247 research outputs found

    Evolutionary Time for Dispersal Limits the Extent but Not the Occupancy of Species’ Potential Ranges in the Tropical Plant Genus Psychotria (Rubiaceae)

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    Explaining the diversity in geographic range sizes among species is a central goal of ecological and evolutionary studies. We tested species age as an explanation of range size variation within a group of understory shrubs in the Neotropics (Psychotria subgenus Psychotria, Rubiaceae). We distinguish between range occupancy (filling an occupied area) and range extent (maximum distances dispersed). We used Bayesian relaxed-clock dating of molecular sequence data to estimate the relative age of species, and we used species distribution modeling to predict species\u27 potential ranges. If the range sizes of species are limited by time for dispersal, we hypothesize that older species should have (1) larger realized range occupancies and realized range extents than younger species, (2) filled a greater proportion of their potential range occupancies, and (3) colonized a greater proportion of their potential range extents. We found (1) a significant but weak positive relationship between species age versus both realized range occupancy and realized range extent, (2) no relationship between species age and filling of potential range occupancies, but (3) that older species had colonized a significantly greater proportion of their potential range extents than younger species. Our results indicate that a time-for-dispersal effect can limit the extent of ranges of species but not necessarily their occupancies

    Complex cytogenetic rearrangements at the DURS1 locus in syndromic Duane retraction syndrome

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    Key Clinical Message A patient with syndromic Duane retraction syndrome harbors a chromosome 811.1q13.2 inversion and 8p11.1-q12.3 marker chromosome containing subregions with differing mosaicism and allele frequencies. This case highlights the potential requirement for multiple genetic methods to gain insight into genotype–phenotype correlation, and ultimately into molecular mechanisms that underlie human disease

    Phylogenetics of Flowering Plants Based on Combined Analysis of Plastid atpB and rbcL Gene Sequences

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    Following (1) the large-scale molecular phylogeny of seed plants based on plastid rbcL gene sequences (published in 1993 by Chase et al., Ann. Missouri Bot. Gard. 80:528-580) and (2) the 18S nuclear phylogeny of flowering plants (published in 1997 by Soltis et al., Ann. Missouri Bot. Gard. 84:1-49), we present a phylogenetic analysis of flowering plants based on a second plastid gene, atpB, analyzed separately and in combination with rbcL sequences for 357 taxa. Despite some discrepancies, the atpB-based phylogenetic trees were highly congruent with those derived from the analysis of rbcL and 18S rDNA, and the combination of atpB and rbcL DNA sequences (comprising ∼3000 base pairs) produced increased bootstrap support for many major sets of taxa. The angiosperms are divided into two major groups: noneudicots with inaperturate or uniaperturate pollen (monocots plus Laurales, Magnoliales, Piperales, Ceratophyllales, and Amborellaceae-Nymphaeaceae-Illiciaceae) and the eudicots with triaperturate pollen (particularly asterids and rosids). Based on rbcL alone and atpB/rbcL combined, the noneudicots (excluding Ceratophyllum) are monophyletic, whereas in the atpB trees they form a grade. Ceratophyllum is sister to the rest of angiosperms with rbcL alone and in the combined atpB/rbcL analysis, whereas with atpB alone, Amborellaceae, Nymphaeaceae, and Illiciaceae/Schisandraceae form a grade at the base of the angiosperms. The phylogenetic information at each codon position and the different types of substitutions (observed transitions and transversions in the trees vs. pairwise comparisons) were examined; taking into account their respective consistency and retention indices, we demonstrate that third-codon positions and transitions are the most useful characters in these phylogenetic reconstructions. This study further demonstrates that phylogenetic analysis of large matrices is feasibl

    Variations in Implementation of Specifications Grading in STEM Courses

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    Specifications grading is an assessment strategy based on mastery learning, clear learning objectives, and frequent evaluations and feedback. Twelve instructors at a southeastern four-year public college implemented the specifications grading method across eight discrete courses in four STEM areas. In this modified assessment strategy, the students controlled their grades through multiple attempts, with limitations, on assessments of course objectives. The instructors designed and executed specifications grading in unique ways that aligned with their content areas, teaching beliefs, and individual teaching styles. Preliminary observations suggest that, regardless of subject area, specifications grading can be used as an alternative to traditional assessment methodologies in STEM courses, regardless of the content area. In general, three major variations of implementation arose from this initial trial. Major differences and commonalities among these types are discussed as they relate to the course subject area in which they are used. The results of this work add a unique set of assessment practices to the current body of knowledge in that other practitioners may gain insight on variations of the specifications grading method that may be practical and applicable in their own classrooms

    Hereditary leiomyomatosis and renal cell cancer: Cutaneous lesions & atypical fibroids

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    Objective: To report a diagnosis of hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome following initial presentation with multiple cutaneous lesions. Design: Case report. Design classification N/A. Setting: Academic tertiary care center. Patient(s) 27-year-old nulligravid woman who presented with multiple red-brown lesions on her skin found to have cutaneous and uterine leiomyoma. Intervention(s) Biopsy of cutaneous lesions and fertility sparing robot-assisted laparoscopic myomectomy (RALM). Main outcome measures(s) Histological assessment of uterine leiomyoma. Results(s) Pathologic examination of uterine leiomyoma revealed diffuse atypia and fumarate hydratase loss phenotype concerning for genetic syndrome. Follow-up DNA sequencing via Sanger sequencing confirmed a pathogenetic R2333H mutation consistent with HLRCC. Conclusion(s) Consideration of HLRCC on differential diagnosis when patients present with cutaneous nodules and atypical or early onset uterine leiomyoma provides opportunity for early surveillance, family member testing, and more thoughtful surgical planning. Precis 27-year-old woman with multiple cutaneous lesions is found to have uterine leiomyomas and undergoes robotic myomectomy. Genetic testing of uterine leiomyomas reveals mutation in fumarate hydratase, etiologic in hereditary leiomyomatosis and renal cell cancer (HLRCC)

    Patient Preferences for Follow-up After Recent Excision of a Localized Melanoma

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    Importance The standard model of follow-up posttreatment of localized melanoma relies on clinician detection of recurrent or new melanoma, through routinely scheduled clinics (clinician-led surveillance). An alternative model is to increase reliance on patient detection of melanoma, with fewer scheduled visits and increased support for patients’ skin self-examination (SSE) (eg, using smartphone apps to instruct, prompt and record SSE, and facilitate teledermatology; patient-led surveillance). Objective To determine the proportion of adults treated for localized melanoma who prefer the standard scheduled visit frequency (as per Australian guideline recommendations) or fewer scheduled visits (adapted from the Melanoma Follow-up [MELFO] study of reduced follow-up). Design, Setting, and Participants This survey study used a telephone interview for surveillance following excision of localized melanoma at an Australian specialist center. We invited a random sample of 400 patients who had completed treatment for localized melanoma in 2014 to participate. They were asked about their preferences for scheduled follow-up, and experience of follow-up in the past 12 months. Those with a recurrent or new primary melanoma diagnosed by the time of interview (0.8-1.7 years since first diagnosis) were asked about how it was first detected and treated. SSE practices were also assessed. Main Outcomes and Measures Proportion preferring standard vs fewer scheduled clinic visits, median delay between detection and treatment of recurrent or new primary melanoma, and SSE practices. Results Of the 262 people who agreed to be interviewed, the mean (SD) age was 64.3 (14.3) years, and 93 (36%) were women. Among the 230 people who did not have a recurrent or new primary melanoma, 149 vs 81 preferred the standard vs fewer scheduled clinic visits option (70% vs 30% after adjusting for sampling frame). Factors independently associated with preferring fewer visits were a higher disease stage, melanoma on a limb, living with others, not having private health insurance, and seeing a specialist for another chronic condition. The median delay between first detection and treatment of recurrent or new primary melanoma was 7 and 3 weeks, respectively. Only 8% missed a scheduled visit, while 40% did not perform SSE or did so at greater than 3-month intervals. Conclusions and Relevance Some patients with melanoma may prefer fewer scheduled visits, if they are supported to do SSE and there is rapid clinical review of anything causing concern (patient-led surveillance)

    Can patient-led surveillance detect subsequent new primary or recurrent melanomas and reduce the need for routinely scheduled follow-up? A protocol for the MEL-SELF randomised controlled trial

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    This research project is funded by a National Health and Medical Research Council (NHMRC) Project grant (#1163054). The funder had no role in the design of the study and will have no role in the collection, analysis, and interpretation of the data; the writing of the report; or the decision to submit the report for publication. Funding Information: AEC is funded by a Career Development Fellowship from the National Health and Medical Research Council (NHMRC; 1147843). JFT is a recipient of an NHMRC Program Grant (1093017). RPMS is supported by Melanoma Institute Australia. RAS is supported by a NHMRC Program Grant and Practitioner Fellowship. For RAS, support from the from colleagues at Melanoma Institute Australia, Royal Prince Alfred Hospital and NSW Health Pathology is also gratefully acknowledged. RLM is supported with an NHMRC Investigator grant (1194703) and a University of Sydney Robinson Fellowship. HPS holds an NHMRC MRFF Next Generation Clinical Researchers Program Practitioner Fellowship (APP1137127). JH is supported by an NHMRC Early Career Fellowship (1112509). KB is supported by an NHMRC Investigator Grant (1174523) and a University of Sydney Research Accelerator (SOAR) Prize.Peer reviewedPublisher PD

    Experiences of Patient-Led Surveillance, Including Patient-Performed Teledermoscopy, in the MEL-SELF Pilot Randomized Controlled Trial: Qualitative Interview Study

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    Current clinician-led melanoma surveillance models require frequent routinely scheduled clinic visits, with associated travel, cost, and time burden for patients. Patient-led surveillance is a new model of follow-up care that could reduce health care use such as clinic visits and medical procedures and their associated costs, increase access to care, and promote early diagnosis of a subsequent new melanoma after treatment of a primary melanoma. Understanding patient experiences may allow improvements in implementation. Objective: This study aims to explore patients’ experiences and perceptions of patient-led surveillance during the 6 months of participation in the MEL-SELF pilot randomized controlled trial. Patient-led surveillance comprised regular skin self-examination, use of a mobile dermatoscope to image lesions of concern, and a smartphone app to track and send images to a teledermatologist for review, in addition to usual care. Methods: Semistructured interviews were conducted with patients previously treated for melanoma localized to the skin in New South Wales, Australia, who were randomized to the patient-led surveillance (intervention group) in the trial. Thematic analysis was used to analyze the data with reference to the technology acceptance model. Results: We interviewed 20 patients (n=8, 40% women and n=12, 60% men; median age 62 years). Patients who were more adherent experienced benefits such as increased awareness of their skin and improved skin self-examination practice, early detection of melanomas, and opportunities to be proactive in managing their clinical follow-up. Most participants experienced difficulty in obtaining clear images and technical problems with the app. These barriers were overcome or persevered by participants with previous experience with digital technology and with effective help from a skin check partner (such as a spouse, sibling, or friend). Having too many or too few moles decreased perceived usefulness
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