Antagonistic Relationship Research Articles

The Relationship between Mercury and Selenium in the Eggshell and Egg Content of the Whiskered Tern (Chlidonias hybridus)

Mercury and its compounds do not have beneficial biological roles in living organisms. In contrast, selenium, within permissible limits, is an essential micronutrient and antioxidant. There is an antagonistic relationship between mercury and selenium. Therefore, the molar ratio of selenium to mercury is used as an appropriate index. Measuring the mercury in the environment without considering the protective effects of selenium does not accurately reflect the risks posed by mercury. This study aimed to measure the mercury, selenium, and the molar ratio Se:Hg in the shell and content of the eggs of the Whiskered Tern (Chlidonias hybridus) in northern Iran. After the onset of egg laying, one egg was collected from each nest (38 eggs in total). The results showed that the concentration of mercury in the egg shell was higher, while the concentration of selenium and the molar ratio Se:Hg were higher in the egg content. A molar ratio Se:Hg in both the eggshell and the egg content indicates a positive effect of selenium in reducing the risks associated with mercury toxicity. The parameters of egg shape index, egg weight, and clutch size did not have a significant effect on the concentrations of mercury, selenium, and the molar ratio Se:Hg in the shell and egg content. There was a significant negative correlation between the concentration of mercury in the shell and the molar ratio Se:Hg in both the shell and egg content. The lack of a positive correlation between the concentrations of mercury or selenium in the shell and egg content suggests that the transferability of heavy metals from the egg to the embryo in the egg content cannot be confirmed.

Interactive effects between extreme temperatures and PM2.5 on cause-specific mortality in thirteen U.S. states

Abstract The extent and robustness of the interaction between exposures to heat and ambient PM2.5 is unclear and little is known of the interaction between exposures to cold and ambient PM2.5. Clarifying these interactions, if any, is crucial due to the omnipresence of PM2.5 in the atmosphere and increasing scope and frequency of extreme temperature events. To investigate both of these interactions, we merged 6,073,575 individual-level mortality records from thirteen states spanning seventeen years with 1-kilometer daily PM2.5 predictions from sophisticated prediction model and 1-kilometer meteorology from Daymet V4. A time-stratified, bidirectional case-crossover design was used to control for confounding by individual-level, long-term and cyclic weekly characteristics. We fitted conditional logistic regressions with an interaction term between PM2.5 and extreme temperature events to investigate the potential interactive effects on mortality. Ambient PM2.5 exposure has the greatest effect on mortality by all internal causes in the 2-day moving average exposure window. Additionally, we found consistently synergistic interactions between a 10 μg m-3 increase in the 2-day moving average of PM2.5 and extreme heat with interaction odds ratios of 1.013 (95% CI: 1.000, 1.026), 1.024 (95% CI: 1.002, 1.046), and 1.033 (95% CI: 0.991, 1.077) for deaths by all internal causes, circulatory causes, and respiratory causes, respectively, which represent 75%, 156%, and 214% increases in the coefficient estimates for PM2.5 on those days. We also found evidence of interactions on the additive scale with corresponding relative excess risks due to interaction (RERIs) of 0.013 (95% CI: 0.003, 0.021), 0.020 (95% CI: 0.008, 0.031), and 0.017 (95% CI: -0.015, 0.036). Interactions with other PM2.5 exposure windows were more pronounced. For extreme cold, our results were suggestive of an antagonistic relationship. These results suggest that ambient PM2.5 interacts synergistically with exposure to extreme heat, yielding greater risks for mortality than only either exposure alone.

Integrated assessment of farm-level mitigation measures for gaseous emissions

ContextSome gaseous emissions continue to pose a serious threat to human health and the environment locally, regionally and globally. This has resulted in several studies advocating for the implementation of mitigation measures to reduce the emissions of harmful gases. ObjectiveWhile the vast majority of studies focus on a single type of gas, much less attention has been paid to the complementary or conflicting effects of mitigation measures across multiple harmful gaseous emissions dimensions. MethodsTo address this research gap, this study uses Irish farm-level data to assess the holistic costs and benefits of a suite of mitigation measures that have the potential to abate greenhouse gases, ammonia or both. A cost-benefit analysis framework is employed to assess the impact of the mitigation measures across five different farm system types. Results and conclusionsResults indicate that the relative effectiveness of the mitigation measure varies depending on the gaseous emission dimension being examined. SignificanceAnalyses that fail to account for such synergistic and antagonistic relationship impacts may lead to flawed policy decisions.

Pleiotropic Associations with Alzheimer’s Disease and Physical Activity: Sex Differences and the Effects of Environment

Physical activity (PA) is a modifiable factor in mitigating/preventing Alzheimer’s disease (AD). It is crucial to identify the conditions under which PA’s effects on AD risk would be beneficial. This study aims to gain insights into pleiotropic predisposition to AD and PA within and across sexes and environmental effects. We performed a genome-wide association study (GWAS) of pleiotropic AD-PA associations in individuals (65 years and older) of European ancestry in a US sample (14,628 individuals), for men and women separately and combined, and contrasted them with the UK biobank (204,789 individuals) to elucidate the effects of the environment. Fisher’s method and Wald's test were used for estimating the significance of pleiotropic associations and differences between the samples. We identified genetic markers in 60 loci with significant pleiotropic associations. Of them, 91.7% of loci exhibited antagonistic relationships characterized by a misalignment of the signs of the associations of the same alleles with AD and PA and a correlation between these phenotypes. Only 16.7% of associations were replicated in the UKB. Phosphorylation and the regulation of transcription were identified as more pronounced biological mechanisms of AD-PA pleiotropy in females and males, respectively. Our results demonstrate the intrinsic heterogeneity of AD-PA pleiotropy and suggest that PA should be used as an intervention against AD with caution, after identifying groups of individuals and combinations of gene–environment interactions with beneficial effects.

Synthetic communities derived from the core endophytic microbiome of hyperaccumulators and their role in cadmium phytoremediation

BackgroundAlthough numerous endophytic bacteria have been isolated and characterized from cadmium (Cd) hyperaccumulators, the contribution and potential application of the core endophytic microbiomes on facilitating phytoremediation were still lack of intensive recognition. Therefore, a 2-year field sampling in different location were firstly conducted to identify the unique core microbiome in Cd hyperaccumulators, among which the representative cultivable bacteria of different genera were then selected to construct synthetic communities (SynComs). Finally, the effects and mechanisms of the optimized SynCom in regulating Cd accumulation in different ecotypes of Sedum alfredii were studied to declare the potential application of the bacterial agents based on core microbiome.ResultsThrough an innovative network analysis workflow, 97 core bacterial taxa unique to hyperaccumulator Sedum was identified based on a 2-year field 16S rRNA sequencing data. A SynCom comprising 13 selected strains belonging to 6 different genera was then constructed. Under the combined selection pressure of the plant and Cd contamination, Alcaligenes sp. exhibited antagonistic relationships with other genera and plant Cd concentration. Five representative strains of the other five genera were further conducted genome resequencing and developed six SynComs, whose effects on Cd phytoremediation were compared with single strains by hydroponic experiments. The results showed that SynCom-NS comprising four strains (including Leifsonia shinshuensis, Novosphingobium lindaniclasticum, Ochrobactrum anthropi, and Pseudomonas izuensis) had the greatest potential to enhance Cd phytoremediation. After inoculation with SynCom-NS, genes related to Cd transport, antioxidative defense, and phytohormone signaling pathways were significantly upregulated in both ecotypes of S. alfredii, so as to promote plant growth, Cd uptake, and translocation.ConclusionIn this study, we designed an innovative network analysis workflow to identify the core endophytic microbiome in hyperaccumulator. Based on the cultivable core bacteria, an optimized SynCom-NS was constructed and verified to have great potential in enhancing phytoremediation. This work not only provided a framework for identifying core microbiomes associated with specific features but also paved the way for the construction of functional synthetic communities derived from core microbiomes to develop high efficient agricultural agents.5KavnCJpVp3k2g6uQCMsTeVideo

Non-antibiotic disinfectant synchronously interferes methane production and antibiotic resistance genes propagation during sludge anaerobic digestion: Activation of microbial adaptation and reconfiguration of bacteria-archaea synergies

Waste activated sludge (WAS) presents both resource recovery potential and pollution risks, making its efficient treatment challenging. Anaerobic digestion is broadly recognized as a green and sustainable approach to WAS treatment, whose efficiency is easily impacted by the exogeneous pollutants in WAS. However, the impact of polyhexamethylene guanidine (PHMG), as a widely-used non-antibiotic disinfectant, on WAS digestion under semi-continuous flow conditions remains unclear. In this study, CH4 production decreased from 16.1 mL/g volatile suspended solids (VSS) in the control to 13.2 mL/g VSS and 0.3 mL/g VSS under low and high PHMG exposure, respectively, while PHMG increased the number of antibiotic resistance gene (ARG) copies per bacterium by 4.6-12.7 %. Molecular docking analysis revealed that PHMG could spontaneously bind to and disintegrate WAS (binding energy:2.35 and -9.62 kcal/mol), increasing the likelihood of microbial exposure to PHMG. This led to an increase in bacterial abundance and a reduction in archaeal populations, resulting in bacterial dominance in ecological niches. The network topology index in PHMG-treated reactors was consistently lower than in the control, with a higher proportion of negatively correlated links, indicating a more antagonistic relationship between bacteria and archaea. Consequently, PHMG significantly interfered with key genes involved in CH4 biosynthesis (e.g., mch and mtd). Interestingly, methanogenic activity and archaeal chemotaxis (e.g., rfk and cheA) partially recovered under low PHMG exposure due to archaeal adaptation through quorum sensing and two-component systems. However, this adaptation process also contributed to the propagation of ARGs through horizontal gene transfer, facilitated by the enhancement of mobile genetic elements and ARGs hosts. These findings confirm the ecological risks of PHMG and highlight the need for effective WAS disposal strategies.

A temperature-ultrasound sensitive nanoparticle delivery system for exploring central neuroinflammation mechanism in stroke-heart syndrome

BackgroundCardiovascular events secondary to stroke–collectively classified as stroke-heart syndrome–greatly impair the patient’s prognosis, however its underlying mechanism has yet to be determined. To investigate the mechanism of central neuroinflammation and its effects on stroke-heart syndrome, a temperature-ultrasound responsive brain-targeted drug delivery system, DATS/MION-LPE, was synthesized to specifically study neuroinflammation in the mouse middle cerebral artery occlusion (MCAO) model.ResultsThe specific polymer of DATS/MION-LPE can close the nanoparticle pores at 37 °C, restricting drug release in the circulation. After the nanoparticles were targeted to brains, the polymer can be cleaved under external ultrasound irradiation, reopening the nanoparticle pores and allowing drug release, therefore directly managing the neuroinflammation. After a stroke, a significant cerebral inflammation occurred, with elevated IL-1β and pyrin domain-containing 3 (NLRP3) inflammasome. Accordingly, significantly increased histone deacetylase 6 (HDAC6) and decreased sirtuin 1 (SIRT1) were observed. An antagonistic relationship between HDAC6 and SIRT1 was found, which can jointly regulate the cerebral NLRP3 expression. The systemic IL-1β and ATP levels were increased after the stroke, accompanied by a significant heart injury including contractile dysfunction, elevated IL-1β levels, and oxidative stress. Meanwhile, neuroinflammation can trigger sympathetic nervous overexcitation with associated heart damage. DATS/MION-LPE can targetedly effect on ischemic brain, exhibiting cerebral and cardiac protective effects including downregulated cerebral NLRP3 and HDAC6 expressions, upregulated SIRT1 expressions in brain, reduced IL-1β and ATP in circulation, and alleviated cardiac impairment.ConclusionThis study introduced the key role of neuroinflammation in stroke-heart syndrome and first investigated the crucial HDAC6/SIRT1-NLRP3 circuit in this process. Heart injury secondary to stroke is mediated by neuroinflammation induced systemic inflammatory responses and sympathoexcitation. DATS/MION-LPE is a unique tool and effective therapeutic agent, which provides new insights into combinational heart and cardiac protection.Graphical

Ultrasound-Assisted Synthesis of Pyrazoline Derivatives as Potential Antagonists of RAGE-Mediated Pathologies: Insights from SAR Studies and Biological Evaluations.

In the context of age-related disorders, the receptor of advanced glycation end products (RAGE), plays a pivotal role in the pathogenesis of these conditions by triggering downstream signaling pathways associated with chronic inflammation and oxidative stress. Targeting this inflammaging phenomenon with RAGE antagonists holds promise for interventions with broad implications in healthy aging and the management of age-related conditions. This study explores the structure-activity relationship (SAR) of pyrazoline-based RAGE antagonists synthesized using an ultrasound-assisted green one-pot two-steps methodology. Our investigation identifies phenylurenyl-pyrazoline 2 g as a promising candidate, demonstrating superior efficiency compared to the reference antagonist Azeliragon (IC50=13 μM). Compound 2 g exhibits potent inhibition of the AGE2-BSA/sRAGE interaction (IC50=22 μM) and favorable affinity in Microscale Thermophoresis (MST) assays (Kd=17.1 μM), along with a favorable safety profile, with no apparent cytotoxicity observed in vitro in the MTS assay. These findings underscore the potential of pyrazoline-derived RAGE antagonists as therapeutic agents for addressing age-related disorders.

Bayesian Evaluation of Growth Rates and Kleiber's Ratios in Harnali Sheep: Dissecting Maternal and Additive Genetic Contributions.

Understanding the genetic basis of growth and metabolic traits in sheep is crucial for improving production efficiency and sustainability. The current study aimed to estimate the genetic influences, both direct and maternal, on growth rate and Kleiber's ratio traits in Harnali sheep using pedigree data under Bayesian inference. The data pertained to 2404 animals spanned over 24 years (1998-2021). Fixed factors such as birth period, lamb sex and dam's weight at lambing were considered. The traits studied included average daily gains (ADGs) categorised into ADG1 (birth to weaning age), ADG2 (weaning to 6 months of age) and ADG3 (6-12 months of age), as well as corresponding Kleiber's ratios (KR1, KR2 and KR3). Six single-trait animal models were employed to estimate covariance components and heritabilities, integrating direct additive and maternal effects alongside significant fixed factors using THRGIBBS1F90 and POSTGIBBSF90 programmes. Direct heritability estimates were obtained for ADG1 (0.11 ± 0.05), ADG2 (0.06 ± 0.03), ADG3 (0.03 ± 0.03), KR1 (0.07 ± 0.03), KR2 (0.06 ± 0.03) and KR3 (0.05 ± 0.03). Maternal genetic effects have contributed significant particularly to pre-weaning traits. The study identified an antagonistic relationship between direct additive and maternal genetic effects. Positive genetic and phenotypic correlations emphasised the intricate relationship between growth and metabolic efficiency in Harnali sheep. The current study offers critical insights into the genetic basis of growth and metabolic traits in Harnali sheep, ultimately contributing to more efficient and sustainable sheep production systems.

GmHSP40.1, a nuclear-localized soybean J domain protein, participates in regulation of flowering time through interacting with EMF1 and JMJ14

Heat shock protein 40s (HSP40s) are a group of J domain proteins (JDPs), which serve as co-chaperones for heat shock protein 70s. We previously reported that over-expression of a soybean class C JDP, GmHSP40.1, in Arabidopsis activated defense responses. Surprisingly, a significantly delayed flowering phenotype was also observed for the GmHSP40.1-overexpressing (OE) lines. We provided evidence that the late-flowering phenotype observed in the GmHSP40.1-OE lines was not due to impaired pri-miRNA processing and pre-mRNA splicing. Instead, we found that GmHSP40.1 interacted and co-localized with both EMF1 and JMJ14, two major components in the EMF1 complex (EMF1c), which plays a key role in depositing and maintaining the H3K27me3 modification in the FT locus. Consistent with these interactions, the H3K27me3 modification at FT chromatin was significantly increased, whereas the H3K27me3 modification at FLC locus was significantly decreased in the GmHSP40.1-OE line compared with the wde-type Col-0. Interestingly, the H3K4me3 modification was just opposite to H3K27me3 modification at FT and FLC loci, suggesting an antagonistic relationship between these two modifications. Accordingly, the expression of FT and FLC was significantly reduced and increased, respectively, in the GmHSP40.1-OE line compared with that of Col-0. Lastly, we showed that both EMF1 and JMJ14 are genetically epistatic to GmHSP40.1-overexpression. Together, our results revealed that GmHSP40.1 negatively regulates flowering time through promoting the function of EMF1c via interacting with both EMF1 and JMJ14.

Interactions between fungi and other microorganisms for better fungal products: a review

Under natural conditions, substrates are occupied by sets of different micro-organisms that interact with one another in synergistic or antagonistic relationships. These interactions can influence the growth, development, and biochemistry of economically important fungi, enhance their beneficial properties, stimulate the growth of fruiting bodies, or accelerate the growth of mycelium used for the production of various products and biotechnology processes where fungi are involved. The paper presents a literature review covering known interactions between fungi and bacteria, fungi and actinomycetes, and between different fungi that can be used to promote the production of fungal products or that need to be taken into account in order to avoid production losses. A brief overview of fungi and micro-organism co-culture strategies is provided as well.

‘Sympathy for the devil’: The strategic use of the populist repertoire in Viktor Orbán’s politics

Populist politicians such as Viktor Orbán are masters at harnessing intense and polarizing moral emotions: they stigmatize the enemies of the people, offer their community protection as self-proclaimed heroes, and at the same time, othering and moral transgressing trigger emotional overreactions from opponents. This article draws on a new analytical framework that incorporates theories of social labeling (moral panic and euphoria, moral entrepreneurship) and heroic/charismatic leadership to explore this multifaceted and antagonistic emotional relationship associated with populists. The theoretical reasoning suggests that these emotional dynamics define the moral cornerstones and boundaries of populist identity politics. Based on an analysis of four illustrative Hungarian cases – the migration crisis, anti-gender politics, the Authorisation Act during the coronavirus pandemic, and Fidesz’s expulsion from the European People’s Party – the article shows that populists can follow different paths to become charismatic heroes in the eyes of his supporters, while others still see them as folk devils due to their controversial moral entrepreneurship.

Resolving the Intricate Effects of Multiple Global Change Drivers on Root Litter Decomposition.

Plant roots represent about a quarter of global plant biomass and constitute a primary source of soil organic carbon (C). Yet, considerable uncertainty persists regarding root litter decomposition and their responses to global change factors (GCFs). Much of this uncertainty stems from a limited understanding of the multifactorial effects of GCFs and it remains unclear how these effects are mediated by litter quality, soil conditions and microbial functionality. Using complementary field decomposition and laboratory incubation approaches, we assessed the relative controls of GCF-mediated changes in root litter traits and soil and microbial properties on fine-root decomposition under warming, nitrogen (N) enrichment, and precipitation alteration. We found that warming and N enrichment accelerated fine-root decomposition by over 10%, and their combination showed an additive effect, while precipitation reduction suppressed decomposition overall by 12%, with the suppressive effect being most significant under warming-alone and N enrichment-alone conditions. Significantly, changes in litter quality played a dominant role and accelerated fine-root decomposition by 15% ~ 18% under warming and N enrichment, while changes in soil and microbial properties were predominant and reduced decomposition by 7% ~ 10% under precipitation reduction and the combined warming and N enrichment. Examining only the decomposition environment or litter properties in isolation can distort global change effects on root decomposition, underestimating precipitation reduction impacts by 38% and overstating warming and N effects by up to 73%. These findings highlight that the net impact of GCFs on root litter decomposition hinges on the interplay between GCF-modulated root decomposability and decomposition environment, as well as on the synergistic or antagonistic relationships among GCFs themselves. Our study emphasizes that integrating the legacy effects of multiple GCFs on root traits, soil conditions and microbial functionality would improve our prediction of C and nutrient cycling under interactive global change scenarios.

Correlation Analysis of the Transcriptome and Gut Microbiota in Salmo trutta Resistance to Aeromonas salmonicida

Aeromonas salmonicida is a major pathogenic bacterium that poses a significant threat to salmonid fish. Yadong County, located in the Xizang Autonomous Region, is renowned for its characteristic industry of Salmo trutta aquaculture. In recent years, the outbreak of Bacterial Gill Disease (BGD) has led to substantial economic losses for S. trutta farmers. Our prior research identified A. salmonicida as one of the primary culprits behind BGD. To mitigate the impact of A. salmonicida on S. trutta, we conducted a comprehensive study aimed at identifying genes associated with resistance to A. salmonicida. This involved transcriptome sequencing and 16S rRNA sequencing of intestinal flora, providing valuable insights for the study of disease resistance in S. trutta. In this study, we identified 324 genera with 5171 ASVs in the susceptible group and 293 genera with 5669 ASVs in the resistant group. Notably, Methylobacterium and Sphingomonas were common bacteria present in the salmon’s gut, and their proportions remained relatively stable before and after infection. Shewanella, with its antagonistic relationship with Aeromonas, may play a crucial role in the salmon’s defense against A. salmonicida. Several related genes were identified, including angptl4, cipcb, grasp, ccr9a, sulf1, mtmr11, B3GNT3, mt2, PLXDC1, and ank1b.

Refocusing social work education on community work in Hong Kong: an urgent call

Abstract A dominant discourse in social work literature and textbooks is that community workers should take a proactive stance to pressure government officials to reform policy. Without any mission to downplay the political role of social work in the first place, the author of this paper argues that activist discourses from the 1970s are too old to inform contemporary struggles. In light of the neo-liberal, neo-managerial, post-colonial, and pan-political realities, antagonistic relationships between stakeholders in the community, politicians, opinion leaders, and the establishment have ushered in new-look community work in Hong Kong. Social work education on community development should undergo a transformation to help social work students reposition themselves in these chaotic times.

Dynamic interplay of cortisol and BDNF in males under acute and chronic psychosocial stress – A randomized controlled study

The neurotrophic protein brain-derived neurotrophic factor (BDNF) plays a pivotal role in brain function and is affected by acute and chronic stress. We here investigate the patterns of BDNF and cortisol stress reactivity and recovery under the standardized stress protocol of the TSST and the effect of perceived chronic stress on the basal BDNF levels in healthy young men. Twenty-nine lean young men underwent the Trier Social Stress Test (TSST) and a resting condition. Serum BDNF and cortisol were measured before and repeatedly after both conditions. The perception of chronic stress was assessed by the Trier Inventory for Chronic Stress (TICS). After the TSST, there was a significant increase over time for BDNF and cortisol. Stronger increase in cortisol in response to stress was linked to an accelerated BDNF decline after stress. Basal resting levels of BDNF was significantly predicted by chronic stress perception. The increased BDNF level following psychosocial stress suggest a stress-induced neuroprotective mechanism. The presumed interplay between BDNF and the HPA-axis indicates an antagonistic relationship of cortisol on BDNF recovery post-stress. Chronically elevated high cortisol levels, as present in chronic stress, could thereby contribute to reduced neurogenesis, and an increased risk of neurodegenerative conditions in persons suffering from chronic stress.

Antagonism between H3K27me3 and genome–lamina association drives atypical spatial genome organization in the totipotent embryo

In mammals, early embryonic development exhibits highly unusual spatial positioning of genomic regions at the nuclear lamina, but the mechanisms underpinning this atypical genome organization remain elusive. Here, we generated single-cell profiles of lamina-associated domains (LADs) coupled with transcriptomics, which revealed a striking overlap between preimplantation-specific LAD dissociation and noncanonical broad domains of H3K27me3. Loss of H3K27me3 resulted in a restoration of canonical LAD profiles, suggesting an antagonistic relationship between lamina association and H3K27me3. Tethering of H3K27me3 to the nuclear periphery showed that the resultant relocalization is partially dependent on the underlying DNA sequence. Collectively, our results suggest that the atypical organization of LADs in early developmental stages is the result of a tug-of-war between intrinsic affinity for the nuclear lamina and H3K27me3, constrained by the available space at the nuclear periphery. This study provides detailed insight into the molecular mechanisms regulating nuclear organization during early mammalian development.

Are UV filters better together? A comparison of the toxicity of individual ultraviolet filters and off-the-shelf sunscreens to Daphnia magna

Organic ultraviolet filters (UVFs) are known to contaminate many aquatic ecosystems, with much environmental contamination attributed to the use of UVF-containing skin care products such as sunscreens during aquatic recreation. Most studies addressing the impact of sunscreen contamination have focused on the effects of UVFs under the assumption that they are the primary contaminants of concern from sunscreen pollution; however, the extent to which the toxicity of UVFs is representative of the environmental impacts of the whole sunscreen mixture is unknown. To address this knowledge gap, this study compared the mixture toxicity of five off-the-shelf sunscreen spray products containing the UVFs avobenzone, homosalate, octisalate, octocrylene and oxybenzone to the toxicity of each UVF in isolation to the freshwater invertebrate Daphnia magna. It was found that sunscreen toxicity was not proportional to their total UVF content, as the sunscreen containing the fewest UVFs was approximately equivalent to the sunscreen with the most UVFs, causing ≥90 % mortality and inhibiting all daphnid reproduction over 21 d exposures. Sunscreen toxicity was typically lower than expected when compared to the toxicity of each individual UVF within the mixture, as some sunscreens causing ≤20 % mortality contained octocrylene and/or oxybenzone at concentrations exceeding those which caused 90 % mortality during exposure to the UVF alone. Despite sunscreens causing large impairments in reproduction, growth and metabolism, poor correlations existed between the severity of most sublethal endpoints with respect to the measured UVF content of each sunscreen. Overall, these results indicate that potential antagonistic relationships between sunscreen ingredients can greatly reduce the toxicity of UVFs, creating more uncertainty regarding the level of threat that UVFs pose to the environment as a result of sunscreen contamination.

341 Impact of genomic selection for growth on feet and leg structure in Angus cattle

Abstract Historically fitness and production traits have shown an antagonistic relationship at the genetic level. Genetic selection mainly focused on growth traits (GT) might have influenced feet and leg structure traits (FT; recently added trait), causing changes over time. We aimed to examine genetic parameter changes in FT and GT over time in Angus cattle. Currently, genetic parameters are estimated using Variance Components Estimation (VCE), which has limitations in handling large datasets and is time demanding. To address these limitations, we explored the use of predictivity-based formulas to estimate heritability and genetic correlations in GT. The analysis was conducted using the blupf90+ family of programs. To estimate variance components (VCE), sampled data (2011-2022) from the American Angus population included 311K GT records [birth (BW), weaning weight (WW), and post-weaning gain (PWG)], ~70K FT records [foot claw set (CS) and foot angle (FA)], and 142K genotypes. FT are taken on the worst foot of the animal and can be scored multiple times throughout the life of the animal, but in this study, we did not include repeated records. The dataset was split into 5-yr intervals. Since FT ranged from 5 to 9, and 5 is ideal, a negative correlation is desired between FT and GT. The correlation FA-PWG, changed in an undesirable way over time, as it changed from -0.10 to 0.02 in the last interval. The correlation FA-WW is becoming more favorable over time, shifting from 0.05 to -0.15. The GT selection process shifted the correlations between CS and GT in the desired direction, changing from positive (~0.1) to almost zero in the more recent two intervals. To test the predictivity-based formulas, Genomic Estimated Breeding Values (GEBV) were estimated using GT data from 6.3M animals born from 2000 to 2022, and 900K genotyped animals. The data were divided into four slices, with a 2-yr validation period. Over time, heritabilities remained constant: ~0.3 for BW and WW, and ~0.2 for PWG. Correlations between GT also remained constant, approximately at 0.45 for BW-WW, 0.30 for BW-PWG, and 0.75 for WW-PWG. Although the formulas show promising results for heritabilities, interpreting the outcomes of genetic correlation estimation remains unclear, needing further tests. While certain correlations between FT and GT suggest a positive impact of genetic selection, some undesirable outcomes are realized. Probably due to the early FT genetic selection implementation (2019). This emphasizes the need for a multi-trait genomic selection approach to mitigate genetic antagonism. Adopting predictivity-based formulas reduces the time for genetic parameter estimation and allows the use of complete data instead of sampled data, as currently done in VCE.

Potential Trypanocidal Activity of Glycerol Analogues.

Glycerol, a versatile and ubiquitous compound, plays a vital role in a plethora of metabolic pathways in both prokaryotes and eukarotyes. Relatively few glycerol analogues have previously been explored for their use as glycerol kinase inhibitors, in addition to their therapeutic potential, however their use as (pro)-drugs in the context of parasitic diseases such as trypanosomiasis is unreported. The literature on glycerol metabolism and particular its synergic anti-profilation behaviour with salicylhydroxamic acid (SHAM) in Trypanosoma brucei is extensive. However, utiliation of glycerol analogues has not been explored as possible superior combinatory compounds. This report describes the synthesis of various glycerol analogues and their subsequent biochemical pheotypic analysis for their effect on lipid metabolism and their possible synergic activity with SHAM on Trypanosoma brucei. The glycerol analogues caused morphological changes;, including detached flagella, cytokinesis defects and 'big-eye' phenotype. All four compounds either matched or marginally increased the toxicity of SHAM when used in combination against Trypanosoma brucei. However, the compounds exhibited mostly an antagonistic relationship with SHAM rather than synergistic. This research highlights the potential of small molecule glycerol analogues for their combination use with SHAM for the treatment of parasitic disease, such as trypanosomiasis.