Background Neutrophil extracellular traps (NETs) consist of DNA filaments and cytoplasmic protein granules, extruded by neutrophils after PAD4-dependent activation. NETs release occurs early during inflammation in various immune-related diseases, further aggravating tissue injury and contributing to fibrosis. Our aim was to investigate the potential profibrotic effect of NETs in Crohn’s disease (CD). Methods NETs and activated fibroblasts were labelled by multiplex immunofluorescence staining on unaffected, inflamed and fibrotic ileum derived from patients with stricturing CD undergoing ileocaecal resection. Intestinal fibroblasts isolated from unaffected CD ileum were co-cultured with NETs for 24 hours to analyse their transcriptome and quantify collagen released with SIRCOL®. Fibroblast migratory activity was investigated with a scratch test. Immunofluorescence intensity of collagen and fibroblast activation protein (FAP) was quantified using the Operetta® Analysis System. Transfection of fibroblasts with NF-kB-luciferase reporter plasmid was performed to evaluate the TLR2/NF-kB pathway, and a specific TLR2 inhibitor (TL2-C29) tested. Finally, mice with selective deletion of PAD4 in neutrophils (PAD4fl/flMRP8Cre+) were subjected to chronic Dextran Sulphate Sodium (DSS) colitis to assess the role of PAD4-mediated NETosis in intestinal fibrosis development. Results We found spatial tissue distribution of clusters of NETs adjacent to FAP+ fibroblasts in ileal ulcerations in patients with active CD. Transcriptomics demonstrated upregulation of various profibrotic processes in fibroblasts stimulated with NETs, including TGFβ-receptor signalling pathway, positive regulation of collagen metabolic process, and TLR-signalling pathways. This correlated with increased proliferation rate (p<0.0001), slower wound healing capability (p<0.0001) and higher collagen release in the medium (p<0.01) in the NET-treated group, as well as higher expression of collagens and FAP. Among TLR genes, TLR2 was found upregulated after stimulation with NETs (p=0.02). Transfection data showed significant upregulation (p<0.05) of NF-kB in the NETs-treated group, whereas its expression and soluble collagen release decreased with the addition of the TLR2 antagonist TL2-C29. In line, a significantly lower amount of collagen deposition was observed in the colon of PAD4fl/flMRP8Cre+ mice subjected to chronic DSS colitis, as well as modulation of MMP2/TIMP2 balance and reduced fibroblast activation. Conclusion NETs may represent an early trigger of intestinal fibroblast activation via the TLR2/NF-kB axis. As NETs are early players during inflammation, blocking PAD4 may reduce inflammation and thus fibrogenesis in CD.

Determination of the Cannabinoid CB1 Receptor's Positive Allosteric Modulator Binding Site through Mutagenesis Studies.

Positive allosteric modulators (PAMs) of the cannabinoid CB1 receptor (CB1) offer potential therapeutic advantages in the treatment of neuropathic pain and addiction by avoiding the adverse effects associated with orthosteric CB1 activation. Here, molecular modeling and mutagenesis were used to identify residues central to PAM activity at CB1. Six putative allosteric binding sites were identified in silico, including novel sites previously associated with cholesterol binding, and key residues within each site were mutated to alanine. The recently determined ZCZ011 binding site was found to be essential for allosteric agonism, as GAT228, GAT229 and ZCZ011 all increased wild-type G protein dissociation in the absence of an orthosteric ligand; activity that was abolished in mutants F191A3.27 and I169A2.56. PAM activity was demonstrated for ZCZ011 in the presence of the orthosteric ligand CP55940, which was only abolished in I169A2.56. In contrast, the PAM activity of GAT229 was reduced for mutants R220A3.56, L404A8.50, F191A3.27 and I169A2.56. This indicates that allosteric modulation may represent the net effect of binding at multiple sites, and that allosteric agonism is likely to be mediated via the ZCZ011 site. This study underlines the need for detailed understanding of ligand receptor interactions in the search for pure CB1 allosteric modulators.

Investigating Fabry disease - some lessons learned

Despite recent advances, there is still much to be learned about the pathogenesis of Fabry disease. The categorization of GLA gene missense mutations has been complicated by the fact that some missense variants may fall into more than one category. For instance, the A143T variant may cause late-onset Fabry disease in some subjects and not result in Fabry disease in others (pseudo-deficient). Efforts to mitigate the pathobiology of α-galactosidase A deficiency should differentiate between damaging (maladaptive) consequences and compensatory (adaptive) changes. Current therapy leaves a significant unmet need, especially concerning cardiovascular complications and cardiological clinical outcomes. Non-Fabry-specific therapy is necessary and quite beneficial and must be utilized. Its contribution should be considered when trying to assess the net effect of Fabry-specific therapy. Enzyme replacement therapy (ERT) can be administered to patients independently of their GLA genotype, as it slows the decline of kidney function in most patients if initiated sufficiently early in the disease course. Migalastat has better tissue penetration than ERT, but its usefulness is restricted to patients with amenable missense GLA variants. However, it is important to realize that in a substantial proportion of common amenable mutations, migalastat increases α-galactosidase A activity level beyond the disease threshold and thus eliminates the metabolic disturbance that is at the center of Fabry disease. Substrate reduction therapy and gene therapy approaches are being developed, but these therapeutic modalities have their own limitations and difficulties.

Flowering time responses to warming drive reproductive fitness in a changing Arctic.

The Arctic is warming at an alarming rate, leading to earlier spring conditions and plant phenology. It is often unclear to what degree changes in reproductive fitness (flower, fruit, seed production) are a direct response to warming versus an indirect response through shifting phenology. This study aims to quantify the relative importance of these direct and indirect pathways and project the net effects of warming on plant phenology and reproductive fitness under current and future climate scenarios. We used two long-term datasets on twelve tundra species in the Canadian Arctic as part of the International Tundra Experiment (ITEX). Phenology and reproductive fitness were recorded annually on tagged individual plants at both Daring Lake, Northwest Territories (64.87, -111.58) and Alexandra Fiord, Nunavut (78.83, -75.80). Plant species encompass a wide taxonomic diversity across a range of plant functional types with circumpolar/boreal distributions. We use Hierarchical Bayesian Structural Equation models to compare the direct and indirect effects of climate warming on phenology and reproductive fitness across species, sites and years. We find that warming, both experimental and ambient, drives earlier flowering across species, which leads to higher numbers of flowers and fruits produced, reflecting directional phenotypic selection for earlier flowering phenology. Furthermore, this indirect effect of climate warming mediated through phenology was generally ~2-3x stronger than the direct effect of climate on reproductive fitness. Under future climate predictions, individual plants showed a ~2 to 4.5-fold increase in their reproductive fitness (flower counts) with advanced flowering phenology. Our results suggest that, on average, the benefits of early flowering, such as increased development time and subsequent enhanced reproductive fitness, may outweigh its risks. Overall, this work provides important insights into population-level consequences of phenological shifts in a warming Arctic over multi-decadal time scales.

Connectedness between (un)conventional monetary policy and islamic and advanced equity markets: A returns and volatility spillover analysis

Using the spillover index, we investigated the relationship between Islamic equity markets and unconventional monetary policy(UMP) in five advanced economies. We documented that the spillovers among equity markets (“intraconnectedness”) are stronger than the spillovers among equity markets and monetary policy (“interconnectedness”), based on a static analysis of both returns and volatility. Second, the time-varying total spillover index showed that the Islamic market is a dominant net receiver of returns and volatility shocks. Furthermore, their spillover effect strengthened during the financial turmoil and UMP periods. Third, the time-varying net spillover effects implied that the US is the most dominant transmitter of return shocks, whereas the EU and UK are the dominant transmitters of volatility shocks. In addition, the US and Canada are the dominant transmitters of monetary policy shocks, whereas Japan is the main net receiver of these shocks. These results will be useful to investors, portfolio managers, and regulators in terms of investment decisions, portfolio allocation, and risk monitoring.

The Impact of New Urbanization on Water Ecological Civilization: Based on the Empirical Analysis of Prefecture-Level Cities in Jiangxi, China

This study aims to improve the level of water ecological civilization (WEC) in the urbanization process based on the data of prefecture-level cities in Jiangxi, China, from 2011 to 2020. This paper applies spatial analysis methods such as the natural fracture method, barycenter transfer model, and standard deviation ellipse method to explore the spatiotemporal evolution characteristics of WEC and the impact of new urbanization (NU) on WEC. The NU pilot construction is further regarded as an exogenous impact, and the “net effect” of the NU pilot policy on WEC is tested. The results showed that (1) the spatial distribution pattern of the east–west polarization of WEC was broken, and a spatial distribution pattern of strong in the north and weak in the south was gradually formed. (2) NU contributes to improving the WEC level, among which population, digital, and green urbanization can significantly promote the WEC level, while economic urbanization impedes the improvement of the WEC. This conclusion is still valid following a series of robustness tests. (3) heterogeneity analysis showed that the impact of NU in improving the level of WEC is more evident in cities with scarce water resources, non-resource-based cities, and non-old industrial base cities after the implementation of NU planning. (4) NU’s pilot policy can help improve the WEC level in the region and the WEC level in neighboring regions through the spillover effect of policy. Therefore, it is necessary to make use of the superimposed effect of multidimensional urbanization based on urban characteristics, implement differentiated policy, break administrative barriers, make use of the spatial spillover effect of pilot policy, and improve the WEC level.

Effect of irrigation on wild and inbred maize with relation to the antioxidant status of pollens, flag leaves, and developing grains.

The investigation was carried out to evaluate the net effect of limited irrigation on the antioxidant status of pollens, flag leaves, and developing grains of wild and inbred maize lines. Teosinte pollens showed the highest activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione-s-transferase (GST), and peroxidase (POX) under stressful conditions while LM 11 showed a significant decrease in APX, CAT, GR, and GST activities. Limited irrigations increased the contents of superoxide and malondialdehyde (MDA) to maximum levels in LM 11 leaves. The pollens, leaves, and developing grains of teosinte had the highest content of total phenols. Proline was maximum in the developing grains of teosinte and CML 32 while lowest in those of LM 11. Principal component analysis showed that LM 11 genotype and the respective antioxidant enzymes were in completely opposite quadrants. Chord analysis showed that CAT activity and total phenol content in pollens, leaves, and developing grains contributed towards most of the variations observed in teosinte and might be responsible for managing the yield attributes of genotype during stress conditions. The pollens and leaves of teosinte, with significant SOD activity, further helped in optimizing plant yield, under stressful conditions. CML 32 occupied intermediate position owing to the unaffected activities of most of the antioxidant enzymes and high content of antioxidants in its tissues. It may be concluded that the overall antioxidant status of tissues decides the tolerance behavior of plants.

COVID-19 and Family and Peer Dynamics in Emerging Adults

Although research on the associations between COVID-19 and social relationships has garnered attention, there has been less of a focus on how COVID-19 was discussed within relationships themselves. The present study deepens the understanding of the wide reach of the pandemic by using quantitative surveys and open-ended responses to explore how individuals discussed and reacted to COVID-19 and related health guidelines in the context of their family and peer relationships. Data were collected from 132 young adults in the U.S. (age = 18.9 years, SD = 0.85; 50% female; 14% ethnically racially minoritized students) using standard procedures established by the university’s undergraduate research pool. Results suggest that young adults talked about COVID-19 more with their families than with their peers. They also reported sharing similar opinions about the pandemic with both their family and their peers. Young adults described COVID-19, overall, as having positive net effects within their family relationships but straining their peer relationships. Qualitative data provide additional, detailed insight on how the pandemic shifted interpersonal dynamics and family and peer relationships.

Optimizing China’s Afforestation Strategy: Biophysical Impacts of Afforestation with Five Locally Adapted Forest Types

Recent research has mapped potential afforestation land to support China’s goal of achieving “carbon neutrality” and has proposed tree species selection to maximize carbon uptake. However, it overlooked biophysical climatic effects, which have a more significant impact on local temperature than CO2 reduction. This study aims to present a comprehensive understanding of how afforestation in China affects local and regional climates through biophysical processes. It focuses on the latitudinal patterns of land surface temperature differences (ΔLST) between five locally adapted forest types and adjacent grasslands using satellite-based observations. Our key findings are as follows: Firstly, broadleaf forests and mixed forests exhibit a stronger cooling effect than coniferous forests due to differences in canopy structure and distribution. Specifically, the net cooling effects of evergreen broadleaf forests (EBFs), deciduous broadleaf forests (DBFs), and mixed forests (MFs) compared to grasslands are −0.50 ± 0.10 °C (mean ± 95% confidence interval), −0.33 ± 0.05 °C, and −0.36 ± 0.06 °C, respectively, while evergreen needleleaf forests (ENFs) compared to grasslands are −0.22 ± 0.11 °C. Deciduous needleleaf forests (DNFs) exhibit warming effects, with a value of 0.69 ± 0.24 °C. In regions suitable for diverse forest types planting, the selection of broadleaf and mixed forests is advisable due to their enhanced local cooling impact. Secondly, temperate forests have a net cooling effect to the south of 43° N, but they have a net warming effect to the north of 48° N compared to grasslands. We recommend caution when planting DNFs, DBFs, and MFs in northeastern China, due to the potential for local warming. Thirdly, in the mountainous areas of southwestern China, especially when planting ENFs and MFs, tree planting may lead to local warming. Overall, our study provides valuable supplementary insights to China’s existing afforestation roadmap, offering policy support for the country’s climate adaptation and mitigation efforts.

Urban sprawl and racial inequality in intergenerational mobility

Abstract Persistent racial inequality in socioeconomic status within urban areas has been a significant concern in both the US and European countries. Differences across racial groups in intergenerational mobility (IM) have been identified as a key source of this persistence. However, efforts to understand racial inequality in IM have rarely considered the role of urban sprawl. This article argues that urban sprawl affects differences in IM between racial groups directly and indirectly through racial segregation, racial bias, and social capital. We analyze data from 874 metropolitan counties in the US using structural equation models to test these direct and indirect effects of sprawl on racial inequality in IM. We found that urban sprawl was negatively associated with racial inequality in IM. The direct effect, which we partially attribute to higher racial disparities in social capital in more compact counties, was statistically significant. For the indirect effects, racial segregation had the largest mediating effects between urban sprawl and racial inequality in IM, followed by economic connectedness (EC) and racial bias. The net indirect effect of sprawl on racial inequality in IM was negative because negative indirect effects through racial segregation and EC outweigh positive indirect effects through racial bias. Our findings demonstrate the significant role of urban form in racial inequality in IM.

Quantifying the effects of institutional shifts on water governance in the Yellow River Basin: A social-ecological system perspective

Water governance in river basins worldwide faces challenges due to complex socio-economic and environmental factors. In the Yellow River Basin (YRB), two major institutional shifts, the 1987 Water Allocation Scheme (87-WAS) and the 1998 Unified Basin Regulation (98-UBR), aimed to address water allocation and usage issues. This study quantifies the net effects of these institutional shifts on water use within the YRB and analyzes the underlying reasons for their success or failure. We employ a Differenced Synthetic Control method to assess the impacts of the institutional shifts. Our analysis suggests that the 87-WAS unexpectedly increased water use by 5.75%, while the 98-UBR successfully reduced water use as anticipated. Our research highlights the role of institutional structures in governance policies, demonstrating that the mismatched structure of the 87-WAS led to increased competition and exploitation of water resources, while the 98-UBR, basin-wide authority and stronger connections between stakeholders, resulted in improved water governance. Our study underscores the importance of designing institutions that are consistent with the scale of the ecological system, promote cooperation among stakeholders, and adapt to changing social-ecological system (SES) contexts. As outdated and inflexible water quotas may no longer meet the demands of sustainable development in the YRB, policymakers must consider the potential consequences of institutional shifts and their impact on water use and sustainability.

Abstract B050: Determining the anti-cancer properties of a ketogenic diet against pancreatic cancer

Abstract Abstract: Background: A ketogenic regimen is high in fat (90%kCal) and low in carbohydrates (5% kCal), resulting in a state of ketosis[2]. Prior studies suggest that a ketogenic diet shifts carbon utilization in cancer cells from one that is predominantly glycolytic, towards the tricarboxylic acid cycle (TCA) in the mitochondria[3]. The net effect on cancer growth remains uncertain, but the majority of studies in the literature favor an anti-cancer signal. We hypothesize that molecular and biochemical insights into how pancreatic cancer cells adapt to a ketogenic diet will uncover metabolic vulnerabilities and nominate rationally designed therapeutic strategies to effectively partner with the diet. Methods: A ketogenic diet was administered to mice, along with a normal diet in control mice. Pancreatic cancer xenografts were monitored for growth and harvested for biochemical analyses. Tumors were analyzed for metabolites by LC/GC-MS and for oxidative stress by measuring the levels of NADP+/NADPH, NAD+/NADH and Lipid Peroxidation assay. Enzyme expression was assessed by Western blot. For in vitro studies, mitochondrial function was analyzed by the Seahorse FX Analyzer and cell growth was measured by PicoGreen DNA quantitation. Result: A ketogenic diet slowed pancreatic cancer growth in multiple in vivo models, including MIA-PaCa2, KPC and patient derived xenografts. TCA metabolites were broadly increased in xenografts exposed to a ketogenic diet. In these mouse tumors, metabolic enzymes associated with the TCA cycle were markedly upregulated, pointing to an effect on gene expression. Specifically, the expression of BDH1 (a ketolytic enzyme allowing ketone body utilization in cancer cells), IDH1 (cytosolic and supports antioxidant defense and mitochondria through NADPH and α-ketoglutarate) and IDH2 (a homolog of IDH1 in the mitochondria) were all increased. In contrast, the glycolytic enzyme, G3P, was reduced. 3). additionally, a ketogenic diet induced oxidative stress in pancreatic cancer in vivo. Based on the adaptations observed in pancreatic cancer, we combined a ketogenic diet with an inhibitor of IDH1 to thwart antioxidant defense and impair mitochondrial function. The combination resulted in markedly reduced tumor proliferation, compared to either treatment alone. In vitro studies revealed that low glucose and fatty acids are likely the major drivers of reduced pancreatic cancer cell proliferation with a ketogenic diet, while exogenous ketone bodies are utilized for energy by mitochondria under glucose withdrawal and generally have a pro-tumor effect. Conclusion: A ketogenic diet has a strong anti-tumor effect in multiple pancreatic cancer mouse models, and the effect is likely a result of the low glucose and increased fatty acid load associated with the diet. Metabolic adaptation towards an OXPHOS phenotype renders pancreatic cancer especially susceptible to antioxidant and mitochondrial inhibitors. Citation Format: Mehrdad Zarei, Soubhi Tahhan, Peter Gallagher, William Beegan, Alexander Loftus, Kevin Lebo, Shihong Lei, Helen Cheng, Anusha Mudigonda, Jonathan Hue, Hallie Graor, Omid Hajihassani, Jordan Winter, Karen Ji, Sydney Alibeckoff. Determining the anti-cancer properties of a ketogenic diet against pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B050.