A new global 1-form in Lyra geometric cosmos model

Dark energy phenomena has inspired lots of investigations on the cosmological constant problems. In order to understand its origin and properties as well as its impacts on universe's evolutions, there are many approaches to modify the well-known General Relativity, such as the Weyl-Lyra Geometry. In the well studied cosmology model within Lyra geometry, there is a problem that the first law of thermodynamics is violated. To unravel this issue, if we use the effective density and pressure in the Lyra cosmology model to preserve the first law of thermodynamics in the cosmos, the former 1-form $(\beta,0,0,0)$ cannot give a proper vacuum behavior. In this paper, the auxiliary 1-form is modified to overcome this difficulty. It can be shown that the complex terms in the field equation derived from the regime of Lyra Geometric$\frac{3}{2}{\phi}^{\mu}{\phi}_{\nu}-\frac{3}{4}{\delta}^{\mu}_{\nu}{\phi}^{\alpha}{\phi}_{\alpha}$with our new 1-form could behave just as the cosmological constant. This work can be regarded as a new exploration on a possible origin of the cosmological constant from a Lyra cosmology model.Comment: 8 pages. Accepted for publication in IJT

Exploring the low redshift universe: two parametric models for effective pressure

Astrophysical observations have put unprecedentedly tight constraints on cosmological theories. The $\Lambda$CDM model, mathematically simple and fits observational data-sets well, is preferred for explaining the behavior of universe. But many basic features of the dark sectors are still unknown, which leaves rooms for various nonstandard cosmological hypotheses. As the pressure of cosmological constant dark energy is unvarying, ignoring contributions from radiation and curvature terms at low redshift, the effective pressure keeps constant. In this paper, we propose two parametric models for non-constant effective pressure in order to study the tiny deviation from $\Lambda$CDM at low redshift. We recover our phenomenological models in the scenarios of quintessence and phantom fields, and explore the behavior of scalar field and potential. We constrain our model parameters with SNe Ia and BAO observations, and detect subtle hints of $\omega_{de}<-1$ from the data fitting results of both models, which indicates possibly a phantom dark energy scenario at present.Comment: 11 pages, 24 figure

Self-Convinced Prompting: Few-Shot Question Answering with Repeated Introspection

While large language models (LLMs) such as ChatGPT and PaLM have demonstrated remarkable performance in various language understanding and generation tasks, their capabilities in complex reasoning and intricate knowledge utilization still fall short of human-level proficiency. Recent studies have established the effectiveness of prompts in steering LLMs towards generating desired outputs. Building on these insights, we introduce a novel framework that harnesses the potential of large-scale pre-trained language models, to iteratively enhance performance of the LLMs. Our framework incorporates three components: \textit{Normal CoT}, a \textit{Convincer}, and an \textit{Answerer}. It processes the output of a typical few-shot chain-of-thought prompt, assesses the correctness of the response, scrutinizes the answer, refines the reasoning, and ultimately produces a new solution. Experimental results on the 7 datasets of miscellaneous problems validate the efficacy of the Self-Convince framework, achieving substantial improvements compared to the baselines. This study contributes to the burgeoning body of research focused on integrating pre-trained language models with tailored prompts and iterative refinement processes to augment their performance in complex tasks

Enhanced oxidation resistance of active nanostructures via dynamic size effect.

A major challenge limiting the practical applications of nanomaterials is that the activities of nanostructures (NSs) increase with reduced size, often sacrificing their stability in the chemical environment. Under oxidative conditions, NSs with smaller sizes and higher defect densities are commonly expected to oxidize more easily, since high-concentration defects can facilitate oxidation by enhancing the reactivity with O2 and providing a fast channel for oxygen incorporation. Here, using FeO NSs as an example, we show to the contrary, that reducing the size of active NSs can drastically increase their oxidation resistance. A maximum oxidation resistance is found for FeO NSs with dimensions below 3.2 nm. Rather than being determined by the structure or electronic properties of active sites, the enhanced oxidation resistance originates from the size-dependent structural dynamics of FeO NSs in O2. We find this dynamic size effect to govern the chemical properties of active NSs

The imitation-innovation link, external knowledge search and China's innovation system

Purpose The authors attempt to answer the basic questions: How is imitation tied to innovation? This question is addressed in the context of China's innovation system in the 2000s where Chinese industrial firms simultaneously implement innovation and imitation strategies in their new product developments. Design/methodology/approach The authors first build on lattice theory and supermodularity theory to provide a rigorous and careful mathematical proof. The authors further conduct the empirical analyses using an original data on Chinese manufacturing firms' innovation and imitation strategies in the development of new products in 2002. Findings This article reveals the complementarity relation between imitation and innovation strategies and identifies external knowledge search as the boundary condition that influences the extent to which two strategies reinforce each other. Research limitations/implications The findings of the imitation-innovation complementarity suggest that imitation is not only an indispensable strategy independent of innovation, but also is vital to the effectiveness of innovation itself. Practical implications The imitation-innovation complementarity finding provides some evidence for the contention that Chinese latecomers exploit the synergies of imitation and innovation, transforming themselves from imitators to innovators and vibrant competitors in the global market (Wu et al., 2016) and, as a result, national innovation system has evolved from a state-sponsored imitation program to the imitation-innovation mixture. Originality/value In contrast to earlier innovation studies in which innovation and imitation are unrelated, this study reveals that imitation complements innovation, and the extent of Chinese firms' external knowledge search affects the complementary relationship between imitation and innovation. These findings add important insights to the innovation management literature and contribute empirical evidence to the interplay of innovation and imitation enhancing national innovation system.© 2020 Emerald Publishing Limited. This manuscript version is made available under the Creative Commons Attribution–NonCommercial 4.0 International (CC BY–NC 4.0) license, https://creativecommons.org/licenses/by-nc/4.0/fi=vertaisarvioitu|en=peerReviewed

Formalize the informal: market segmentation and integration in the formal and informal credit markets in Wenzhou.

In 2012, the Chinese government designated Wenzhou city as a testbed for policy experimentation aimed at institutionalizing informal lending practices. This study investigates how interest rates in the formal and informal credit markets interacted before and after this policy experimentation. Hence, we use the vector autoregression models and ordinary multiple regression method, which is based on the financial repression theory. We document large yield spreads between the formal and informal credit markets in Wenzhou before (2003–2011) and after (2013–2018) the reforms. We find an increase in the responsiveness of the informal sector to the formal sector, after the reforms. We argue that the informal financial system serves as a one-way substitute for the formal financial sector in Wenzhou. An analysis of the transaction-level data suggests thatmaturity, availability of collateralization, loan purpose, and the amount of loans determine informal lending rates. Thus, this study provides important policy implications for reforming China’s financial syste

Pathogenic alpha-synuclein aggregates preferentially bind to mitochondria and affect cellular respiration

Abstract Misfolded alpha-synuclein (αSyn) is a major constituent of Lewy bodies and Lewy neurites, which are pathological hallmarks of Parkinson’s disease (PD). The contribution of αSyn to PD is well established, but the detailed mechanism remains obscure. Using a model in which αSyn aggregation in primary neurons was seeded by exogenously added, preformed αSyn amyloid fibrils (PFF), we found that a majority of pathogenic αSyn (indicated by serine 129 phosphorylated αSyn, ps-αSyn) was membrane-bound and associated with mitochondria. In contrast, only a minuscule amount of physiological αSyn was mitochondrial bound. In vitro, αSyn PFF displayed a stronger binding to purified mitochondria than did αSyn monomer, revealing a preferential mitochondria binding by aggregated αSyn. This selective mitochondrial ps-αSyn accumulation was confirmed in other neuronal and animal αSyn aggregation models that do not require exogenously added PFF and, more importantly, in postmortem brain tissues of patients suffering from PD and other neurodegenerative diseases with αSyn aggregation (α-synucleinopathies). We also showed that the mitochondrial ps-αSyn accumulation was accompanied by defects in cellular respiration in primary neurons, suggesting a link to mitochondrial dysfunction. Together, our results show that, contrary to physiological αSyn, pathogenic αSyn aggregates preferentially bind to mitochondria, indicating mitochondrial dysfunction as the common downstream mechanism for α-synucleinopathies. Our findings suggest a plausible model explaining the formation and the peculiar morphology of Lewy body and reveal that disrupting the interaction between ps-αSyn and the mitochondria is a therapeutic target for α-synucleinopathies.https://deepblue.lib.umich.edu/bitstream/2027.42/148288/1/40478_2019_Article_696.pd