Atom probe tomography and transmission electron microscopy (TEM) have been used to determine the location and distribution of carbon and alloying elements associated with the complex structural ...changes that occur at the atomic and nanoscale in 4340 steel after quenching to martensite and tempering at 325, 450 or 575°C. Tempering at 325°C resulted in carbide formation without partitioning of chromium, manganese, molybdenum, aluminum, nickel or phosphorus, but with early-stage silicon rejection from the carbide. TEM verified the presence of cementite and the Bagaryatsky orientation relationship with the tempered martensite matrix and detected complex precipitate structures. Tempering at 450 or 575°C developed concentrations of all alloying elements at ferrite–cementite interfaces: chromium, manganese and molybdenum partitioned into the cementite, and silicon, aluminum, nickel and phosphorus were clearly rejected from the cementite. These results provide direct evidence for staged cementite growth, where early-stage growth likely occurs under paraequilibrium conditions, followed by initial silicon redistribution and subsequent alloying element redistribution during late-stage growth. Tempering at 575°C induced spheroidization of the cementite, loss of the Bagaryatsky orientation relationship, and phosphorus concentrations at Cottrell atmospheres within the cementite and at ferrite–cementite interfaces, correlating with early observations of the retardation of spheroidization by phosphorus.
The goal of the quench and partition (Q&P) process for steel heat treatment is to enrich austenite with carbon during a partitioning treatment after initial quenching below the martensite start ...temperature (Ms). Two proposed mechanisms for austenite carbon enrichment during partitioning include carbon transport from martensite and/or the formation of carbide-free bainite. Theoretical calculations show experimentally measured austenite fractions are difficult to explain based upon a mechanism involving solely bainite formation. Carbon partitioning from martensite provides a more satisfactory explanation, although the formation of bainite during partitioning cannot be completely excluded.
•We review attributes and methods of vegetation condition monitoring within Australia.•Site-based and remote sensing approaches both offer important information about vegetation ...condition.•Integration of the two approaches opens up new avenues for monitoring vegetation condition across a range of scales.•Consequently we recommend a number of key areas for future research in order to improve vegetation condition assessment for the purposes of evidence-based decision making.
Native vegetation around the world is under threat from historical and ongoing clearance, overgrazing, invasive species, increasing soil and water salinity, altered fire regimes, poor land management and other factors, resulting in a degradation of natural ecosystem services. Consequently, maintaining and improving native vegetation condition is a target frequently adopted by natural resource managers and government agencies world-wide. Adequate monitoring of vegetation condition remains a prerequisite for environmental decision-making and for tracking progress towards management goals. Throughout we consider vegetation condition to include the compositional, structural and functional attributes of vegetation relative to undisturbed vegetation of the same type.
Site-based methods have long been used to assess compositional, structural and functional attributes as indicators of vegetation condition, and these methods continue to be used widely today. With developing technologies, remote sensing methods are being employed increasingly for monitoring a range of remotely detectable properties of vegetation, and there is now a growing demand to explicitly integrate the two approaches for mapping and monitoring vegetation condition across a range of scales.
Here we review the attributes of vegetation identified as important for monitoring vegetation condition, those indicators that are best measured using traditional site-based methods and those that are more readily detectable using remote sensing methods, including their application in operational programmes within Australia. Further to this we review recent literature on the integration of the two approaches for monitoring indicators of vegetation condition.
We find that remote sensing methods have the advantage of offering broad scale automated and repeatable methods for monitoring indicators of vegetation condition, but when combined with detailed ecological site-based data, together can improve monitoring for answering ecological questions across a range of scales. Further work, however, is required to effectively integrate the two approaches for mapping and monitoring vegetation condition.
Resident organizations and unions have a powerful role in advocating for resident physicians with disabilities. Ongoing efforts to ensure accessibility for resident physicians with disabilities would ...be promoted through the inclusion of clauses in resident contracts that ensure accessible work environments.
The American Thoracic Society committee on Proficiency Standards for Pulmonary Function Laboratories has recognized the need for a standardized reporting format for pulmonary function tests. Although ...prior documents have offered guidance on the reporting of test data, there is considerable variability in how these results are presented to end users, leading to potential confusion and miscommunication.
A project task force, consisting of the committee as a whole, was approved to develop a new Technical Standard on reporting pulmonary function test results. Three working groups addressed the presentation format, the reference data supporting interpretation of results, and a system for grading quality of test efforts. Each group reviewed relevant literature and wrote drafts that were merged into the final document.
This document presents a reporting format in test-specific units for spirometry, lung volumes, and diffusing capacity that can be assembled into a report appropriate for a laboratory's practice. Recommended reference sources are updated with data for spirometry and diffusing capacity published since prior documents. A grading system is presented to encourage uniformity in the important function of test quality assessment.
The committee believes that wide adoption of these formats and their underlying principles by equipment manufacturers and pulmonary function laboratories can improve the interpretation, communication, and understanding of test results.
Structural hippocampal abnormalities are common in many neurological and psychiatric disorders, and variation in hippocampal measures is related to cognitive performance and other complex phenotypes ...such as stress sensitivity. Hippocampal subregions are increasingly studied, as automated algorithms have become available for mapping and volume quantification. In the context of the Enhancing Neuro Imaging Genetics through Meta Analysis Consortium, several Disease Working Groups are using the FreeSurfer software to analyze hippocampal subregion (subfield) volumes in patients with neurological and psychiatric conditions along with data from matched controls. In this overview, we explain the algorithm's principles, summarize measurement reliability studies, and demonstrate two additional aspects (subfield autocorrelation and volume/reliability correlation) with illustrative data. We then explain the rationale for a standardized hippocampal subfield segmentation quality control (QC) procedure for improved pipeline harmonization. To guide researchers to make optimal use of the algorithm, we discuss how global size and age effects can be modeled, how QC steps can be incorporated and how subfields may be aggregated into composite volumes. This discussion is based on a synopsis of 162 published neuroimaging studies (01/2013–12/2019) that applied the FreeSurfer hippocampal subfield segmentation in a broad range of domains including cognition and healthy aging, brain development and neurodegeneration, affective disorders, psychosis, stress regulation, neurotoxicity, epilepsy, inflammatory disease, childhood adversity and posttraumatic stress disorder, and candidate and whole genome (epi‐)genetics. Finally, we highlight points where FreeSurfer‐based hippocampal subfield studies may be optimized.
Hippocampal subfield analysis is increasingly performed with the availability of automated magnetic resonance imaging segmentation methods. We give a synopsis of the FreeSurfer hippocampal subfield segmentation algorithm, measurement reliability studies and application domains. We discuss how global size and age effects can be modeled and suggest a standardized hippocampal subfield segmentation quality control procedure for improved pipeline harmonization.
To review and synthesise prognostic indices that predict subsequent risk, prescriptive indices that moderate treatment response, and mechanisms that underlie each with respect to relapse and ...recurrence of depression in adults.
Childhood maltreatment, post-treatment residual symptoms, and a history of recurrence emerged as strong prognostic indicators of risk and each could be used prescriptively to indicate who benefits most from continued or prophylactic treatment. Targeting prognostic indices or their “down-stream” consequences will be particularly beneficial because each is either a cause or a consequence of the causal mechanisms underlying risk of recurrence. The cognitive and neural mechanisms that underlie the prognostic indices are likely addressed by the effects of treatments that are moderated by the prescriptive factors. For example, psychosocial interventions that target the consequences of childhood maltreatment, extending pharmacotherapy or adapting psychological therapies to deal with residual symptoms, or using cognitive or mindfulness-based therapies for those with prior histories of recurrence. Future research that focuses on understanding causal pathways that link childhood maltreatment, or cognitive diatheses, to dysfunction in the neocortical and limbic pathways that process affective information and facilitate cognitive control, might result in more enduring effects of treatments for depression.
•Prognostic risk factors for recurrence were in order of strength of evidence:•1st: childhood maltreatment, residual symptoms and history of prior episodes•2nd: comorbid anxiety, rumination, neuroticism and age of onset•Some also may be prescriptive but evidence for such effects was limited•Neurocognitive and neuroendocrine factors were identified as potential risk factors•A conceptual framework considering the risk factors and mechanisms was developed.
Quenching and partitioning (Q&P) produces steel microstructures with martensite and austenite that exhibit promising property combinations for third generation advanced high strength steels. ...Understanding the kinetics of reactions that compete for available carbon, such as carbide formation, is critical for alloying and processing design and achieving austenite enrichment and retention during Q&P. Mössbauer effect spectroscopy (MES) was used to characterize Q&P microstructures in a 0.38C–1.54Mn–1.48Siwt.% steel after quenching to 225°C and partitioning at 400°C for 10 or 300s, with an emphasis on transition carbides. The recoilless fraction for η-carbide was calculated and a correction for saturation of the MES absorption spectrum was applied, making quantitative measurements of small amounts of η-carbide, including non-stoichiometric η-carbide, possible in Q&P microstructures. Complementary transmission electron microscopy confirmed the presence of η-carbides, and MES and X-ray diffraction were used to characterize the austenite. The amount of η-carbide formed during Q&P ranged from 1.4 to 2.4at.%, accounting for a substantial portion (∼24% to 41%) of the bulk carbon content of the steel. The amount (5.0at.%) of η-carbide that formed after quenching and tempering (Q&T) at 400°C for 300s was significantly greater than after partitioning at 400°C for 300s (2.4at.%), suggesting that carbon partitioning from martensite to austenite occurs in conjunction with η-carbide formation during Q&P in these specimens.
Towed bottom-fishing gears are thought to constitute one of the largest global anthropogenic sources of disturbance to the seabed and its biota. The current drive towards an ecosystem approach in ...fisheries management requires a consideration of the implications of habitat deterioration and an understanding of the potential for restoration. We undertook a meta-analysis of 101 different fishing impact manipulations. The direct effects of different types of fishing gear were strongly habitat-specific. The most severe impact occurred in biogenic habitats in response to scallop-dredging. Analysis of the response of different feeding guilds to disturbance from fishing revealed that both deposit- and suspension-feeders were consistently vulnerable to scallop dredging across gravel, sand and mud habitats, while the response of these groups to beam-trawling was highly dependent upon habitat type. The biota of soft-sediment habitats, in particular muddy sands, were surprisingly vulnerable, with predicted recovery times measured in years. Slow-growing large-biomass biota such as sponges and soft corals took much longer to recover (up to 8 yr) than biota with shorter life-spans such as polychaetes (<1 yr). The results give a possible basis for predicting the outcome of the use of different fishing gears in a variety of habitats with potential utility in a management context.
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