Synergistic Influences Research Articles

Internal heating and distribution in electromagnetic Powell-Eyring [formula omitted]/glycerin hybridized nanomaterial with radiation and wall slip conditions

The synergistic influences of the hybridization of molybdenum disulfide (MoS2) and graphene oxide (GO) nanoparticles on electromagnetic radiation absorption and augmentation of thermal conductivity coupled with the industrial demand for an enhanced non-Newtonian working fluid spurred this study. Therefore, the study examines the radiative properties and thermal behaviour of hybridized MoS2 and GO nanoparticle systems dispersed in a glycerin Powell-Eyring fluid with wall slip conditions. A theoretical mathematical setup is modelled for the nanoparticle thermophysical characteristics with viscous dissipation and heat generation under the influence of the electromagnetic Riga plate. The model is transformed into an invariant dimensionless form and solved utilizing the pseudo-spectral collocation technique. The effect of fluid rheology, nanoparticle concentration, and fluid-wall slip conditions interface on radiative heat transfer and thermal propagation is investigated. The results reveal momentous augments in radiation absorption and thermal conductivity of about 4.13% to 10.22% due to MoS2 and GO hybridized nanoparticles. Also, it was found that thermal transport is enhanced close to the solid boundary wall slip, leading to an improve heat distribution rate. Hence, this study contributes to the interplay complexity between external stimuli, fluid dynamics, and nanoparticle morphology in thermal systems, offering insights into the advanced materials synthesis, thermal management systems, and optimization and design of nanoparticle fluid enhancement applications.

Comprehensive investigation of flue gas component separation and CO2 sequestration in water-saturated porous media of subsurface formation

Flue gas poses subsurface direct storage inefficiency due to its high non-CO2 content, while surface separation, desulfurization and denitrification processes require additional equipment and financial resources. To address these challenges, flue gas subsurface component separation and CO2 sequestration within aquifer were proposed in this paper. CO2 migrates notably slower than N2, leading to the gathering of N2 at gas flooding front and the occurrence of CO2 hysteresis during flue gas filtration within the aquifer. The phenomenon, characterized by gas composition deviations from the original injection mole fractions of N2 and CO2, is referred to as the flue gas component separation. Numerical simulation results indicate that the solubility difference between N2 and CO2 is the primary force driving the separation of components, and the asynchronous filtration velocities of the gas and aqueous phases further promote the separation. Thus, simultaneous N2 separation and CO2 storage can achieve by the optimized gas-water alternate injection, and the efficiencies of N2 separation and CO2 storage are inversely correlated. Increasing N2 mole fraction within the injected flue gas enhances the efficiency of N2 separation, while having a slight effect on CO2 storage. Water vapor in flue gas condenses and integrates into the liquid phase, while O₂ component is produced slightly later than N₂, leading to a marginal reduction in N₂ separation efficiency. The synergistic influences of aquifer temperature and pressure exhibit bidirectionality, stemming from the shift between the dominant factors between CO2 dissolution and gas sweep efficiency. Conditions of relatively lower aquifer temperatures and moderate pressures, particularly in medium permeability aquifers, are more favorable for enhancing N₂ separation and CO₂ storage. This proposal method holds the potential for efficient subsurface separation of flue gas components and concurrent underground storage of CO2, thereby contributing to the reduction of greenhouse gas emissions and mitigation of climate change.

Effects of lignin syringyl to guaiacyl ratio on cottonwood biochar adsorbent properties and performance

Lignin syringyl to guaiacyl ratio (S/G) has long been suspected to have measurable impacts on biochar formation, but these effects are challenging to observe in biochars formed from whole biomass. When the model bioenergy feedstock Populus trichocarpa (cottonwood), with predictable lignin macromolecular structure tied to genetic variation, is used as feedstock for biochar production, these effects become visible. In this work, two P. trichocarpa variants having lignin S/G of 1.67 and 3.88 were ground and pyrolyzed at 700 °C. Water-demineralization of feedstock was used to simultaneously evaluate any synergistic influences of S/G and naturally-occurring potassium on biochar physicochemical properties and performance. The strongest effects of lignin S/G were observed on specific surface area (SBET) and oxygen-content, with S/G of 1.67 improving SBET by 11% and S/G of 3.88 increasing total oxygen content in demineralized biochars. Functional performance was evaluated by breakthrough testing in 1% NH3. Breakthrough times for biochars were nearly double that of a highly microporous activated carbon reference material, and biochar with S/G of 3.88 had 10% longer breakthrough time than its lower S/G corollary. Results support a combination of pore structure and oxygen-functionalities in controlling ammonia breakthrough for biochar.

Boosting the photocatalytic performance of swiftly produced carbon nitride: Impact of cyano group and oxygen doping within the matrix

We present a significant advancement in the synthesis of carbon nitride framework (CN) using a rapid electric bunsen burner (EBB) method, achieving notable outcomes within a mere 10-min timeframe. The resulting material, designated as U10, exhibits amplified porosity and a semi-scrolling structure with a thickness measuring at 2.1 nm. In comparison to conventionally synthesized urea-derived carbon nitride (UCN) through a box furnace, the U10 demonstrates significantly heightened photocatalytic activity in both hydrogen (H2) production and the removal of organic dye (methylene blue) from aqueous solutions. To ensure the robustness and reliability of this synthetic approach, two additional precursors were subjected to testing, and their rates of H2 production were analyzed. The exceptional photocatalytic performance of the U10 material arises from its distinctive structural attributes and the synergistic influences of oxygen doping (O-doping) and the cyano (-CΞN) functional group, which are introduced during the rapid synthesis strategy. This innovative and streamlined strategy for synthesizing CN not only conserves energy and time but also significantly reduces production costs, rendering it a feasible method for the large-scale production of carbon nitride material.

Aligning Ambition and Reality: A Multiple Case Study Into Synergistic Influences of Financial and Other Factors on the Outcomes of Integrated Care Projects.

While the benefits of integrated care are widely acknowledged, its implementation has proven difficult. Together with other factors, financial factors are known to influence progress towards care integration, but in-depth insight in their influence on the envisioned outcomes of integrated care projects is limited. We conducted a multiple case study of four integrated care projects in the Netherlands. The projects were purposely sampled to be representative of integrated care in its different forms. A total of 29 semi-structured interviews were held with project members, both medical and non-medical staff. In addition, 141 documents were analyzed, including scientific publications and minutes of meetings. Based on elaborate project descriptions we deduced the synergistic influences of financial and other factors on the outcomes of the projects. Financial factors have an important influence on integrated care projects, though this influence is neither deterministic nor isolated. This is because the likelihood of realizing a positive outcome is affected by the degree to which four key conditions are fulfilled: 1) willingness to change, 2) alignment of interests and uniformity goal, 3) availability of resources to change, and 4) effectiveness of management of external actors. Financial factors have an impact on the outcomes of integrated care projects and must be viewed in synergy with interrelated other factors. Crucial for realizing success in integrated care, a balance must be struck between the level of ambition set in a project and the reality of the prevailing key conditions.

Synergistic influences of ground granulated blast-furnace slag and silica fume on the viscosity of extremely low W/B cement pastes

Particularly with a low water/binder ratio, the synergistic effects of supplemental cementitious materials (SCMs) have drawn a lot of interest in improving the characteristics of cement-based products. The effects of SCMs, such as silica fume (SF) and ground granulated blast furnace slag (GGBS) with varying fineness, on the setting time, saturation point, and viscosity of ultra-high performance cement pastes (UHPCP), are examined experimentally in this work. 56 mixes with various SF and BFS substitutions and exceptionally low water/binder ratios (0.16, 0.20) were used in the experiments. This work demonstrates the synergistic effects of SCMs from several angles, including the UHPCP fresh characteristics. It is shown that carefully regulating the water/binder ratio, the BFS fineness, and most significantly the addition of an ideal SF content will have a beneficial synergistic effect on the fresh qualities of UHPCP. However, utilizing high BFS replacement is discouraged as it may have a negative impact on viscosity.

Ultrafine particles formation from ozonolysis of gas- and particle-phases of cigarette smoke

Cigarette smoke and ozone (O3) are two main pollutants in indoor environments and their mutual reaction can generate substantial detrimental substances having synergistic influences on the environment and human health. The aging process of cigarette smoke in the atmosphere is mainly gone through ozonolysis reaction attracting increasing attention in recent years. Herein, the ozonolysis reaction of cigarette smoke with indoor O3 concentrations has been investigated in a Teflon chamber. The gas- and particle-phases of cigarette smoke are divided and their individual ozonolysis process can generate ultrafine particles (UFPs) with high number concentrations. The chemical compositions of the gas- and particle-phases of cigarette smoke as well as their nascent UFPs are measured and their differences during the ozonolysis have been clearly observed with vacuum ultraviolet (VUV) photoionization mass spectrometry. In particular, several representative key species of cigarette smoke, i.e., the gas-phase furan and 2,5-dimethylfuran and the particle-phase nicotine, as well as their ozonolysis products are definitely identified and play an important role in the nucleation formation of UFPs. Their ozonolysis reaction mechanisms are also discussed. In addition, this work demonstrates that the ozonolysis of the particle-phase of cigarette smoke contributes more UFPs than that of the gas-phase.

Exploring Loneliness, Trust, and Psychosocial Meanings Among Primary Care Attendees: A Cross-Sectional Study From a General Practice Setting in Crete, Greece.

Loneliness is often associated with behavioral, psychological, social, and mental and physical health aspects, while the relationship between trust and loneliness is still challenging in terms of research. The present study aimed to investigate to what extent loneliness and trust interact and if there is any association between loneliness and routine events or behaviors that affect overall well-being. This cross-sectional sample of 120 participants, aged between 40 and 75 years, was collected from an urban Primary Health Care Unit, between May and July 2023, in a consecutive manner, after criteria application. The University of California, Los Angeles (UCLA) Loneliness Scale (Version 3) and the Personal Trust and Connections Scale (PerTC) were completed. Hierarchical multiple linear regression analysis in steps and multiple logistic regression analysis were performed. The mean age of the participants was 59.8 years and the majority were females (73.3%). Only 10.8% were found to have no Behavioral Risk Factors (BRFs). A higher sense of loneliness was associated with being widowed/unmarried/divorced (unstandardized β=-4.10, p=0.045), not having children (β=-2.80, p=0.038), having more BRFs (β=2.03, p=0.032), or being in contact with fewer friends (β=-0.56, p<0.001). A higher sense of loneliness was related to lower levels of trust (β=-1.29, p=0.032). Lower odds of demonstrating high levels of loneliness were found among married individuals (odds ratio (OR): 0.38; 95% confidence interval (CI) 0.15, 0.95; p=0.039) and those who reported six or more routine contacts or meetings with friends (OR: 0.31; 95% CI 0.13, 0.74; p=0.008). A lower score on the total PerTC scale was related to higher odds of increased loneliness (OR: 2.78; 95%CI 1.01, 7.62; p=0.048). Being married and coming in contact or meeting with more friends was associated with lower odds of reporting high feelings of loneliness, while lower trust was correlated with increased odds of loneliness. Also, persons with more BRFs were found to have a higher loneliness score. Given their inverse correlation, tools that measure levels of loneliness and trust, like the UCLA and PerTC scales, may be used within primary care consultation to offer new insights on health risk behaviors and their possible synergistic influences.

Improving of the electrochemical performance of acacia wood porous carbon/MnO2 nanocomposite as an advanced electrode for supercapacitor and oxygen evolution reaction

Effective energy storage has now become increasingly critical as global energy demand has skyrocketed. Asymmetric supercapacitors using electrodes made of acacia wood-derived carbon doped with MnO2. A hydrothermal process was used to synthesize the AWPC/MnO2 composite. Techniques such as XRD, SEM, TEM, XPS, FTIR spectra, Ramman spectra, and N2 adsorption-desorption isotherms. We looked at the electrochemical properties of the materials we made in an electrolyte using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). A hydrothermal synthesis approach is used to graft MnO2 wire-like nanostructures onto acacia wood-derived activated carbon. Good electrochemical performance is shown by the carbon/MnO2 hybrid composite electrode, which has high specific capacitances of 301 F g−1 at 500 mA s−1, low Tafel slope of 54 mV dec−1, which is attributed to the synergistic influences between MnO2 and waste biomass-produced carbon. Moreover, an asymmetric supercapacitor operating in the voltage range of 1.8 V and exhibiting a high energy density of 25 Wh kg−1 at a power density of 450 W kg−1 demonstrates the significant potential of the activated carbon/MnO2 composite generated from synthesized biomass. The AWPC/MnO2's oxygen evolution reaction (OER) activity was checked to see how well the improved nanostructure could be used. The results offer a fresh perspective on the fabrication of electrochemical energy storage devices with outstanding performance.

Co-exposure to deltamethrin and cyazofamid: variations in enzyme activity and gene transcription in the earthworm (Eisenia fetida).

Pesticide formulations are typically applied as mixtures, and their synergistic effects can increase toxicity to the organisms in the environment. Despite pesticide mixtures being the leading cause of pesticide exposure incidents, little attention has been given to assessing their combined toxicity and interactions. This survey purposed to reveal the cumulative toxic effects of deltamethrin (DEL) and cyazofamid (CYA) on earthworms (Eisenia fetida) by examining multiple endpoints. Our findings revealed that the LC50 values of DEL for E. fetida, following 7- and 14-day exposures, ranged from 887.7 (728-1095) to 1552 (1226-2298) mg kg-1, while those of CYA ranged from 316.8 (246.2-489.4) to 483.2 (326.1-1202) mg kg-1. The combinations of DEL and CYA induced synergistic influences on the organisms. The contents of Cu/Zn-SOD and CarE showed significant variations when exposed to DEL, CYA, and their combinations compared to the untreated group. Furthermore, the mixture administration resulted in more pronounced alterations in the expression of five genes (hsp70, tctp, gst, mt, and crt) associated with cellular stress, carcinogenesis, detoxification, and endoplasmic reticulum compared to single exposures. In conclusion, our comprehensive findings provided detailed insights into the cumulative toxic effects of chemical mixtures across miscellaneous endpoints and concentration ranges. These results underscored the importance of considering mixture administration during ecological risk evaluations of chemicals.

Hierarchical synchronization with structured multi-granularity interaction for video question answering

Video Question Answering (VideoQA) requires a thorough comprehension of linguistic and visual modalities. However, recent methods confront two problems: (1) Synchronous modeling of object action and frame scene instead of a step-by-step manner, which can better mine potential semantic attributes of videos, lacks research; (2) The relationship between cross-modal alignments at different granularity of abstraction is not fully utilized. Based on these insights, we propose a novel method named hierarchical synchronization with structured multi-granularity interaction (HSSMI) for VideoQA. First, a hierarchical synchronous reasoning module is put forward to model objects’ relations and dynamics and synchronously capture their synergistic influences over time when analyzing whole frames. It is seen as multiple Object ConvLSTMs (O-CLSTMs) in isolation or a Frame ConvLSTM (F-CLSTM) in collectivity. Specifically, O-CLSTM learns the object-level action states under neighboring spatial interplays. Meanwhile, F-CLSTM learns the frame-level scene state, where action information from O-CLSTMs is selectively aggregated into a common memory cell of F-CLSTM as instructed by questions. Besides, a boundary detector is equipped to discover scene discontinuities, enabling F-CLSTM to alter its time connectivity and adapt its sequential encoding process to videos. Thereafter, we develop a conditional VLAD with topic constraints for discriminative modality summarization. Last, a structured multi-granularity interaction module is proposed to integrate complemented clues on the global alignment between scene summary and full question and the local alignments between action summaries and words. This module encourages useful information passing through compositional syntactical topologies of questions to predict answers. Experiments on three public benchmark datasets demonstrate the superiority of our HSSMI against other state-of-the-art methods. Codes will be publicly available at https://github.com/Qiss33/HSSMI.

Multiomics analyses reveal the mechanisms of the responses of subalpine treeline trees to phenology and winter low-temperature stress.

Withstanding extreme cold stress is a prerequisite for alpine treeline trees to persist and survive. However, the underlying mechanism by which treeline trees sense phenological changes and survive hard winters has not been fully elucidated. Here, we investigated the physiology, transcriptome, and metabolome of the subalpine treeline species Larix chinensis to identify the molecular mechanism of phenological and cold resistance. Calcium and antioxidant enzyme activities (e.g., superoxide dismutase and glutathione peroxidase) are essential for coping with winter cold stress in L. chinensis. Transcriptome analysis revealed that circadian rhythm and phytohormone signalling transduction played important roles in regulating L. chinensis phenological changes and cold stress responses. The variations in the transcriptome identified were accompanied by the specific accumulation of flavones, flavonols, and monosaccharides. The flavonoid biosynthesis and phenylpropanoid biosynthesis pathways played important roles in the adaptation of L. chinensis to the extreme winter environment, and flavone and flavonol biosynthesis was an important pathway involved in bud burst. In addition, temperature and photoperiod had synergistic influences on the formation and release of bud dormancy. Thus, our findings provided new insights into the mechanism of subalpine treeline formation.

An Integrative Approach to the Development of the "Mental Retreat" Wellness Program to Prevent Early Aging

In today's society, where everyday challenges and pressures can significantly impact one's psych-emotional state, it is crucial to develop effective stress reduction strategies and maintain mental well-being. Prolonged stress, as recognized in global practice, can trigger the development of various ailments, such as cardiovascular pathologies, endocrine disorders, and psychosomatic deviations, and can also predispose individuals to autoimmune and oncological conditions. Furthermore, the influence of stressful situations over one's lifetime is a well-acknowledged risk factor that heightens the likelihood of early-onset age-associated illnesses and premature death. The primary objective of this study is to analyze and assess the effectiveness of health-promoting procedures in reducing stress levels and to develop a comprehensive wellness Program called "Mental Retreat." The application of this Program aims to mitigate the risk of various chronic diseases and preempt changes at the gene expression level to decelerate intracellular aging, enhance the body's antioxidant system, and stimulate the immune system. This work lays the groundwork for understanding the effects of procedures with substantial empirical support, highlighting synergistic influences in their combination, such as meditative practices, respiratory exercises, aromatherapy, outdoor physical activities, thermal and contrast procedures with elements of aroma and halotherapy, as well as lymphatic drainage massage effects, among others. The developed wellness Program is intended to be evaluated through dynamic observation and monitoring of integrative organism indicators: based on results from bioimpedance analysis (body composition), assessment of stress levels, and biological age accounting for the imbalance between the parasympathetic and sympathetic nervous systems and heart rate variability. Based on a global analysis of existing research, it has been found that the use of a variety of wellness methods has proven to improve concentration and overall psycho-emotional well-being, have a positive effect on the respiratory and cardiovascular systems, promote relaxation and improve sleep, strengthen the immune system and metabolism, increase stress tolerance, and can also have a positive effect on skin health. It's worth underscoring that the successful implementation of such a wellness Program could have immense implications for public healthcare by preventing the onset of numerous chronic diseases and contributing to an overall enhancement of quality of life.

Lifestyle patterns in European preschoolers: Associations with socio-demographic factors and body mass index.

Energy balance-related behaviours (EBRBs), that is, dietary intake, screen, outdoor play and sleep, tend to combine into 'lifestyle patterns', with potential synergistic influences on health. To date, studies addressing this theme mainly focused on school children and rarely accounted for sleep, with a cross-country perspective. We aimed at comparing lifestyle patterns among preschool-aged children across Europe, their associations with socio-demographic factors and their links with body mass index (BMI). Harmonized data on 2-5-year-olds participating in nine European birth cohorts from the EU Child Cohort Network were used (EBRBs, socio-demographics and anthropometrics). Principal component analysis and multivariable linear and logistic regressions were performed. The most consistent pattern identified across cohorts was defined by at least three of the following EBRBs: discretionary consumption, high screen time, low outdoor play time and low sleep duration. Consistently, children from low-income households and born to mothers with low education level had higher scores on this pattern compared to their socioeconomically advantaged counterparts. Furthermore, it was associated with higher BMI z-scores in the Spanish and Italian cohorts (β = 0.06, 95% CI = [0.02; 0.10], both studies). These findings may be valuable in informing early multi-behavioural interventions aimed at reducing social inequalities in health at a European scale.

Kinetic Modeling of Anaerobic Co-Digestion Of Plant Solid Waste with Sewage Sludge: Synergistic Influences of Total Solids and Substrate Particle Size in Biogas Generation

Kinetic Modeling of Anaerobic Co-Digestion Of Plant Solid Waste with Sewage Sludge: Synergistic Influences of Total Solids and Substrate Particle Size in Biogas Generation

Planktonic microbial community and biological metabolism in a subtropical drinking water river-reservoir system

To understand the dynamics of planktonic microbial community and its metabolism processes in subtropical drinking water river-reservoir system with lower man-made pollution loading, this study selected Dongzhen river-reservoir system in Mulan Creek as object to investigate spatial-temporal characteristics of community profile and functional genes involved in biological metabolism, and to analyze the influence of environmental factors. The results indicated that Proteobacteria and Actinobacteria were the most diverse phyla with proportion ranges of 9%–80% in target system, and carbohydrate metabolism (5.76-7.12 × 10−2), amino acid metabolism (5.78-7.21 × 10−2) and energy metabolism (4.07-5.17 × 10−2) were found to be the dominant pathways of biological metabolism. Although there were variations in biological properties both spatially and temporally, seasonal variation had a greater influence on microbial community and biological metabolism, than locational differences. Regarding the role of environmental factors, this study revealed that microbial diversity could be affected by multiple abiotic factors, with total organic carbon, total phosphorus and temperature being more influential (absolute value of standardized regression weights >2.13). Stochastic processes dominated the microbial community assembly (R2 of neutral community model = 0.645), while niche-based processes differences represented by nutrients, temperature and pH level played secondary roles (R > 0.388, P < 0.01). Notably, the synergistic influences among the environmental factors accounted for the higher percentages of community variation (maximum proportion up to 17.6%). Additionally, pH level, temperature, and concentrations of dissolved oxygen, carbon and nitrogen were found to be the significant factors affecting carbon metabolism pathways (P < 0.05), yet only total organic carbon significantly affected on nitrogen transformation (P < 0.05). In summary, the microbial profile in reservoir is not completely dominated by that in feeding river, and planktonic microbial community and its metabolism in subtropical drinking water river-reservoir system are shaped by multiple abiotic and biotic factors with underlying interactions.

Release mechanism of UV responded chitosan-decorated TiO2 microcapsules: Regulation of humidity

In this research, the synergistic influences of UV light and relative humidity on the structure and immediate triggered release abilities of microcapsules loaded with oregano essential oil (OEO) were investigated. The microcapsules sufficiently were encouraged to release OEO by UV irradiation and regulated by ambient humidity. Relatively low humidity from 23 to 58% had no impact on the encapsulation efficiency and release processes of microcapsules in food simulations and air significantly. Analysis of microstructure showed that UV irradiation and higher relative humidity were conducive to fracturing glycosidic bonds of microcapsule shell through hydroxyl radicals generated by TiO2 and vapour. Finally, microcapsules were applied to the preservation of chicken breasts for 6 d and the results showed that chicken breasts with microcapsules that had been irradiated by UV light at 76 %RH would have better quality and the shelf life was extended, which evidenced its excellent foreground in meat preservation.

Analysis of pore morphology evolution of all-wastes ceramic foams based on the variation of composition and sintering process

Utilization of wastes for the preparation of ceramic foams has gradually become a major direction in the development of new building materials. In this paper, all wastes-based ceramic foams based on electrical insulators waste (EIW) and red mud (RM) were prepared through the high-temperature foaming method. The factors affecting the increase in pore size under different preparation conditions (RM content, temperature and time) were investigated separately by studying the changes in pore size. With the increase of RM content, sintering temperature and sintering time, the pore morphology gradually evolved from a regular spherical shape to a polygonal or irregular shape with a corresponding increase in pore size, albeit at different rates. The pore size enhancement ascribed to changes in RM content was primarily attributed to the synergistic influences of a plurality of factors including glass phase content, viscosity, and gas phase content. Sintering temperature mainly affected the balance between the forces acting inside and outside the pores and the gas phase solubility in the liquid phase to adjust the size of pores. The influence of sintering time on pore size and morphology emanated from the glass phase viscosity and the resulting changes in the release rate of gas phase. In summary, the study will help to investigate the actual controlling factors of composition and process on the pore structure, and provides significant insights into the optimization and adjustment of pore structure for samples obtained by high-temperature sintering.

Stand transpiration and canopy conductance dynamics of Populus popularis under varying water availability in an arid area

As a tree species of shelterbelts, Populus popularis maintains significant ecological functions in arid and semiarid areas. However, stand transpiration (T) and canopy conductance (gc) dynamics of P. popularis are unclear in arid irrigated areas with shallow groundwater fluctuations. To better understand the responses of T and gc to meteorological factors, soil water, and shallow groundwater in arid areas, we observed the environmental conditions and sap flow of P. popularis, and quantified T and gc in three growing seasons of 2018–2020 in a typical arid area of China. Results showed T and gc ranged from 0.18 to 6.11 mm day−1 and 2.26–12.54 mm s−1 in 2018–2020, respectively. Solar radiation and vapor pressure deficit (VPD) were major drivers of T at daily scales. It was consistently found that T exponentially decreased with increasing groundwater table depth (GTD) and decreasing reference evapotranspiration in three years. gc is primarily influenced by VPD and is positively related to soil water content in 0–30 cm soil layer (SWC0–30 cm). Moreover, low SWC0–30 cm and deepening GTD jointly decreased T and gc by 22.45 % and 30.41 %, respectively. The response of gc to VPD was susceptible to groundwater fluctuations, and the synergistic influences of VPD and GTD on gc could be well described by the logarithmic function, especially in 2019. The sensitivity of gc to VPD and its variations under different environmental conditions suggested that a flexible stomatal regulation of transpiration occurred in the observed P. popularis with the arid climate and shallow groundwater. These findings provided the essential basis for the water use strategy of P. popularis and stand water resources management in arid regions.

Climate change, wildfire, and past forest management challenge conservation of Canada lynx in Washington, USA

AbstractThe synergistic effects of climate change, wildfires, fire suppression, and past forest management are challenging efforts to protect and recover Canada lynx (Lynx canadensis) in the North Cascades of Washington, USA. Canada lynx is a threatened species in the United States and a focal species used to gain insights into the structure and function of boreal forest ecosystems. To understand how multiple stressors are influencing lynx populations and the boreal forest in Washington, we developed a spatially explicit carrying capacity model in HexSim using local data on lynx resource selection and life history. We used this model to estimate changes in carrying capacity and population persistence for 3 time steps: year 2000, which represented limited historical wildfire and aggressive fire suppression; year 2013, after nearly 2,000 km2 of wildfires burned about 17% of lynx habitat; and year 2020, after an additional 2,000 km2 of wildfires burned another 15% of lynx habitat in our study area. Fires altered habitat distribution and landscape capacity to support Canada lynx. There was a 66–73% reduction in lynx carrying capacity in our study area because of large, high‐severity fires that have occurred from 2000–2020, despite aggressive fire suppression. This reduction in carrying capacity was concurrent with decreases in the probability of lynx persistence from year 2000 to year 2020 simulations and was most pronounced for simulations that included no immigration and the largest home range size. The negative synergistic influences of long‐term fire suppression, timber harvest, increased drought, longer wildfire seasons, declining mountain snowpack, and increasingly frequent large fires pose considerable challenges to the conservation and recovery of Canada lynx and the boreal forest ecosystem upon which they depend. We discuss an alternative approach to vegetation and fire management to conserve and restore lynx habitat and populations in Washington.