Ethnography of pedagogy and visual cultures in contemporary structural biology

Thesis (Ph. D. in History, Anthropology, and Science, Technology and Society (HASTS))--Massachusetts Institute of Technology, Program in Science, Technology and Society, 2007.Includes bibliographical references (p. 260-277).This ethnography tracks visualization and pedagogy in the burgeoning field of structural biology. Structural biologists are a multidisciplinary group of researchers who produce models and animations of protein molecules using three-dimensional interactive computer graphics. As they ramp up the pace of structure determination, modeling a vast array of proteins, these researchers are shifting life science research agendas from decoding genetic sequence data to interpreting the multidimensional forms of molecular life. One major hurdle they face is training a new generation of scientists to work with multi-dimensional data forms. In this study I document the formation and propagation of tacit knowledge in structural biology laboratories, in classrooms, and at conferences. This research shows that structural biologists-in-training must cultivate a feel for proteins in order to visualize and interpret their activity in cells. I find that protein modeling relies heavily on a set of practices I call the body-work of modeling. These tacit skills include: a) forms of kinesthetic knowledge that structural biologists gain through building and manipulating molecular models, and by using their own bodies as mimetic models to help them figure out how proteins move and interact; and b) narrative strategies that assume a teleological relationship between form and function, and which figure proteins through analogies with familiar human-scale phenomena, such as the pervasive description of proteins as "machines." What I find is that these researchers are not only transforming the objects of life science research: they are training a new generation of life scientists in forms of knowing attuned to the chemical affinities, physical forces and movements of protein molecules, and keyed to the tangible logic and rhetoric of "molecular machines."(cont.) This research builds on concerns in the feminist science studies literature on modes of embodiment in scientific practice, and contributes to studies of performance in science by examining visual cultures as performance cultures. In addition, I incorporate historical studies of the life sciences to map the making of the protein-this intricately crafted entity whose forms and functions, I argue, are recalibrating scientific expertise, reanimating biological imaginations, and reconfiguring the very contours and temporalities of "life itself."by Natasha Myers.Ph.D.in History, Anthropology, and Science, Technology and Society (HAST

Effect of Phacoemulsification on Intraocular Pressure in Eyes with Functioning Tube Shunts

Purpose: To evaluate the effect of phacoemulsification on intraocular pressure (IOP) in eyes with functioning tube shunts. Methods: This was a retrospective chart review of primary open-angle glaucoma (POAG) patients with a functioning tube who underwent phacoemulsification and had ≥24 months of follow-up. The primary end point was defined as surgical failure (IOP > 21 mmHg) at month 24, progression to no light perception (NLP) vision, glaucoma reoperation, or implant removal. Surgical failure defined as IOP >18 and >15 mmHg, changes in visual acuity (VA), IOP, and number of medications were assessed. Results: Twenty-seven eyes of 27 patients with moderate or severe POAG were included. The mean age of the patients was 64.2 ± 10.8 years. The interval between the tube shunt and phacoemulsification was 28.8 ± 25.0 months. At the end of the study, four (14.8%) eyes met the failure criteria; the average time to failure was 9.3 ± 3.8 months. The causes of failure were high IOP in two (50.0%) and glaucoma reoperation in two (50.0%) eyes; however, no eyes progressed to NLP vision. Surgical failure defined as IOP >18 and >15 mmHg showed an increasing failure rate (18.5% and 48.5%, respectively). The mean IOP and medications number remained stable at month 24 compared to baseline (P = 0.131 and P = 0.302, respectively). Initially, VA showed improvement, with the greatest improvement at 6 months (P = 0.001), but at 24 months the improvement was no longer significant (P = 0.430). Conclusion: Phacoemulsification in patients with functioning tubes did not change the mean IOP in most of the patients (86.2%); the number of medications also did not increase

AMI observations of unmatched Planck ERCSC LFI sources at 15.75 GHz

The Planck Early Release Compact Source Catalogue includes 26 sources with no obvious matches in other radio catalogues (of primarily extragalactic sources). Here we present observations made with the Arcminute Microkelvin Imager Small Array (AMI SA) at 15.75 GHz of the eight of the unmatched sources at declination > +10 degrees. Of the eight, four are detected and are associated with known objects. The other four are not detected with the AMI SA, and are thought to be spurious.Comment: 6 pages, 5 figures, 4 table

AHRQ series on complex intervention systematic reviews-paper 5: advanced analytic methods.

BACKGROUND AND OBJECTIVE: Advanced analytic methods for synthesizing evidence about complex interventions continue to be developed. In this paper, we emphasize that the specific research question posed in the review should be used as a guide for choosing the appropriate analytic method. METHODS: We present advanced analytic approaches that address four common questions that guide reviews of complex interventions: (1) How effective is the intervention? (2) For whom does the intervention work and in what contexts? (3) What happens when the intervention is implemented? and (4) What decisions are possible given the results of the synthesis? CONCLUSION: The analytic approaches presented in this paper are particularly useful when each primary study differs in components, mechanisms of action, context, implementation, timing, and many other domains

Ahmed vs Baerveldt Glaucoma Drainage Device in Uveitic Glaucoma

Introduction: Uveitis is an inflammatory eye disorder which may elevate intraocular pressure (IOP), causing sight-threatening glaucoma. Treatment of refractory uveitic glaucoma involves implantation of a glaucoma drainage device (GDD). Uveitic glaucoma has been a minority diagnosis in prior studies comparing the valved Ahmed GDD and non-valved Baerveldt GDD. Here we compare the safety and efficacy of the Ahmed and Baerveldt GDD in uveitic glaucoma. Methods: This retrospective comparative study was conducted on patients with uveitic glaucoma (≥14 years old) who underwent Ahmed or Baerveldt GDD implantation between 2006–2018 with a minimum follow-up of 3 months. Success was defined as IOP of 6-21 mmHg with (complete success) or without (qualified success) medications, with at least light perception vision and no further glaucoma surgery. Pearson Chi-squared test, independent t test, and Kaplan-Meier survival model were utilized for statistical analysis. Results: 137 eyes of 122 patients (67 Ahmed and 70 Baerveldt) were included. Baseline characteristics were comparable in both groups. The Baerveldt group experienced greater IOP reduction (60.3% vs. 44.5%), higher complete success rate (28.6% vs. 10.4%), higher complication rate (44.3% vs. 20.9%), and higher hypotony rate (10% vs. 0%) than the Ahmed group (all p values \u3c0.05). Discussion: Our results are in line with pooled analysis of previous GDD comparison studies on various types of glaucoma. For patients with uveitic glaucoma, the Baerveldt implant provided a significantly higher success rate and greater IOP reduction with fewer medications, but was associated with a higher complication rate, compared to the Ahmed implant

Mesenchymal Stem Cells Expressing Insulin-like Growth Factor-I (MSCIGF) Promote Fracture Healing and Restore New Bone Formation in Irs1 Knockout Mice: Analyses of MSCIGF Autocrine and Paracrine Regenerative Effects

Failures of fracture repair (non-unions) occur in 10% of all fractures. The use of mesenchymal stem cells (MSC) in tissue regeneration appears to be rationale, safe and feasible. The contributions of MSC to the reparative process can occur through autocrine as well as paracrine effects. The primary objective of this study is to find a novel mean, by transplanting primary cultures of bone marrow-derived MSC expressing insulin-like growth factor-I (MSCIGF), to promote these seed-and-soil actions of MSC to fully implement their regenerative abilities in fracture repair and non-unions. MSCIGF or traceable MSCIGF-Lac-Z were transplanted into wild-type or insulin-receptor-substrate knock-out (Irs1−/−) mice with a stabilized tibia fracture. Healing was assed using biomechanical testing, micro-computed-tomography (µCT) and histological analyses. We found that systemically transplanted MSCIGF through autocrine and paracrine actions improved the fracture mechanical strength and increased new bone content while accelerating mineralization. We determined that IGF-I adapted the response of transplanted MSCIGF to promote their differentiation into osteoblasts. In vitro and in vivo studies showed that IGF-I-induced induced osteoglastogenesis in MSC was dependent of an intact IRS1-PI3K signaling. Furthermore, using Irs1−/− mice as a non-union fracture model through altered IGF signaling, we demonstrated that the autocrine effect of IGF-I on MSC restored the fracture new bone formation and promoted the occurrence of a well-organized callus that bridged the gap; a callus that basically absent in Irs1−/− left untransplanted or transplanted with MSC. We provided evidence of effects and mechanisms for transplanted MSCIGF in fracture repair and potentially to treat non-unions

AMI Large Array radio continuum observations of Spitzer c2d small clouds and cores

We perform deep 1.8 cm radio continuum imaging towards thirteen protostellar regions selected from the Spitzer c2d small clouds and cores programme at high resolution (25") in order to detect and quantify the cm-wave emission from deeply embedded young protostars. Within these regions we detect fifteen compact radio sources which we identify as radio protostars including two probable new detections. The sample is in general of low bolometric luminosity and contains several of the newly detected VeLLO sources. We determine the 1.8 cm radio luminosity to bolometric luminosity correlation, L_rad -L_bol, for the sample and discuss the nature of the radio emission in terms of the available sources of ionized gas. We also investigate the L_rad-L_IR correlation and suggest that radio flux density may be used as a proxy for the internal luminosity of low luminosity protostars.Comment: submitted MNRA