Heterotopic ossification (HO) is the pathologic development of ectopic bone in soft tissues because of a local or systemic inflammatory insult, such as burn injury or trauma. In HO, mesenchymal stem cells (MSCs) are inappropriately activated to undergo osteogenic differentiation. Through the correlation of in vitro assays and in vivo studies (dorsal scald burn with Achilles tenotomy), we have shown that burn injury enhances the osteogenic potential of MSCs and causes ectopic endochondral heterotopic bone formation and functional contractures through bone morphogenetic protein–mediated canonical SMAD signaling. We further demonstrated a prevention strategy for HO through adenosine triphosphate (ATP) hydrolysis at the burn site using apyrase. Burn site apyrase treatment decreased ATP, increased adenosine 3′,5′-monophosphate, and decreased phosphorylation of SMAD1/5/8 in MSCs in vitro. This ATP hydrolysis also decreased HO formation and mitigated functional impairment in vivo. Similarly, selective inhibition of SMAD1/5/8 phosphorylation with LDN-193189 decreased HO formation and increased range of motion at the injury site in our burn model in vivo. Our results suggest that burn injury–exacerbated HO formation can be treated through therapeutics that target burn site ATP hydrolysis and modulation of SMAD1/5/8 phosphorylation.

In this paper, we present results from a study of prehensile human hand use during the daily work activities of four subjects: two housekeepers and two machinists. Subjects wore a head-mounted camera that recorded their hand usage during their daily work activities in their typical place of work. For each subject, 7.45 hours of video was analyzed, recording the type of grasp being used and its duration. From this data, we extracted overall grasp frequency, duration distributions for each grasp, and common transitions between grasps. The results show that for 80 percent of the study duration the housekeepers used just five grasps and the machinists used 10. The grasping patterns for the different subjects were compared, and the overall top 10 grasps are discussed in detail. The results of this study not only lend insight into how people use their hands during daily tasks, but can also inform the design of effective robotic and prosthetic hands.

Abstract. The climate in the Arctic is changing faster than anywhere else on earth. Poorly understood feedback processes relating to Arctic clouds and aerosol-cloud interactions contribute to a poor understanding of the present changes in the Arctic climate system, and also to a large spread in projections of future climate in the Arctic. The problem is exacerbated by the paucity of research-quality observations in the central Arctic. Improved formulations in climate models require such observations, which can only come from measurements in situ in this difficult-to-reach region with logistically demanding environmental conditions.The Arctic Summer Cloud Ocean Study (ASCOS) was the most extensive central Arctic Ocean expedition with an atmospheric focus during the International Polar Year (IPY) [2007][2008]. ASCOS focused on the study of the formation and life cycle of low-level Arctic clouds. ASCOS departed from Longyearbyen on Svalbard on 2 August and returned on 9 September 2008. In transit into and out of the pack ice, four short research stations were undertaken in the Fram Strait: two in open water and two in the marginal ice zone. After traversing the pack ice northward, an ice camp was set up on 12 August at 87 • 21 N, 01 • 29 W and remained in operation through 1 September, drifting with the ice. During this time, extensive measurements were taken of atmospheric gas and particle chemistry and physics, mesoscale and boundarylayer meteorology, marine biology and chemistry, and upper ocean physics.ASCOS provides a unique interdisciplinary data set for development and testing of new hypotheses on cloud processes, their interactions with the sea ice and ocean and associated physical, chemical, and biological processes and interactions. For example, the first-ever quantitative observation of bubbles in Arctic leads, combined with the unique discovery of marine organic material, polymer gels with an origin in the ocean, inside cloud droplets suggests the possibility of primary marine organically derived cloud condensation nuclei in Arctic stratocumulus clouds. Direct observations of surface fluxes of aerosols could, however, not explain observed variability in aerosol concentrations, and the balance between local and remote aerosols sources remains open. Lack of cloud condensation nuclei (CCN) was at times a controlling factor in low-level cloud formation, and hence for the impact of clouds on the surface energy budget. AS-COS provided detailed measurements of the surface energy balance from late summer melt into the initial autumn freezeup, and documented the effects of clouds and storms on the surface energy balance during this transition. In addition to such process-level studies, the unique, independent ASCOS data set can and is being used for validation of satellite retrievals, operational models, and reanalysis data sets.

Introduction Heterotopic ossification (HO), or the abnormal formation of bone in soft tissue, occurs in over 60% of major burn injuries and blast traumas. A significant need exists to improve the current diagnostic modalities for HO which are inadequate to diagnose and intervene on HO at early time-points. Raman spectroscopy has been used in previous studies to report on changes in bone composition during bone development but has not yet been applied to burn induced HO. In this study, we validate transcutaneous, in-vivo Raman spectroscopy as a methodology for early diagnosis of HO in mice following a burn injury. Methods An Achilles tenotomy model was used to study HO formation. Following tenotomy, mice were divided into burn and sham groups with exposure of 30% surface area on the dorsum to 60° water or 30° water for 18 seconds respectively. In-vivo, transcutaneous Raman spectroscopy was performed at early time points (5 days, 2 and 3 weeks) and a late time point (3 months) on both the tenotomized and non-injured leg. These same samples were then dissected down to the bone and ex-vivo Raman measurements were performed on the excised tissue. Bone formation was verified with Micro CT and histology at corresponding time-points. Results Our Raman probe allowed non-invasive, transcutaneous evaluation of heterotopic bone formation. Raman data showed significantly increased bone mineral signaling in the tenotomy compared to control leg at 5 days post injury, with the difference increasing over time whereas Micro CT did not demonstrate heterotopic bone until three weeks. Ex-vivo Raman measurements showed significant differences in the amount of HO in the burn compared to sham groups and also showed differences in the spectra of new, ectopic bone compared to pre-existing cortical bone. Conclusions Burn injury increases the likelihood of developing HO when combined with traumatic injury. In our in-vivo mouse model, Raman spectroscopy allowed for detection of HO formation as early as 5 days post injury. Changes in bone mineral and matrix composition of the new bone were also evidenced in the Raman spectra which could facilitate early identification of HO and allow more timely therapy decisions for HO patients.

Objective To demonstrate the pro-osteogenic effect of burn injury on heterotopic bone formation using a novel burn ossicle in vivo model. Background Heterotopic ossification (HO), or the abnormal formation of bone in soft tissue, is a troubling sequela of burn and trauma injuries. The exact mechanism by which burn injury influences bone formation is unknown. The aim of this study was to develop a mouse model to study the effect of burn injury on heterotopic bone formation. We hypothesized that burn injury would enhance early vascularization and subsequent bone formation of subcutaneously implanted mesenchymal stem cells. Methods Mouse adipose-derived stem cells were harvested from C57/BL6 mice, transfected with a BMP-2 adenovirus, seeded on collagen scaffolds (ossicles), and implanted subcutaneously in the flank region of 8 adult mice. Burn and sham groups were created with exposure of 30% surface area on the dorsum to 60°C water or 30°C water for 18 seconds, respectively (n = 4/group). Heterotopic bone volume was analyzed in vivo by micro-computed tomography for 3 months. Histological analysis of vasculogenesis was performed with platelet endothelial cell adhesion molecule staining. Osteogenic histological analysis was performed by Safranin O, Picrosirius red, and aniline blue staining. Qualitative analysis of heterotopic bone composition was completed with ex vivo Raman spectroscopy. Results Subcutaneously implanted ossicles formed heterotopic bone. Ossicles from mice with burn injuries developed significantly more bone than sham control mice, analyzed by micro-computed tomography at 1, 2, and 3 months (P < 0.05), and had enhanced early and late endochondral ossification as demonstrated by Safranin O, Picrosirius red, and aniline blue staining. In addition, burn injury enhanced vascularization of the ossicles (P < 0.05). All ossicles demonstrated chemical composition characteristic of bone as demonstrated by Raman spectroscopy. Conclusions Burn injury increases the predilection to osteogenic differentiation of ectopically implanted ossicles. Early differences in vascularity correlated with later bone development. Understanding the role of burn injury on heterotopic bone formation is an important first step toward the development of treatment strategies aimed to prevent unwanted and detrimental heterotopic bone formation.