33 research outputs found
Temporal diagenetic alternations in Adélie penguin eggshells throughout the late holocene of Antarctica
Data from scanning electron microscopy (SEM) coupled with energy dispersive X-ray
(EDX) analysis of late Holocene Adélie penguin (Pygoscelis adeliae) eggshell fragments were
used to investigate the role of diagenesis on paleoecological reconstructions using stable
isotopes. The results of this study demonstrate that clear diagenetic alterations occur in eggshell
carbonate following burial in ornithogenic, or bird formed, soils. Diagenesis progresses from
blocky calcium carbonate (CaCO3) rhombs in the modern eggshells to botryoidal fluorapatite
crystals (Ca5(PO4)3F), as indicated by the increased weight percentages of phosphorus and
fluorine with sampling depth. Carbon weight percent was found to decrease, with statistical
significance, in relation to phosphorus, indicating that carbon is preferentially removed from the
eggshell through time. Diagenesis in the fossils is predictable, with early stage alterations
occurring along the outer margins of the eggshells first, and slowly progressing inward towards
the center. Despite these trends, the inclusion of unaltered CO3
2- from the original eggshell
material allows for the fossil’s use in isotopic reconstructions
Protection From Retinopathy and Other Complications in Patients With Type 1 Diabetes of Extreme Duration: The Joslin 50-Year Medalist Study
Objective: To assess complication prevalence and identify protective factors in patients with diabetes duration of 50 years. Characterization of a complication-free subgroup in this cohort would suggest that some individuals are protected from diabetes complications and allow identification of endogenous protective factors. Research Design and Methods: Cross-sectional, observational study of 351 U.S. residents who have survived with type 1 diabetes for 50 years (Medalists). Retinopathy, nephropathy, neuropathy, and cardiovascular disease were assessed in relation to HbA, lipids, and advanced glycation end products (AGEs). Retrospective chart review provided longitudinal ophthalmic data for a subgroup. Results: A high proportion of Medalists remain free from proliferative diabetic retinopathy (PDR) (42.6%), nephropathy (86.9%), neuropathy (39.4%), or cardiovascular disease (51.5%). Current and longitudinal (the past 15 years) glycemic control were unrelated to complications. Subjects with high plasma carboxyethyl-lysine and pentosidine were 7.2-fold more likely to have any complication. Of Medalists without PDR, 96% with no retinopathy progression over the first 17 years of follow-up did not experience retinopathy worsening thereafter. Conclusions: The Medalist population is likely enriched for protective factors against complications. These factors might prove useful to the general population with diabetes if they can be used to induce protection against long-term complications. Specific AGE combinations were strongly associated with complications, indicating a link between AGE formation or processing with development of diabetic vasculopathy
Implementation and first-year screening results of an ocular telehealth system for diabetic retinopathy in China
<p>Abstract</p> <p>Background</p> <p>To describe implementation and first-year screening results of the first Chinese telehealth system for diabetic retinopathy (DR) - the Beixinjing Community Diabetic Retinopathy Telehealth system (BCDRT).</p> <p>Methods</p> <p>BCDRT implementation was based on the acquisition of adequate digital retinographs, secure digital transmission, storage and retrieval of participants' data and reader-generated medical reports. Local diabetic residents meeting inclusion criteria were enrolled into the BCDRT system beginning in 2009. Participants recommended for further in-person examination with ophthalmologists were followed, and the consistencies in diagnoses between BCDRT and ophthalmologists for DR or macular edema were calculated.</p> <p>Results</p> <p>A total of 471 diabetic residents participated in BCDRT screening in 2009. The proportions of total DR, proliferative DR, and diabetic macular edema were 24.42% (115 patients), 2.12% (10 patients) and 6.47% (24 patients), respectively: 56 patients consulted ophthalmologists for further in-person retinal examination with funduscopy after pupil dilation. High rates of consistency between BCDRT screening and ophthalmologists were observed for macular edema (Kappa = 0.81), moderate or severe non-proliferative DR grade (Kappa = 0.92), and other DR grades (Kappa = 1). A total of 456 (96.82%) patients were willing to participate in the next BCDRT screening.</p> <p>Conclusions</p> <p>BCDRT was a reliable and valid system for DR screening, and offers the potential to increase DR annual screening rates in local residents.</p
Imager Evaluation of Diabetic Retinopathy at the Time of Imaging in a Telemedicine Program
The Seeing Machine Camera: An Artistic Tool for the Visually Challenged Conceived by a Visually Challenged Artist
The Vision Group at the Center for Advanced Visual Studies (CAVS) at the Massachusetts Institute of Technology (MIT) has developed the Seeing Machine Camera (SMC) under the direction of Elizabeth Goldring, a visually challenged artist. The SMC is an innovative tool that enables artistic expression for those with decreased vision. The camera enhances the ability to see the face of a loved one, look at a painting in a museum, photograph landscapes or create digital artwork. For visually challenged artists who may feel isolated from their visual world, the SMC provides an opportunity to connect to the people around them, enjoy a greater sense of independence and expand their creativity