42 research outputs found
Glutamate Receptor Expression After Traumatic Brain Injury In A Rat Model Of Depression
No full textBy Maxon Knott, Neurobiology; Noah Ziemba, University of Pittsburgh; Jennifer McGuire, University of Cincinnati; Erika Correll, University of Massachusetts Amherst
Advisor: Laura Ngwenya
Abstract: Traumatic Brain Injury (TBI) patients with pre-existing psychiatric diagnoses have worse outcomes after TBI but are almost universally excluded from clinical TBI research. In order to study processes that impede recovery in vulnerable individuals, we used the Wistar-Kyoto (WKY) rat. The WKY strain has a behavioral phenotype that recapitulates aspects of human depression. Dysregulation of glutamate signaling is implicated in the etiology of multiple neurobehavioral disorders including major depression. We hypothesized that TBI would impact glutamate signalling more in the WKY rats than the Wistar (WIS) parent strain. We used the lateral fluid percussion model to induce TBI in adult male WKY and WIS rats, with sham controls for each strain. We used Western blotting to determine proteinlevels of_-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid(AMPA) receptor subunits, GluA1 and GluA2,N-methyl-D-aspartate(NMDA) receptor subunits, GluN2A and GluN2B, and the astrocytic glutamate transporter GLAST in the hippocampus 21 days after TBI. Western blot data were analyzed using two-way ANOVA. We found no effect of strain or TBI on expression of GluA1 or GluA2. Expression of GluN2Awas significantly higher in WKY than WIS rats (p=0.014) but was unaffected by TBI. GLAST expression was also higher in WKY rats (strain, p=0.0315) and not significantly altered by TBI. We found a significant effect of TBI (p=0.018) and an interaction of TBI and strain (p=0.005) on expression of GluN2B. GluN2B protein was significantly increased after TBI in WIS rats compared to WIS sham (p=0.0023) and both WKY groups (WKY sham, p=0.031; WKY TBI, p=0.017). Our data indicate that there are initial difference
Review of \u3ci\u3e The Real Roadrunner\u3c/i\u3e by Martha Anne Maxon
No full textThis lively little book is the ninth installment in the Animal Natural History Series published by University of Oklahoma Press. Its author, Martha Maxon, has aptly chosen to reveal the true nature of the greater roadrunner, a veritable icon of southwestern bird life. Perhaps no one is better able to accomplish this: Maxon arguably possesses greater intimate knowledge of roadrunners\u27 private lives than any other ornithologist
New or noteworthy ferns from the Dominican Republic
No full textIn an earlier paper, this author dealt briefly with an interesting collection of ferns obtained by Dr. W. L. Abbott in the northeastern part of the Dominican Republic from November, 1920, to May, 1921, describing a new species of Anemia and listing a number of additional species that were either little known or new to the Dominican Republic. The present notes relate chiefly to the ferns of two more recent collections, made respectively in 1922 and the early part of 1923
A neutron scattering study of the elementary excitations of superfluid"4He and the effects of confinement in restricted geometries
No full textNeutron inelastic scattering measurements of the low energy excitations of liquid "4He are presented. High resolution measurements of three wavevector regions of the bulk liquid are described: at the roton, the maxon and the region beyond the roton. In the bulk liquid, a very high resolution study of the temperature dependence of the roton energy is made, and an argument as to whether or not there is a deviation from the successful theory of Bedell, Pines and Zawadowski is resolved conclusively in favour of the existing theory. The behaviour of the maxon energy at temperatures close to the transition temperature is studied, and some attempt is made to link the excitation signal to the Bose condensate. The wavevector region above the roton is studied, and the excitation spectrum is compared with the theory of Clyde and Griffin. Confining liquid "4He in restricted geometries dramatically affects its properties. The effects of confining the liquid in disordered environments provided by porous aerogel glass, xerogel glass, and MCM-48 glass on the microscopic excitations are studied, and the excitation spectrum is found to have two main components: a sharp signal at the phonon-maxon-roton energy arising from the bulk-like three dimensional excitation, and a low-energy, low-intensity mode arising from the layer mode existing in liquid layers close to the walls of the confining medium. The characteristics of this layer mode appear to be highly dependent on the microscopic geometry of the medium. Some uncertainty within the community regarding the temperature dependence of the bulk-like excitation energy is conclusively resolved. Some work is directed at establishing a link between the microscopic and macroscopic effects of confining the helium in restricted geometries. (author)SIGLEAvailable from British Library Document Supply Centre- DSC:DXN057717 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Global Trends in the Neurosurgical Literature: A 20-Year Bibliometric Analysis by Country Income Group
No full textDespite growing global interest in neurosurgical equity, research output remains concentrated in high-income countries (HICs), with limited representation from lower-middle-income countries (LMICs). Although the global neurosurgery movement has highlighted these disparities, its impact on authorship and research equity is unclear. This study uses bibliometric analysis to evaluate 20-year trends in neurosurgical publications, focusing on authorship patterns across World Bank income groups.BACKGROUND AND OBJECTIVESDespite growing global interest in neurosurgical equity, research output remains concentrated in high-income countries (HICs), with limited representation from lower-middle-income countries (LMICs). Although the global neurosurgery movement has highlighted these disparities, its impact on authorship and research equity is unclear. This study uses bibliometric analysis to evaluate 20-year trends in neurosurgical publications, focusing on authorship patterns across World Bank income groups.A bibliometric analysis of publications with topic of "neurosurgery" indexed in the Web of Science database from 2005 to 2024 was conducted. Author affiliations were categorized by World Bank income classifications: HIC, upper-middle-income countries, LMICs, and low-income countries (LICs). Lorenz curves and Gini coefficients were used to assess inequality in research output, and the Mann-Kendall trend test evaluated trends over time.METHODSA bibliometric analysis of publications with topic of "neurosurgery" indexed in the Web of Science database from 2005 to 2024 was conducted. Author affiliations were categorized by World Bank income classifications: HIC, upper-middle-income countries, LMICs, and low-income countries (LICs). Lorenz curves and Gini coefficients were used to assess inequality in research output, and the Mann-Kendall trend test evaluated trends over time.A total of 27 391 neurosurgical publications from 170 countries were analyzed. HICs contributed 80.55% of overall authorship and 77.16% of corresponding authorship. By contrast, LICs contributed just 2.54% of overall authorship and 0.33% of corresponding authorship. Multicountry collaborations accounted for 26.13% of all publications, of which 95.37% included HIC authors, whereas only 9.14% included LIC authors. From 2005 to 2024, the share of corresponding authorship from HICs declined from 86.16% to 58.88%, whereas contributions from upper-middle-income countries, LMICs, and LICs rose significantly (P < .001). Overall, Gini coefficients improved from 0.74 in 2005 to 0.61 in 2023, indicating a modest but statistically significant reduction in research inequality over time (tau = -0.79, P < .001).RESULTSA total of 27 391 neurosurgical publications from 170 countries were analyzed. HICs contributed 80.55% of overall authorship and 77.16% of corresponding authorship. By contrast, LICs contributed just 2.54% of overall authorship and 0.33% of corresponding authorship. Multicountry collaborations accounted for 26.13% of all publications, of which 95.37% included HIC authors, whereas only 9.14% included LIC authors. From 2005 to 2024, the share of corresponding authorship from HICs declined from 86.16% to 58.88%, whereas contributions from upper-middle-income countries, LMICs, and LICs rose significantly (P < .001). Overall, Gini coefficients improved from 0.74 in 2005 to 0.61 in 2023, indicating a modest but statistically significant reduction in research inequality over time (tau = -0.79, P < .001).Despite a 4-fold increase in publication volume and rising international collaboration, neurosurgical research remains heavily dominated by HICs. While authorship equity has modestly improved over the past 2 decades, disparities remain stark, especially for LICs. These findings highlight the need for targeted, sustainable efforts to promote equitable research partnerships, capacity building, and lower-middle-income country leadership in global neurosurgery.CONCLUSIONDespite a 4-fold increase in publication volume and rising international collaboration, neurosurgical research remains heavily dominated by HICs. While authorship equity has modestly improved over the past 2 decades, disparities remain stark, especially for LICs. These findings highlight the need for targeted, sustainable efforts to promote equitable research partnerships, capacity building, and lower-middle-income country leadership in global neurosurgery
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QLTI-11. PREDICTORS OF PROLONGED LENGTH OF STAY IN LASER INTERSTITIAL THERMAL THERAPY FOR INTRACRANIAL PATHOLOGIES: A SINGLE CENTER EXPERIENCE
No full textAbstract INTRODUCTION Laser interstitial thermal therapy (LITT) offers a minimally invasive approach for treating intracranial pathologies, often with shorter hospital stays than traditional craniotomies. Yet, some patients still face prolonged length of stay (PLOS), highlighting the need to identify contributing factors and improve post-LITT outcomes. OBJECTIVE To evaluate factors contributing to PLOS following LITT for intracranial pathologies. METHODS A retrospective review was conducted between 2013-2023 for patients undergoing LITT for intracranial pathology at a tertiary care center. PLOS was defined as discharge >2 days. Multivariate logistic regression analyzed variables as contributors to PLOS including ICU LOS (hours), preoperative maximum tumor diameter (cm), lesion location, lesion pathology (high grade glioma (HGG)/glioblastoma (GBM) vs. other), and mFI-11 score (binary ≥ or < 75th percentile). RESULTS The cohort consisted of 288 patients, with 29% (83/288) and 71% (205/288) having PLOS and non-PLOS, respectively. Mean age was similar between the PLOS (63-years) and non-PLOS (60-years) groups (p=0.09). The PLOS group had a 55% male predominance compared to 57% female in the non-PLOS group. Greater mFI-11 scores showed increased risk of PLOS [4.01, (2.11, 7.60), p<0.000]. Lesions having a subcortical location [3.43 (1.70, 6.95), p=0.001] or diagnosis of HGG or GBM [2.87 (1.54, 5.34), p=0.001] had increased risk of PLOS. Importantly, maximum pre-operative diameter did not significantly alter risk of PLOS [1.05 (0.98, 1.13), p=0.151]. CONCLUSION For the first time, we show that patient comorbidities, subcortical lesion location, HGG/GBM pathology, and greater time spent in the ICU portend increased risk of PLOS following LITT. Future work should validate our model with the goal of optimizing post-operative patient management and resource allocation
Development of six degree of freedom SCARA robot / Syazwan Ab Rahim Halimi
No full textSCARA Robot is one of the types of robot that exist today. The SCARA acronym stands for Selective Compliant Assembly Robot Arm or Selective Compliant Articulated Robot Arm. By virtue of the SCARA's parallel-axis joint layout, the arm is slightly compliant in the 'X-Y' direction but rigid in the 'Z' direction. Regarding this project, the author has designed the actuators, also known as servo motors for the SCARA robot that has been initially designed by students from the previous year. The strength of the SCARA robot has been determined analytically using Finite Element Analysis via CATIA. The actuators are designed not just to move the SCARA arms in the appropriate order but to determine the most efficient cost that should be spent on them. The process of designing the actuators involved the calculations of inertia, voltage, current, speed, torque and etc. Most of the calculations are based on calculations provided by Maxon Motor Company; a company that has been so tremendous in robotics and plays a major part in supplying this project. However, the results from the machine-human interface provided by Maxon depend on manual calculations of equation of motion. Every aspect must be considered so that the actuators, which going to be selected at the end of the research shall work as expected and the programming process may run smoothly. In term of control system, transfer functions that relate the torque constant, rotor inductance and terminal resistance are produced. These transfer functions are manipulated in order to obtain stability for each actuator respectively. The study on the stability is then conducted using Simulink of MATLAB. Simulink would enable the system to be controlled appropriately by bounding some characteristics such as settling time, rise time and peak time within specified value that would make it dynamically stabl
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No full textDistinguished Alumni Award Program author. RDML Philip J. Coady Jr.USN (Ret) (Presented 27 Mar 06)The thesis considers the impact of return on investment, progress payments, and cash flow in the shipbuilding industry. Analysis is devoted to the progress payment method recommended by the Navy Task Group to Study Shipbuilding Progress Payments. An examination is made of both Government profit policy and contract financing as they relate to the shipbuilding industry. A computer model was developed which makes explicit the discounted cash flow in a given contract and displays all government payments to the contractor as well as the contractor's share of contract financing. The time-adjusted rate of return which is implied by the terms and conditions of the contract is computed by the model. A decision process for computing a profit negotiation position is developed which integrates (1) the IAC profit computation system, (2) the proposed shipbuilding progress payment method, and (3) the prevailing market conditions.NANAhttp://archive.org/details/considerationsof109451604
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INNV-17. SAME-DAY DISCHARGE AFTER LASER INTERSTITIAL THERMAL THERAPY: A PROSPECTIVE COHORT PILOT STUDY WITH A MATCHED CONTROL GROUP
No full textAbstract BACKGROUND Laser interstitial thermal therapy (LITT) has emerged as a minimally invasive treatment modality for intracranial pathologies, offering precision and control over tissue damage. With implementation of enhanced recovery after surgery (ERAS) protocols within neurosurgery, identifying patients amenable for same-day discharge (SDD) is an important step towards streamlining perioperative care following LITT, and correspondingly, we aim to summarize our initial experience. METHODS We conducted a prospective study at the University of Miami Hospital of 7 patients who underwent LITT for intracranial pathologies and were discharged on the same day of ablation (post-ablation day 0, PAD0). We then performed a retrospective case-control study against a historic matched PAD1 cohort comparing categorical and continuous variables for statistical significance. RESULTS The mean age of the PAD0 cohort was 55 years with 71% males. Preoperative neurological status and comorbidities did not differ significantly between the PAD0 and PAD1 cohorts for KPS (median [IQR]: 80 [80-90] vs. 90 [80-90], p=0.40), mFI-5 (median [IQR]: 1 [1.5] vs. 0 [1], p=0.54), and mFI-11 (median [IQR]: 1 [1.5] vs. 1 [1], p=0.52). PAD0 outcomes demonstrated no immediate complications, neurosurgical readmissions, or significant neurological deficits within 6 months post-procedure and were non-significantly different than PAD1 patients. No PAD0 patient experienced intracranial hemorrhage or vasogenic edema following LITT that necessitated further intervention. CONCLUSIONS Our study demonstrates the safety and feasibility of same-day discharge following LITT for intracranial pathologies in the appropriately selected patient. Through meticulous patient selection and optimized perioperative protocols, expedited recovery without compromising patient outcomes was achieved. This approach holds potential for substantial cost savings and resource optimization within healthcare systems. Further research and quality improvement initiatives are warranted to refine patient selection criteria and maximize the benefits of same-day discharge in LITT practice
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SURG-30. SURVIVAL AND OUTCOMES ANALYSIS OF PATIENTS TREATED WITH LASER INTERSTITIAL THERMAL THERAPY FOR LARGE-VOLUME GLIOBLASTOMA
No full textAbstract INTRODUCTION Laser interstitial thermal therapy (LITT) has shown increased patient survival and outcomes in glioblastoma multiforme (GBM). However, its safety and survival in large-volume GBM tumors has been poorly elucidated. OBJECTIVE To evaluate the use of LITT in large-volume GBMs. METHODS A retrospective cohort of adult patients with grade IV IDH-wt GBM measuring ≥ 10 cm3 who were treated with LITT was compared to a control group with volumes 0.05). Across the entire cohort, mFI-11 score, recurrent lesions, and EOA showed no significance as individual predictors of death (p>0.25). AOS (p<0.005) and 30-day readmission (p<0.005) showed significantly increased hazard for the entire cohort. Importantly, volume group did not significantly increase hazard (1.16 [0.68, 1.98], p=0.60). CONCLUSION This is the first study evaluating the safety and efficacy of LITT in large-volume GBMs, specifically, with a larger cohort than any existing analysis sub-grouped by volume. We show LITT can be safe and efficacious, without significantly increased mortality compared to in small-volume GBMs
