30 research outputs found

    Stem Development, Medullary Bundles, and Wood Anatomy of \u3ci\u3eCroton Glandulosus Var. Septentrionalis\u3c/i\u3e (Euphorbiaceae)

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    Anatomy and development of vascular tissues in the annual stems of Croton glandulosus var. septentrionalis are described. In primary stages of growth the stem possesses a eustele of bicollateral bundles; international phloem is notably more extensive than the external. In addition to a vascular cambium and secondary xylem that form in the usual fashion, additional cambia add cells to the internal phloem portion of the bicollateral bundles, forming well-marked medullary bundles at the perimeter of the pith. At first, the perimedullary cambial strands produce only internal secondary phloem; later, internal secondary xylem is present, the medullary bundles have an inverted orientation, i.e., phloem innermost (towards centre of pith) and xylem outermost (near protoxylem). Cells of the medullary bundles include sieve tube elements, vessel elements, and fibres. Normal (external) secondary phloem is weakly developed. Normal secondary xylem contains short vessel elements with simple perforation plates and alternate intervascular pits, libriform fibres, narrow heterocellular rays, and lacks axial parenchyma

    A Revision of \u3ci\u3eDiscocarpus\u3c/i\u3e (Euphorbiaceae)

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    As revised here, Discocarpus is interpreted to consist of three neotropical species: D. essequeboensis Klotzsch, D. gentryi S. M. Hayden, which is described and named herein as new to science, and D. spruceanus MĂŒll. Arg. One previously accepted name, D. brasiliensis Klotzsch ex MĂŒll. Arg., is reduced to synonymy of D. essequeboensis. Lecto-types are proposed for the two species previously described. One species is newly excluded from Discocarpus, as are three others, following previous literature. Foliar anatomy is described with a focus on epidermal sclereids, which are shown to occur on both epidermides. Evidence presented supports close relationships with Lachnostylis Turcz. and Amanoa Aubl.; little was found to support previous hypotheses concerning a relationship with Chonocentrum Pierre ex Pax & K. Hoffm

    Wood Anatomy and Relationships of \u3ci\u3eBetula uber\u3c/i\u3e

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    Wood anatomy of Betula uber (Ashe) Fernald is described and compared with woods of other birches belonging to series Humiles and series Costatae. Anatomically, wood of B. uber is typical of birches in general. On the basis of pore size and frequency, fiber characteristics, axial xylem parenchyma distribution, and absence of aggregate rays, it is argued that B. uber is properly classified in series Costatae. Resolution of its relationships within series Costatae is not apparent from wood data

    Celebrating Garden Genius : A Handbook to Selected Gardens by Charles F. Gillette

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    Celebrating Garden Genius : A Handbook to Selected Gardens by Charles F. Gillette was created as part of the 1992 Charles F. Gillette Forum at The Lewis Ginter Botanical Garden in Richmond, Virginia. W. John Hayden, Professor of Biology at the University of Richmond, and Sheila Hayden, Biology Research Associate at the University of Richmond, served as editors of the handbook. _________________________________________Charles F. Gillette(1886-1969) Arriving in Richmond on November 9, 1911 —a dull, damp, dreary day—Charles F. Gillette began his career in the Southeast as clerk of the record for landscape architect Warren Manning, who, working with architects Cram, Goodhue and Ferguson, was responsible for building the new campus of the University of Richmond in Westhampton. As one of Warren Manning\u27s apprentices at the Tremont Street studio in Boston, Gillette had received invaluable training in landscape art. Manning, moreover, had served his apprenticeship under Frederick Law Olmsted and had shared in the work at Biltmore in Asheville, North Carolina. A tradition from Olmsted to Manning to Gillette had thus been born. By 1914, Gillette, recently wed, made a momentous decision. He would practice landscape architecture in Richmond, Virginia. Since that rainy day in 1911 Gillette did nothing less than create the image of Virginia gardens as they are known and loved today. Developing a distinctly regional landscape architecture, one geared, as Professor Reuben Rainey has observed, to the Piedmont and the Tidewater, he won the admiration of men and women as remote in time and place as Douglas South all Freeman, Paul Green, Ellen Glasgow, and Francis Pendleton Gaines. His designs remain today the paradigm of the Virginia garden. The genius loci of the middle Atlantic, Gillette was drawn to the spiritual in nature. The garden, etymologically an enclosing, was instinctually real to him as the paradisus was to the medieval basilica. Like Emerson, he knew, after all, that nature was language whereby God speaks to man. One senses that today in the magic of a Gillette garden. Gillette\u27s eclecticism is rich in the traditions of landscape art. The Georgian Revival, the Country Place Movement, the English cottage garden, the designs and motifs of Capability Brown, Inigo Jones, or Gertrude Jekyll form organically, in the vernacular, the Gillette look or the Southern garden. English boxwood, Virginia cedar, azalea, camellia, crepe myrtle, Cunninghamia, daffodil and yew, brick, stone, water, and bronze form the palette of his art. The native and the imported thrive side by side. One leaves the Gillette garden with the echo of a John Hersey line, True genius rearranges old material in a way never seen . . . before. --George C. Longesthttps://scholarship.richmond.edu/bookshelf/1204/thumbnail.jp

    Hearing treatment for reducing cognitive decline: Design and methods of the Aging and Cognitive Health Evaluation in Elders randomized controlled trial

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    IntroductionHearing impairment is highly prevalent and independently associated with cognitive decline. The Aging and Cognitive Health Evaluation in Elders study is a multicenter randomized controlled trial to determine efficacy of hearing treatment in reducing cognitive decline in older adults. Clinicaltrials.gov Identifier: NCT03243422.MethodsEight hundred fifty participants without dementia aged 70 to 84 years with mild-to-moderate hearing impairment recruited from four United States field sites and randomized 1:1 to a best-practices hearing intervention or health education control. Primary study outcome is 3-year change in global cognitive function. Secondary outcomes include domain-specific cognitive decline, incident dementia, brain structural changes on magnetic resonance imaging, health-related quality of life, physical and social function, and physical activity.ResultsTrial enrollment began January 4, 2018 and is ongoing.DiscussionWhen completed in 2022, Aging and Cognitive Health Evaluation in Elders study should provide definitive evidence of the effect of hearing treatment versus education control on cognitive decline in community-dwelling older adults with mild-to-moderate hearing impairment

    Recruitment and baseline data of the Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study: A randomized trial of a hearing loss intervention for reducing cognitive decline

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    INTRODUCTIONHearing loss is highly prevalent among older adults and independently associated with cognitive decline. The Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study is a multicenter randomized control trial (partially nested within the infrastructure of an observational cohort study, the Atherosclerosis Risk in Communities [ARIC] study) to determine the efficacy of best-practice hearing treatment to reduce cognitive decline over 3 years. The goal of this paper is to describe the recruitment process and baseline results.METHODSMultiple strategies were used to recruit community-dwelling 70–84-year-old participants with adult-onset hearing loss who were free of substantial cognitive impairment from the parent ARIC study and de novo from the surrounding communities into the trial. Participants completed telephone screening, an in-person hearing, vision, and cognitive screening, and a comprehensive hearing assessment to determine eligibility.RESULTSOver a 24-month period, 3004 telephone screenings resulted in 2344 in-person hearing, vision, and cognition screenings and 1294 comprehensive hearing screenings. Among 1102 eligible, 977 were randomized into the trial (median age = 76.4 years; 53.5% female; 87.8% White; 53.3% held a Bachelor's degree or higher). Participants recruited through the ARIC study were recruited much earlier and were less likely to report hearing loss interfered with their quality of life relative to participants recruited de novo from the community. Minor differences in baseline hearing or health characteristics were found by recruitment route (i.e., ARIC study or de novo) and by study site.DISCUSSIONThe ACHIEVE study successfully completed enrollment over 2 years that met originally projected rates of recruitment. Substantial operational and scientific efficiencies during study startup were achieved through embedding this trial within the infrastructure of a longstanding and well-established observational study.HighlightsThe ACHIEVE study tests the effect of hearing intervention on cognitive decline.The study is partially nested within an existing cohort study.Over 2 years, 977 participants recruited and enrolled.Eligibility assessed by telephone and in-person for hearing, vision, and cognitive screening.The ACHIEVE study findings will have significant public health implications

    Hearing loss and cognition: A protocol for ensuring speech understanding before neurocognitive assessment

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    INTRODUCTION: Many neurocognitive evaluations involve auditory stimuli, yet there are no standard testing guidelines for individuals with hearing loss. The ensuring speech understanding (ESU) test was developed to confirm speech understanding and determine whether hearing accommodations are necessary for neurocognitive testing. METHODS: Hearing was assessed using audiometry. The probability of ESU test failure by hearing status was estimated in 2679 participants (mean age: 81.4 ± 4.6 years) using multivariate logistic regression. RESULTS: Only 2.2% (N = 58) of participants failed the ESU test. The probability of failure increased with hearing loss severity; similar results were observed for those with and without mild cognitive impairment or dementia. DISCUSSION: The ESU test is appropriate for individuals who have variable degrees of hearing loss and cognitive function. This test can be used prior to neurocognitive testing to help reduce the risk of hearing loss and compromised auditory access to speech stimuli causing poorer performance on neurocognitive evaluation

    Description of the Baseline Audiologic Characteristics of the Participants Enrolled in the Aging and Cognitive Health Evaluation in Elders Study

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    Purpose:The Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study is a randomized clinical trial designed to determine the effects of a best-practice hearing intervention versus a successful aging health education control intervention on cognitive decline among community-dwelling older adults with untreated mild-to-moderate hearing loss. We describe the baseline audiologic characteristics of the ACHIEVE participants.Method:Participants aged 70–84 years (N = 977; Mage = 76.8) were enrolled at four U.S. sites through two recruitment routes: (a) an ongoing longitudinal study and (b) de novo through the community. Participants underwent diagnostic evaluation including otoscopy, tympanometry, pure-tone and speech audiometry, speech-in-noise testing, and provided self-reported hearing abilities. Baseline characteristics are reported as frequencies (percentages) for categorical variables or medians (interquartiles, Q1–Q3) for continuous variables. Between-groups comparisons were conducted using chi-square tests for categorical variables or Kruskal–Wallis test for continuous variables. Spearman correlations assessed relationships between measured hearing function and self-reported hearing handicap.Results:The median four-frequency pure-tone average of the better ear was 39 dB HL, and the median speech-in-noise performance was a 6-dB SNR loss, indicating mild speech-in-noise difficulty. No clinically meaningful differences were found across sites. Significant differences in subjective measures were found for recruitment route. Expected correlations between hearing measurements and self-reported handicap were found.Conclusions:The extensive baseline audiologic characteristics reported here will inform future analyses examining associations between hearing loss and cognitive decline. The final ACHIEVE data set will be publicly available for use among the scientific community

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
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