Transient Local Bone Remodeling Effects of rhBMP-2 in an Ovine Interbody Spine Fusion Model

Background: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a powerful osteoinductive morphogen capable of stimulating the migration of mesenchymal stem cells (MSCs) to the site of implantation and inducing the proliferation and differentiation of these MSCs into osteoblasts. Vertebral end-plate and vertebral body resorption has been reported after interbody fusion with high doses of rhBMP-2. In this study, we investigated the effects of 2 rhBMP-2 doses on peri-implant bone resorption and bone remodeling at 7 time points in an end-plate-sparing ovine interbody fusion model. Methods: Twenty-one female sheep underwent an end-plate-sparing discectomy followed by interbody fusion at L2-L3 and L4-L5 using a custom polyetheretherketone (PEEK) interbody fusion device. The PEEK interbody device was filled with 1 of 2 different doses of rhBMP-2 on an absorbable collagen sponge (ACS): 0.13 mg (1·) or 0.90 mg (7·). Bone remodeling and interbody fusion were assessed via high-resolution radiography and histological analyses at 1, 2, 3, 4, 8, 12, and 20 weeks postoperatively. Results: Peri-implant bone resorption peaked between 3 and 8 weeks in both the 1· and the 7· rhBMP-2/ACS-dose group. Osteoclastic activity and corresponding peri-implant bone resorption was dose-dependent, with moderate-tomarked resorption at the 7·-dose level and less resorption at the 1·-dose level. Both dose (p \u3c 0.0007) and time (p \u3c 0.0025) affected bone resorption significantly. Transient bone-resorption areas were fully healed by 12 weeks. Osseous bridging was seen at all but 1 spinal level at 12 and at 20 weeks. Conclusions: In the ovine end-plate-sparing interbody fusion model, rhBMP-2 dose-dependent osteoclastic resorption is a transient phenomenon that peaks at 4 weeks postoperatively. Clinical Relevance: Using the U.S. Food and Drug Administration (FDA)-approved rhBMP-2 concentration and matching the volume of rhBMP-2/ACS with the volume of desired bone formation within the interbody construct may limit the occurrence of transient bone resorption

Impact Of Two-Stage Weaning On Calf Growth, Behavior, and Vocalizations

https://scholarworks.moreheadstate.edu/student_scholarship_posters/1174/thumbnail.jp

The transcriptome of the bowhead whale Balaena mysticetus reveals adaptations of the longest-lived mammal

Mammals vary dramatically in lifespan, by at least two-orders of magnitude, but the molecular basis for this difference remains largely unknown. The bowhead whale Balaena mysticetus is the longest-lived mammal known, with an estimated maximal lifespan in excess of two hundred years. It is also one of the two largest animals and the most cold-adapted baleen whale species. Here, we report the first genome-wide gene expression analyses of the bowhead whale, based on the de novo assembly of its transcriptome. Bowhead whale or cetacean-specific changes in gene expression were identified in the liver, kidney and heart, and complemented with analyses of positively selected genes. Changes associated with altered insulin signaling and other gene expression patterns could help explain the remarkable longevity of bowhead whales as well as their adaptation to a lipid-rich diet. The data also reveal parallels in candidate longevity adaptations of the bowhead whale, naked mole rat and Brandt's bat. The bowhead whale transcriptome is a valuable resource for the study of this remarkable animal, including the evolution of longevity and its important correlates such as resistance to cancer and other diseases

High-frequency acoustic scattering from turbulent oceanic microstructure : the importance of density fluctuations

Author Posting. © Acoustical Society of America, 2003. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 114 (2003): 2685-2697, doi:10.1121/1.1614258.Acoustic scattering techniques provide a unique and powerful tool to remotely investigate the physical properties of the ocean interior over large spatial and temporal scales. With high-frequency acoustic scattering it is possible to probe physical processes that occur at the microstructure scale, spanning submillimeter to centimeter scale processes. An acoustic scattering model for turbulent oceanic microstructure is presented in which the current theory, which only accounts for fluctuations in the sound speed, has been extended to include fluctuations in the density as well. The inclusion of density fluctuations results in an expression for the scattering cross section per unit volume, σv, that is explicitly dependent on the scattering angle. By relating the variability in the density and sound speed to random fluctuations in oceanic temperature and salinity, σv has been expressed in terms of the temperature and salinity wave number spectra, and the temperature-salinity co-spectrum. A Batchelor spectrum for temperature and salinity, which depends on parameters such as the dissipation rates of turbulent kinetic energy and temperature variance, has been used to evaluate σv. Two models for the temperature-salinity co-spectrum have also been used. The predictions indicate that fluctuations in the density could be as important in determining backscattering as fluctuations in the sound speed. Using data obtained in the ocean with a high resolution vertical microstructure profiler, it is predicted that scattering from oceanic microstructure can be as strong as scattering from zooplankton.This work was supported in part by ONR, NSF, and the Woods Hole Oceanographic Institution

Holz-Beton-Verbünde mit konduktiv erwärmter Schnellklebetechnik

Innovationen im Bauwesen zielen häufig auf Kostenreduktion durch Materialeinspa-rung mit neuen Materialkombinationen und schnellerem Baufortschritt durch hohen Vorfertigungsgrad. Weiterhin kommen dem zunehmenden Wunsch nach Nutzung nach-wachsender Rohstoffe im Bauwesen insbesondere Holz-basierte Bauweisen entgegen, die schon seit langem im Fertighausbau für kleinere Gebäude wie 1- und 2-Familien-häuser am Markt verfügbar sind. Da reine Holzbauweisen jedoch für größere Gebäude auf verschiedene Hindernisse stoßen, sind sinnvolle Materialkombinationen mit etab-lierten Baustoffen des Hochbaus eine Lösung. Holz-Beton-Verbünde können in häufig verwendeten Bauelement-Bereichen wie Zwischendecken oder Dächern ihre Eigen-schaften günstig kombinieren und werden bisher üblicherweise entweder mit zahlrei-chen mechanischen Verbindungsmitteln (lange Schrauben) oder durch Verguss von Frischbeton auf Holz realisiert. Eine neuartige Schnellklebetechnik (erstmals untersucht für den Fertighausbau) vermeidet verschiedene Nachteile und ermöglicht Kleben im Hochbau mit beheizter Klebefuge. Strukturelle Klebstoffe können so schneller aushär-ten und ermöglichen einen beschleunigten Baufortschritt im Vergleich zu konventionell kalthärtenden Klebungen. Die Beheizung der Klebefuge wird dabei durch einen dünnen elektrisch leitfähigen Klebebandträger realisiert, der als Strom durchflossener linearer Widerstand kontrolliert erwärmt werden kann. In einem laufenden Forschungsprojekt der Industriellen Gemeinschafts-Forschung (IGF) wird diese Schnellbautechnik für den Einsatz auf der Baustelle von Hochbauten untersucht. Der Beitrag stellt die klebtechni-schen Herausforderungen an verschiedene Konstruktionsklebstoffe speziell an den Grenzflächen der sehr unterschiedlichen Werkstoffe wie Beton, Nadel- oder Laubholz sowie metallischen Klebebandträgern dar

Genomics of post-bottleneck recovery in the northern elephant seal.

Populations and species are threatened by human pressure, but their fate is variable. Some depleted populations, such as that of the northern elephant seal (Mirounga angustirostris), recover rapidly even when the surviving population was small. The northern elephant seal was hunted extensively and taken by collectors between the early 1800s and 1892, suffering an extreme population bottleneck as a consequence. Recovery was rapid and now there are over 200,000 individuals. We sequenced 260 modern and 8 historical northern elephant seal nuclear genomes to assess the impact of the population bottleneck on individual northern elephant seals and to better understand their recovery. Here we show that inbreeding, an increase in the frequency of alleles compromised by lost function, and allele frequency distortion, reduced the fitness of breeding males and females, as well as the performance of adult females on foraging migrations. We provide a detailed investigation of the impact of a severe bottleneck on fitness at the genomic level and report on the role of specific gene systems. [Abstract copyright: © 2024. The Author(s).

Quantifying vertical mixing in estuaries

© 2008 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Environmental Fluid Mechanics 8 (2008): 495-509, doi:10.1007/s10652-008-9107-2.Estuarine turbulence is notable in that both the dissipation rate and the buoyancy frequency extend to much higher values than in other natural environments. The high dissipation rates lead to a distinct inertial subrange in the velocity and scalar spectra, which can be exploited for quantifying the turbulence quantities. However, high buoyancy frequencies lead to small Ozmidov scales, which require high sampling rates and small spatial aperture to resolve the turbulent fluxes. A set of observations in a highly stratified estuary demonstrate the effectiveness of a vessel-mounted turbulence array for resolving turbulent processes, and for relating the turbulence to the forcing by the Reynolds-averaged flow. The observations focus on the ebb, when most of the buoyancy flux occurs. Three stages of mixing are observed: (1) intermittent and localized but intense shear instability during the early ebb; (2) continuous and relatively homogeneous shear-induced mixing during the mid-ebb, and weakly stratified, boundary-layer mixing during the late ebb. The mixing efficiency as quantified by the flux Richardson number Rf was frequently observed to be higher than the canonical value of 0.15 from Osborn (J Phys Oceanogr 10:83–89, 1980). The high efficiency may be linked to the temporal–spatial evolution of shear instabilities.The funding for this research was obtained from ONR Grant N00014-06-1-0292 and NSF Grant OCE-0729547

Annual and Seasonal Surface Circulation Over the Mid-Atlantic Bight Continental Shelf Derived From a Decade of High Frequency Radar Observations

A decade (2007–2016) of hourly 6-km-resolution maps of the surface currents across the Mid-Atlantic Bight (MAB) generated by a regional-scale High Frequency Radar network are used to reveal new insights into the spatial patterns of the annual and seasonal mean surface flows. Across the 10-year time series, temporal means and interannual and intra-annual variability are used to quantify the variability of spatial surface current patterns. The 10-year annual mean surface flows are weaker and mostly cross-shelf near the coast, increasing in speed and rotating to more alongshore directions near the shelfbreak, and increasing in speed and rotating to flow off-shelf in the southern MAB. The annual mean surface current pattern is relatively stable year to year compared to the hourly variations within a year. The 10-year seasonal means exhibit similar current patterns, with winter and summer more cross-shore while spring and fall transitions are more alongshore. Fall and winter mean speeds are larger and correspond to when mean winds are stronger and cross-shore. Summer mean currents are weakest and correspond to a time when the mean wind opposes the alongshore flow. Again, intra-annual variability is much greater than interannual, with the fall season exhibiting the most interseasonal variability in the surface current patterns. The extreme fall seasons of 2009 and 2011 are related to extremes in the wind and river discharge events caused by different persistent synoptic meteorological conditions, resulting in more or less rapid fall transitions from stratified summer to well-mixed winter conditions

Next Steps for Human-Computer Integration

Human-Computer Integration (HInt) is an emerging paradigm in which computational and human systems are closely interwoven. Integrating computers with the human body is not new. however, we believe that with rapid technological advancements, increasing real-world deployments, and growing ethical and societal implications, it is critical to identify an agenda for future research. We present a set of challenges for HInt research, formulated over the course of a five-day workshop consisting of 29 experts who have designed, deployed and studied HInt systems. This agenda aims to guide researchers in a structured way towards a more coordinated and conscientious future of human-computer integration