Static Universe Research Articles

Cosmological models in scale-independent energy-momentum squared gravity

Scale-independent EMSG is a particular model of energy–momentum squared gravity (EMSG) in which the new terms in the Einstein field equations arising from the EMSG theory enter with the same power as the usual terms from Einstein–Hilbert part of the action. However, the model violates the local energy–momentum conservation and matter-current conservation in general and hence, permits a process of matter creation/annihilation in an expanding universe. Consequently, the scale factor dependencies of the energy densities are modified by the dimensionless model parameter α. We revisit some nostalgias such as static universes and de Sitter/steady state universes. We reproduce the original ones, moreover, present some novelties, e.g., a spatially flat static universe, de Sitter expansion by negative vacuum energy, steady state universes in the presence of arbitrary fluids with constant equation of state (EoS) parameter other than dust, etc. We also investigate the possible dynamics of dust dominated and radiation dominated universes. Depending on the value of α, dust/radiation dominated universe exhibits power-law accelerated/decelerated expansion, corresponds to a steady state model or may end in a big rip. In the framework of anisotropic cosmology, we reproduce Barrow’s quiescent universe in the presence of stiff fluid and extend it to fluids with arbitrary constant EoS parameter. We also relax the condition for isotropic initial singularity (big bang) owing to that EMSG effectively allows ultra-stiff EoS parameters.

Transport Inequality in Today’s Cities at the Intersection of Mobility and Inequality

One aspect of social inequality in today’s cities concerns transport inequality. This simply refers to the transport advantages of the rich compared to the poor (Gebresselassie & Sanchez, 2019). The transport inequality intersects with other forms of marginalization as well, based on gender, age, disability, and ethnicity. Yet for the mobile or kinetic elite (Andreotti, Le Gallès, & Moreno-Fuentes, 2013), all places and transport means are readily available. Furthermore, transport-related mega-projects accentuate the existing social inequalities of the neoliberal city. However, urban policy makers have begun to realize the importance of transport inequality and develop inclusive policies, such as “accessibility planning” in the UK (Lucas, 2012). Urban citizens are also forming mobility justice movements to protest against the increasing transport costs, as in Latin America (Díaz Pabón & Palacio Ludeña, 2021) and France. The encompassing mobility research is largely connected to social and environmental sustainability ideals. Hence, this paper will study the relationship between mobility and inequality through a thematic analysis of approximately 100 publications that were selected with certain keywords from the results of Web of Science searches, a few books, institutional reports and other sources. This literature review shows that transport inequalities are a reflection of the capitalist system and one of the main sources of social conflict in contemporary societies. Against the solution suggestions that range from rehabilitating the system to revolution as a process in the related literature, formation of place-based solutions that take into consideration both universal and local conditions is suggested in this study.

Assessment of Selective and Universal Screening for Suicide Risk in a Pediatric Emergency Department.

According to National Patient Safety Goal 15.01.01, all individuals being treated or evaluated for behavioral health conditions as their primary reason for care in hospitals and behavioral health care organizations accredited by The Joint Commission should be screened for suicide risk using a validated tool. Existing suicide risk screens have minimal or no high-quality evidence of association with future suicide-related outcomes. To test the association between results of the Ask Suicide-Screening Questions (ASQ) instrument in a pediatric emergency department (ED), implemented through selective and universal screening approaches, and subsequent suicide-related outcomes. In this retrospective cohort study at an urban pediatric ED in the United States, the ASQ was administered to youths aged 8 to 18 years with behavioral and psychiatric presenting problems from March 18, 2013, to December 31, 2016 (selective condition), and then to youths aged 10 to 18 years with medical presenting problems (in addition to those aged 8-18 years with behavioral and psychiatric presenting problems) from January 1, 2017, to December 31, 2018 (universal condition). Positive ASQ screen at baseline ED visit. The main outcomes were subsequent ED visits with suicide-related presenting problems (ie, ideation or attempts) based on electronic health records and death by suicide identified through state medical examiner records. Association with suicide-related outcomes was calculated over the entire study period using survival analyses and at 3-month follow-up for both conditions using relative risk. The complete sample was 15003 youths (7044 47.0%] male; 10209 [68.0%] black; mean [SD] age, 14.5 [3.1] years at baseline). The follow-up for the selective condition was a mean (SD) of 1133.7 (433.3) days; for the universal condition, it was 366.2 (209.2) days. In the selective condition, there were 275 suicide-related ED visits and 3 deaths by suicide. In the universal condition, there were 118 suicide-related ED visits and no deaths during the follow-up period. Adjusting for demographic characteristics and baseline presenting problem, positive ASQ screens were associated with greater risk of suicide-related outcomes among both the universal sample (hazard ratio, 6.8 [95% CI, 4.2-11.1]) and the selective sample (hazard ratio, 4.8 [95% CI, 3.5-6.5]). Positive results of both selective and universal screening for suicide risk in pediatric EDs appear to be associated with subsequent suicidal behavior. Screening may be a particularly effective way to detect suicide risk among those who did not present with ideation or attempt. Future studies should examine the impact of screening in combination with other policies and procedures aimed at reducing suicide risk.Appeared originally in JAMA Netw Open 2019; 2:e1914070.

Tidal emersion effects on universal metrics, elemental contents, and health conditions of Pacific oyster (Crassostrea gigas) on artificial reefs in Yellow River Delta, China

Oysters form natural reefs and are important coastal foundation species that provide a wide range of ecosystem services. Clarification of the mechanisms by which tidal emersion affects oyster reef performance will help guide and direct future oyster reef restoration efforts. In the present study, we constructed artificial Pacific oyster (Crassostrea gigas) reefs in the coastal zones of the Yellow River Delta and quantified the effects of tidal emersion on the growth, density, biomass, element (carbon, nitrogen, phosphorus) content within tissues, and health conditions of oysters. The results showed that temperature change driven by the tidal emersion effect was one of the major forces affecting reef performance. In the experimental field, fully immersed oysters performed better than partially exposed ones in terms of growth and density. The mean biomass of the fully immersed oysters was 2.88-fold higher than that of the partially exposed oysters (p < 0.05). However, we found that tidal emersion had no significant effect on the carbon, nitrogen, and phosphorus content within oyster tissues. Oyster health condition revealed by the biochemical marker and whole-genome gene expression analyses demonstrated that the oysters partially exposed to air presented enhanced oxidative and lipid metabolism and were forced to allocate metabolic energy towards defense against stress rather than growth, which suggested sub-optimal health conditions. Overall, the study indicated that full immersion is optimal for oyster reef restoration in the experimental field. The results of this research will provide future conservationists, aquaculturists, and other specialists with a better understanding of tidal emersion effects on the success of oyster reef restoration to achieve region-specific restoration goals and improve protection of the coastal environment.

Quasicircles and quasiperiodic surfaces in pseudo-hyperbolic spaces

We study in this paper quasiperiodic maximal surfaces in pseudo-hyperbolic spaces and show that they are characterised by a curvature condition, Gromov hyperbolicity or conformal hyperbolicity. We show that the limit curves of these surfaces in the Einstein Universe admits a canonical quasisymmetric parametrisation, while conversely every quasisymmetric curve in the Einstein Universe bounds a quasiperiodic surface in such a way that the quasisymmetric parametrisation is a continuous extension of the uniformisation; we give applications of these results to asymptotically hyperbolic surfaces, rigidity of Anosov representations and a version of the universal Teichmüller space.

Stability Analysis of the Inhomogeneous Perturbed Einstein Universe in Energy–Momentum Squared Gravity

The main objective of this article is to examine the stability of Einstein static universe using inhomogeneous perturbations in the context of energy–momentum squared gravity. For this purpose, we used FRW spacetime with perfect matter distribution and formulated static as well as perturbed field equations. We took a minimal model of this theory to investigate the stable regions of the Einstein universe for conserved and non-conserved energy–momentum tensors. We found that stable modes of the Einstein universe appeared in both conserved and non-conserved cases for all values of the equation of state and model parameters corresponding to both open and closed cosmic models. We found that stable solutions in this modified theory were obtained for a broader ω-region compared to other modified theories.

Assessing urban micro-climates with vertical and horizontal building morphological cutting deep transfer learning neural networks

The weather condition is the major external factor that affects annual building energy usage and determines the reliability of building energy assessment and simulation models. In city-scale studies, buildings’ energy assessment and simulation rely on one universal Typical Meteorological Year weather condition for the whole city. However, due to the unique morphological features and environmental conditions, each location in a city has its unique microclimate conditions. To predict and simulate more accurate and realistic building energy usage, this study developed a deep transfer learning neural network that can integrate morphological features and frontal areas' depth distribution. The frontal areas are represented as stripes with different cutting methods to reflect the impact of depth distribution. To validate the proposed method, this study conducted an on-campus experiment with a wireless sensing system. The results suggest that the proposed stripe-enabled geometry segmentation method can effectively improve the accuracy of local microclimate condition prediction. Also, the combined vertical and horizontal cutting method shows the highest performance.

Tight Bounds and the Role of Optical Loss in Polariton-Mediated Near-Field Heat Transfer

We introduce an analytical framework for near-field radiative heat transfer in bulk plasmonic and polar media. Considering material dispersion, we derive a closed-form expression for the radiative thermal conductance, which disentangles the role of optical loss from other material dispersion characteristics, such as the spectral width of the Reststrahlen band in polar dielectrics, as well as from the temperature. We provide a universal condition for maximizing heat transfer that defines the optimal interplay between a material's optical loss and polariton resonance frequency, based on which we introduce tight bounds to near-field heat transfer. With this formalism, one can quantitatively evaluate all polaritonic materials in terms of their performance as near-field thermal emitters.

A frame based approach to computing symmetries with non-trivial isotropy groups

A frame approach to determining the most general solution admitting a desired symmetry group has previously been examined in Riemannian and teleparallel geometries with some success. In teleparallel geometries, one must determine the general form of the frame and spin connection to generate a general solution admitting the desired symmetry group. Current approaches often rely on the use of the proper frame, where the spin connection is zero. However, this leads to particular theoretical and practical problems. In this paper, we introduce an entirely general approach to determining the most general Riemann–Cartan geometries that admit a given symmetry group and apply these results to teleparallel geometries. To illustrate the approach, we determine the most general geometries, with the minimal number of arbitrary functions, for particular choices of symmetry groups with dimension one, three, six, and seven. In addition, we rigorously show how the teleparallel analog of the Robertson–Walker, de Sitter, and Einstein static spacetimes can be determined.

Equation of state and Joule-Thomson expansion for the FRW universe in the brane world scenario

We study the thermodynamic properties of the Friedmann-Robertson-Walker (FRW) universe in the brane world scenario, concentrating on the Randall-Sundrum II model. From the first law of thermodynamics for the FRW universe, we find that the work density W can be identified with the thermodynamic pressure P. We construct the equation of state P=P(V,T) for the FRW universe in the brane world scenario, which does not show P-V phase transition. We further study the Joule-Thomson expansion of the FRW universe, and derive the Joule-Thomson coefficient, which has an inversion point that is affected by the brane tension. These results could provide new ways to test the brane world scenario and extra dimension.

열반 적정과 엘리엇의 『네 사중주』

Four Quartets expresses suffering as the universal condition of human beings and seeks a way to escape from it through the theme of time. By mixing individual sensibility and intelligence with thoughts of Christianity, Buddhism, and Hinduism, the poem atriculates the themes in phrases and sentences with various connotative and contradictory meanings. Typical examples include phrases such as “The first world”, “Rose garden”, “Midwinter spring”, “Zero summer”, “A white light still and moving”, and a sentence “At the still point of the turning world. Neither flesh nor fleshless; / Neither from nor towards; at the still point, there the dance is, / But neither arrest nor movement.” These connotative and contradictory meanings would be hard to understand by common readers. Foregrounding Nirvana Samatha in Buddhism as a main subject of Four Quartet, this article delves into the sub-themes such as time(world of phenomenon), eternity, and salvation(redeption). As a Christian poet, Eliot presents Christ/God as the redeemer of humanity in diverse and, even, contradictory ways in the poem. The Lord becomes the end point toward which sufferings human being strive to save themselves, and the archytype of human redemption. Ways to go toward the Lord include repentance, prayer, emptying, humility, and practicing love. Buddhism’s nirvana is much similar to this, but seems a little different from Christianity in the method of seeking. Nirvana is based on internal inquiry. But Both of them are ultimately equal in that they are based on salvation for the eternal happiness of mankind. The ending of the poem, where a fire and a rose become one, visually signifies that humanity can be redeemed by empting herself and loving each other genuinely, and exemplies a poetic expression that unites the religious redemption of the East and the West.

Reconstruction of f(Q,T) Lagrangian for various cosmological scenario

The variety of theories that can account for the dark energy phenomenon encourages current research to concentrate on a more in-depth examination of the potential impacts of modified gravity on both local and cosmic scales. We discuss some cosmological reconstruction in f(Q,T) cosmology (where Q is the non-metricity scalar, and T is the trace of the energy-momentum tensor) corresponding to the evolution background in Friedmann-Laîmatre-Robertson-Walker (FLRW) universe. This helps us to determine how any FLRW cosmology can arise from a specific f(Q,T) theory. We use the reconstruction technique to derive explicit forms of f(Q,T) Lagrangian for the different kinds of matter sources and Einstein's static universe. We also formulate the models using several ansatz forms of the f(Q,T) function for p=ωρ. We demonstrate that several classes of f(Q,T) theories admit the power-law and de-Sitter solutions in some ranges of ω. Additionally, we reconstruct the cosmological model for the scalar field with a specific form of f(Q,T). These new models with cosmological inspiration may impact gravitational phenomena at other cosmological scales.

Development of real-time PCR method for rapid and accurate detection of Centipedes (Scolopendra mutilans) in food.

Centipedes contain pharmacologically active compounds used as important medicinal material. However, the poisons produced by centipedes can cause human diseases; therefore, its use as a food ingredient is prohibited. This is the first report to develop a real-time PCR method for detection of centipedes. The primer and probe targeting the mitochondrial cytochrome c oxidase subunit 1 (COI) gene were newly designed. The specificity was verified using ten species and was confirmed to amplify only the centipede species. The real-time PCR method exhibited good linearity with a high-determination coefficient (R 2 = 0.999) and a detection limit was 0.001ng. The performance of our method was also verified using five real-time PCR platforms under Universal and Fast PCR conditions. Finally, its applicability to processed food was evaluated using binary insect mixtures, and at least 0.1% of centipedes was detected. Therefore, our method can specifically and sensitively detect centipedes in food, contributing to food safety.

Fully planar laser-generated focused ultrasound transmitter

Laser-generated focused ultrasound (LGFU) has been attracting great interest due to its great potential in high-resolution ultrasound imaging and high-precision therapy. However, the existing methods suffer from distinct issues such as complicated film coating control, difficult technical transfer toward device miniaturization, and limited output acoustic pressure as well as operation condition. In order to explore an effective solution for LGFU working under more universal excitation conditions with a single nanosecond pulsed laser, a new strategy based on directly patterning the flat photoacoustic (PA) source is developed in this paper. For proof of concept demonstration, a planar PA transmitter is constructed using a chromium mask with transparent rings as the substrate. Considering the broadband nature of the generated PA signal, the effects of the ring structure on focusing characteristics are explored experimentally for the first time. Besides, its capability to provide a X-wave like focused acoustic field with output pressure at MPa level and a small lateral size of several hundred micrometers yet large focal depth of a few centimeters has been successfully demonstrated, which would benefit applications requiring large ultrasound working distance. Based on the same concept, various methods can also be involved to increase its adaptability and applicability further. • A planar ring-shape photoacoustic transmitter is used for focused ultrasound. • The effects of the ring parameters on the focusing characteristics are revealed. • X-wave like focused acoustic field with extended focal depth has been demonstrated.

Insights of Lipid Vesicular and Particulate Carrier Mediated Approach for Acne Management.

Acne vulgaris is a universal multifactorial human skin condition of the pilosebaceous units. Although acne majorly prevails in teenagers, it is neither restricted to age group nor gender. Multifarious causative factors like Propionibacterium acnes, dysregulated sebum secretion, and androgens play an integral role in the manifestation of acne. Though abundant new chemical entities are convenient for acne therapy, none can treat this condition without compromising patient compliance. Furthermore, accessible treatment prevents the ailment and alleviates signs and symptoms with no absolute cure. So presently, despite the variety of topical formulations, the current market demands an ideal remedy to fulfill the unmet need for acne management. Extensive research has proved the upper hand of novel carrier systems over conventional formulations by substantially improving efficacy and eliminating unpleasant side effects. Lipid-based vesicular and particulate systems are promising prospects due to their closeness to the intrinsic structure of the skin, which offer delivery of the actives in a more desirable approach. This review underlines the practicability and superiority of liposomes, niosomes, transfersomes, ethosomes, cubosomes, solid lipid nanoparticles, and nanostructured lipid carriers over conventional therapies for acne. The review also highlights acne product market survey and available conventional as well as novel formulations portraying their scope in the market. In a nutshell, lipid-based vesicular and particulate systems prevail as a propitious modality for treating acne vulgaris as they conduce better penetrability, localized action, and reduce adverse effects. These systems have the ability to open a window of opportunities for effective acne alleviation.

Smooth Compactifications of the Abel-Jacobi Section

Abstract For $\theta $ a small generic universal stability condition of degree $0$ and A a vector of integers adding up to $-k(2g-2+n)$ , the spaces $\overline {\mathcal {M}}_{g,A}^\theta $ constructed in [AP21, HMP+22] are observed to lie inside the space $\textbf {Div}$ of [MW20], and their pullback under $\textbf {Rub} \to \textbf {Div}$ of loc. cit. to be smooth. This provides smooth and modular modifications $\widetilde {\mathcal {M}}_{g,A}^\theta $ of $\overline {\mathcal {M}}_{g,n}$ on which the logarithmic double ramification cycle can be calculated by several methods.

Improving Graph Neural Network Expressivity via Subgraph Isomorphism Counting.

While Graph Neural Networks (GNNs) have achieved remarkable results in a variety of applications, recent studies exposed important shortcomings in their ability to capture the structure of the underlying graph. It has been shown that the expressive power of standard GNNs is bounded by the Weisfeiler-Leman (WL) graph isomorphism test, from which they inherit proven limitations such as the inability to detect and count graph substructures. On the other hand, there is significant empirical evidence, e.g. in network science and bioinformatics, that substructures are often intimately related to downstream tasks. To this end, we propose "Graph Substructure Networks" (GSN), a topologically-aware message passing scheme based on substructure encoding. We theoretically analyse the expressive power of our architecture, showing that it is strictly more expressive than the WL test, and provide sufficient conditions for universality. Importantly, we do not attempt to adhere to the WL hierarchy; this allows us to retain multiple attractive properties of standard GNNs such as locality and linear network complexity, while being able to disambiguate even hard instances of graph isomorphism. We perform an extensive experimental evaluation on graph classification and regression tasks and obtain state-of-the-art results in diverse real-world settings including molecular graphs and social networks.

Художественный образ американского Среднего Запада в романах У. Гэсса и Д. Ф. Уоллеса как метафора человеческого существования

The article deals with the image of the U.S. Midwest and its significance as the setting ofWilliam Н.Gass’s and David FosterWallace’s philosophical novels. The analysis of the artistic details rep-resenting the everyday life of the characters, together with the studies of the works by prominent philoso-phers and historians, lead the authors of the article to the conclusion that for both writers the Midwest ap-pears to be more than a geographical location, turning into an important symbol of human life as areality created and defined by language. In the analyzed novels, the living conditions in the Midwest, traditionally perceived as the most typical for America, become a philosophical reflection of the general conditions of human existence as immersion in the world created by language. Emptiness and loneliness, characteristic of the Midwestern life due to the geographical and historical circumstances under which the region has devel-oped, are considered by Gass and Wallace as universal conditions of human existence. A person, thrown into the material emptiness of an objectively existing world, tries to seek salvation with the help of language as the only philosophical tool at his disposal. The characters in the novels try to fill the void of their existence with words, thus striving to give shape and meaning to reality. But limited by the framework of language as a pragmatically conditioned reflection of the material facts, a person does not find an opportunity to reach the sphere of the metaphysical and the ethical, and, as a result, the external boredom of the provincial Midwest lifestyle turns into inner emptiness as the dominant feeling of the characters in the novels. Gass does not see an opportunity for his characters to escape from the trap set by the language-dominated world, while Wallace is actively looking for the ways to overcome the adverse circumstances through an ethical action as the opposite of the word.

Development of reverse-transcription loop-mediated isothermal amplification assays for point-of-care testing of human influenza virus subtypes H1N1 and H3N2.

Influenza A virus (IAV) is the most widespread pathogen causing human respiratory infections. Although polymerase chain reaction (PCR)-based methods are currently the mostcommonly used tools for IAV detection, PCR is not ideal for point-of-care testing. In thisstudy, we aimed to develop a more rapid and sensitive method than PCR-based tools todetect IAV using loop-mediated isothermal amplification (LAMP) technology. We designedreverse-transcriptional (RT)-LAMP primers targeting the hemagglutinin gene. RNAs fromreference H1N1 and H3N2 showed specific RT-LAMP signals with the designed primers.We optimized the reaction conditions and developed universal reaction conditions for bothLAMP assays. Under these conditions, the detection limit was 50 copies for both RT-LAMPassays. There was no non-specific signal to 19 non-IAV respiratory viruses, such as influenza B virus, coronaviruses, and respiratory syncytial viruses. Regarding the reaction time, apositive signal was detected within 25 min after starting the reaction. In conclusion, ourRT-LAMP assay has high sensitivity and specificity for the detection of the H1 and H3 subtypes, making it suitable for point-of-care IAV testing.

Social pathologies of informational privacy

Social pathologies of informational privacy