Hexavalent chromium [Cr(VI)] is a common environmental pollutant. However, little is known about the genetic basis of microbial evolution under Cr(VI) stress and the influence of the prior evolution histories on the subsequent evolution under Cr(VI) stress. In this study, Desulfovibrio vulgaris Hildenborough (DvH), a model sulfate-reducing bacterium, was experimentally evolved for 600 generations. By evolving the replicate populations of three genetically diverse DvH clones, including ancestor (AN, without prior experimental evolution history), non-stress-evolved EC3-10, and salt stress-evolved ES9-11, the contributions of adaptation, chance, and pre-existing genetic divergence to the evolution under Cr(VI) stress were able to be dissected. Significantly decreased lag phases under Cr(VI) stress were observed in most evolved populations, while increased Cr(VI) reduction rates were primarily observed in populations evolved from EC3-10 and ES9-11. The pre-existing genetic divergence in the starting clones showednce are largely unknown. Given the genetic divergence of microbial populations in nature, knowledge on how this divergence affects the microbial adaptation to a new environment such as Cr(VI) stress is very limited. Taking advantage of our previous study, three groups of genetically diverse D. vulgaris Hildenborough populations with or without prior experimental evolution histories were propagated under Cr(VI) stress for 600 generations. Whole-population genome resequencing of the evolved populations revealed the genomic changes underlying the improved Cr(VI) tolerance. The strong influence of the pre-existing genetic divergence in the starting clones on evolution under Cr(VI) stress conditions was demonstrated at both phenotypic and genetic levels.Multifaceted and divergent manifestations across tissues and cell types have curtailed advances in deciphering the cellular events that accompany advanced age and contribute to morbidities and mortalities. Increase in human lifespan during the past century has heightened awareness of the need to prevent age-associated frailty of neuronal and sensory systems to allow a healthy and productive life. In this review, we discuss molecular and physiological attributes of aging of the retina, with a goal of understanding age-related impairment of visual function. We highlight the epigenome-metabolism nexus and proteostasis as key contributors to retinal aging and discuss lifestyle changes as potential modulators of retinal function. Finally, we deliberate promising intervention strategies for promoting healthy aging of the retina for improved vision. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http//www.annualreviews.org/page/journal/pubdates for revised estimates.Intraocular pressure (IOP) is the cardinal and only modifiable risk factor for glaucoma, the leading cause of irreparable blindness worldwide.  https://www.selleckchem.com/products/AZD0530.html  Twin and family studies estimate the heritability of IOP to be 40-70%, and linkage studies for IOP have identified numerous loci. Mutations in MYOC can cause markedly elevated IOP and aggressive glaucoma often requiring surgical intervention. However, the majority of the genetic basis for raised IOP and glaucoma in populations is complex, and recent large genome-wide association studies (GWASs) have identified over 100 common variants that contribute to IOP variation. In combination, these loci are predictive for primary open-angle glaucoma in independent populations, achieving an area under the receiver operating characteristic curve of 76% for high-pressure primary open-angle glaucoma; this suggests the possibility of targeted screening in the future. Additionally, GWAS findings have identified important biological pathways underlying IOP regulation, including lymphangiogenesis and lipid metabolism, providing novel targets for new therapies. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http//www.annualreviews.org/page/journal/pubdates for revised estimates.Purpose Limited evidence-based guidelines for test selection continue to result in inconsistency in test use and interpretation in speech-language pathology. A major barrier is the lack of explicit and consistent adoption of a validity framework by our field. In this viewpoint, we argue that adopting the conceptual validity framework in the Standards for Educational and Psychological Testing (American Educational Research Association et al., 2014) would support both the development of more meaningful and feasible clinical tests and more appropriate use and interpretation of tests in speech-language pathology. Method We describe and evaluate the Standards for Educational and Psychological Testing (American Educational Research Association et al., 2014) validity framework and consider its relevance to speech-language pathology. We describe how the validity framework could be integrated into clinical practice and include examples of how it could be applied to support common clinical decisions. We evaluate the costs and benefits of adopting this framework, from the perspectives of speech-language pathologists, clients, and test developers. Results The Standards' validity framework clarifies complex validity issues by shifting the focus of validity from tests to the decisions speech-language pathologists make based on test results. By focusing on decisions, the framework requires critical evaluation of test use, rather than evaluating tests against sets of criteria. Adopting this framework has the potential for appreciable improvement in the way tests are used and valued across our profession. Conclusions Speech-language pathologists, test developers, and clients will benefit from improved evidence-based assessment practices. It is recommended that regulators, test developers, professional associations, universities, and researchers adopt the framework and endorse it as best practice moving forward. This viewpoint proposes a series of first steps toward supporting uptake of the framework into research and practice.