10,711 results on '"Mitchell B"'
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52. 6. “One Picture May Not Be Worth Ten Thousand Words, but the White House Is Betting It’s Worth Ten Thousand Votes'
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
53. 5. Subtraction by Addition
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
54. 11. The Domestic Politics of Superpower Rapprochement
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
55. 8. Forging Consensus on Vietnamese Reeducation Camp Detainees
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
56. Conclusion. Politics, Diplomacy, and the State of the Field
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
57. 9. The Congressional Human Rights Caucus and the Plight of the Refuseniks
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
58. 7. Creating an Ethnic Lobby
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
59. 10. Peace through Austerity
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
60. List of Contributors
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
61. Index
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
62. Acknowledgments
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Andrew L. Johns, Mitchell B. Lerner, Autumn Lass, David L. Prentice, and Christopher Foss
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- 2018
63. Bounding the systematic error in quantum error mitigation due to model violation
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Govia, L. C. G., Majumder, S., Barron, S. V., Mitchell, B., Seif, A., Kim, Y., Wood, C. J., Pritchett, E. J., Merkel, S. T., and McKay, D. C.
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Quantum Physics - Abstract
Quantum error mitigation is a promising route to achieving quantum utility, and potentially quantum advantage in the near-term. Many state-of-the-art error mitigation schemes use knowledge of the errors in the quantum processor, which opens the question to what extent inaccuracy in the error model impacts the performance of error mitigation. In this work, we develop a methodology to efficiently compute upper bounds on the impact of error-model inaccuracy in error mitigation. Our protocols require no additional experiments, and instead rely on comparisons between the error model and the error-learning data from which the model is generated. We demonstrate the efficacy of our methodology by deploying it on an IBM Quantum superconducting qubit quantum processor, and through numerical simulation of standard error models. We show that our estimated upper bounds are typically close to the worst observed performance of error mitigation on random circuits. Our methodology can also be understood as an operationally meaningful metric to assess the quality of error models, and we further extend our methodology to allow for comparison between error models. Finally, contrary to what one might expect we show that observable error in noisy layered circuits of sufficient depth is not always maximized by a Clifford circuit, which may be of independent interest., Comment: 22 pages including references and appendices, 9 figures
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- 2024
64. Measuring glitch recoveries and braking indices with Bayesian model selection
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Liu, Yang, Keith, Michael J., Antonopoulou, Danai, Weltevrede, Patrick, Shaw, Benjamin, Stappers, Benjamin W., Lyne, Andrew G., Mickaliger, Mitchell B., and Basu, Avishek
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Astrophysics - High Energy Astrophysical Phenomena - Abstract
For a selection of 35 pulsars with large spin-up glitches ($\Delta{\nu}/\nu\geq10^{-6}$), which are monitored by the Jodrell Bank Observatory, we analyse 157 glitches and their recoveries. All parameters are measured consistently and we choose the best model to describe the post-glitch recovery based on Bayesian evidence. We present updated glitch epochs, sizes, changes of spin down rate, exponentially recovering components (amplitude and corresponding timescale) when present, as well as pulsars' second frequency derivatives and their glitch associated changes if detected. We discuss the different observed styles of post-glitch recovery as well as some particularly interesting sources. Several correlations are revealed between glitch parameters and pulsar spin parameters, including a very strong correlation between a pulsar's interglitch $|\ddot{\nu}|$ and $\dot{\nu}$, as well as between the glitch-induced spin-down rate change $\Delta\dot{\nu}_{\rm p}$ that does not relax exponentially and $\dot{\nu}$. We find that the ratio $\left|\Delta \dot{\nu}_{\mathrm{p}}/\ddot{\nu}\right|$ can be used as an estimate of glitch recurrence times, especially for those pulsars for which there are indications of a characteristic glitch size and interglitch waiting time. We calculate the interglitch braking index $n$ and find that pulsars with large glitches typically have $n$ greater than $3$, suggesting that internal torques dominate the rotational evolution between glitches. The external torque, e.g. from electromagnetic dipole radiation, could dominate the observed $\ddot{\nu}$ for the youngest pulsars ($\lesssim10^{4}\;\mathrm{yr}$), which may be expected to display $n\sim3$., Comment: 24 pages, 14 figures, 8 tables. Accepted for publication in MNRAS
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- 2024
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65. Outpatient vs. inpatient hip arthroplasty: a matched case-control study on a 90-day complication rate and 2-year patient-reported outcomes
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Philip J. Rosinsky, Sarah L. Chen, Mitchell J. Yelton, Ajay C. Lall, David R. Maldonado, Jacob Shapira, Mitchell B. Meghpara, and Benjamin G. Domb
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Total hip arthroplasty ,Outpatient arthroplasty ,Patient-reported outcomes ,Orthopedic surgery ,RD701-811 ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
Abstract Background The transition to outpatient-based surgery is a major development occurring in recent years in the field of total hip arthroplasty (THA). The effect of this transition on patient-reported outcomes (PROs) is still not well established. The purpose of the current study was to compare patients undergoing inpatient THA (iTHA) to patients undergoing outpatient THA (oTHA) regarding (1) perioperative variables including surgical time, blood loss, and length of stay (2) 90-day complication rates and unplanned emergency room or office visits (3) 2-year PROs including modified Harris hip score (mHHS), Harris hip score (HHS), forgotten joint score (FJS), pain, and satisfaction, as well as the quality of live measures. Methods The American Hip Institute registry was analyzed for patients undergoing THA between July 2014 and April 2016. The first 100 patients undergoing oTHA were selected and matched to 100 patients undergoing iTHA via propensity matching based on the following variables: age, sex, body mass index (BMI), Charlson comorbidity index (CCI), and smoking status. The primary outcomes were PROs at 2 years post-operatively. The secondary outcomes were perioperative surgical variables, 90-day complication rates, and unplanned emergency and clinic visits. Results After exclusions, 91 patients remained in each group and were compared. The oTHA group showed improved 2-year PROs with regard to mHHS (91.5 vs. 86.2; P = 0.02), HHS (92.3 vs. 87.4; P = 0.02), and pain (1.0 vs. 1.5; P = 0.04). The oTHA group had an average length of stay of 6.8 h compared to 43.2 h for the iTHA group (P < 0.001). There were no significant differences between the groups regarding readmissions, emergency room visits, and unplanned clinic visits. Complications and revision rates were similar in both groups. Conclusion In appropriately selected, younger patients, oTHA can achieve improved postoperative 2-year PROs compared to iTHA. We found no differences regarding postoperative short-term complications or 2-year revision rates, and no differences in unplanned office visits or readmissions. Level of evidence Prognostic level 3.
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- 2020
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66. Return to play after hip arthroscopy among tennis players: outcomes with minimum five-year follow-up
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David R. Maldonado, Mitchell J. Yelton, Philip J. Rosinsky, Jacob Shapira, Mitchell B. Meghpara, Ajay C. Lall, and Benjamin G. Domb
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Hip arthroscopy ,Return to sport ,Patient-reported outcomes ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
Abstract Background Playing tennis is associated with various movements that can lead to labral injuries and may require arthroscopic surgery. While hip arthroscopies have demonstrated good outcomes in athletes, there is limited literature reporting patient reported outcomes (PROs) and return to sport (RTS) in competitive or recreational tennis players after arthroscopic hip surgery. Therefore, the purpose of the present study was to (1) report minimum five-year PROs and RTS in tennis players who underwent arthroscopic hip surgery and (2) compare outcomes between recreational and competitive tennis players. Methods Data for patients who underwent hip arthroscopy surgery in the setting of femoroacetabular impingement and labral tears between March 2009 and January 2014 and who played tennis within one-year of surgery were retrospectively reviewed. Patients with preoperative and minimum five-year postoperative scores for the following PROs were included: modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sport Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain. Patient Acceptable Symptomatic State (PASS) and Minimal Clinically Important Difference (MCID) for mHHS and HOS-SSS were calculated. Results Of 28 patients, 31 hips met all inclusion and exclusion criteria of which 28 (90.3%) had minimum 5-year follow-up (mean: 72.8 ± 13.9 months). There were 3 professional, 3 collegiate, 2 high school, 2 organized amateur, and 18 recreational level tennis players. All PROs significantly improved at latest follow-up: mHHS from 67.0 to 86.7 (P
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- 2020
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67. Altered motor system function in post-concussion syndrome as assessed via transcranial magnetic stimulation
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Mitchell B. Locke, Stephen L. Toepp, Claudia V. Turco, Diana H. Harasym, Michel P. Rathbone, Michael D. Noseworthy, and Aimee J. Nelson
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Transcranial magnetic stimulation ,Post-concussion syndrome ,Concussion ,Inhibition ,Motor cortex ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Objective: It is unclear why specific individuals incur chronic symptoms following a concussion. This exploratory research aims to identify and characterize any neurophysiological differences that may exist in motor cortex function in post-concussion syndrome (PCS). Methods: Fifteen adults with PCS and 13 healthy, non-injured adults were tested. All participants completed symptom questionnaires, and transcranial magnetic stimulation (TMS) was used to measure intracortical and transcallosal excitability and inhibition in the dominant motor cortex. Results: Cortical silent period (p = 0.02, g = 0.96) and ipsilateral silent period (p = 0.04, g = 0.78) were shorter in the PCS group compared to the control group which may reflect reduced GABA-mediated inhibition in PCS. Furthermore, increased corticomotor excitability was observed in the left hemisphere but not the right hemisphere. Conclusions: These data suggest that persistent neurophysiological differences are present in those with PCS. The exact contributing factors to such changes remain to be investigated by future studies. Significance: This study provides novel evidence of lasting neurophysiological changes in PCS.
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- 2020
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68. Isolated Endoscopic Gluteus Medius Repair Can Achieve Successful Clinical Outcomes at Minimum 2-Year Follow-up
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Mitchell B. Meghpara, M.D., Mitchell J. Yelton, B.S., Rachel M. Glein, B.S., Mohammad S. Malik, M.D., Philip J. Rosinsky, M.D., Jacob Shapira, M.D., David R. Maldonado, M.D., Hari K. Ankem, M.D., Ajay C. Lall, M.D., M.S., and Benjamin G. Domb, M.D.
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Sports medicine ,RC1200-1245 - Abstract
Purpose: To report on clinical presentations and outcomes in patients who underwent an isolated endoscopic gluteus medius (GM) repair. Methods: We retrospectively reviewed and prospectively collected data on patients who underwent a primary isolated endoscopic GM repair. Patients were included if the following patient-reported outcome scores were obtained preoperatively and at minimum 2-year follow-up: modified Harris Hip Score (mHHS), Non-arthritic Hip Score (NAHS), and visual analog scale (VAS) score. The minimal clinically important difference (MCID) for the mHHS, NAHS, and Hip Outcome Score–Sports Specific Scale was uniquely calculated for this study. Patients who underwent concomitant procedures including hip arthroplasty and hip arthroscopy were excluded. Results: A total of 26 hips met all inclusion and exclusion criteria, of which 23 hips (88.5%) (22 patients) had a minimum 2-year follow-up. Nineteen hips had a partial-thickness GM tear; 17 (89.5%) were high-grade partial-thickness tears treated with a side-to-side repair through a transtendinous window. Four full-thickness tears with no retraction or fatty infiltration were able to be repaired endoscopically. The mHHS, NAHS, and VAS score all significantly improved (P < .05) from baseline: The mHHS improved from 55.9 to 75.4 (P = .005); the NAHS, from 58.8 to 79.2 (P = .003); and the VAS score, from 5.9 to 3.6 (P = .009). The MCID was calculated for the mHHS, NAHS, and Hip Outcome Score–Sports Specific Scale as 5.8, 7.1, and 11.0, respectively. Most patients achieved the MCID for all 3 patient-reported outcome scores. Conclusions: Appropriately selected patients without concomitant intra-articular hip pathology may achieve successful outcomes at a minimum 2-year follow-up after an isolated endoscopic GM repair. Most isolated endoscopic GM repairs were performed for partial-thickness GM tears. Level of Evidence: Level IV, case-series study.
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- 2021
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69. Machine Learning Prediction of Liver Allograft Utilization From Deceased Organ Donors Using the National Donor Management Goals Registry
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Andrew M. Bishara, MD, Dmytro S. Lituiev, PhD, Dieter Adelmann, MD, PhD, Rishi P. Kothari, MD, Darren J. Malinoski, MD, Jacob D. Nudel, MD, Mitchell B. Sally, MD, Ryutaro Hirose, MD,, Dexter D. Hadley, MD, PhD, and Claus U. Niemann, MD
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Surgery ,RD1-811 - Abstract
Background. Early prediction of whether a liver allograft will be utilized for transplantation may allow better resource deployment during donor management and improve organ allocation. The national donor management goals (DMG) registry contains critical care data collected during donor management. We developed a machine learning model to predict transplantation of a liver graft based on data from the DMG registry. Methods. Several machine learning classifiers were trained to predict transplantation of a liver graft. We utilized 127 variables available in the DMG dataset. We included data from potential deceased organ donors between April 2012 and January 2019. The outcome was defined as liver recovery for transplantation in the operating room. The prediction was made based on data available 12–18 h after the time of authorization for transplantation. The data were randomly separated into training (60%), validation (20%), and test sets (20%). We compared the performance of our models to the Liver Discard Risk Index. Results. Of 13 629 donors in the dataset, 9255 (68%) livers were recovered and transplanted, 1519 recovered but used for research or discarded, 2855 were not recovered. The optimized gradient boosting machine classifier achieved an area under the curve of the receiver operator characteristic of 0.84 on the test set, outperforming all other classifiers. Conclusions. This model predicts successful liver recovery for transplantation in the operating room, using data available early during donor management. It performs favorably when compared to existing models. It may provide real-time decision support during organ donor management and transplant logistics.
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- 2021
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70. coastTrain: A Global Reference Library for Coastal Ecosystems
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Nicholas J. Murray, Pete Bunting, Robert F. Canto, Lammert Hilarides, Emma V. Kennedy, Richard M. Lucas, Mitchell B. Lyons, Alejandro Navarro, Chris M. Roelfsema, Ake Rosenqvist, Mark D. Spalding, Maren Toor, and Thomas A. Worthington
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mangroves ,tidal flats ,mudflats ,tidal marshes ,tidal wetlands ,training set ,Science - Abstract
Estimating the distribution, extent and change of coastal ecosystems is essential for monitoring global change. However, spatial models developed to estimate the distribution of land cover types require accurate and up-to-date reference data to support model development, model training and data validations. Owing to the labor-intensive tasks required to develop reference datasets, often requiring intensive campaigns of image interpretation and/or field work, the availability of sufficiently large quality and well distributed reference datasets has emerged as a major bottleneck hindering advances in the field of continental to global-scale ecosystem mapping. To enhance our ability to model coastal ecosystem distributions globally, we developed a global reference dataset of 193,105 occurrence records of seven coastal ecosystem types—muddy shorelines, mangroves, coral reefs, coastal saltmarshes, seagrass meadows, rocky shoreline, and kelp forests—suitable for supporting current and next-generation remote sensing classification models. coastTrain version 1.0 contains curated occurrence records collected by several global mapping initiatives, including the Allen Coral Atlas, Global Tidal Flats, Global Mangrove Watch and Global Tidal Wetlands Change. To facilitate use and support consistency across studies, coastTrain has been harmonized to the International Union for the Conservation of Nature’s (IUCN) Global Ecosystem Typology. coastTrain is an ongoing collaborative initiative designed to support sharing of reference data for coastal ecosystems, and is expected to support novel global mapping initiatives, promote validations of independently developed data products and to enable improved monitoring of rapidly changing coastal environments worldwide.
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- 2022
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71. Reply to: A Bisphosphonate With a Low Hydroxyapatite Binding Affinity Prevents Bone Loss in Mice After Ovariectomy and Reverses Rapidly With Treatment Cessation
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Abigail A Coffman, Jelena Basta‐Pljakic, Rosa M Guerra, Frank H Ebetino, Mark W Lundy, Robert J Majeska, and Mitchell B Schaffler
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Orthopedic surgery ,RD701-811 ,Diseases of the musculoskeletal system ,RC925-935 - Published
- 2021
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72. Skeletal Response to Insulin in the Naturally Occurring Type 1 Diabetes Mellitus Mouse Model
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Manisha Dixit, Zhongbo Liu, Sher Bahadur Poudel, Gozde Yildirim, Yanjiao Zhang Zhang, Shilpa Mehta, Omer Murik, Geona Altarescu, Yoshifumi Kobayashi, Emi Shimizu, Mitchell B. Schaffler, and Shoshana Yakar
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BONE ,MICRO‐CT ,NOD MICE ,OSTEOCYTE ,RAMAN SPECTROSCOPY ,TYPE 1 DIABETES MELLITUS ,Orthopedic surgery ,RD701-811 ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
ABSTRACT Patients with type 1 diabetes mellitus (T1DM) exhibit reduced BMD and significant increases in fracture risk. Changes in BMD are attributed to blunted osteoblast activity and inhibited bone remodeling, but these cannot fully explain the impaired bone integrity in T1DM. The goal of this study was to determine the cellular mechanisms that contribute to impaired bone morphology and composition in T1DM. Nonobese diabetic (NOD) mice were used, along with μCT, histomorphometry, histology, Raman spectroscopy, and RNAseq analyses of several skeletal sites in response to naturally occurring hyperglycemia and insulin treatment. The bone volume in the axial skeleton was found to be severely reduced in diabetic NOD mice and was not completely resolved with insulin treatment. Decreased bone volume in diabetic mice was associated with increased sclerostin expression in osteocytes and attenuation of bone formation indices without changes in bone resorption. In the face of blunted bone remodeling, decreases in the mineral:matrix ratio were found in cortical bones of diabetic mice by Raman microspectroscopy, suggesting that T1DM did not affect the bone mineralization process per se, but rather resulted in microenvironmental alterations that favored mineral loss. Bone transcriptome analysis indicated metabolic shifts in response to T1DM. Dysregulation of genes involved in fatty acid oxidation, transport, and synthesis was found in diabetic NOD mice. Specifically, pyruvate dehydrogenase kinase isoenzyme 4 and glucose transporter 1 levels were increased, whereas phosphorylated‐AKT levels were significantly reduced in diabetic NOD mice. In conclusion, in addition to the blunted bone formation, osteoblasts and osteocytes undergo metabolic shifts in response to T1DM that may alter the microenvironment and contribute to mineral loss from the bone matrix. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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- 2021
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73. Arthroscopic Triple Reconstruction in the Hip Joint: Restoration of Soft-Tissue Stabilizers in Revision Surgery for Gross Instability
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Hari K. Ankem, M.D., Samantha C. Diulus, B.S., Mitchell B. Meghpara, M.D., Philip J. Rosinsky, M.D., Jacob Shapira, M.D., David R. Maldonado, M.D., Ajay C. Lall, M.D., M.S., and Benjamin G. Domb, M.D.
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Orthopedic surgery ,RD701-811 - Abstract
Gross hip instability in an active adult with previous normal hip anatomy is usually due to disruption of the static stabilizers of the hip joint. Although such a disruption can result from a high-grade injury, it can be iatrogenic after previous hip arthroscopy. The patient may present with a painful limp and recurrent subluxation sensation in the affected hip joint. Revision hip arthroscopy in this scenario is generally complicated, and it is not uncommon for all the soft-tissue stabilizers to be compromised. The labrum, ligamentum teres (LT), and capsule of the hip joint are often so damaged that reparation is not an option. Reconstruction of the torn LT is an established method to add secondary stability while addressing the labral pathology in the hip joint with microinstability. Concomitant reconstruction of all the static restraints has yet to be described addressing triple instability. This Technical Note presents a stepwise approach, including tips and pearls, for arthroscopic triple reconstruction of the labrum, LT, and capsule. We believe this method is a safe and reproducible way to effectively treat gross hip instability in young patients.
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- 2021
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74. A Bisphosphonate With a Low Hydroxyapatite Binding Affinity Prevents Bone Loss in Mice After Ovariectomy and Reverses Rapidly With Treatment Cessation
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Abigail A Coffman, Jelena Basta‐Pljakic, Rosa M Guerra, Frank H Ebetino, Mark W Lundy, Robert J Majeska, and Mitchell B Schaffler
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ANALYSIS/QUANTITATION OF BONE ,ANTIRESORPTIVES ,BONE HISTOMORPHOMETRY ,BONE MICRO‐COMPUTED TOMOGRAPHY (μCT) ,BONE MODELING AND REMODELING ,BONE QUANTITATIVE (QCT) ,Orthopedic surgery ,RD701-811 ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
ABSTRACT Bisphosphonates (BPs) are a mainstay of osteoporosis treatment; however, concerns about bone health based on oversuppression of remodeling remain. Long‐term bone remodeling suppression adversely affects bone material properties with microdamage accumulation and reduced fracture toughness in animals and increases in matrix mineralization and atypical femur fractures in patients. Although a “drug holiday” from BPs to restore remodeling and improve bone quality seems reasonable, clinical BPs have long functional half‐lives because of their high hydroxyapatite (HAP) binding affinities. This places a practical limit on the reversibility and effectiveness of a drug holiday. BPs with low HAP affinity and strong osteoclast inhibition potentially offer an alternative approach; their antiresorptive effect should reverse rapidly when dosing is discontinued. This study tested this concept using NE‐58025, a BP with low HAP affinity and moderate osteoclast inhibition potential. Young adult female C57Bl/6 mice were ovariectomized (OVX) and treated with NE‐58025, risedronate, or PBS vehicle for 3 months to test effectiveness in preventing long‐term bone loss. Bone microarchitecture, histomorphometry, and whole‐bone mechanical properties were assessed. To test reversibility, OVX mice were similarly treated for 3 months, treatment was stopped, and bone was assessed up to 3 months post‐treatment. NE‐58025 and RIS inhibited long‐term OVX‐induced bone loss, but NE‐58025 antiresorptive effects were more pronounced. Withdrawing NE‐58025 treatment led to the rapid onset of trabecular resorption with a 200% increase in osteoclast surface and bone loss within 1 month. Cessation of risedronate treatment did not lead to increases in resorption indices or bone loss. These results show that NE‐58025 prevents OVX‐induced bone loss, and its effects reverse quickly following cessation treatment in vivo. Low‐HAP affinity BPs may have use as reversible, antiresorptive agents with a rapid on/off profile, which may be useful for maintaining bone health with long‐term BP treatment. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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- 2021
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75. Repair of Symptomatic Partial Gluteus Medius Tear During Total Hip Arthroplasty Through the Direct Anterior Approach
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David R. Maldonado, M.D., Samantha C. Diulus, B.S., Mitchell B. Meghpara, M.D., Rachel M. Glein, B.S., Hari K. Ankem, M.D., Ajay C. Lall, M.D., M.S., and Benjamin G. Domb, M.D.
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Orthopedic surgery ,RD701-811 - Abstract
Gluteus medius (GM) tears are a well-established source of pain and disability. Considering previous studies, which have reported rates of incidental GM tears in 20% of patients undergoing primary total hip arthroplasty (THA) and a 3-fold greater rate in elderly female patients, additional focus should be placed on identifying treatment options. The direct anterior approach (DAA) for primary THA has gained popularity within the past few years. However, there has been a paucity in the literature on how to address symptomatic and partial GM tears through this approach. The purpose of this Technical Note is to describe a method to repair partial GM tears during primary THA using the DAA.
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- 2021
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76. Capsular Management of the Hip During Arthroscopic Acetabular Chondral Resurfacing: Pearls, Pitfalls, and Optimal Surgical Technique
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Ajay C. Lall, M.D., M.S., Hari K. Ankem, M.D., Samantha C. Diulus, B.S., David R. Maldonado, M.D., Mitchell B. Meghpara, M.D., Philip J. Rosinsky, M.D., Jacob Shapira, M.D., and Benjamin G. Domb, M.D.
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Orthopedic surgery ,RD701-811 - Abstract
Treatment of hip joint chondral damage is a well-recognized aspect of the arthroscopic management of femoroacetabular impingement syndrome. Hip chondral resurfacing has evolved from microfracture to different forms of cartilage grafting, all with variable long-term outcomes. Recent literature has focused on techniques using different cartilage sources (native and synthetic products) that are available for clinicians to choose from during hip arthroscopy. None of the published reports on cartilage grafts have commented on hip joint capsular management as part of the procedure. This is likely because of the increased difficulty of capsular closure in the dry arthroscopic environment required for graft stabilization. However, potential iatrogenic hip instability induced by an unrepaired interportal capsulotomy can be detrimental to the existing joint architecture and possibly to the cartilage graft. This article presents a step-by-step approach, including tips and pearls, for capsular closure during arthroscopic acetabular chondral resurfacing with BioCartilage (Arthrex, Naples, FL). This method is a safe and reproducible way to close the joint capsule during chondral resurfacing in patients undergoing hip preservation that can potentially enhance the chances of a successful outcome.
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- 2021
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77. Arthroscopic-Assisted Intraosseous Bioplasty of the Acetabulum
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Hari K. Ankem, M.D., Samantha C. Diulus, B.S., David R. Maldonado, M.D., Victor Ortiz-Declet, M.D., Philip J. Rosinsky, M.D., Mitchell B. Meghpara, M.D., Jacob Shapira, M.D., Ajay C. Lall, M.D., M.S., and Benjamin G. Domb, M.D.
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Orthopedic surgery ,RD701-811 - Abstract
Intraosseous bioplasty (IOBP), has been previously described for arthroscopic-assisted treatment of subchondral bone cysts in the proximal tibia associated with early stages of knee osteoarthritis (OA). This technique entails combining bone marrow aspirate concentrate or concentrated platelet-rich plasma with demineralized bone matrix as a bone substitute before injecting into a subchondral bone defect under fluoroscopic guidance. The principles of IOBP as a procedure that combines core decompression with biologic bone substitute augmentation can be extended to treat subchondral bone marrow lesions such as acetabular and femoral cysts in degenerative hip OA. Intraosseous bioplasty of the hip, in particular the acetabulum, when done using this technique, is a useful alternative that can be beneficial in treating young patients with early hip arthritis to achieve successful outcomes while delaying more invasive procedures. The Technical Note described here presents a step-by-step approach, including tips and pearls for arthroscopic-assisted IOBP with decompression of the subchondral cyst in the acetabulum followed by bone substitute injection under fluoroscopic guidance. We believe this method is a safe and reproducible way to treat subchondral defects in young patients with signs of early osteoarthritis of the hip joint.
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- 2020
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78. Acute high-intensity and moderate-intensity interval exercise do not change corticospinal excitability in low fit, young adults.
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Jenin El-Sayes, Claudia V Turco, Lauren E Skelly, Mitchell B Locke, Martin J Gibala, and Aimee J Nelson
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Medicine ,Science - Abstract
Previous research has demonstrated a lack of neuroplasticity induced by acute exercise in low fit individuals, but the influence of exercise intensity is unclear. In the present study, we assessed the effect of acute high-intensity (HI) or moderate-intensity (MOD) interval exercise on neuroplasticity in individuals with low fitness, as determined by a peak oxygen uptake (VO2peak) test (n = 19). Transcranial magnetic stimulation (TMS) was used to assess corticospinal excitability via area under the motor evoked potential (MEP) recruitment curve before and following training. Corticospinal excitability was unchanged after HI and MOD, suggesting no effect of acute exercise on neuroplasticity as measured via TMS in sedentary, young individuals. Repeated bouts of exercise, i.e., physical training, may be required to induce short-term changes in corticospinal excitability in previously sedentary individuals.
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- 2020
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79. Tripartite factors leading to molecular divergence between human and murine smooth muscle.
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Soo Jung Lee, Sabrina Blanchett-Anderson, Simon G Keep, Mitchell B Gasche, and Michael M Wang
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Medicine ,Science - Abstract
A large number of pre-clinical and developmental investigations involve experimental vertebrate animals, of which mice have emerged as a favored organism. Recognition of the differences between humans and mice is essential for assessment of the relevance of animal studies to humans. The primary purpose of this study was to gauge the conservation between human and mouse vascular smooth muscle cell (VSMC) proteins mined from an analysis of the Human Protein Atlas. Two comparison were made: a) immunohistochemistry for 16 proteins in brain, heart, esophagus, bladder, stomach, lung, kidney, and aorta enabled comparison between human and mouse of protein localization in VSMC and non-vascular SMC; and b) multi-species primary protein sequence analysis of an expanded set vascular molecules enabled comparison between VSMC sequences among vertebrate species. In total, three dimensions of diversity were uncovered. First, a significant number of factors show human/mouse differences in cellular expression; these differences occurred in both VSMC and non-vascular SMC in an organ and cell-type dependent fashion. Many markers demonstrated notable cell-to-cell and regional heterogeneity in VSMC of the aorta and non-vascular SMC of the esophagus, bladder, and stomach. Second, species specificity can arise by genetic deletions as exemplified by the human protein adipogenesis regulatory factor (ADIRF), which is not present due to a large sequence gap in mice. Third, we describe significant cross-species protein sequence divergence in selected VSMC proteins which may result in altered orthologue function. In a sample of 346 vascular molecules, 15% demonstrate incomplete vertebrate species gene conservation. Divergence of predicted human/mouse VSMC protein sequences is higher than for endothelial proteins in all species examined. In the future, each of these three cross-species differences could be neutralized using gene manipulation, resulting in improved translational potential of murine experimental models.
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- 2020
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80. The rodent vaginal microbiome across the estrous cycle and the effect of genital nerve electrical stimulation.
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Micah Levy, Christine M Bassis, Eric Kennedy, Katie E Yoest, Jill B Becker, Jason Bell, Mitchell B Berger, and Tim M Bruns
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Medicine ,Science - Abstract
Treatment options are limited for the approximately 40% of postmenopausal women worldwide who suffer from female sexual dysfunction (FSD). Neural stimulation has shown potential as a treatment for genital arousal FSD, however the mechanisms for its improvement are unknown. One potential cause of some cases of genital arousal FSD are changes to the composition of the vaginal microbiota, which is associated with vulvovaginal atrophy. The primary hypothesis of this study was that neural stimulation may induce healthy changes in the vaginal microbiome, thereby improving genital arousal FSD symptoms. In this study we used healthy rats, which are a common animal model for sexual function, however the rat vaginal microbiome is understudied. Thus this study also sought to examine the composition of the rat vaginal microbiota. Treatment rats (n = 5) received 30 minutes of cutaneous electrical stimulation targeting the genital branch of the pudendal nerve, and Control animals (n = 4) had 30-minute sessions without stimulation. Vaginal lavage samples were taken during a 14-day baseline period including multiple estrous periods and after twice-weekly 30-minute sessions across a six-week trial period. Analysis of 16S rRNA gene sequences was used to characterize the rat vaginal microbiota in baseline samples and determine the effect of stimulation. We found that the rat vaginal microbiota is dominated by Proteobacteria, Firmicutes, and Actinobacteria, which changed in relative abundance during the estrous cycle and in relationship to each other. While the overall stimulation effects were unclear in these healthy rats, some Treatment animals had less alteration in microbiota composition between sequential samples than Control animals, suggesting that stimulation may help stabilize the vaginal microbiome. Future studies may consider additional physiological parameters, in addition to the microbiome composition, to further examine vaginal health and the effects of stimulation.
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- 2020
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81. Anti-GD2 induced allodynia in rats can be reduced by pretreatment with DFMO.
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Mitchell B Diccianni, Katarzyna Kempińska, Jon A Gangoti, Alice L Yu, and Linda S Sorkin
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Medicine ,Science - Abstract
BackgroundAnti-GD2 therapy with dinutuximab is effective in improving the survival of high-risk neuroblastoma patients in remission and after relapse. However, allodynia is the major dose-limiting side effect, hindering its use for neuroblastoma patients at higher doses and for other GD2-expressing malignancies. As polyamines can enhance neuronal sensitization, including development of allodynia and other forms of pathological pain, we hypothesized that polyamine depletion might prove an effective strategy for relief of anti-GD2 induced allodynia.MethodSprague-Dawley rats were allowed to drink water containing various concentrations of difluoromethylornithine (DFMO) for several days prior to behavioral testing. Anti-GD2 (14G2a) was injected into the tail vein of lightly sedated animals and basal mechanical hindpaw withdrawal threshold assessed by von Frey filaments. Endpoint serum DFMO and polyamines, assessed 24h after 14G2a injection, were measured by HPLC and mass spectrometry.ResultsAn i.v. injection of 14G2a causes increased paw sensitivity to light touch in this model, a response that closely mimics patient allodynia. Animals allowed to drink water containing 1% DFMO exhibited a significant reduction of 14G2a-induced pain sensitivity (allodynia). Increasing the dosage of the immunotherapeutic increased the magnitude (intensity and duration) of the pain behavior. Administration of DFMO attenuated the enhanced sensitivity. Consistent with the known actions of DFMO on ornithine decarboxylase (ODC), serum putrescene and spermidine levels were significantly reduced by DFMO, though the decrease in endpoint polyamine levels did not directly correlate with the behavioral changes.ConclusionsOur results demonstrate that DFMO is an effective agent for reducing anti-GD2 -induced allodynia. Using DFMO in conjunction with dinutuximab may allow for dose escalation in neuroblastoma patients. The reduction in pain may be sufficient to allow new patient populations to utilize this therapy given the more acceptable side effect profile. Thus, DFMO may be an important adjunct to anti-GD2 immunotherapy in addition to a role as a potential anti-cancer therapeutic.
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- 2020
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82. A porcine model to study the effect of brain death on kidney genomic responses
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Mitchell B. Sally, Darren J. Malinoski, Frank P. Zaldivar, Tony Le, Matin Khoshnevis, William A. Pinette, Michael Hutchens, and Shlomit Radom-Aizik
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Basic translational research ,brain death ,porcine model ,transplantation ,inflammation ,genomic ,donor management ,Medicine - Abstract
IntroductionA majority of transplanted organs come from donors after brain death (BD). Renal grafts from these donors have higher delayed graft function and lower long-term survival rates compared to living donors. We designed a novel porcine BD model to better delineate the incompletely understood inflammatory response to BD, hypothesizing that adhesion molecule pathways would be upregulated in BD.MethodsAnimals were anesthetized and instrumented with monitors and a balloon catheter, then randomized to control and BD groups. BD was induced by inflating the balloon catheter and animals were maintained for 6 hours. RNA was extracted from kidneys, and gene expression pattern was determined.ResultsIn total, 902 gene pairs were differently expressed between groups. Eleven selected pathways were upregulated after BD, including cell adhesion molecules.ConclusionsThese results should be confirmed in human organ donors. Treatment strategies should target involved pathways and lessen the negative effects of BD on transplantable organs.
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- 2018
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83. Translational geroscience: From invertebrate models to companion animal and human interventions
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Mitchell B. Lee and Matt Kaeberlein
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Medicine - Abstract
Translational geroscience is an interdisciplinary field descended from basic gerontology that seeks to identify, validate, and clinically apply interventions to maximize healthy, disease-free lifespan. In this review, we describe a research pipeline for the identification and validation of lifespan extending interventions. Beginning in invertebrate model systems, interventions are discovered and then characterized using other invertebrate model systems (evolutionary translation), models of genetic diversity, and disease models. Vertebrate model systems, particularly mice, can then be utilized to validate interventions in mammalian systems. Collaborative, multi-site efforts, like the Interventions Testing Program (ITP), provide a key resource to assess intervention robustness in genetically diverse mice. Mouse disease models provide a tool to understand the broader utility of longevity interventions. Beyond mouse models, we advocate for studies in companion pets. The Dog Aging Project is an exciting example of translating research in dogs, both to develop a model system and to extend their healthy lifespan as a goal in itself. Finally, we discuss proposed and ongoing intervention studies in humans, unmet needs for validating interventions in humans, and speculate on how differences in survival among human populations may influence intervention efficacy. Keywords: Translational geroscience, Healthspan, Longevity, Aging, Rapamycin, Metformin, mTOR, Companion animals
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- 2018
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84. How Much Shallow Coral Habitat Is There on the Great Barrier Reef?
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Chris M. Roelfsema, Mitchell B. Lyons, Carolina Castro-Sanguino, Eva M. Kovacs, David Callaghan, Magnus Wettle, Kathryn Markey, Rodney Borrego-Acevedo, Paul Tudman, Meredith Roe, Emma V. Kennedy, Manuel Gonzalez-Rivero, Nicholas Murray, and Stuart R. Phinn
- Subjects
coral reef ,Great Barrier Reef ,geomorphic ,benthic ,habitat map ,Sentinel-2 ,Science - Abstract
Australia’s Great Barrier Reef (GBR) is a globally unique and precious national resource; however, the geomorphic and benthic composition and the extent of coral habitat per reef are greatly understudied. However, this is critical to understand the spatial extent of disturbance impacts and recovery potential. This study characterizes and quantifies coral habitat based on depth, geomorphic and benthic composition maps of more than 2164 shallow offshore GBR reefs. The mapping approach combined a Sentinel-2 satellite surface reflectance image mosaic and derived depth, wave climate, reef slope and field data in a random-forest machine learning and object-based protocol. Area calculations, for the first time, incorporated the 3D characteristic of the reef surface above 20 m. Geomorphic zonation maps (0–20 m) provided a reef extent estimate of 28,261 km2 (a 31% increase to current estimates), while benthic composition maps (0–10 m) estimated that ~10,600 km2 of reef area (~57% of shallow offshore reef area) was covered by hard substrate suitable for coral growth, the first estimate of potential coral habitat based on substrate availability. Our high-resolution maps provide valuable information for future monitoring and ecological modeling studies and constitute key tools for supporting the management, conservation and restoration efforts of the GBR.
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- 2021
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85. Temporal Changes in Association Patterns of Cattle Grazing at Two Stocking Densities in a Central Arizona Rangeland
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Colin T. Tobin, Derek W. Bailey, Mitchell B. Stephenson, and Mark G. Trotter
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GPS tracking ,grazing distribution ,forage utilization ,social associations ,cattle ,Veterinary medicine ,SF600-1100 ,Zoology ,QL1-991 - Abstract
Proper grazing management of arid and semi-arid rangelands requires experienced personnel and monitoring. Applications of GPS tracking and sensor technologies could help ranchers identify livestock well-being and grazing management issues so that they can promptly respond. The objective of this case study was to evaluate temporal changes in cattle association patterns using global positioning system (GPS) tracking in pastures with different stocking densities (low stocking density [LSD] = 0.123 animals ha−1, high stocking density [HSD] = 0.417 animals ha−1) at a ranch near Prescott, Arizona. Both pastures contained similar herd sizes (135 and 130 cows, respectively). A total of 32 cows in the HSD herd and 29 cows in the LSD herd were tracked using GPS collars at location fixes of 30 min during a 6-week trial in the summer of 2019. A half-weight index (HWI) value was calculated for each pair of GPS-tracked cattle (i.e., dyads) to determine the proportion of time that cattle were within 75 m and 500 m of each other. Forage mass of both pastures were relatively similar at the beginning of the study and forage utilization increased from 5 to 24% in the HSD pasture and increased from 10 to 20% in the LSD pasture. Cattle in both pastures exhibited relatively low mean association values (HWI < 0.25) at both spatial scales. Near the end of the study, cattle began to disperse likely in search of forages (p < 0.01) and travelled farther (p < 0.01) from water than during earlier periods. Real-time GPS tracking has the potential to remotely detect changes in animal spatial association (e.g., HWI), and identify when cows disperse, likely searching for forage.
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- 2021
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86. Author Correction: Reef Cover, a coral reef classification for global habitat mapping from remote sensing
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Emma V. Kennedy, Chris M. Roelfsema, Mitchell B. Lyons, Eva M. Kovacs, Rodney Borrego-Acevedo, Meredith Roe, Stuart R. Phinn, Kirk Larsen, Nicholas J. Murray, Doddy Yuwono, Jeremy Wolff, and Paul Tudman
- Subjects
Science - Published
- 2021
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87. A Colourimetric Approach to Ecological Remote Sensing: Case Study for the Rainforests of South-Eastern Australia
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Ricardo A. Aravena, Mitchell B. Lyons, Adam Roff, and David A. Keith
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ecological remote sensing ,satellite imagery interpretation ,false colour colourimetry ,rainforests ,Science - Abstract
To facilitate the simplification, visualisation and communicability of satellite imagery classifications, this study applied visual analytics to validate a colourimetric approach via the direct and scalable measurement of hue angle from enhanced false colour band ratio RGB composites. A holistic visual analysis of the landscape was formalised by creating and applying an ontological image interpretation key from an ecological-colourimetric deduction for rainforests within the variegated landscapes of south-eastern Australia. A workflow based on simple one-class, one-index density slicing was developed to implement this deductive approach to mapping using freely available Sentinel-2 imagery and the super computing power from Google Earth Engine for general public use. A comprehensive accuracy assessment based on existing field observations showed that the hue from a new false colour blend combining two band ratio RGBs provided the best overall results, producing a 15 m classification with an overall average accuracy of 79%. Additionally, a new index based on a band ratio subtraction performed better than any existing vegetation index typically used for tropical evergreen forests with comparable results to the false colour blend. The results emphasise the importance of the SWIR1 band in discriminating rainforests from other vegetation types. While traditional vegetation indices focus on productivity, colourimetric measurement offers versatile multivariate indicators that can encapsulate properties such as greenness, wetness and brightness as physiognomic indicators. The results confirmed the potential for the large-scale, high-resolution mapping of broadly defined vegetation types.
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- 2021
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88. [UAAC Awards]
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Frank, Mitchell B., Bresnahan, Keith, and Silver, Erin
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- 2024
89. RACAR at 50 : A Brief History
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Frank, Mitchell B.
- Published
- 2024
90. Assessing precipitation, evapotranspiration, and NDVI as controls of U.S. Great Plains plant production
- Author
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Maosi Chen, William J. Parton, Melannie D. Hartman, Stephen J. Del Grosso, William K. Smith, Alan K. Knapp, Susan Lutz, Justin D. Derner, Compton J. Tucker, Dennis S. Ojima, Jerry D. Volesky, Mitchell B. Stephenson, Walter H. Schacht, and Wei Gao
- Subjects
aboveground net primary production ,cumulative actual evapotranspiration water loss ,cumulative growing season normalized difference vegetation index ,North American Great Plains grasslands ,Ecology ,QH540-549.5 - Abstract
Abstract Productivity throughout the North American Great Plains grasslands is generally considered to be water limited, with the strength of this limitation increasing as precipitation decreases. We hypothesize that cumulative actual evapotranspiration water loss (AET) from April to July is the precipitation‐related variable most correlated to aboveground net primary production (ANPP) in the U.S. Great Plains (GP). We tested this by evaluating the relationship of ANPP to AET, precipitation, and plant transpiration (Tr). We used multi‐year ANPP data from five sites ranging from semiarid grasslands in Colorado and Wyoming to mesic grasslands in Nebraska and Kansas, mean annual NRCS ANPP, and satellite‐derived normalized difference vegetation index (NDVI) data. Results from the five sites showed that cumulative April‐to‐July AET, precipitation, and Tr were well correlated (R2: 0.54–0.70) to annual changes in ANPP for all but the wettest site. AET and Tr were better correlated to annual changes in ANPP compared to precipitation for the drier sites, and precipitation in August and September had little impact on productivity in drier sites. April‐to‐July cumulative precipitation was best correlated (R2 = 0.63) with interannual variability in ANPP in the most mesic site, while AET and Tr were poorly correlated with ANPP at this site. Cumulative growing season (May‐to‐September) NDVI (iNDVI) was strongly correlated with annual ANPP at the five sites (R2 = 0.90). Using iNDVI as a surrogate for ANPP, we found that county‐level cumulative April–July AET was more strongly correlated to ANPP than precipitation for more than 80% of the GP counties, with precipitation tending to perform better in the eastern more mesic portion of the GP. Including the ratio of AET to potential evapotranspiration (PET) improved the correlation of AET to both iNDVI and mean county‐level NRCS ANPP. Accounting for how different precipitation‐related variables control ANPP (AET in drier portion, precipitation in wetter portion) provides opportunity to develop spatially explicit forecasting of ANPP across the GP for enhancing decision‐making by land managers and use of grassland ANPP for biofuels.
- Published
- 2019
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91. A review of epigenetics in human consciousness
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Mitchell B. Liester and Erin E. Sullivan
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cellular memory ,brain ,chromatin ,dna ,dna methylation ,histone modification ,neuroepigenetics ,non-coding rnas ,transgenerational epigenetic inheritance ,Psychology ,BF1-990 ,Neurophysiology and neuropsychology ,QP351-495 - Abstract
The field of epigenetics, which is the study of factors regulating gene transcription, is expanding rapidly. Yet one area that has received little attention is the influence of epigenetic factors on human consciousness. We examine this topic by investigating how transcriptional regulation modulates the development and ongoing functioning of the human brain, mediates interactions between the environment and the genome, and may contribute to the evolution of consciousness. Epigenetics is demonstrated to play an instrumental role in human consciousness throughout the lifespan and over the course of multiple generations. Further research is recommended to broaden and deepen our understanding of the relationship between epigenetics and human consciousness.
- Published
- 2019
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92. A Cacophony of Echoes from daily monitoring of the Crab Pulsar at Jodrell Bank
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Nadeau, Thierry Serafin, van Kerkwijk, Marten H., Bassa, Cees G., Stappers, Ben W., Mickaliger, Mitchell B., and Lyne, Andrew G.
- Subjects
Astrophysics - High Energy Astrophysical Phenomena - Abstract
Using archival data from the 42 foot telescope at the Jodrell Bank Observatory, we produce daily stacks of aligned giant pulses for the Crab pulsar, to study changes to the daily profiles between April 2012 to December 2016. From these, we identify echoes, where intervening material away from the line of sight causes pulsed emission to be redirected towards the observer, with delay corresponding to the increased distance of travel, resulting in additional profile components. These observations show that such echoes may be far more common than implied by the previous rate of detections. All the observed echoes are consistent with approaching zero-delay at their closest approach to the normal giant pulse emission. This indicates that the structures responsible for producing these events must be highly anisotropic, with typical lengths greater than $\sim 4\textrm{AU}$, typical widths on the sky of $\sim 0.1 \textrm{AU}$ and typical depths of $\sim 5\textrm{AU}$, given the previously observed electron densities of the nebular filaments, on the order of 1000 cm$^{-3}$. This suggests that these inhomogeneities are likely to be offshoot substructure from the larger nebular filaments of the Crab nebula., Comment: 11 pages, 7 figures, accepted for publication in The Astrophysical Journal
- Published
- 2023
93. Cover
- Author
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Mitchell B. Hart
- Published
- 2011
94. Jews and Race: An Introductory Essay
- Author
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Mitchell B. Hart
- Published
- 2011
95. Acknowledgments
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Mitchell B. Hart
- Published
- 2011
96. Title Page
- Author
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Mitchell B. Hart
- Published
- 2011
97. Frontmatter
- Author
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Mitchell B. Hart
- Published
- 2011
98. Part II Anthropology
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Mitchell B. Hart
- Published
- 2011
99. 2 Reflections on the Jews
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Mitchell B. Hart
- Published
- 2011
100. 5 On the Origins and Race of the Jews
- Author
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Mitchell B. Hart
- Published
- 2011
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