In the present paper, first, a
ψ$$ \psi $$‐delayed Mittag–Leffler type function is introduced, which generalizes the existing delayed Mittag–Leffler type function. Second, by means of
ψ$$ \psi ...$$‐delayed Mittag–Leffler type function, an exact analytical solution formula to non‐homogeneous linear delayed Langevin equations involving two distinct
ψ$$ \psi $$‐Caputo type fractional derivatives of general orders is obtained. Moreover, existence and uniqueness, stability of solution to nonlinear delayed Langevin fractional differential equations is obtained in the weighted space. Numerical and simulated examples are shared to exemplify the theoretical findings.
The use of styrene-maleic acid copolymers (SMAs) to produce membrane protein-containing nanodiscs without the initial detergent isolation has gained significant interest over the last decade. We have ...previously shown that a Photosystem I SMALP from the thermophilic cyanobacterium, Thermosynechococcus elongatus (PSI-SMALP), has much more rapid energy transfer and charge separation in vitro than detergent isolated PSI complexes. In this study, we have utilized small-angle neutron scattering (SANS) to better understand the geometry of these SMALPs. These techniques allow us to investigate the size and shape of these particles in their fully solvated state. Further, the particle's proteolipid core and detergent shell or copolymer belt can be interrogated separately using contrast variation, a capability unique to SANS. Here we report the dimensions of the Thermosynechococcus elongatus PSI-SMALP containing a PSI trimer. At ~1.5 MDa, PSI-SMALP is the largest SMALP to be isolated; our lipidomic analysis indicates it contains ~1300 lipids/per trimeric particle, >40-fold more than the PSI-DDM particle and > 100 fold more than identified in the 1JB0 crystal structure. Interestingly, the lipid composition to the PSI trimer in the PSI-SMALP differs significantly from bulk thylakoid composition, being enriched ~50 % in the anionic sulfolipid, SQDG. Finally, utilizing the contrast match point for the SMA 1440 copolymer, we also can observe the ~1 nm SMA copolymer belt surrounding this SMALP for the first time, consistent with most models of SMA organization.
Display omitted
•SANS analysis of the largest membrane protein isolated via a SMALP.•Lipidomics reveal PSI-SMALP contains ~1200 lipids per PSI trimer.•Large lipid annulus agrees with the preliminary model based on SANS.•The membrane environment within and surrounding PSI is enriched in SQDG.•The inclusion of the anionic SQDG may explain the faster photochemistry observed in the PSI-SMALP.
Interpretation of the fast chlorophyll a fluorescence induction is still a subject of continuing discussion. One of the contentious issues is the influence of photosystem I (PSI) activity on the ...kinetics of the thermal JIP-phase of OJIP rise. To demonstrate this influence, we realized a series of measurements in wheat leaves subjected to PSI photoinactivation by the sequence of red saturation pulses (15,000μmolphotonsm−2s−1 for 0.3s, every 10s) applied in darkness. Such a treatment led to a moderate decrease of maximum quantum efficiency of PSII (by ~8%), but a strong decrease of the number of oxidizable PSI (by ~55%), which considerably limited linear electron transport and CO2 assimilation. Surprisingly, the PSI photoinactivation had low effects on OJIP kinetics of variable fluorescence. In particular, the amplitude of variable fluorescence of IP-step (ΔVIP), which has been considered to be a measure of PSI content, was not decreased, despite the low content of photooxidizable PSI. On the other hand, the slower relaxation of chlorophyll fluorescence after saturation pulse as well as the results of the double-hit method suggest that PSI inactivation treatment led to an increase of the fraction of QB-nonreducing PSII reaction centers. Our results somewhat challenge the mainstream interpretations of JIP-thermal phase, and at least suggest that the IP amplitude cannot serve to estimate reliably the PSI content or the PSI to PSII ratio. Moreover, these results recommend the use of the novel method of PSI inactivation, which might help clarify some important issues needed for the correct understanding of the OJIP fluorescence rise.
•Saturation pulse treatment led to a severe inactivation of photosystem I (PSI).•Low content of active PSI strongly limited linear electron flow and CO2 assimilation.•PSI inactivation caused only minor changes of OJIP kinetics of variable fluorescence.•Amplitude of IP-phase of OJIP rise seemed to be independent of PSI content.•PSI inactivation led to a higher fraction of QB-non-reducing PSII reaction centers.
Mosses are one of the earliest land plants that diverged from fresh-water green algae. They are considered to have acquired a higher capacity for thermal energy dissipation to cope with dynamically ...changing solar irradiance by utilizing both the “algal-type” light-harvesting complex stress-related (LHCSR)-dependent and the “plant-type” PsbS-dependent mechanisms. It is hypothesized that the formation of photosystem (PS) I and II megacomplex is another mechanism to protect photosynthetic machinery from strong irradiance. Herein, we describe the analysis of the PSI–PSII megacomplex from the model moss,
Physcomitrella patens
, which was resolved using large-pore clear-native polyacrylamide gel electrophoresis (lpCN-PAGE). The similarity in the migration distance of the
Physcomitrella
PSI–PSII megacomplex to the Arabidopsis megacomplex shown during lpCN-PAGE suggested that the
Physcomitrella
PSI–PSII and Arabidopsis megacomplexes have similar structures. Time-resolved chlorophyll fluorescence measurements show that excitation energy was rapidly and efficiently transferred from PSII to PSI, providing evidence of an ordered association of the two photosystems. We also found that LHCSR and PsbS co-migrated with the
Physcomitrella
PSI–PSII megacomplex. The megacomplex showed pH-dependent chlorophyll fluorescence quenching, which may have been induced by LHCSR and/or PsbS proteins with the collaboration of zeaxanthin. We discuss the mechanism that regulates the energy distribution balance between two photosystems in
Physcomitrella
.
Integration of photovoltaic (PV) power generation and energy storage has been widely believed to be the ultimate solution for future energy demands. Herein, an ingenious method was reported to make ...full use of photovoltaic silicon cutting waste (SiCW) natural characters fabricating PSi@SiOx/Nano-Ag composite as anode material for high-performance lithium-ion batteries. The sheet-like structure with nano/micropores and native SiOx layer addressed the volume expansion issues of Si material. Ag nanoparticles greatly enhanced electrical conductivity of composite and promoted Li+/e− transport. Synergistic effect of the designed PSi@SiOx/Nano-Ag composite contributed outstanding cyclic performance with reversible capacity of 1409mAhg−1 after 500 cycles. Notably, full LIBs with PSi@SiOx/Nano-Ag anode and commercial LiNi0.6Co0.2Mn0.2O2 (NCM622) cathode delivered stable capacity of 137.5mAhg−1 at current density of 200 mA g−1, accompanying with a high energy density of 438 Wh kg−1. Furthermore, electrochemical Li+ storage behavior of this PSi@SiOx/Nano-Ag electrode was studied, and reaction mechanism and crystal structure evolution during cycles were also revealed by in-situ XRD analysis. The synthesis method is facile and cost-effective, which paves a novel way towards high-performance Si-based anodes and promising markets for both solar photovoltaic and lithium-ion battery industries.
Display omitted
•A novel and promising method to fabricate PSi@SiOx/Nano-Ag composite was proposed.•SiCWP natural characters of ultrafine particle and sheet-like structure are full used.•The properties of the electrochemical Li+ store/release behavior were clarified.•In-situ XRD analysis revealed the crystal structure evolution and reaction mechanism.•The PSi@SiOx/Nano-Ag as LIBs anodes exhibit an excellent electrochemical performance.
This study aims to assess the agreement between three Road Safety Performance Indicators (RSPIs) used to evaluate road surface condition, namely Pavement Condition Distress Index (PCI), Present ...Serviceability Index (PSI), and International Road Assessment Program star ratings scores (iRAP). To achieve this, the study conducted field survey to gather pavement functional condition data on 12 roads that are known for having a higher frequency of accidents in the city of Kuching, Malaysia. The results indicated a significant correlation between PSI and PCI, with a moderately strong correlation coefficient (R2) of 0.7354. This suggests that PSI can be used as a surrogate for PCI when resources and time are limited. However, the correlation between PCI and iRAP star rating scores for vehicle occupants and motorcyclists was not satisfactory, with R2 values of 0.167 and 0.3611, respectively.
Research on the link between affect and creativity rests on the assumption that creativity unfolds as a stimulus-driven response to affective states. We challenge this assumption and examine whether ...personality dynamics moderate the relationships between positive and negative mood with creativity.
According to our model, personality dynamics that generate and maintain positive affect and downregulate negative affect energize creativity. Based on this model, we expect high creativity in response to negative mood if people engage in self-motivation and achieve a reduction in negative mood. We further derive that individual differences in action versus state orientation moderate the within-person relationship between mood and creativity.
We conducted an experience-sampling study and examined the relationship between mood and creativity in everyday work-life. Two hundred and ten participants indicated their action-state orientation and reported their mood three times a day over five consecutive workdays. At noon of each day, we assessed self-motivation and in the evening the extent to which participants had generated novel and useful ideas during the day.
We observed high creativity when negative mood declined and self-motivation was high. Action-state orientation moderated the within-person relationships of positive and negative mood with creativity.
Personality dynamics determine whether positive and negative mood result in creativity.
Summary
Natural growth environments commonly include fluctuating conditions that can disrupt the photosynthetic energy balance and induce photoinhibition through inactivation of the photosynthetic ...apparatus. Photosystem II (PSII) photoinhibition is efficiently reversed by the PSII repair cycle, whereas photoinhibited photosystem I (PSI) recovers much more slowly. In the current study, treatment of the Arabidopsis thaliana mutant proton gradient regulation 5 (pgr5) with excess light was used to compromise PSI functionality in order to investigate the impact of photoinhibition and subsequent recovery on photosynthesis and carbon metabolism. The negative impact of PSI photoinhibition on CO2 fixation was especially deleterious under low irradiance. Impaired starch accumulation after PSI photoinhibition was reflected in reduced respiration in the dark, but this was not attributed to impaired sugar synthesis. Normal chloroplast and mitochondrial metabolisms were shown to recover despite the persistence of substantial PSI photoinhibition for several days. The results of this study indicate that the recovery of PSI function involves the reorganization of the light‐harvesting antennae, and suggest a pool of surplus PSI that can be recruited to support photosynthesis under demanding conditions.
Significance Statement
This work details the impact of PSI photoinhibition and recovery on photosynthesis, CO2 assimilation and carbohydrate metabolism.
PDF
