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A critical examination is made of the use of the line-spring model to represent fiber bridging of matrix cracks in the analysis of failure phenomena in fiber-reinforced brittle matrix composites. Attention is focused on composite systems designed to undergo fiber debonding and sliding when matrix cracking occurs. For most composites of this class, it is found that the distance along the fiber within which sliding occurs is often too large to justify use of the line-spring representation. A model which allows for large scale sliding (the LSS model) is proposed and applied to three problems : a matrix crack emerging from a semi-infinite unbridged through-crack in a uni-directional fiber-reinforced composite, the same problem for the finite length unbridged through-crack, and matrix cracking of a cross-ply composite. Primary emphasis is placed on the stress concentration in the bridging fibers. Predictions from the LSS model are compared with those from the line-spring model. In general, the line-spring model is found to overestimate the stress concentration in critically located fibers. A discussion of the significance of the lower estimates of the stress concentration factors is given for several composite systems.

Abstract This chapter first discusses conceptual definitions and terminologies that are commonly used in the physical activity literature. Next it reviews reference measures of energy expenditure and objective and self-reported methods for measuring physical activity. Then it describes validation studies of physical activity questionnaires that have been used in large epidemiologic studies. Finally, it discusses methodological issues in the analysis of physical activity and disease risk, including measurement error correction, confounding, reverse causation, and isotemporal analysis.

Cardiac electrophysiologic derangements often coexist with disorders of the circulatory system. Capturing and diagnosing arrhythmias and conduction system disease may lead to a change in diagnosis, clinical management and patient outcomes. Standard 12-lead electrocardiogram (ECG), Holter monitors and event recorders have served as useful diagnostic tools over the last few decades. However, their shortcomings are only recently being addressed by emerging technologies. With advances in device miniaturization and wireless technologies, and changing consumer expectations, wearable "on-body" ECG patch devices have evolved to meet contemporary needs. These devices are unobtrusive and easy to use, leading to increased device wear time and diagnostic yield. While becoming the standard for detecting arrhythmias and conduction system disorders in the outpatient setting where continuous ECG monitoring in the short to medium term (days to weeks) is indicated, these cardiac devices and related digital mobile health technologies are reshaping the clinician-patient interface with important implications for future healthcare delivery.

Background: The potential health effects of dietary glutamine and glutamate have been studied in healthy populations, but evidence among individuals with type 2 diabetes (T2D) who have altered macronutrient metabolism and elevated cardiovascular disease (CVD) risk is limited. Objectives: We aimed to examine dietary glutamine and glutamate in relation to subsequent risk of CVD, including coronary heart disease and stroke, and all-cause and cause-specific mortality among individuals with T2D. Methods: We prospectively followed 15,040 men and women with T2D at baseline or diagnosed during follow-up (Nurses' Health Study: 1980-2014, Health Professionals Follow-Up Study: 1986-2018). Diet was repeatedly assessed using validated food frequency questionnaires every 2-4 years since baseline. Associations of energy-adjusted glutamine and glutamate intake, as well as their ratio, with CVD risk and mortality were assessed using Cox proportional hazards models with adjustments for demographics, dietary and lifestyle factors, and medical history. Results: During 196,955 and 225,371person-years of follow-up in participants with T2D, there were 2,927 incident CVD cases and 4,898 deaths, respectively. Higher intake of glutamine was associated with lower risk of incident CVD, total mortality and CVD mortality: comparing extreme quintiles, the HRs (95%CIs) were 0.88 (0.77, 0.99), 0.85 (0.77, 0.94), and 0.82 (0.69, 0.98), respectively (all P trend <0.05). In contrast, higher intake of glutamate was associated with higher risk of incident CVD, total mortality, and CVD mortality; the HRs were 1.30 (1.15, 1.46), 1.19 (1.08, 1.31), and 1.42 (1.21, 1.67), respectively (all P trend <0.05). Furthermore, comparing extreme quintiles, higher dietary glutamine-to-glutamate ratio was associated with lower risk of CVD incidence (0.84 (0.75, 0.95)), total mortality (0.83 (0.76, 0.91)), and CVD mortality (0.69 (0.59, 0.80)). In addition, compared with participants without increment in glutamine-to-glutamate ratio from pre- to post-diabetes diagnosis, those who increased the ratio had a 15% (3%, 25%) lower CVD mortality. Conclusions: In patients with T2D, dietary glutamine and glutamate demonstrated divergent associations with CVD incidence and mortality, and higher dietary glutamine-to-glutamate ratio was significantly associated with lower CVD incidence and mortality. These data suggest a potential critical role of these two amino acids in the etiology of cardiometabolic diseases and early deaths also among adults with T2D.

We appreciate the suggestion by Avena and colleagues that addiction-like behaviors and related brain changes may perpetuate overeating highly palatable foods that tend to contain high amounts of added sugars. This interesting hypothesis needs to be tested in well-designed interventions and mechanistic studies. Although the high consumption of added sugars in the US population (on average, approximately 22 teaspoons per day) is possibly related to the “addictive” property of the palatable foods and the reward system in the brain, the abundance of added sugars in the current food environment and influential advertising by the food industry may also play an important role.1 Our data indicate that the majority of US adults consumed more added sugars than is recommended for a healthy diet. Our results, along with the findings of many other studies,2–5 support current recommendations to reduce the intake of added sugars in US diets.6

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolyacrylamides bearing pendant .alpha.-sialoside groups strongly inhibit agglutination of erythrocytes by influenza virusAndreas Spaltenstein and George M. WhitesidesCite this: J. Am. Chem. Soc. 1991, 113, 2, 686–687Publication Date (Print):January 1, 1991Publication History Published online1 May 2002Published inissue 1 January 1991https://pubs.acs.org/doi/10.1021/ja00002a053https://doi.org/10.1021/ja00002a053research-articleACS PublicationsRequest reuse permissionsArticle Views530Altmetric-Citations183LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

article Free Access Share on A comparison of some numerical integration programs Authors: J. Casaletto Purdue University Purdue UniversityView Profile , M. Pickett Purdue University Purdue UniversityView Profile , J. Rice Purdue University Purdue UniversityView Profile Authors Info & Claims ACM SIGNUM NewsletterVolume 4Issue 3October 1969 pp 30–40https://doi.org/10.1145/1198442.1198448Published:01 October 1969Publication History 23citation120DownloadsMetricsTotal Citations23Total Downloads120Last 12 Months13Last 6 weeks7 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

This paper is concerned with an analysis of strain localization in ductile crystals deforming by single slip. The plastic flow is modelled as rate-insensitive, and localization, viewed as a bifurcation from a homogeneous deformation mode to one which is concentrated in a narrow ‘shear band’, is found to be possible only when the plastic hardening modulus for the slip system has fallen to a certain critical value h cr, sensitive to the precise form of the constitutive law governing incremental shear. We develop the general form of this constitutive law, incorporating within it the possibility of deviations from the Schmid rule of a critical resolved shear stress, and we show that h cr may in fact be positive when there are deviations from the Schmid rule. It is suggested that micromechanical processes such as ‘cross-slip’ in crystals provide specific cases for which stresses other than the Schmid stress may influence plastic response and, further, there is an experimental association of localization with the onset of large amounts of cross-slip. Thus, we give the specific form of h cr for a constitutive model that corresponds to non-Schmid effects in cross-slip, and we develop a dislocation model of the process from which we estimate the magnitude of the parameters involved. The work supports the notion that localization can occur with positive strain-hardening, h cr > 0, and the often invoked notions of the attainment of an ideally-plastic or strain-softening state for localization may be unnecessary.

A class of phenomenological flow theories of plasticity is proposed which models time-independent incremental behavior at a corner of the yield surface of a polycrystalline metal. The proposal is consistent with the physical theories of plasticity based on single crystal slip. Conditions for convexity, ensuring invertibility of the incremental relations, are derived. The simplest candidate, called J2 corner theory, coincides with the J2 deformation theory of plasticity for nearly proportional stress increments and incorporates a smooth transition to elastic unloading for increasingly non-proportional increments. The theory is applied to the bifurcation and imperfection-sensitivity analysis of necking in a thin sheet. For this example, like many others involving bifurcation in the plastic range, the corner theory appears to circumvent some of the difficulties associated with use of the standard phenomenological plasticity laws.