On using an aerosol thermodynamic model to calculate aerosol acidity of coarse particles.

Thermodynamic modeling is still the most widely used method to characterize aerosol acidity, a critical physicochemical property of atmospheric aerosols. However, it remains unclear whether gas-aerosol partitioning should be incorporated when thermodynamic models are employed to estimate the acidity of coarse particles. In this work, field measurements were conducted at a coastal city in northern China across three seasons, and covered wide ranges of temperature, relative humidity and NH3 concentrations. We examined the performance of different modes of ISORROPIA-II (a widely used aerosol thermodynamic model) in estimating aerosol acidity of coarse and fine particles. The M0 mode, which incorporates gas-phase data and runs the model in the forward mode, provided reasonable estimation of aerosol acidity for coarse and fine particles. Compared to M0, the M1 mode, which runs the model in the forward mode but does not include gas-phase data, may capture the general trend of aerosol acidity but underestimates pH for both coarse and fine particles; M2, which runs the model in the reverse mode, results in large errors in estimated aerosol pH for both coarse and fine particles and should not be used for aerosol acidity calculations. However, M1 significantly underestimates liquid water contents for both fine and coarse particles, while M2 provides reliable estimation of liquid water contents. In summary, our work highlights the importance of incorporating gas-aerosol partitioning when estimating coarse particle acidity, and thus may help improve our understanding of acidity of coarse particles.

Estimation of gaseous polycyclic aromatic hydrocarbons (PAHs) and characteristics of atmospheric PAHs at a traffic site in Kanazawa, Japan.

Size-fractionated particulate matter (PM2.5 and PM>2.5) was collected at a traffic site in Kanazawa, Japan in a seasonal sampling work in 2020. Nine polycyclic aromatic hydrocarbons (4- to 6-ring PAHs) were determined in fine and coarse particles. The gas/particle partitioning coefficients (Kp) of the PAHs were calculated from the supercooled liquid vapour pressure and octanol-air partitioning coefficient based on the relationships obtained in previous traffic pollution-related studies. Gaseous PAHs were estimated by Kp and the concentrations of PM and particulate PAHs. The concentrations of total PAHs were 32.5, 320.1 and 5646.2 pg/m3 in the PM>2.5, PM2.5 and gas phases, respectively. Significant seasonal trends in PAHs were observed (particle phase: lowest in summer, gas phase: lowest in spring, particle and gas phase: lowest in spring). Compared to 2019, the total PAH concentrations (in particles) decreased in 2020, especially in spring and summer, which might be due to reduced traffic trips during the COVID-19 outbreak. The incremental lifetime cancer risk (ILCR) calculated from the toxic equivalent concentrations relative to benzo[a]pyrene (BaPeq) was lower than the acceptable limit issued by the US Environmental Protection Agency, indicating a low cancer risk in long-term exposure to current PAH levels. It is notable that gaseous PAHs considerably contributed to BaPeq and ILCR (over 50%), which highlighted the significance of gaseous PAH monitoring for public health protection. This low-cost estimation method for gaseous PAHs can be expected to reliably and conveniently obtain PAH concentrations as a surrogate for traditional sampling in the future work.

Reducing red light proportion in full-spectrum LEDs enhances runner plant propagation by promoting the growth and development of mother plants in strawberry.

Full-spectrum light-emitting diodes (LEDs) have gradually replaced narrow-spectrum LEDs and are widely used in plant factories with artificial lighting (PFALs). However, the specific effect of LED light quality on dry mass allocation in runner plant propagation remains unclear. Hence, we cultivated "Akihime" strawberries as mother plants for 115 days to conduct runner plant propagation experiment under white LEDs (W100), white and red LEDs (W84R16 and W55R45), red and blue LEDs (RB100), and red, blue and green LEDs (RB80G20) in PFALs, and determined key factors affecting dry mass accumulation and allocation among mother plants and runner plants based on growth component analysis. The results showed that the net photosynthetic rate and total leaf area in mother plants in W100 increased by 11% and 31%, respectively, compared with W55R45. In comparison to W84R16 and W55R45, W100 increased the dry mass (23%-30%) of runner plants mainly by increasing the total dry mass (TDM) (23%) of strawberry plants, without significantly affecting the fraction of dry mass partitioning to runner plants. However, the number of runners in W55R45 was 5.1 per plant, representing only 78% of that in W100. Compared with RB100, RB80G20 significantly increased the number of runner plants and runner numbers by 16% and 19% to 13.0 per plant and 5.8 per plant, respectively. The partial replacement of blue light with green light in RB80G20 induced a shade avoidance response in runner plants, resulting in a 55% increase in the total leaf area of runner plants compared with RB100. Data from growth component analysis showed that compared with red and blue LEDs, white LEDs increased the TDM of runner plants by 83% by increasing the plant TDM accumulation (44%) and the fraction of dry mass partitioning to runner plants (37%). Additionally, the dry mass (g) of runner plants per mol and per kilowatt-hour under in W100 were 0.11 and 0.75, respectively, significantly higher than other treatments. Therefore, reducing red light proportion in full-spectrum LEDs is beneficial for strawberry runner plant propagation in PFALs.

Smaller islands, bigger appetites: evolutionary strategies of insular endemic skinks.

Competitive dietary and morphological divergence among co-occurring species are fundamental aspects of ecological communities, particularly on islands. Cabo Verde (~570 km west of continental Africa) hosts several endemic reptiles descended from common ancestors, with sympatric species exhibiting wide morphological variation and competing for limited resources. To explore the mechanisms of resource partitioning between coexisting species, DNA metabarcoding was used to compare the diets of large and small skinks, Chioninia vaillantii and Chioninia delalandii, in sympatric and allopatric contexts on Fogo Island and in a more competitive context on the small and resource-poor Cima Islet. The morphological variation of all populations was also examined to test the character displacement hypothesis and to compare the effect of different competitive scenarios. Results showed significant differences in diet and linear measurements between species and populations. The two sympatric populations of C. delalandii on Fogo and Cima showed similar changes in head morphology compared to the allopatric population, supporting character displacement. The effect of higher competitive pressure on Cima was evidenced by the increased morphological and dietary variation observed. This study demonstrates how sister species develop dietary adaptations/morphologies to maintain stable coexistence, especially in highly competitive scenarios, providing useful insights for effective conservation strategies.

Methane emission, nitrogen excretion, and energy partitioning in Hanwoo steers fed a typical TMR diet supplemented with Pharbitis nil seeds.

Two in vivo experiments were conducted to evaluate the potential of Pharbitis nil seeds (PA) as an anti-methanogenic additive to ruminant feed. In experiment 1, six Hanwoo steers (459.0 ± 25.8 kg) were fed either a total mixed ration (TMR; 32-d period) or TMR supplemented with PA at 5% dry matter (DM) intake (TMR-PA; 45-d period) for two consecutive periods. Fecal and urine outputs were measured in an apparent digestibility trial in both periods. Methane (CH4) yield and heat energy (HE) were measured using respiratory chambers equipped with gas analyzers. In experiment 2, five rumen cannulated Holstein steers (744 ± 35 kg) were fed the same TMR or TMR-PA diets for 40 days; rumen samples were collected at 0, 1.5, and 3 h after feeding on the last day of the feeding period. In experiment 1, although there were no differences (p > 0.05) in nutrients or gross energy intake (GEI) between the groups, an increase (p < 0.05) in the apparent digestibility of DM (9.1%) and neutral detergent fiber (22.9%) was observed in the TMR-PA fed Hanwoo steers. Pronounced decreases (p < 0.05) in CH4 (g/Kg DM; 17.1%) and urinary N excretion (% N intake; 7.6%) were observed in the TMR-PA group, leading to a 14.7% increase in metabolizable energy intake (% GEI). However, only a numerical increase (p > 0.05) in retained energy was observed due to the increase in HE loss. In experiment 2, a drastic decrease (p < 0.05) in rumen ammonia concentration (56.3%) associated with an increased (p = 0.091) rumen short-chain fatty acid concentration 1.5 h after feeding were observed in TMR-PA fed Holstein steers. A 26.6% increase (p < 0.05) in the propionate proportion during the treatment period clearly reflected a shift in the ruminal H2 sink after 3 h of feeding. A 40% reduction (p = 0.067) in the relative abundance of rumen protozoa Entodinium caudatum was also observed. It was concluded that PA could be a natural feed additive for CH4 and N emission abatement.

Seasonal and anthropogenic effects on niche overlap and habitat selection by sympatric bears (Ursus arctos marsicanus) and wolves (Canis lupus) in a human-dominated landscape.

Interspecific interactions among species of the same guild play a critical role in shaping their realized niches, and their understanding may disclose mechanisms of coexistence. Investigating interactions among apex predators is of ecological and management interest, especially in human-dominated landscapes where type and intensity of their interspecific competition may be affected by human interference. During 2005-2010, we investigated, by means of GPS-telemetry, interactions between brown bears (n = 19) and wolves (n = 7) in a long-established national park in the central Apennines, Italy, where bears and wolves have always coexisted close to humans. Based on a K-select analysis and a randomization approach, we assessed the extent of overlap between the species' niches on a seasonal basis. Bears and wolves clearly segregated in fall but not during summer when overlap between their realized niches suggests a convergent adaptation to a seasonal peak of anthropogenic pressure. However, using multi-species resource selection functions (RSFs) at the home range level (i.e., third-order selection), we revealed that habitat selection by bears and wolves was reciprocally affected also when their niches overlapped, possibly disclosing mechanisms of fine-scale resource partitioning. In early summer, bears selected areas with a high probability of resource selection by wolves, but in late summer avoided areas positively selected by wolves. On the contrary, wolves avoided areas where the probability of resource selection by bears was high, both in late summer and fall. These results indicate that bears and wolves do interact in our study area and, although the actual behavioral mechanisms are unknown, they reciprocally and asymmetrically affect their realized niche and habitat selection patterns. Further research is needed to better understand how anthropogenic factors impact intraguild interactions and what are the effects at the population and community levels.

Molecular Insights into Gas-Particle Partitioning and Viscosity of Atmospheric Brown Carbon.

Biomass burning organic aerosol (BBOA), containing brown carbon chromophores, plays a critical role in atmospheric chemistry and climate forcing. However, the effects of evaporation on BBOA volatility and viscosity under different environmental conditions remain poorly understood. This study focuses on the molecular characterization of laboratory-generated BBOA proxies from wood pyrolysis emissions. The initial mixture, "pyrolysis oil (PO1)", was progressively evaporated to produce more concentrated mixtures (PO1.33, PO2, and PO3) with volume reduction factors of 1.33, 2, and 3, respectively. Chemical speciation and volatility were investigated using temperature-programmed desorption combined with direct analysis in real-time ionization and high-resolution mass spectrometry (TPD-DART-HRMS). This novel approach quantified saturation vapor pressures and enthalpies of individual species, enabling the construction of volatility basis set distributions and the quantification of gas-particle partitioning. Viscosity estimates, validated by poke-flow experiments, showed a significant increase with evaporation, slowing particle-phase diffusion and extending equilibration times. These findings suggest that highly viscous tar ball particles in aged biomass burning emissions form as semivolatile components evaporate. The study highlights the importance of evaporation processes in shaping BBOA properties, underscoring the need to incorporate these factors into atmospheric models for better predictions of BBOA aging and its environmental impact.

Sorption of per- and polyfluoroalkyl substances by lignin in pulp and paper wastewater.

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic chemicals commonly found in the environment. PFAS pose multifaceted challenges including identifying sources and exposure pathways, detecting and quantifying their presence, characterizing their fate and transport, and assessing their risks. PFAS and fluorotelomer polymers can be found in the pulp and paper (P&P) wastewater systems, but their behavior remains poorly understood. The constituents of P&P waste include lignin hydrolysis products, hence PFAS interactions with lignin likely affect PFAS removal efforts. This study employed quantitative ultra-performance liquid chromatography triple quadrupole mass spectrometry (UPLC-MS/MS) to investigate the sorption-desorption capacity and mechanisms of PFAS interaction with lignin. PFAS with sulfonate functional groups displayed higher affinity for lignin (solid phase) based on their partitioning coefficient (Kd), while PFAS with carboxylate head groups persisted in the P&P wastewater (aqueous phase). Sorption to lignin exhibited an increase with chain length (CF2)n among compounds with the same functional group. Long-chain (C ≥ 6) PFAS demonstrated higher sorption compared to short-chain (C ≤ 5) homologs. The sorption-desorption capacities, partitioning coefficients, and kinetics of PFAS reported in this study can facilitate predictive models for PFAS and assist in the development of efficient P&P waste treatment and management.

Regulation of terrestrial input and ocean processes on the occurrence and transport of traditional and emerging per- and polyfluoroalkyl substances in the inner shelf of the East China Sea.

Coastal oceans, serving as transitional zones between land and sea, possess unique geographical features and complex hydrological conditions, functioning as regional reservoirs and crucial transport pathways for anthropogenic pollutants such as per- and polyfluoroalkyl substances (PFASs) to the open ocean. This study comprehensively investigates traditional perfluoroalkyl carboxylic and sulphonic acids (PFCAs and PFSAs) and emerging perfluoroalkyl ether carboxylic and sulfonic acids (PFECAs and PFESAs), fluorotelomer sulfonates (FTSAs) in seawater columns and surface sediments from the inner shelf of the East China Sea, by integrating hydrological and biogeochemical data. Comparable levels of traditional and emerging PFASs were observed in seawater samples, in contrast to higher concentrations of traditional PFASs in surface sediments. Waterborne PFASs exhibited a nearshore-to-offshore decreasing trend and a surface enrichment pattern in offshore waters, typically influenced by terrestrial inputs and oceanic processes. Significant terrestrial inputs for waterborne PFASs were identified, including large rivers like the Changjiang River (Yangtze) and semi-enclosed coastal bays such as Xiangshan Port and Sanmen Bay, where prolonged hydraulic retention times contribute to PFAS accumulation. The source apportionment model demonstrated that emerging fluorochemical manufacturing, textile production, and high-performance fluoropolymer materials are primary sources, consistent with PFAS releases from commercial products and industrial processes along the Changjiang River and in Xiangshan County. Hydrologically, the offshore transport barrier effect created by river plume fronts, and the vertical stratification of different water masses were significant for PFASs. Sediment inputs and resuspension also played a crucial role, with surface sediment-bottom water partitioning behavior primarily regulated by the hydrophobicity of PFASs and salting-out effects. While the overall ecological risks of PFASs were low, elevated risks associated with legacy perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and emerging hexafluoropropylene oxide dimer acid (HFPO-DA) warrant closer attention due to their accumulation in the environment. The methodologies and findings of this research provide valuable insights into PFAS cycling in coastal oceans worldwide.

MCTP controls nucleocytoplasmic partitioning of AUXIN RESPONSE FACTORs during lateral root development.

The plant hormone auxin orchestrates almost all aspects of plant growth and development. AUXIN RESPONSE FACTORs (ARFs) control the transcription of auxin-responsive genes, forming cytoplasmic condensates to modulate auxin sensitivity and diversify auxin response regulation. However, the dynamic control of ARF distribution across different subcellular compartments remains largely obscure. Here, we show that three MULTIPLE C2 DOMAIN AND TRANSMEMBRANE REGION PROTEINs (MCTPs), MCTP3, MCTP4, and MCTP6, control ARF nucleocytoplasmic partitioning and determine lateral root development. MCTP3/4/6 are highly expressed in lateral roots and specifically interact with ARF7 and ARF19 to dissolve their cytoplasmic condensates. This promotes ARF nuclear localization in lateral root primordia and enhances auxin signaling during lateral root formation. Our findings confer MCTP as a key switch to modulate auxin responses and outline an MCTP-ARF signaling cascade that is crucial for the establishment of the plant root system.

Changes in the Phylogenetic Structure of Alpine Grassland Plant Communities on the Qinghai-Tibetan Plateau with Long-Term Nitrogen Deposition.

Nitrogen (N) deposition rates have notably increased around the world, especially in high-altitude regions like the Qinghai-Tibetan Plateau (QTP). We conducted a six-year comprehensive experiment to simulate nitrogen deposition in an alpine grassland area near Qinghai Lake. Four levels of nitrogen depositions, i.e., 0 (CK), 8 kg N ha-1year-1 (N1), 40 kg N ha-1year-1 (N2), and 72 kg N ha-1year-1 (N3), with three replicates for each N treatment, were tested annually in early May and early July, with the meticulous collection of plant and soil samples during the peak growth period from 15 July to 15 August. We used the null model to evaluate the impact of environmental filtration and interspecific competition on the dynamics of the plant community was assessed based on the level of discrete species affinities within the plant community by constructing a phylogenetic tree. The results showed that the environmental filter was the predominant driver for the change of community's genealogical fabric. The N2 and N3 treatments increased the influence of soil factors on the change of plant community structure. Climatic factors played a crucial role on the change of plant community in the CK grassland area, while soil factors were dominant in the N1- and N3-treated grasslands.

Phylogenomic insights into the worldwide evolutionary relationships of the stingless bees (Apidae, Meliponini).

Stingless bees (tribe Meliponini) are remarkable for their characteristically large social colonies, their capacity to produce honey and other useful products, and their morphological and behavioral diversity. They have a disjunct pan-tropical distribution, primarily occurring in warm and humid environments in the Neotropical, Afrotropical, and Indo-Australasian regions. Even though phylogenetic hypotheses have been proposed for Meliponini based on morphology and molecular data, many questions are still unsolved regarding the evolutionary relationships and systematics of the tribe. In this contribution, we present a large phylogenomic dataset comprising over 2500 ultra-conserved element (UCE) loci sequenced for 153 species of Meliponini, representing all known genera of stingless bees. The genera Camargoia, Paratrigonoides, Plectoplebeia, Cleptotrigona, Ebaiotrigona, Papuatrigona, Pariotrigona, Platytrigona, and Sahulotrigona were included in molecular phylogenetic analyses for the first time. Concatenated and species-tree analyses were performed using different partitioning strategies and summary methods. We performed gene-genealogy interrogation (GGI) on several recalcitrant nodes to resolve discordances among recovered tree topologies. Results were mostly consistent among analyses, recovering three main lineages of Meliponini congruent with the biogeographic domains to which they are associated. Within major clades, discordances were found in relation to previous works. The genus Frieseomelitta was recovered as paraphyletic in relation to Trichotrigona, and the genus Lepidotrigona was revealed to be composed of two independent lineages. Even though concatenated and weighted ASTRAL analyses were mostly effective in recovering the relationships favored by GGI, they retrieved different results in relation to the phylogenetic placements of Oxytrigona and Cephalotrigona. The most favored hypothesis in GGI analyses was not found in any other analyses, being more congruent with morphological evidence and highlighting the relevance of exploring the support given to alternative hypotheses through topological tests. Recent advances in our capacity to generate molecular sequences from old specimens using modern sequencing methods allowed for unparalleled sampling across genera, yielding a backbone for the phylogenetic relationships of stingless bees, which will further investigations into their systematics and evolution.

Predicting Functional Outcome After Nonoperative Treatment of Proximal Humeral Fractures Involving the Surgical Neck.

BACKGROUND: In nonoperative treated proximal humeral fractures (PHF), uncertainty remains regarding functional outcome. Therefore, the aim was to identify predictors of functional outcome following nonoperative treatment of PHF and to develop predictive models. METHODS: Adults with a nonoperatively treated PHF involving the surgical neck were followed for 1 year. Radiographic parameters included fracture configuration, displacement, bone quality, and the critical shoulder angle (CSA). The neck-shaft angle (NSA) and humeral head offset assessed displacement. The greater tuberosity index (GTI) addressed greater tuberosity (GT) displacement relative to the articular surface while the impingement index addressed GT-displacement relative to the acromion. Multivariate regression models determined predictors of impaired function as measured by Constant Score (CS), flexion, and external rotation (ER). Recursive partitioning created a decision tree model over dichotomized functional outcome that combined flexion and ER (good = flexion ≥ 120° and ER ≥ 40°). RESULTS: In 272 consecutive patients (mean age: 66 years, 69% women and 31% men), mean functional outcomes were a CS of 74 points, 138° flexion, and 50° ER. Older age was a predictor for impaired CS, flexion, and ER (p < 0.001), while sex only influenced CS (p = 0.040). Every 10% increase in GTI assessed on the Y-view explained a decrease of 3 CS points, 7° of flexion, and 5° of ER (p < 0.001). Every 10° of varus angulation assessed on anterior-posterior (ap) views in internal rotation resulted in a decrease of 1 CS point and 4° of flexion (p ≤ 0.004). Subgroups of combined important GT-displacement (GTI ≥ 1.15) with age > 76 years or < 119° varus angulation demonstrated the worst function. Linear prediction models estimated flexion, ER, and CS with a mean difference of 10°, 3°, and 3 points, respectively. The decision tree model predicted good function with 80% accuracy (positive predictive value = 81%; negative predictive value = 78%). CONCLUSION: Demographic and radiographic predictors were identified allowing for accurate functional prognosis of nonoperatively treated PHF involving the surgical neck. A combined assessment of the ap-view in internal rotation and Y-view is sufficient for accurate function prediction. The identified subgroups resulting in good or impaired function, and the predictive models may be useful for patient counseling and guidance of treatment-related expectations.

Occurrence, bioaccumulation, and partitioning of phthalate acid esters in the third largest freshwater lake (Lake Taihu) in China.

Phthalate acid esters (PAEs) are a category of plasticizers that are ubiquitous in freshwater environments attributable to extensive utilization. We collected water, suspended particulate matter (SPM), surface sediments, phytoplankton, and zooplankton from 23 sampling sites to investigate and complement the occurrence, bioaccumulation, and partitioning of five PAEs including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), and di (2-ethylhexyl) phthalate (DEHP) in the third largest freshwater lake (Lake Taihu) of China. PAEs were extracted using Soxhlet extraction and solid phase extraction, and determined by gas chromatography-mass spectrometry. The average concentrations of the five PAEs in the water column, SPM, sediments, phytoplankton, and zooplankton of Lake Taihu were 1.93 ± 1.57 µg L-1, 765 ± 766 µg g-1, 1.68 ± 1.47 µg g-1, 1358 ± 1877 µg g-1, and 72.7 ± 134 µg g-1, respectively. DBP and DEHP were the dominant PAE congeners in the five environment compartments. The logarithmic concentrations of DBP, BBP, and DEHP in the SPM were negatively correlated with the logarithmic content of the SPM. Biodilution significantly impacted the occurrence of PAEs in the plankton. Bioaccumulation of PAEs was found in the plankton with log BCF (bioconcentration factor) in the phytoplankton ranging from 1.78 ± 0.86 to 4.13 ± 1.23 and log BAF (bioaccumulation factor) in the zooplankton varying from -0.10 ± 0.26 to 3.04 ± 0.64. Biomagnification of the PAEs from phytoplankton to zooplankton was not observed. DMP, DEP, and BBP migrated from sediments to water. DBP was in dynamic equilibrium in the sediment-water system. DEHP transferred from water to sediments. Our results provide crucial complementary knowledge on bioaccumulation and transfer of PAEs in planktonic food web, and their partitioning in different compartments of waters.

It's about (taking up) space: Discreteness of individuals and the strength of spatial coexistence mechanisms.

One strand of modern coexistence theory (MCT) partitions invader growth rates (IGR) to quantify how different mechanisms contribute to species coexistence, highlighting fluctuation-dependent mechanisms. A general conclusion from the classical analytic MCT theory is that coexistence mechanisms relying on temporal variation (such as the temporal storage effect) are generally less effective at promoting coexistence than mechanisms relying on spatial or spatiotemporal variation (primarily growth-density covariance). However, the analytic theory assumes continuous population density, and IGRs are calculated for infinitesimally rare invaders that have infinite time to find their preferred habitat and regrow, without ever experiencing intraspecific competition. Here we ask if the disparity between spatial and temporal mechanisms persists when individuals are, instead, discrete and occupy finite amounts of space. We present a simulation-based approach to quantifying IGRs in this situation, building on our previous approach for spatially non-varying habitats. As expected, we found that spatial mechanisms are weakened; unexpectedly, the contribution to IGR from growth-density covariance could even become negative, opposing coexistence. We also found shifts in which demographic parameters had the largest effect on the strength of spatial coexistence mechanisms. Our substantive conclusions are statements about one model, across parameter ranges that we subjectively considered realistic. Using the methods developed here, effects of individual discreteness should be explored theoretically across a broader range of conditions, and in models parameterized from empirical data on real communities.

Heterogeneity in the association between social support and mental distress in old-age retirees - a computational approach using longitudinal cohort data.

BACKGROUND: Mental distress among retirees and older people is a severe public health challenge, and information on new risk groups is needed. This study aims to identify subgroups of old-age retirees with varying associations between low social support and mental distress by applying model-based recursive partitioning (MOB). METHODS: We used the Helsinki Health Study follow-up survey data of old-age retired former municipal sector employees of the City of Helsinki, Finland. Phase 1 data were collected in 2000-2002, when all participants were employed, Phase 2 in 2007, Phase 3 in 2012, Phase 4 in 2017, and Phase 5 in 2022 (n = 4,466, 81% women). Social support and covariates were measured at each Phase 1-5 and the outcome, mental distress (Depression Anxiety Stress Scales [DASS-21]) was measured at a single occasion, during Phase 5. The three subscales and the common factor of general distress were analysed separately. An approach rooted in computational statistics was used to investigate risk factor heterogeneity in the association of low social support and mental distress. MOB combines decision trees with regression analysis to identify subgroups with the most significant heterogeneity among risk factors. RESULTS: Median (IQR) general distress score from DASS-21 was 5.7 (3.0, 9.0), while Social Support Questionnaire number-score (SSQN) was 1.5 (1.15, 2.05). The primary effect modifier for the association between social support and general distress was education (p < 0.001). Those with high education had a different association of low social support and general distress than those with low or medium education. Additionally, the subgroup with low and medium education had a significant effect modification for age (p = 0.01). For the association between low social support and depressive symptoms, the moderating effect of education was dependent on gender, as men with medium-high education had the weakest association, while for women with medium-high education the association was strongest. CONCLUSIONS: Our results suggest that stratification by sociodemographic variables is justifiable when investigating risk factors of mental distress in old-age retirees. The incongruent association of low social support and depressive symptoms in men with medium-high education compared to women with medium-high education is a promising target for confirmatory research.

Understanding Oxygen "Buffering" by Caveolae Using Coarse-Grained Molecular Dynamics Simulations.

The "oxygen paradox" embodies the delicate interplay between two opposing biological processes involving oxygen (O2). O2 is indispensable for aerobic metabolism, fuelling oxidative phosphorylation in mitochondria. However, excess O2 can generate reactive species that harm cells. Thus, maintaining O2 balance is paramount, requiring the prioritisation of its benefits while minimising potential harm. Previous research hypothesised that caveolae, specialised cholesterol-rich membrane structures with a curved morphology, regulate cellular O2 levels. Their role in absorbing and controlling O2 release to mitochondria remains unclear. To address this gap, we aim to explore how the structural features of caveolae, particularly membrane curvature, influence local O2 levels. Using coarse-grained (CG) molecular dynamics simulations, we simulate a caveola-like curved membrane and select a CG bead as the O2 model. Comparing a flat bilayer and a liposome of 10 nm diameter, composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), allows us to study changes in the O2 free energy profile. Our findings reveal that curvature has a contrasting effect on the free energy of the outer and inner layers. These findings show the membrane curvature's impact on O2 partitioning in the membrane and O2 permeation barriers, paving the way towards our understanding of the role of caveolae curvature in O2 homeostasis.

Effects of temperature, relative humidity and soil organic carbon content on soil-air partitioning coefficients of volatile PFAS.

Soil-air partitioning coefficient (KSA) values are often used to assess the environmental fate of organic contaminants in soil. Till now, sufficient KSA values have not yet been measured for many compounds of interest, including some emerging pollutants such as volatile PFAS. Moreover, the effects of environmental factors such as temperature, relative humidity and soil organic carbon content on KSA of volatile PFAS are also unclear. In this study, the KSA values of target volatile PFAS were measured under various temperature (20-40 °C), relative humidity (30-100 %) and soil organic carbon content (2.1 %-8.0 %) using a modified solid-phase fugacity meter. The results showed that higher temperatures, higher relative humidity and lower organic carbon content in soil may accelerate the diffusion of target volatile PFAS. Furthermore, the KSA measurements were used to derive a multiple linear regression model to depict the relationship between logKSA and temperature, relative humidity, soil organic carbon content and PFAS-specific logKOA. When compared with the predictions obtained from semi-empirical model, we argued that the multiple linear regression model is more robust and easier to implement for target volatile PFAS or other emerging volatile PFAS than the semi-empirical approach to help depict the diffusion process at target volatile PFAS contaminated sites.

Spatial-Aware and Load Balancing Distributed Data Partitioning Strategies for Content-Based Multimedia Retrieval.

Content-Based Multimedia Retrieval (CBMR) has become very popular in several applications, driven by the growing routine use of multimedia data. Since the datasets used in real-world applications are very large and descriptor's dimensionality is high, querying is an expensive, albeit important functionality. Further, exact search is prohibitive in most cases, motivating the use of Approximate Nearest Neighbour Search (ANNS) algorithms, trading accuracy for performance. These have been mainly developed targeting a sequential execution in a single node. However, the large and increasing datasets used and the high query loads submitted to those systems typically surpass the memory and computing resources available in a single node. This motivated the development of parallel distributed memory ANNS solutions to meet the computing capabilities required by those applications. A common problem that must be handled when using distributed memory systems is data partitioning and its impact on load imbalance. Several data partitioning approaches have already been proposed, including elaborated spatial-aware strategies. However, little effort has been put into carefully analyzing the performance of those strategies at scale. Here, we evaluated the commonly used data partitioning strategies in ANNS and identified their limitations to propose a novel class of partitioning algorithms that can minimize load imbalance while improving data locality to attain high performance on the distributed memory search. Experimentally, we found that our proposed algorithms (SABBS and SABBSR) improved search performance by up to 1.64× compared to the best previous solution. In a distributed memory weak scaling evaluation, with up to 12 billion 128-dimensional descriptors and 60 compute nodes, the gains were maintained as the system scaled with our novel approaches. These results demonstrate the efficiency of our new algorithms for billion-scale ANNS and the importance of considering not only data locality but also data and load imbalance in the data partitioning.

Temporal and spatial distribution of novel brominated flame retardants in atmosphere of the Beijing-Tianjin-Hebei region, China.

The occurrence and spatio-temporal distribution of atmospheric novel brominated flame retardants (NBFRs) were studied across five sampling sites in the Beijing-Tianjin-Hebei (BTH) region over a whole year. By collecting samples (gas and particle) with a high-volume active air sampler (HV-AAS), nine NBFRs were analyzed and the sum concentrations ranged from 1.65 to 344 pg/m3, with the highest value found in the urban sampling site in Shijiazhuang City. Decabromodiphenylethane (DBDPE) was the predominant congener, which accounted for 60% of ∑9NBFRs on average, while it was 90% of ∑9NBFRs in the rural site and significantly higher than those observed in the urban sites (one-way ANOVA, p < 0.05). The levels of particle-bound NBFRs were significantly correlated with the variation of total suspended particulates (TSP) and temperature (p < 0.01), indicating their evident impact on the spatio-temporal distribution of NBFRs. Moreover, a significantly positive correlation was observed between the concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis (2-ethyl-1-hexyl) tetrabromophthalate (BEH-TEBP) (p < 0.01). Monocyclic brominated flame retardants (including PBBz, PBT, PBEB, HBB and TBP-DBPE) were correlated with each other (p < 0.01) in both gas and particle phase, suggesting their co-occurrence and the similar source in the environment. The gas-particle partitioning behavior was well predicted by the Li-Jia Empirical Model, and the results indicated that the target NBFRs did not reach the equilibrium state in air. This is one of very few studies revealed the spatio-temporal distribution of atmospheric NBFRs in the BTH region.