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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ahj.2010.06.006 Byline: Asha Asthana, Heather M. Johnson, Megan E. Piper, Michael C. Fiore, Timothy B. Baker, James H. Stein Abstract: Cigarette smoking has been associated with increases in C-reactive protein (CRP) and leukocyte counts (white blood cell [WBC]); however, the effects of smoking intensity and smoking cessation on inflammatory markers have not been evaluated prospectively in a large, modern cohort of current smokers. Author Affiliation: University of Wisconsin School of Medicine and Public Health, Madison, WI Article History: Received 5 March 2010; Accepted 2 June 2010

Climate change and biodiversity loss are deeply intertwined anthropogenic global crises, for which forests provide powerful nature-based solutions. Biodiverse forests are more resilient to climate change than monocultures, thereby enhancing long-term carbon storage and ecosystem-based adaptation. Awareness of these interdependencies is slowly growing, but we know little about how countries are considering biodiversity within climate policies. Island and low-lying coastal states are particularly vulnerable to climate change and biodiversity loss. Here we assessed if and how the members of the Alliance of Small Island States (AOSIS) are integrating biodiversity into their national climate action plans through forest-based climate solutions. Our analysis shows that these solutions are a missed opportunity for tackling the twin crises together. Only five of the 39 countries explore co-benefits and synergies between forest-based climate solutions and biodiversity conservation measures. An additional nine mention them separately. Among these 14 countries, only a narrow range of interventions were proposed. While 28 AOSIS members prioritised forests for combating climate change, mostly for mitigation, only three prioritised their unique and globally important biodiversity. This omission is potentially risky, since mitigation measures, such as planting rapidly growing non-native trees, can have negative outcomes for biodiversity. Climate action plans must place a greater emphasis on concrete and measurable targets that create synergies with biodiversity conservation, including through the protection of old-growth forests and forest restoration. Our results highlight that forums such as the United Nations Climate Change Conferences need to continue pushing for a stronger integration of biodiversity into climate policies. • Biodiversity is not integrated into climate action plans of small island states. • Synergies between forest-based climate solutions and conservation are unexplored. • Forests are largely prioritised for mitigation. • National climate policy undervalues the global importance of island biodiversity. • More inclusive approaches with measurable targets are necessary. [ABSTRACT FROM AUTHOR]

Medical students are at a disproportionate risk for experiencing burnout, making management of burnout a critical skill to teach in medical education. If left unmanaged, students may develop maladaptive coping strategies as well as substance misuse, suicidal ideation, and poorer quality patient care. This study examined the impact of Acceptance and Commitment Training (ACT) as a burnout management curriculum with medical students at a western U.S. medical school. Participants (n = 281) completed measures pertaining to psychological flexibility (i.e., the Acceptance and Action Questionnaire-II; AAQ-II) and burnout (i.e., the Implicit Relational Assessment Procedure; IRAP). Assessments were collected at three time points over the first two years of medical school. ACT was provided between Time 1 and 2, and not between Time 2 and 3. Results demonstrated statistically significant improvements, specifically for students starting medical school with clinically relevant levels of distress on the AAQ-II (n = 53). Positivity bias and negativity bias were measured with a burnout themed Modified-IRAP (MD-IRAP). Positivity bias maintained across all three time points, despite an increase in negativity bias. Implications for teaching psychological flexibility as a burnout management tool in higher education and healthcare systems will be discussed. • ACT is a feasible technology to apply in medical education. • ACT may be most beneficial for medical students with clinically significant levels of distress. • Medical educators should target burnout and psychological flexibility early in students' careers within the required curriculum. • The Implicit Relational Assessment Procedure is a tool to consider for assessing curricular-based interventions. [ABSTRACT FROM AUTHOR]

Research has been conducted on the flavivirus structure. Results suggest that the flaviviruses employ a fusion mechanism to insert distal domain II beta barrels of the glycoprotein E into the cellular membrane.

This article describes the mechanistic aspects of the nonenveloped animal reovirus penetration through cell membrane without membrane fusion. Membrane penetration is facilitated by the outer-capsid protein, mu1 and its 'protector' protein, sigma3.

A 25 angstrom resolution cryo-electron microscopic and image reconstruction study of Ross River virus helps study the organization of alpha-viruses. Twelve pentamers and 30 hexamers constitute the monomeric subunits that form the nucleocapsid core. The inner nucleocapsid core and outer envelope glycoproteins flank the lipid bilayer membrane. The quasi-threefold axes carry 60 spikes, each of which is bound to three SiN capsid protein (SCP) subunits among the pentamers and hexamers while the spikes on isohedral threefold axes are linked to three SCP units on hexamers.

Introduction: Patients who use tobacco are too rarely connected with tobacco use treatment during healthcare visits. Electronic health record enhancements may increase such referrals in primary care settings. This project used the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework to assess the implementation of a healthcare system change carried out in an externally valid manner (executed by the healthcare system).Methods: The healthcare system used their standard, computer-based training approach to implement the electronic health record and clinic workflow changes for electronic referral in 30 primary care clinics that previously used faxed quitline referral. Electronic health record data captured rates of assessment of readiness to quit and quitline referral 4 months before implementation and 8 months (May-December 2017) after implementation. Data, analyzed from October 2018 to June 2019, also reflected intervention reach, adoption, and maintenance.Results: For reach and effectiveness, from before to after implementation for electronic referral, among adult patients who smoked, assessment of readiness to quit increased from 24.8% (2,126 of 8,569) to 93.2% (11,163 of 11,977), quitline referrals increased from 1.7% (143 of 8,569) to 11.3% (1,351 of 11,977), and 3.6% were connected with the quitline after implementation. For representativeness of reach, electronic referral rates were especially high for women, African Americans, and Medicaid patients. For adoption, 52.6% of staff who roomed at least 1 patient who smoked referred to the quitline. For maintenance, electronic referral rates fell by approximately 60% over 8 months but remained higher than pre-implementation rates.Conclusions: Real-world implementation of an electronic health record-based electronic referral system markedly increased readiness to quit assessment and quitline referral rates in primary care patients. Future research should focus on implementation methods that produce more consistent implementation and better maintenance of electronic referral. [ABSTRACT FROM AUTHOR]

Tropical biomes are the most diverse plant communities on Earth, and quantifying this diversity at large spatial scales is vital for many purposes. As macroecological approaches proliferate, the taxonomic uncertainties in species occurrence data are easily neglected and can lead to spurious findings in downstream analyses. Here, we argue that technological approaches offer potential solutions, but there is no single silver bullet to resolve uncertainty in plant biodiversity quantification. Instead, we propose the use of artificial intelligence (AI) approaches to build a data-driven framework that integrates several data sources – including spectroscopy, DNA sequences, image recognition, and morphological data. Such a framework would provide a foundation for improving species identification in macroecological analyses while simultaneously improving the taxonomic process of species delimitation. Quantifying plant biodiversity in tropical forests is a major challenge. Increasingly, large-scale synthetic studies are attempting to meet this challenge but are limited by insufficient species occurrence data that is exacerbated by taxonomic uncertainties. To quantify tropical forest biodiversity fully depends upon accurate species identifications, and we argue that these can be achieved by using an integrated synthesis of technological approaches including spectroscopy, DNA sequencing, and image recognition, alongside traditional morphological approaches to species delimitation and identification. Crucially, AI approaches could be used to integrate these different technologies and data sources in an objective, repeatable, and scalable way. Our approach would maximize the utility of existing data and collections to build a standardised framework for identifying tropical plants and at the same time could contribute to species discovery and improve underlying taxonomy. [ABSTRACT FROM AUTHOR]

The progression of smoking in a cohort of 321 low-level and occasional smokers is investigated. The results showed that over the course of 4 years, 45% of low-level and occasional users had become nonsmokers, 35% became occasional smokers, and 20% became daily smokers.

Objectives: To determine the cost-effectiveness of an incentive-based stop-smoking intervention that paid Medicaid recipients who smoke to take calls from a tobacco quit line.Methods: A cost-effectiveness analysis was conducted alongside a randomized controlled trial. The analysis was conducted from a health care systems perspective on the basis of costs and effectiveness over a 6-month follow-up. Participants (n = 1900) were recruited from May 2013 to June 2015 through quit line (n = 980), clinic-based (n = 444), or community-based (n = 476) referrals. Incentive group participants (n = 948) received $30 a call for taking up to five tobacco quit line calls and $40 for biochemically verified tobacco abstinence at 6 months. Control group participants (n = 952) did not receive financial incentives for taking quit line calls. Intervention resource costs included incentive payments to participants, counselor and administrative staff time, and smoking cessation medications. Smoking status at baseline and 6 months was determined for all study participants via carbon monoxide (CO) breath tests (abstinence: CO < 7 ppm). Cost-effectiveness analysis calculated the incremental cost-effectiveness ratio (ICER).Results: Incentive treatment produced higher 6-month CO-confirmed 7-day point-prevalence abstinence than did the control treatment (21.6 vs. 13.8%; P < 0.001). The ICER of the financial incentives intervention was $2316 (95% confidence interval $1582-$4270) per additional person who quit. The study ICER compares favorably with other smoking treatments, such as varenicline combined with proactive telephone counseling, whose ICER has been estimated at $2600 per additional smoker who quits.Conclusions: Use of financial incentives to engage with tobacco quit line treatment is a cost-effective option to enhance smoking cessation rates for low-income smokers. [ABSTRACT FROM AUTHOR]

Smoking is the leading preventable cause of death and disease in the U.S. This study evaluates the cost-effectiveness from a healthcare system perspective of a comprehensive primary care intervention to reduce smoking rates. This pragmatic trial implemented electronic health record prompts during primary care visits and employed certified tobacco cessation specialists to offer proactive outreach and smoking cessation treatment to patients who smoke. The data, analyzed in 2022, included 10,683 patients in the smoking registry from 2017 to 2020. Pre–post analyses compared intervention costs to treatment engagement, successful self-reported smoking cessation, and acute health care utilization (urgent care, emergency department visits, and inpatient hospitalization). Cost per quality-adjusted life year was determined by applying conversion factors obtained from the tobacco research literature to the cost per patient who quit smoking. Tobacco cessation outreach, medication, and counseling costs increased from $2.64 to $6.44 per patient per month, for a total post-implementation intervention cost of $500,216. Smoking cessation rates increased from 1.3% pre-implementation to 8.7% post-implementation, for an incremental effectiveness of 7.4%. The incremental cost-effectiveness ratio was $628 (95% CI: $568, $695) per person who quit smoking, and $905 (95% CI: $822, $1,001) per quality-adjusted life year gained. Acute health care costs decreased by an average of $42 (95% CI: −$59, $145) per patient per month for patients in the smoking registry. Implementation of a comprehensive and proactive smoking cessation outreach and treatment program for adult primary care patients who smoke meets typical cost-effectiveness thresholds for healthcare. [ABSTRACT FROM AUTHOR]

A three-dimensional reconstruction of a prolate, tailed phage and its empty prohead precursor was described and examined using cryo-electron microscopy. The head-tail connector was visualized within a Bacillus subtilis dsDNA phage. The connector appeared to fit loosely into a pentameric vertex of the head that may be required to rotate the connector to package DNA. Reconstruction of an emptied phage particle showed that the connector and neck/tail assembly undergo conformational changes upon ejection of DNA.

Factorial experiments have rarely been used in the development or evaluation of clinical interventions. However, factorial designs offer advantages over randomized controlled trial designs, the latter being much more frequently used in such research. Factorial designs are highly efficient (permitting evaluation of multiple intervention components with good statistical power) and present the opportunity to detect interactions amongst intervention components. Such advantages have led methodologists to advocate for the greater use of factorial designs in research on clinical interventions (Collins, Dziak, & Li, 2009). However, researchers considering the use of such designs in clinical research face a series of choices that have consequential implications for the interpretability and value of the experimental results. These choices include: whether to use a factorial design, selection of the number and type of factors to include, how to address the compatibility of the different factors included, whether and how to avoid confounds between the type and number of interventions a participant receives, and how to interpret interactions. The use of factorial designs in clinical intervention research poses choices that differ from those typically considered in randomized clinical trial designs. However, the great information yield of the former encourages clinical researchers' increased and careful execution of such designs. [ABSTRACT FROM AUTHOR]

Closer collaboration among ecologists, systematists, and evolutionary biologists working in tropical forests, centred on studies within long-term permanent plots, would be highly beneficial for their respective fields. With a key unifying theme of the importance of vouchered collection and precise identification of species, especially rare ones, we identify four priority areas where improving links between these communities could achieve significant progress in biodiversity and conservation science: (i) increasing the pace of species discovery; (ii) documenting species turnover across space and time; (iii) improving models of ecosystem change; and (iv) understanding the evolutionary assembly of communities and biomes. [ABSTRACT FROM AUTHOR]

One challenge in the dietary supplement industry is confirmation of species identity for processed raw materials, i.e. those modified by milling, drying, or extraction, which move through a multilevel supply chain before reaching the finished product. This is particularly difficult for samples containing fungal mycelia, where processing removes morphological characteristics, such that they do not present sufficient variation to differentiate species by traditional techniques. To address this issue, we have demonstrated the utility of DNA barcoding to verify the taxonomic identity of fungi found commonly in the food and dietary supplement industry; such data are critical for protecting consumer health, by assuring both safety and quality. By using DNA barcoding of nuclear ribosomal internal transcribed spacer (ITS) of the rRNA gene with fungal specific ITS primers, ITS barcodes were generated for 33 representative fungal samples, all of which could be used by consumers for food and/or dietary supplement purposes. In the majority of cases, we were able to sequence the ITS region from powdered mycelium samples, grocery store mushrooms, and capsules from commercial dietary supplements. After generating ITS barcodes utilizing standard procedures accepted by the Consortium for the Barcode of Life, we tested their utility by performing a BLAST search against authenticate published ITS sequences in GenBank. In some cases, we also downloaded published, homologous sequences of the ITS region of fungi inspected in this study and examined the phylogenetic relationships of barcoded fungal species in light of modern taxonomic and phylogenetic studies. We anticipate that these data will motivate discussions on DNA barcoding based species identification as applied to the verification/certification of mushroom-containing dietary supplements. [ABSTRACT FROM AUTHOR]

Objective Recent evidence suggests that the efficacy of smoking cessation pharmacotherapy can vary across patients based on their genotypes. This study tests whether the coding variant rs16969968 in the CHRNA5 nicotinic receptor gene predicts the effects of combination nicotine replacement therapy (cNRT) and varenicline on treatment outcomes. Method In two randomized smoking cessation trials comparing cNRT vs. placebo, and varenicline vs. placebo, we used logistic regression to model associations between CHRNA5 rs16969968 and abstinence at end of treatment. Results For abstinence at end of treatment, there was an interaction between cNRT and rs16969968 ( X 2 = 8.15, d f = 2, omnibus- p = 0.017 for the interaction); individuals with the high-risk AA genotype were more likely to benefit from cNRT. In contrast, varenicline increased abstinence, but its effect did not vary with CHRNA5 . However, the genetic effects differed between the placebo control groups across two trials (wald = 3.94, d f = 1, p = 0.047), this non-replication can alter the interpretation of pharmacogenetic findings. Conclusions Results from two complementary smoking cessation trials demonstrate inconsistent genetic results in the placebo arms. This evidence highlights the need to compare the most effective pharmacotherapies with the same placebo control to establish pharmacogenetic evidence to aid decisions on medication choice for patients trying to quit smoking. [ABSTRACT FROM AUTHOR]

Road widening schemes in urban areas are often proposed as a solution to traffic congestion and as a means of stimulating economic growth. There is however clear evidence that new or expanded roads rapidly fill with either displaced or induced traffic, offsetting any short-term gains in eased traffic flows. What has not been addressed in any great detail is the impact of such schemes on air quality, with modelled impact predictions seldom validated by measurements after the expansion of road capacity. In this study we made use of a road widening project in London to investigate the impact on ambient air quality (particulate matter, NO X , NO 2 ) during and after the completion of the road works. PM 10 increased during the construction period up to 15 μg m − 3 during working hours compared to concentrations before the road works. A box modelling approach was used to determine a median emission factor of 0.0022 kg PM 10 m − 2 month − 1 , three times larger than that used in the UK emission inventory (0.0007 kg PM 10 m − 2 month − 1 ). Peaks of activity released 0.0130 kg PM 10 m − 2 month − 1 , three and eight times smaller than the peak values used in the European and US inventories. After the completion of the widening there was an increase in all pollutants from the road during rush hour: 2–4 μg m − 3 for PM 10 ; 1 μg m − 3 for PM 2.5 ; 40 and 8 μg m − 3 for NO X and NO 2 , respectively. NO 2 EU Limit Value was breached after the road development illustrating a notable deterioration in residential air quality. Additionally, PM 10 , but not PM 2.5 , glutathione dependent oxidative potential increased after the road was widened consistent with an increase in pro-oxidant components in the coarse particle mode, related to vehicle abrasion processes. These increased air pollution indices were associated with an increase in the number of cars, taxis and LGVs. [ABSTRACT FROM AUTHOR]

Background This study tests whether the genetic predictor ( CHRNA5 nicotine receptor gene variants) and an environmental risk factor (partner smoking) interact in the prediction of smoking reduction. Methods Subjects were from a community-based, longitudinal study of women ( n = 1856) who smoked before pregnancy, and a randomized comparative effectiveness smoking cessation trial ( n = 1065). Smoking reduction was defined as the trajectory of self-reported smoking quantities over time in the observational study, and as the trajectory of alveolar CO levels in the cessation trial. Results In the pregnancy study, rs16969968 genotype and partner smoking status interacted such that the smoking reduction was lowest for expectant mothers with high genetic risk and partner smoking, and highest for those with high genetic risk but not partner smoking (interaction of genotype × partner smoking on smoking quantity trajectory slope β = 0.071, 95%CI = 0.013, 0.13, p = 0.017). In the clinical trial, a similar interaction was found (interaction β = 0.20, 95%CI = 0.049, 0.36, p = 0.010). Furthermore, these associations were moderated by pharmacotherapy such that the interactive relation of genetic and environmental factors occurred in the placebo group, but not in the active pharmacotherapy group (interaction of genotype × partner smoking × pharmacotherapy on CO trajectory slope β = −0.25, 95%CI = −0.42, −0.091, p = 0.0023). Conclusions The CHRNA5 genetic risk synergized the effect of partner smoking, producing an especially low likelihood of successful smoking reduction in two complementary studies. This suggests that the genetic vulnerability may be mitigated by altering environmental factors. In addition, cessation pharmacotherapy neutralizes the increase in cessation failure associated with combined genetic and environmental risks, which has possible relevance to treatment algorithms. [ABSTRACT FROM AUTHOR]

Highlights: [•] We develop analytical methods for estimating wood production in forest plots. [•] Our corrections provide suggested methods to minimise three time-sensitive biases. [•] In Amazonia, uncorrected estimates of wood production are underestimated by 13%. [ABSTRACT FROM AUTHOR]

Highlights: [•] We created an extensive dataset of directly-measured palm biomass including 9 species. [•] We developed the first comprehensive equations to estimate AGB and BGB for palms. [•] We report both single- and mixed-species models with a variety of input variables. [•] Palm biomass density was 29% or 40% greater than estimated using two models for dicots. [Copyright &y& Elsevier]

Background: Fax referral programs quickly and economically can link smokers'' visiting primary care clinics to state-based telephone quitlines. Yet, it is unclear how to optimize use of this strategy. Purpose: To evaluate the potential of enhanced academic detailing in clinics (i.e., on-site training, technical assistance, and performance feedback) to boost utilization of a fax referral program called Fax to Quit. Design: Participants were randomized to one of two intervention conditions. Setting/participants: Participants were drawn from 49 primary care clinics in southeastern Wisconsin. The sample size was based on a power analysis in which the control intervention condition was estimated to generate 0.5 referrals/clinic/month and the experimental condition 2.0 referrals/clinic/month. Interventions: One of two fax referral program interventions was administered: the control condition Fax to Quit–Only (F2Q-Only) or the experimental condition Fax to Quit plus Enhanced Academic Detailing (F2Q+EAD). Main outcome measures: Clinic- and clinician-specific referral and quality referral rates (those resulting in quitline enrollment) were measured for 13 months post-intervention, starting in March 2009. Results: Mean number of post-intervention referrals/clinician to the Wisconsin Tobacco Quitline was 5.6 times greater for F2Q+EAD (8.5, SD=7.0) compared to F2Q-Only (1.6, SD=3.6, p<0.001). The F2Q+EAD (4.8, SD=4.1) condition produced a greater mean number of quality referrals/clinician than did the F2Q-Only (0.86, SD=1.8, p<0.001) condition. Data were analyzed in 2010. Conclusions: Enhanced academic detailing, which included on-site training, technical assistance, and performance feedback, increased the number of referrals more than fivefold over a fax referral program implemented without such enhanced academic detailing. Trial registration: This study is registered at Clinicaltrials.gov NCT00989755. [ABSTRACT FROM AUTHOR]

Background: The effects of smoking and smoking cessation on lipoproteins have not been studied in a large contemporary group of smokers. This study was designed to determine the effects of smoking cessation on lipoproteins. Methods: This was a 1-year, prospective, double-blind, randomized, placebo-controlled clinical trial of the effects of 5 smoking cessation pharmacotherapies. Fasting nuclear magnetic resonance spectroscopy lipoprotein profiles were obtained before and 1 year after the target smoking cessation date. The effects of smoking cessation and predictors of changes in lipoproteins after 1 year were identified by multivariable regression. Results: The 1,504 current smokers were (mean [SD]) 45.4 (11.3) years old and smoked 21.4 (8.9) cigarettes per day at baseline. Of the 923 adult smokers who returned at 1 year, 334 (36.2%) had quit smoking. Despite gaining more weight (4.6 kg [5.7] vs 0.7 kg [5.1], P < .001], abstainers had increases in high-density lipoprotein cholesterol (HDL-C) (2.4 [8.3] vs 0.1 [8.8] mg/dL, P < .001), total HDL (1.0 [4.6] vs −0.3 µmol/L [5.0], P < .001), and large HDL (0.6 [2.2] vs 0.1 [2.1] µmol/L, P = .003) particles compared with continuing smokers. Significant changes in low-density lipoprotein (LDL) cholesterol and particles were not observed. After adjustment, abstinence from smoking (P < .001) was independently associated with increases in HDL-C and total HDL particles. These effects were stronger in women. Conclusions: Despite weight gain, smoking cessation improved HDL-C, total HDL, and large HDL particles, especially in women. Smoking cessation did not affect LDL or LDL size. Increases in HDL may mediate part of the reduced cardiovascular disease risk observed after smoking cessation. [Copyright &y& Elsevier]

Background: Smoking is associated with decreased high-density lipoprotein cholesterol (HDL-C) and increased levels of triglycerides. Objective: We sought to evaluate the effects of five markers of smoking intensity on lipoprotein concentrations and particle sizes in a large, modern cohort of current smokers. Methods: Fasting nuclear magnetic resonance spectroscopy lipoprotein profiles were obtained in a large cohort of current smokers enrolled in a smoking-cessation trial. Multivariate linear regression models were constructed to determine predictors of lipoprotein fractions. Models included age, sex, race, waist circumference, level of physical activity, and alcohol consumption. Smoking intensity parameters included current cigarettes smoked/day, pack-years, the Fagerström Test of Nicotine Dependence score, and carbon monoxide (CO) levels. Results: The 1504 subjects (58% women, 84% white) had a mean (standard deviation) age of 45 (11.0) years. They smoked 21.4 (8.9) cigarettes/day (29.4 [20.4] pack-years). HDL-C (42.0 [13.5] mg/dL) and total HDL particles (30.3 [5.9] μmol/L) were low. Cigarettes smoked/day independently predicted greater total cholesterol (P =.009), low-density lipoprotein cholesterol (P =.023), and triglycerides (P =.002). CO levels predicted lower HDL-C (P =.027) and total HDL particles (P =.009). However, the incremental R2 for each marker of smoking intensity on each lipoprotein was small. Relationships between the Fagerström Test of Nicotine Dependence score and lipoproteins were weak and inconsistent. Participants in the lowest quintiles of current smoking, pack-years, and CO had more favorable lipoproteins (all P < .04). Conclusions: Among current smokers, increased smoking burden is associated with small increases in total cholesterol, low-density lipoprotein cholesterol, and triglycerides. Increased recent smoke exposure is associated with small decreases in HDL-C and HDL particles. [Copyright &y& Elsevier]

Abstract: This paper presents the results of a combined experimental and theoretical study of the effects of Na2O addition on the microstructure, viscoelastic toughening and thermal shock resistance of aluminosilicate refractory ceramics. The Na2O was added to change the viscosity–temperature characteristics of the glassy phase and to promote viscoelastic toughening. It was observed that doping of an aluminosilicate with 4–6wt.% Na2O significantly alters the microstructure, from mullite within a glassy matrix to aluminum oxide laths within a glassy matrix. The glassy matrix is shown to form viscoelastic ligaments. These bridge cracks form and grow during cold shock from elevated temperatures (1100–1400°C). The viscoelastic bridges have the net effect of shielding the crack tips from transient thermal stresses due to thermal shock. They therefore improve the cold shock resistance of the ceramic. The insights developed from the experiments were used to guide the development of a fracture mechanics model for the prediction of viscoelastic toughening due to crack bridging. [Copyright &y& Elsevier]

Abstract: The accuracy of a finite element computation depends on the mesh size and the distribution of mesh points. Adapting the mesh to capture the salient features in the finite element computation can provide a much more accurate solution without imposing an excessive increase in mesh size and computational cost. When the shape of the meshed domain is evolving in time mesh adaptation is essential in order to maintain conformity of the mesh with the domain boundaries. Mesh adaptation for time evolving domains can be accomplished through a combination of mesh movement with mesh modification by selective coarsening and enrichment of various regions in the mesh. Large deformations of the computational domain and boundary can be accommodated if overall mesh quality is maintained after each adaptation cycle. [Copyright &y& Elsevier]