44 research outputs found
Relationship between electrochemical reaction processes and environment-assisted crack growth under static and dynamic atmospheric conditions
Environment-assisted cracking (EAC) of aluminum alloys in corrosive atmospheres is an important maintenance and safety issue for aerospace structures. EAC initiation and propagation are influenced by the interaction of load, environment, and alloy properties. For atmospheric corrosion, environmental conditions are dynamic; where temperature, relative humidity, and surface contaminants interact to control thin film electrolyte properties. Recent studies have determined that stage II stress corrosion crack (SCC) propagation, under atmospheric conditions is strongly dependent on humidity. SCC propagation in AA5083 and AA7075 alloys is a maximum during drying processes at intermediate humidity levels at or below the deliquescence relative humidity (DRH) for the applied corrosive salt. An improved understanding of the dependence of cracking on atmospheric conditions is important to testing material performance, establishing durable designs, and managing structural integrity.
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The Influence of Secondhand Smoke Exposure on Birth Outcomes in Jordan
This study investigates how secondhand smoke (SHS) exposure influences neonatal birth weight in Jordan, a country with high smoking prevalence. The findings revealed that as the average number of SHS exposure hours per week increased in the second trimester, the neonatal birth weight decreased while holding all covariates constant. Women who reported a higher average number of SHS exposure hours per week from work in the second trimester, home in the third trimester, and outside in the third trimester were at greater risk for having a low birth weight neonate than women who reported a lower average number of SHS exposure hours
How Immunocontraception Can Contribute to Elephant Management in Small, Enclosed Reserves: Munyawana Population as a Case Study
Immunocontraception has been widely used as a management tool to reduce population growth in captive as well as wild populations of various fauna. We model the use of an individual-based rotational immunocontraception plan on a wild elephant, Loxodonta africana, population and quantify the social and reproductive advantages of this method of implementation using adaptive management. The use of immunocontraception on an individual, rotational basis stretches the inter-calving interval for each individual female elephant to a management-determined interval, preventing exposing females to unlimited long-term immunocontraception use (which may have as yet undocumented negative effects). Such rotational immunocontraception can effectively lower population growth rates, age the population, and alter the age structure. Furthermore, such structured intervention can simulate natural process such as predation or episodic catastrophic events (e.g., drought), which regulates calf recruitment within an abnormally structured population. A rotational immunocontraception plan is a feasible and useful elephant population management tool, especially in a small, enclosed conservation area. Such approaches should be considered for other long-lived, social species in enclosed areas where the long-term consequences of consistent contraception may be unknown
Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission
AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p
How do children become adult sentence producers?
We join other responders in thanking Clahsen and Felser (CF) for pulling together these observations about the development of language processing. We are especially impressed by the generality and inclusiveness of CF\u27s treatment of development in L1 and L2. Because most of their specifics concerned comprehension processes, our contribution will emphasize the added value of an appeal to production processes. In particular, we will articulate the value of applying existing production models to developmental phenomena. Language development can be interpreted in revealing ways through the lens of adult sentence production models. These models specify how lexical, syntactic, morphological, and phonological knowledge are integrated in real time as we produce sentences. They are performance models, but they go well beyond general measures of working memory and general notions of limited capacity and resources
ReCLIP: A Strong Zero-Shot Baseline for Referring Expression Comprehension
Training a referring expression comprehension (ReC) model for a new visual
domain requires collecting referring expressions, and potentially corresponding
bounding boxes, for images in the domain. While large-scale pre-trained models
are useful for image classification across domains, it remains unclear if they
can be applied in a zero-shot manner to more complex tasks like ReC. We present
ReCLIP, a simple but strong zero-shot baseline that repurposes CLIP, a
state-of-the-art large-scale model, for ReC. Motivated by the close connection
between ReC and CLIP's contrastive pre-training objective, the first component
of ReCLIP is a region-scoring method that isolates object proposals via
cropping and blurring, and passes them to CLIP. However, through controlled
experiments on a synthetic dataset, we find that CLIP is largely incapable of
performing spatial reasoning off-the-shelf. Thus, the second component of
ReCLIP is a spatial relation resolver that handles several types of spatial
relations. We reduce the gap between zero-shot baselines from prior work and
supervised models by as much as 29% on RefCOCOg, and on RefGTA (video game
imagery), ReCLIP's relative improvement over supervised ReC models trained on
real images is 8%.Comment: ACL 202