Hasil untuk "History"

Jacob Haqq-Misra

Evidence for fluvial features and standing liquid water indicate that Mars was a warmer and wetter place in its past; however, climate models have historically been unable to produce conditions to yield a warm early Mars under the faint young sun. Some models invoke thick greenhouse atmospheres to produce continuously warm conditions, but others have argued that available geologic evidence is more consistent with short-duration and transient warming events on an otherwise cold Mars. One possibility of harmonizing these perspectives is that early Mars experienced climate limit cycles that caused the climate to oscillate between short periods of warmth and prolonged periods of glaciation, due to modulation of greenhouse warming by the carbonate-silicate cycle. This study suggests that episodic limit cycling during the Noachian and Hesperian periods provides a hypothetical explanation for the timing and formation of fluvial features on Mars. A schematic time-forward trajectory of the full history of Mars is calculated using an energy balance climate model, which includes an active carbonate-silicate cycle, instellation changes due to the sun's main sequence evolution, variations in the obliquity of Mars, and supplemental warming from additional greenhouse gases beyond carbon dioxide alone. These calculations demonstrate the viability of a climate history for Mars involving episodic limit cycling to enable the formation of the valley networks at 4.1-3.5 Ga and delta features at 3.3-3.0 Ga, interspersed with cold stable climates and ending in the late Amazonian in a carbon dioxide condensation regime. This schematic climate trajectory provides a plausible narrative that remains consistent with available geologic data, and further exploration of warming mechanisms for the climate of Mars should consider the possibility of episodic transient events driven by carbonate-silicate limit cycling.

Zewei Wu, Andrey Kravtsov, Harley Katz

We present model calculations of the reionization history of hydrogen using star formation histories, computed with a galaxy formation model which reproduces properties of local dwarf galaxies and UV luminosity functions of galaxies at $z=5-16$. We use the ionizing photon density functions predicted by the model along with different models for the escape fraction of ionizing photons, $f_{\rm esc}$, to study the effects of ionizing photons from faint galaxies and different assumptions about $f_{\rm esc}$ on the evolution of hydrogen ionized fraction with redshift, $Q_{\rm HII}(z)$. We show that accounting for the contribution of faint galaxies with UV luminosities $M_{1500}>-13$, and with a constant ionizing photon escape fraction of $f_{\rm esc}=0.1$ results in the hydrogen reionization history consistent with all current observational constraints. Comparing results of the $f_{\rm esc}=0.1$ model and two alternative models shows that the model with a strong luminosity dependence of $f_{\rm esc}$, which assigns high $f_{\rm esc}$ to faint galaxies, results in early reionization inconsistent with observational constraints. However, the model in which $f_{\rm esc}$ follows a universal redshift-independent correlation with the recent maximum specific star formation rate, motivated by the results of the SPHINX galaxy formation simulation, results in the reionization history in good agreement with existing observational constraints, even though this model produces a sizeable ionized hydrogen fraction of $Q_{\rm HII}\approx 0.15-0.2$ at redshifts $z=8-12$. Our results show that the relative contribution of faint dwarf galaxies to reionization depends sensitively on assumptions about the escape fraction for galaxies of different luminosities, and that this is the main source of uncertainty in modeling hydrogen reionization.

Arpana Pandit, Biswash Sapkota, Nishan Poudel et al.

Studies have shown that the knowledge of diabetes among adults in Nepal is poor. This study aimed to evaluate the knowledge regarding diabetes in secondary level (i.e., Grade 11 and 12) science students. We assessed the student's knowledge and awareness regarding diabetes through self-administered questionnaires consisting of 26 questions associated with symptoms, treatment, prevention, and complications of diabetes. Eight higher secondary schools with science streams in Kaski district were selected. A total of 561 students were in the study. Almost all the students (96%) expressed that they had heard about diabetes but only 37% of students correctly indicated the risk factors of it. One-fourth of the total students were able to distinguish between type 1 and type 2 diabetes. Only 13% of students knew about the third type of diabetes, i.e., gestational diabetes. Nearly 47% of students had a wrong perception that diabetes cannot be prevented or delayed. Though early diagnosis of diabetes is essential to prevent complications, only 61% knew about this fact. In our study, 26% of respondents had a family history of diabetes. Overall, 53% showed poor knowledge, 44% showed average knowledge and only 3% showed good knowledge regarding diabetes. The study showed that the gender of the participants and the type of college (government or private) they were studying had no significant relationship with the knowledge level regarding diabetes. However, family history and educational level (class 11 or 12) showed a positive relationship with the level of knowledge regarding diabetes. Students had good knowledge regarding the symptoms of diabetes but had poor knowledge about risk factors, complications, and prevention strategies for diabetes. Overall diabetes knowledge was inadequate in the students, indicating that there is a necessity for urgent action to enhance students' knowledge regarding diabetes.

Nick Collins, Mick Grierson

As future musical AIs adhere closely to human music, they may form their own attachments to particular human artists in their databases, and these biases may in the worst case lead to potential existential threats to all musical history. AI super fans may act to corrupt the historical record and extant recordings in favour of their own preferences, and preservation of the diversity of world music culture may become even more of a pressing issue than the imposition of 12 tone equal temperament or other Western homogenisations. We discuss the technical capability of AI cover software and produce Taylor's Versions of famous tracks from Western pop history as provocative examples; the quality of these productions does not affect the overall argument (which might even see a future AI try to impose the sound of paperclips onto all existing audio files, let alone Taylor Swift). We discuss some potential defenses against the danger of future musical monopolies, whilst analysing the feasibility of a maximal 'Taylor Swiftication' of the complete musical record.

Qi Xu, Yuyuan Gao, Jiangrong Shen et al.

Spiking neural networks (SNNs) serve as one type of efficient model to process spatio-temporal patterns in time series, such as the Address-Event Representation data collected from Dynamic Vision Sensor (DVS). Although convolutional SNNs have achieved remarkable performance on these AER datasets, benefiting from the predominant spatial feature extraction ability of convolutional structure, they ignore temporal features related to sequential time points. In this paper, we develop a recurrent spiking neural network (RSNN) model embedded with an advanced spiking convolutional block attention module (SCBAM) component to combine both spatial and temporal features of spatio-temporal patterns. It invokes the history information in spatial and temporal channels adaptively through SCBAM, which brings the advantages of efficient memory calling and history redundancy elimination. The performance of our model was evaluated in DVS128-Gesture dataset and other time-series datasets. The experimental results show that the proposed SRNN-SCBAM model makes better use of the history information in spatial and temporal dimensions with less memory space, and achieves higher accuracy compared to other models.

Grace Gomez Felix Gomez, Mei Wang, Zasim A. Siddiqui et al.

Abstract Background Decreased salivary secretion is not only a risk factor for carious lesions in Sjögren’s disease (SD) but also an indicator of deterioration of teeth with every restorative replacement. This study determined the longevity of direct dental restorations placed in patients with SD using matched electronic dental record (EDR) and electronic health record (EHR) data. Methods We conducted a retrospective cohort study using EDR and EHR data of Indiana University School of Dentistry patients who have a SD diagnosis in their EHR. Treatment history of patients during 15 years with SD (cases) and their matched controls with at least one direct dental restoration were retrieved from the EDR. Descriptive statistics summarized the study population characteristics. Cox regression models with random effects analyzed differences between cases and controls for time to direct restoration failure. Further the model explored the effect of covariates such as age, sex, race, dental insurance, medical insurance, medical diagnosis, medication use, preventive dental visits per year, and the number of tooth surfaces on time to restoration failure. Results At least one completed direct restoration was present for 102 cases and 42 controls resulting in a cohort of 144 patients’ EDR and EHR data. The cases were distributed as 21 positives, 57 negatives, and 24 uncertain cases based on clinical findings. The average age was 56, about 93% were females, 54% were White, 74% had no dental insurance, 61% had public medical insurance, < 1 preventive dental visit per year, 94% used medications and 93% had a medical diagnosis that potentially causes dry mouth within the overall study cohort. About 529 direct dental restorations were present in cases with SD and 140 restorations in corresponding controls. Hazard ratios of 2.99 (1.48–6.03; p = 0.002) and 3.30 (1.49–7.31, p-value: 0.003) showed significantly decreased time to restoration failure among cases and positive for SD cases compared to controls, respectively. Except for the number of tooth surfaces, no other covariates had a significant influence on the survival time. Conclusion Considering the rapid failure of dental restorations, appropriate post-treatment assessment, management, and evaluation should be implemented while planning restorative dental procedures among cases with SD. Since survival time is decreased with an increase in the number of surfaces, guidelines for restorative procedures should be formulated specifically for patients with SD.

Krisztina Kállai

.

Huanqing Chen, Joshua Speagle, Keir K. Rogers

Understanding the entire history of the ionization state of the intergalactic medium (IGM) is at the frontier of astrophysics and cosmology. A promising method to achieve this is by extracting the damping wing signal from the neutral IGM. As hundreds of redshift $z>6$ quasars are observed, we anticipate determining the detailed time evolution of the ionization fraction with unprecedented fidelity. However, traditional approaches to parameter inference are not sufficiently accurate. We assess the performance of a simulation-based inference (SBI) method to infer the neutral fraction of the universe from quasar spectra. The SBI method adeptly exploits the shape information of the damping wing, enabling precise estimations of the neutral fraction $\left<x_{\rm HI}\right>_{\rm v}$ and the wing position $w_p$. Importantly, the SBI framework successfully breaks the degeneracy between these two parameters, offering unbiased estimates of both. This makes the SBI superior to the traditional method using a pseudo-likelihood function. We anticipate that SBI will be essential to determine robustly the ionization history of the Universe through joint inference from the hundreds of high-$z$ spectra we will observe.

Marc Hellmuth, Peter F. Stadler

Most genes are part of larger families of evolutionary related genes. The history of gene families typically involves duplications and losses of genes as well as horizontal transfers into other organisms. The reconstruction of detailed gene family histories, i.e., the precise dating of evolutionary events relative to phylogenetic tree of the underlying species has remained a challenging topic despite their importance as a basis for detailed investigations into adaptation and functional evolution of individual members of the gene family. The identification of orthologs, moreover, is a particularly important subproblem of the more general setting considered here. In the last few years, an extensive body of mathematical results has appeared that tightly links orthology, a formal notion of best matches among genes, and horizontal gene transfer. The purpose of this chapter is the broadly outline some of the key mathematical insights and to discuss their implication for practical applications. In particular, we focus on tree-free methods, i.e., methods to infer orthology or horizontal gene transfer as well as gene trees, species trees and reconciliations between them without using \emph{a priori} knowledge of the underlying trees or statistical models for the inference of phylogenetic trees. Instead, the initial step aims to extract binary relations among genes.

Jacobo Lopez Felipe

El presente artículo plantea un recorrido sobre cómo se ha abordado e investigado el auge y consolidación de vox, la formación de extrema derecha que desde 2018 ha penetrado en las instituciones del Estado jugando un papel destacado en la agenda política de los distintos niveles de gobierno. En este sentido, se ponen de relieve las publicaciones más importantes tanto de académicos como de personajes públicos que se han aproximado a este fenómeno, con dispares niveles de rigurosidad, contribuyendo al conocimiento colectivo sobre las causas y la naturaleza del éxito relámpago de la formación de Santiago Abascal.

Zhenhua Dong, Zhe Wang, Jun Xu et al.

Soon after the invention of the Internet, the recommender system emerged and related technologies have been extensively studied and applied by both academia and industry. Currently, recommender system has become one of the most successful web applications, serving billions of people in each day through recommending different kinds of contents, including news feeds, videos, e-commerce products, music, movies, books, games, friends, jobs etc. These successful stories have proved that recommender system can transfer big data to high values. This article briefly reviews the history of web recommender systems, mainly from two aspects: (1) recommendation models, (2) architectures of typical recommender systems. We hope the brief review can help us to know the dots about the progress of web recommender systems, and the dots will somehow connect in the future, which inspires us to build more advanced recommendation services for changing the world better.

Karim Hammou

What were the aspirations of women who began a rapping career in 1990s France? Were they looking to make it in a male-dominated world? To leave behind a dominated social position and enjoy an artist’s life? To assert the public existence of postcolonial minorities? Based primarily on life narratives, this article analyses the social mobility of female French rappers in the 1990s. It shows the importance of considering both subjective and objective career experiences, as well as the manifold power relations informing trajectories within a social space whose hierarchies are multidimensional. An often unseen dimension in the analysis of artistic careers, the transformations of social hierarchies from childhood to adulthood, and by extension age relations, are crucial here. At odds with the commonplace assumption that women get into male-dominated rap artist careers to subvert the gender order, this study shows that for a majority of these women, rap works as a generational matrix of politicization in which the experience of territorial and ethno-racial discriminations is key. As they grow older, however, this politicization contributes to denaturalizing new social hierarchies, starting with gender hierarchies. The impact of power relations is notable in both subjective and objective career experiences. Subjectively, the taste for rap and the transition to its practice are part of a politicization of inequalities which is perceived as a “generational” experience, which can be transferred from one type of inequality to the next over the course of a career or retrospectively played down as “teenage revolt”. Objectively, age relations redefine gender relations by exacerbating the double bind to which female rappers are confronted throughout their careers, during which the main turning points occur from childhood to adulthood. Still, for most of these women, the practice of rap contributes to an upward social mobility, particularly in comparison to their parents, most of whom are working-class and/or members of racialized minorities, and who have often performed subordinate jobs with demanding working hours.

Yevgeny Tsodikovich, Xavier Venel, Anna Zseleva

We study zero-sum repeated games where the minimizing player has to pay a certain cost each time he changes his action. Our contribution is twofold. First, we show that the value of the game exists in stationary strategies, depending solely on the previous action of the minimizing player, not the entire history. We provide a full characterization of the value and the optimal strategies. The strategies exhibit a robustness property and typically do not change with a small perturbation of the switching costs. Second, we consider a case where the minimizing player is limited to playing simpler strategies that are completely history-independent. Here too, we provide a full characterization of the (minimax) value and the strategies for obtaining it. Moreover, we present several bounds on the loss due to this limitation.

Rachel C. Zhang, Bing Zhang

The redshift distribution of fast radio bursts (FRBs) is not well constrained. The association of the Galactic FRB 200428 with the young magnetar SGR 1935+2154 raises the working hypothesis that FRB sources track the star formation history of the universe. The discovery of FRB 20200120E in association with a globular cluster in the nearby galaxy M81, however, casts doubts on such an assumption. We apply the Monte Carlo method developed in a previous work to test different FRB redshift distribution models against the recently released first CHIME FRB catalog in terms of their distributions in specific fluence, external dispersion measure ($\rm DM_E$), and inferred isotropic energy. Our results clearly rule out the hypothesis that all FRBs track the star formation history of the universe. The hypothesis that all FRBs track the accumulated stars throughout history describes the data better but still cannot meet both the $\rm DM_E$ and the energy criteria. The data seem to be better modeled with either a redshift distribution model invoking a significant delay with respect to star formation or a hybrid model invoking both a dominant delayed population and a subdominant star formation population. We discuss the implications of this finding for FRB source models.

Sahar Esfandyari, Ashraf Aleyasin, Zahra Noroozi et al.

Objective: Sulforaphane (SFN) is a natural free radical scavenger that can reduce oxidative stress (OS) through mediating nuclear factor (erythroid-derived 2)-like 2 (NF-E2-related factor 2 or NRF2)/antioxidant response element (ARE) signaling pathway and the downstream antioxidant enzymes. Here, we intended to study the role of SFN in OSinduced human granulosa cells (GCs) by investigating the intracellular levels of reactive oxygen species (ROS), cell death, and NRF2-ARE pathway. Materials and Methods: This experimental study was conducted on GCs of 12 healthy women who had normal menstrual cycles with no history of polycystic ovary syndrome (PCOS), endometriosis, menstrual disorders, hyperprolactinemia, or hormonal therapy. After isolation of GCs, the MTT assay was performed to explore GCs viability after treatment with SFN in the presence or absence of H2O2. Flow cytometry was utilized to determine the intracellular ROS production and the apoptosis rate. Evaluation of the mRNA and protein expression levels of NRF2 and phase II enzymes including superoxide dismutase (SOD) and catalase (CAT) was performed by quantitative real-time polymerase chain reaction (PCR) and western blotting. Finally, the data were analyzed by SPSS software using One-way ANOVA and the suitable post-hoc test. Significance level was considered as P<0.05. Results: Pretreatment of GCs with SFN attenuated intracellular ROS production and apoptosis rate in the H2O2-exposed cells. Moreover, SFN treatment increased the mRNA expression level of NRF2, SOD, and CAT. Higher expression of NRF2 and SOD was also observed at the protein level. Conclusion: Our study demonstrated that SFN protects human GCs against H2O2 induced-OS by reducing the intracellular ROS production and the following apoptosis through a mechanism by which NRF2 increases the antioxidant enzymes such as SOD and CAT. This result may have a potential application in assisted reproduction cycles by improving the quality of GCs and the embedded oocyte, especially in PCOS patients.

mehdi amraei, Morteza Afshar, Khashayar Ghazizade

Inlaid art has undergone alternations from the beginning of its existence in Iran until the present era. Companionship in inlaid art can be examined from several perspectives; the first is the association of this art with the nature of its raw materials, which takes on a diverse shape and form due to the characteristics of these materials; second, the role of wood art accompaniment as an art complement to inlaid art from the point of view of technique and procedure, however, the most significant of these are the effects of traditional patterns on inlaid art in terms of design and the developments that occur in the field of contemporary inlay and so far comprehensively has not been purposefully studied. This research is accomplished via a descriptive and analytical methods by the means of library data. The findings of the research indicate that these accompaniments have always been associated with remarkable innovations and developments in contemporary inlaid art, and this research focuses on the analysis of traditional motifs in contemporary inlays in order to achieve changes in the inlaid art by relying on the contemporary artworks of Tehran; in such a way that the influence of traditional motifs in achieving luxurious formulations can be achieved. It is certain that inlaid art, due to the inherent need for role and design, has continuously benefited from the combination of beautiful and executable designs and designs in each period throughout history, and in the contemporary period with artistic developments in Tehran and the presence of prominent artists in the capital. Art has also manifested itself with new, valuable and glorious innovations and formulations that are unprecedented in the history of Iranian inlay. Research aims: 1. A study of traditional motifs in Iranian inlaid art. 2. An overview on the widespread effects of designs on contemporary Iranian inlay. Research questions: 1. What is the role of traditional patterns in the "design" of the magnificent works of contemporary inlay? 2. How are the bases for using traditional motifs in contemporary inlay formed?

Yuxian Meng, Chun Fan, Zijun Sun et al.

Any prediction from a model is made by a combination of learning history and test stimuli. This provides significant insights for improving model interpretability: {\it because of which part(s) of which training example(s), the model attends to which part(s) of a test example}. Unfortunately, existing methods to interpret a model's predictions are only able to capture a single aspect of either test stimuli or learning history, and evidences from both are never combined or integrated. In this paper, we propose an efficient and differentiable approach to make it feasible to interpret a model's prediction by jointly examining training history and test stimuli. Test stimuli is first identified by gradient-based methods, signifying {\it the part of a test example that the model attends to}. The gradient-based saliency scores are then propagated to training examples using influence functions to identify {\it which part(s) of which training example(s)} make the model attends to the test stimuli. The system is differentiable and time efficient: the adoption of saliency scores from gradient-based methods allows us to efficiently trace a model's prediction through test stimuli, and then back to training examples through influence functions. We demonstrate that the proposed methodology offers clear explanations about neural model decisions, along with being useful for performing error analysis, crafting adversarial examples and fixing erroneously classified examples.

Denis V. Tumanov

A new species of the genus Mesobiotus is described from the Republic of South Africa using a traditional morphological approach (light and scanning electron microscopy) combined with molecular analysis (18S rRNA, 28S rRNA, ITS-2 and COI markers). Mesobiotus anastasiae sp. nov. differs from all known Mesobiotus species by having a unique combination of characters of the adult animals and the eggs. Adults of the new species have an oral cavity armature without elongate teeth in the second band, while the processes of the egg chorion have a basal collar and distinct rows of large pores. An updated key to the species of the genus Mesobiotus, including 66 of 70 currently described species, is given. An aquatic mite species from the Lobohalacarus weberi complex (freshwater Halacaridae) co-occurs with M. anastasiae sp. nov., suggesting that the newly described tardigrade inhabits constantly wet moss cushion habitats.

E. Erikson

María I. Hermoso, María I. Hermoso, Victoria Y. Martin et al.

Divers have widely participated in citizen science (CS) projects and are one of the main groups of marine citizen scientists. However, there is little knowledge about profiles of, and incentives for potential divers to join CS projects. To date, most studies have focused on the SCUBA diving industry; nevertheless, there is a diversity of divers, not all using SCUBA, who engage in different activities during their dives. Differences in diver profiles could affect their willingness and ability to contribute to CS. In this study, we compare the diving profile, interests, preferences and motivations to participate in CS of five diver types (artisanal fishermen, recreational divers, instructors, scientific divers, and others). All divers have strong interests in participating in CS projects, with no major differences among diver types. In general, they are interested in a wide variety of themes related to CS but they prefer simple sampling protocols. Divers are motivated to participate in CS to learn about the sea and contribute to science. Some important differences among diver types were found, with artisanal fishermen having significantly more dive experience than other diver types, but less free time during their dives and limited access to some communication channels and technologies. These characteristics make them ideal partners to contribute their local ecological knowledge (LEK) to local CS projects. In contrast, recreational divers have the least experience but most free time during their dives and good access to cameras and communications channels, making them suitable partners for large-scale CS projects that do not require a high level of species knowledge. Instructors and scientific divers are well-placed to coordinate and supervise CS activities. The results confirm that divers are not all alike and specific considerations have to be taken into account to improve the contribution of each diver type to CS. The findings provide essential information for the design of different types of CS projects. By considering the relevant incentives and opportunities for diverse diver groups, marine CS projects will make efficient gains in volunteer recruitment, retention, and collaborative generation of knowledge about the marine environment.