Motivated by a widely practiced strategy to combine the growth of the solar energy sector with poverty mitigation, we propose stylized models of households selling extra solar energy back to the ...grid, which generates a steady stream of income to overcome adoption barriers for solar panels, that is, high adoption cost and generation variability. By considering households' strategic consumption shifting behavior in response to varying intertemporal market electricity prices, we have presented the equilibrium adoption number and households' equilibrium profit. We have also demonstrated the government's optimal subsidy to reach a socially optimal adoption level. Furthermore, we investigate the popular Public Private Partnership (PPP) model in developing countries to promote the investment of solar panels. Under the PPP program, the private firms share both upfront cost and electricity revenue with households, while the government may provide subsidy to further encourage adoption. Despite the popularity of the PPP scheme, our model documents an unexpected negative implication by inducing a lower overall adoption level than the traditional scheme: As the PPP scheme relieves budgetary burden of households in adopting solar panels (infrastructure cost), anticipating the long‐term revenue loss, they are less likely to participate in the first place. However, combined with the government intervention via adoption subsidy, the PPP scheme can lead to a win‐win solution for all.
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The use of functionalized aldimines has been demonstrated as newly structural 1,4‐dipole precursors under carbene catalysis. More importantly, enantiodivergent organocatalysis has been successfully ...developed using carbene catalysts with the same absolute configuration, leading to both (R)‐ and (S)‐ enantiomers of six‐membered heterocycles with quaternary carbon centers. This strategy features a broad substrate scope, mild reaction conditions, and good enantiomeric ratio. DFT calculation results indicated that hydrogen bond C−H⋅⋅⋅F interactions between the catalyst and substrate are the key factors for controlling and even switching the enantioselectivity. These new 1,4‐dipoles can also react with isatin and its imines under carbene catalysis, allowing for access to the spiro oxindoles with excellent enantiomeric ratios.
Enantiodivergent organocatalysis has been successfully developed via a 1,4‐dipolar cycloaddition of functionalized aldimines with trifluoromethyl ketones catalyzed by carbene catalysts with the same absolute configuration, leading to both (R)‐ and (S)‐ enantiomers of six‐membered heterocycles. These new 1,4‐dipoles can also react with isatin and its imines under carbene catalysis, allowing for access to the spiro oxindoles with excellent enantiomeric ratios.
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This study aims to examine and design operational strategies for mixed flows of autonomous vehicles (AVs) and human‐driven vehicles (HVs). We propose a stylized model wherein utilitarian individuals ...either drive HVs or take privately operated AVs that are collectively dispatched. In the baseline mixed policy where AVs and HVs share the same lanes, we find that AVs under‐join the traffic (queue) while HVs over‐join. We identify a “crowding‐out effect” such that AVs will tend to mitigate the over‐joining HVs and reduce overall congestion/throughput. To improve the traffic efficiency of the baseline mixed policy, we consider a fully dedicated policy in which both AVs and HVs are segregated to different lanes and a partially dedicated policy in which only AVs enjoy dedicated lanes. We find that dedicated policies outperform the mixed policy in both social welfare and the aggregate throughput when the platooning effect is moderate or strong. Exact conditions are derived for the selection of fully dedicated policy and partially dedicated policy. Furthermore, we find that a carefully designed subsidy is necessary for the dedicated policy to simultaneously improve the social welfare and the throughput when the platooning effect is very weak. These results shed interesting light on the policy regulation for the emerging mixed autonomous paradigm: a dedicated policy with proper lane design and subsidy (if necessary) will improve both social welfare and aggregate throughput.
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The physical origin of fast radio bursts (FRBs) is still unknown. Multiwavelength and polarization observations of an FRB source would be helpful to diagnose its progenitor and environment. So far ...only the first repeating source FRB 121102 appears to be spatially coincident with a persistent radio emission. Its bursts also have very large values of the Faraday rotation measure (RM), i.e., . We show that theoretically there should be a simple relation between RM and the luminosity of the persistent source of an FRB source if the observed RM mostly arises from the persistent emission region. FRB 121102 follows this relation given that the magnetic field in the persistent emission region is highly ordered and that the number of relativistic electrons powering the persistent emission is comparable to that of nonrelativistic electrons that contribute to RM. The nondetections of persistent emission sources from all other localized FRB sources are consistent with their relatively small RMs ( ) according to this relation. Based on this picture, the majority of FRBs without a large RM are not supposed to be associated with bright persistent sources.
In this study, we propose an integrated model of two‐sided stochastic matching platforms to understand the design and operations of free‐float shared‐mobility systems. In particular, we address the ...joint design of incentives (via “crowd‐sourcing”) and spatial capacity allocations (enabled by “geo‐fencing”). From the platform's perspective, we formulate stylized models based on strategic double‐ended queues. We optimize the design and operations of such systems in a case study using a data set from a leading free‐float bicycle‐sharing system, and solve it via mixed‐integer second‐order conic programs (SOCPs). Both stylized results and computational studies generate insights about fundamental trade‐offs and triangular relationships among operational costs, capacity utilization rates and service levels. Interestingly, we identify the role of spatial capacity (parking) management to fine‐tune the market thickness (transient service availability) in such a two‐sided marketplace. We show that a “capacity‐dependent approximation” can be very close to optimality, and outperforms policies ignoring capacity management. We also demonstrate that this framework can be operationalized in multiple directions, which generates insights concerning matching efficiency, performance comparison between crowd‐sourcing and repositioning, strategic server behaviors and network externalities. Our insights guide the platform and the policy‐maker to embrace “crowd‐sourcing” and “geo‐fencing” technologies for shared‐mobility systems.
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Summary
Many statistical estimators for high-dimensional linear regression are $M$-estimators, formed through minimizing a data-dependent square loss function plus a regularizer. This work considers ...a new class of estimators implicitly defined through a discretized gradient dynamic system under overparameterization. We show that, under suitable restricted isometry conditions, overparameterization leads to implicit regularization: if we directly apply gradient descent to the residual sum of squares with sufficiently small initial values then, under some proper early stopping rule, the iterates converge to a nearly sparse rate-optimal solution that improves over explicitly regularized approaches. In particular, the resulting estimator does not suffer from extra bias due to explicit penalties, and can achieve the parametric root-$n$ rate when the signal-to-noise ratio is sufficiently high. We also perform simulations to compare our methods with high-dimensional linear regression with explicit regularization. Our results illustrate the advantages of using implicit regularization via gradient descent after overparameterization in sparse vector estimation.
The first repeating fast radio burst (FRB), FRB 121102, was found to be associated with a spatially coincident, persistent nonthermal radio source, but the origin of the persistent emission remains ...unknown. In this paper, we propose that the persistent emission is produced via a synchrotron-heating process by multiple bursts of FRB 121102 in a self-absorbed synchrotron nebula. With a population of bursts of the repeating FRB absorbed by the synchrotron nebula, the energy distribution of electrons in the nebula will change significantly. As a result, the spectrum of the nebula will show a hump steadily. For the persistent emission of FRB 121102, the total energy of bursts injecting into the nebula is required to be about 3.3 × 1049 erg, the burst injection age is over 6.7 × 104 yr, the nebula size is ∼0.02 pc, and the electron number is about 3.2 × 1055. We predict that as more bursts inject, the brightness of the nebula would be brighter than the current observation, and meanwhile, the peak frequency would become higher. Due to the synchrotron absorption of the nebula, some low-frequency bursts would be absorbed, which may explain why most bursts were detected above ∼1 GHz.
Background
Sleep disorders are associated with temporomandibular disorders (TMDs). Limited studies have focused on excessive daytime sleepiness (EDS) and its impact on jaw functions in TMD patients.
...Objective
The aim of the present investigation was to identify the impact of EDS on pain and jaw function in TMD patients.
Methods
A total of 338 TMD patients (50 males and 288 females) was included. The Epworth Sleepiness Scale (ESS) was used to classify patients into EDS group (score ≥ 10) and non‐EDS group (score < 10). The Jaw Functional Limitation Scale 8‐item (JFLS‐8) was used to assess the severity of jaw dysfunction. Pain intensity was evaluated using the Visual Analogue Scale (VAS). Anxiety and depression were evaluated using the Generalised Anxiety Disorder 7‐item (GAD‐7) and the Patient Health Questionnaire 9‐item (PHQ‐9). All included patients were diagnosed with pain‐related TMD (PT), intra‐articular TMD (IT) or combined TMD (CT).
Results
Compared with non‐EDS patients, EDS patients exhibited more severe jaw dysfunction, greater pain intensity and higher PHQ‐9 scores (p < .05). Multivariate analyses showed that EDS (B = 3.69), female gender (B = 3.69), and elevated GAD‐7 score (B = 0.73) were significantly associated with an increased score on the JFLS‐8 (p < .05). Moreover, bivariate logistic regression analysis indicated a significant relationship between EDS and PT (OR = 2.70, p = .007).
Conclusion
The presence of EDS was more closely related to PT, but the causal relationship between them needs to be further confirmed. More concern and intervention to alleviate poor sleep quality might be highlighted during the treatment of TMD, especially PT subtype.
The presence of excessive daytime sleepiness was significantly associated with increased odds of pain‐related temporomandibular disorders and a higher score on the jaw functional limitation scale.
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Lactate is closely related to various cellular processes, such as angiogenesis, responses to hypoxia, and macrophage polarization, while regulating natural immune signaling pathways and promoting ...neurogenesis and cognitive function. Lysine lactylation (Kla) is a novel posttranslational modification, the examination of which may lead to new understanding of the nonmetabolic functions of lactate and the various physiological and pathological processes in which lactate is involved, such as infection, tumorigenesis and tumor development. Using liquid chromatography–tandem mass spectrometry (LC‒MS/MS), researchers have identified lactylation in human gastric cancer cells and some other species, but no research on lactylation in human lungs has been reported. In this study, we performed global profiling of lactylation in human lungs under normal physiological conditions, and 724 Kla sites in 451 proteins were identified. After comparing the identified proteins with those reported in human lactylation datasets, 141 proteins that undergo lactylation were identified for the first time in this study. Our work expands the database on human lactylation and helps advance the study on lactylation function and regulation under physiological and pathological conditions.
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Abstract
The physical origin of fast radio bursts (FRBs) remains unclear. Finding multiwavelength counterparts of FRBs can provide a breakthrough for understanding their nature. In this work, we ...perform a systematic search for astronomical transients whose positions are consistent with FRBs. We find an unclassified optical transient AT2020hur (
α
= 01
h
58
m
00.ˢ750 ± 1″,
δ
=
65
°
43
′
00
.″
30
±
1
″
) that is spatially coincident with the repeating FRB 180916B (
α
= 01
h
58
m
00.ˢ7502 ± 2.3 mas,
δ
=
65
°
43
′
00
.″
3152
±
2.3
mas; Marcote et al. 2020). The chance possibility of the AT2020hur–FRB 180916B association is about 0.04%, which corresponds to a significance of 3.5
σ
. We develop a giant flare (GF) afterglow model to fit AT2020hur. Although the GF afterglow model can interpret the observations of AT2020hur, the derived kinetic energy of such a GF is at least three orders of magnitude larger than that of a typical GF, and a lot of fine-tuning and coincidences are required for this model. Another possible explanation is that AT2020hur might consist of two or more optical flares originating from the FRB source, e.g., fast optical bursts produced by the inverse Compton scattering of FRB emission. Besides, AT2020hur is located in one of the activity windows of FRB 180916B, which provides independent support for the association. This coincidence may be due to the optical counterparts being subject to the same periodic modulation as FRB 180916B, as implied by the prompt FRB counterparts. Future simultaneous observations of FRBs and their optical counterparts may help to reveal their physical origin.
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