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Experimental studies of the lifetime and reproducibility of the Pb(Zr, Ti)O3(PZT) ceramic ferroelectric cathode with high current density is reported. A lifetime of lead zirconate-titanate ceramic cathode with composition related to a ferroelectric phase is examined.

The authenticity of classical Arabic poetry has long been challenged by claims that some part of the pre-Islamic poetic heritage should not be attributed to this era. According to these assertions, some of this legacy was produced after the advent of Islam and ascribed, for different reasons, to pre-Islamic poets. As pre-Islamic poets were illiterate, medieval Arabic literature devotees relied on Bedouin oral transmission when writing down and collecting the poems about two centuries later. This process left the identity of the real poets who composed these poems and the period in which they worked unresolved. In this work, we seek to answer the questions of how and to what extent we can identify the period in which classical Arabic poetry was composed, where we exploit modern-day automatic text processing techniques for this aim. We consider a dataset of Arabic poetry collected from the diwans (‘collections of poems’) of thirteen Arabic poets that corresponds to two main eras: the pre-ʿAbbāsid era (covering the period between the 6th and the 8th centuries CE) and the ʿAbbāsid era (starting in the year 750 CE). Some poems in each diwan are considered ‘original’; i.e., poems that are attributed to a certain poet with high confidence. The diwans also include, however, an additional section of poems that are attributed to a poet with reservations, meaning that these poems might have been composed by another poet and/or in another period. We trained a set of machine learning algorithms (classifiers) in order to explore the potential of machine learning techniques to automatically identify the period in which a poem had been written. In the training phase, we represent each poem using various types of features (characteristics) designed to capture lexical, topical, and stylistic aspects of this poetry. By training and assessing automatic models of period prediction using the ‘original’ poetry, we obtained highly encouraging results, measuring between 0.73–0.90 in terms of F1 for the various periods. Moreover, we observe that the stylistic features, which pertain to elements that characterize Arabic poetry, as well as the other feature types, are all indicative of the period in which the poem had been written. We applied the resulting prediction models to poems for which the authorship period is under dispute (‘attributed’) and got interesting results, suggesting that some of the poems may belong to different eras—an issue to be further examined by Arabic poetry researchers. The resulting prediction models may be applied to poems for which the authorship period is under dispute. We demonstrate this research direction, presenting some interesting anecdotal results.

Electron emission from ferroelectric cathodes is investigated, it is commonly suggested as an electron source for different applications due to its special characteristics such as high current density, easy treatment, and operation. In this experimental research, a lifetime of lead zirconate-titanate ceramic cathode with composition related to a ferroelectric phase was studied. The strong plasma emission from the cathode was excited in a nonreversal (nonswitching) mode by application of unipolar high stress. Severe damage to the cathodes was observed, especially in a high repetition rate. An upper limit of the lifetime of the ferroelectric cathode with plasma-induced emission was estimated at about ∼10[sup 6] pulses of ∼200 ns each at ∼100 Hz repetition rate. Possible applications of the limited lifetime ferroelectric cathode are discussed. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Catatonia is a clinical syndrome characterized by a distinct constellation of psychomotor disturbances. It is known as a clinical manifestation of many medical and psychiatric conditions. Neuroglycopenia is a term that refers to a shortage of glucose in the brain resulting in the alteration of neuronal function. Catatonia has been observed in hypoglycemic states. We present a single case report of a 36-year-old male, with no known medical or psychiatric history, presenting with catatonia and hypoglycemia due to malnutrition. Catatonia and hypoglycemia may present similarly, and can present a challenge in differentiating the underlying etiology. It is unclear whether the hypoglycemia-catatonia overlap phenomenon is rare or rather underdiagnosed.

The two-stage ferroelectric electron gun operation in free-electron master (FEM) oscillator is presented. The FEM interaction mechanism in this experiment is confirmed.

Social world knowledge is a key ingredient in effective communication and information processing by humans and machines alike. As of today, there exist many knowledge bases that represent factual world knowledge. Yet, there is no resource that is designed to capture social aspects of world knowledge. We believe that this work makes an important step towards the formulation and construction of such a resource. We introduce SocialVec, a general framework for eliciting low-dimensional entity embeddings from the social contexts in which they occur in social networks. In this framework, entities correspond to highly popular accounts which invoke general interest. We assume that entities that individual users tend to co-follow are socially related, and use this definition of social context to learn the entity embeddings. Similar to word embeddings which facilitate tasks that involve text semantics, we expect the learned social entity embeddings to benefit multiple tasks of social flavor. In this work, we elicited the social embeddings of roughly 200K entities from a sample of 1.3M Twitter users and the accounts that they follow. We employ and gauge the resulting embeddings on two tasks of social importance. First, we assess the political bias of news sources in terms of entity similarity in the social embedding space. Second, we predict the personal traits of individual Twitter users based on the social embeddings of entities that they follow. In both cases, we show advantageous or competitive performance using our approach compared with task-specific baselines. We further show that existing entity embedding schemes, which are fact-based, fail to capture social aspects of knowledge. We make the learned social entity embeddings available to the research community to support further exploration of social world knowledge and its applications.

Background: Coronavirus disease 2019 (COVID-19) has significantly the delivery of healthcare all around the world. In part, an abnormal and unexplained high non-COVID-related cardiovascular mortality rate was reported during the outbreak. We assess the correlation between anxiety level and decision to seek medical care (DSMC) during the COVID-19 pandemic. Materials and methods: We recruited patients with cardiovascular complaints admitted to the emergency department in a single institute in Israel between February and September 2020. Anxiety level was measured using available questionnaires. DSMC was assessed with a newly designed questionnaire (DM-19). Results: Two-hundreds seventy patients were included in the study. The mean age was 52.6 ± 14.9 (females represent 36.2%). 23.6% of the patients had at least moderate cardiovascular risk. High anxiety levels were (HAL) reported in nearly half of the patients (57.1% and 49.8% for General Anxiety Disorder Assessment [GAD-7] and Beck Anxiety Inventory [BAI], respectively). It was more prevalent in old, married, and unemployed patients (significant p-value for all in both questionnaires). Age was an independent factor (χ2 = 6.33, p < 0.001, odds-ratio: 4.8) and had a positive correlation on anxiety level (r = 0.81, p < 0.001 and r = 0.62, p < 0.001, for GAD-7 and BAI, respectively). The DM-19 revealed a strong and positive correlation of seeking medical care with anxiety level (R2 linear = 0.44, r = 0.70, p < 0.001 and R2 linear = 0.30, r = 0.58, p < 0.001 for GAD-7 and BAI, respectively) and results in deferring medical care for several days than patient with low anxiety level (p = 0.02). Conclusions: We observed an abnormal prevalence of a high level of anxiety among non-COVID patients with cardiovascular complaints, which affected the patient’s likelihood to seek medical care and resulted in an unreasonable postponement of medical treatment. Our results may explain cardiovascular mortality trends during the outbreak and should be considered in health crisis management. Future studies will involve multi-institutional efforts to address reproducibility of our findings across geographic regions in the state of the global impact. Additionally, it is imperative to understand the effects of the coronavirus vaccine on patient consideration to seek medical care.

This article is a case study of the Morris Justice Project (MJP), a participatory action research (PAR) study in a South Bronx neighborhood of New York City (NYC) designed to understand residents’ experiences with and attitudes towards the New York Police Department (NYPD). An illustration of public science, the research was conducted in solidarity with an emerging police reform movement and in response to an ongoing and particularly aggressive set of policing policies that most heavily impacts poor communities and communities of color. The case study describes a set of ongoing participatory, research-action, “sidewalk science” strategies, developed in 42 square blocks of the South Bronx, designed to better understand and challenge the ongoing structural violence of the carceral state. Collaboratively written with members of the Morris Justice collective, we tell our story across three sections that outline the genesis of the project, describe our major commitments, and offers PAR and public science as a possible “intervention” in traditional university practice.

As people around the world continue to have their voices, desires, and movements restricted, and their pasts and futures told on their behalf, we are interested in the critical project of decolonizing, which involves contesting dominant narratives and hegemonic representations. Ignacio Martín-Baró called these the “collective lies” told about people and politics. This essay reflects within and across two sites of injustice, located in Israel/Palestine and in South Africa, to excavate the circuits of structural violence, internalized colonization and possible reworking of those toward resistance that can be revealed within the stubborn particulars of place, history, and culture. The projects presented here are locally rooted, site-specific inquiries into contexts that bear the brunt of colonialism, dispossession, and occupation. Using visual research methodologies such as embroideries that produce counter-narratives and counter-maps that divulge the complexity of land-struggles, we search for fitting research practices that amplify unheard voices and excavate the social psychological soil that grows critical analysis and resistance. We discuss here the practices and dilemmas of doing decolonial research and highlight the need for research that excavates the specifics of a historical material context and produces evidence of previously silenced narratives.