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Aviation Fuel Supply Chain Risk Assessment for the United States Air Force
No full textThe increase in frequency and severity of natural disasters and extreme weather events due to climate change is a growing concern for the Operational Energy Office of US Air Force (USAF). Through a series of secondary research, supply chain modelling, and analysis, this study analyzes the current climate risk to the USAF’s Aviation Fuel supply chain along the Gulf and East coasts of the United States. Leveraging these findings, this report models risk reduction through the strategic integration of Sustainable Aviation Fuel into the existing supply chain. The collection of data and modeling techniques employed in this study will enable the USAF to initiate exploration of cost-risk analysis for the integration of SAF in its supply chain operations in the future
Sounds of senescence: Male swamp sparrows respond less aggressively to the songs of older individuals
No full textAge-related changes in assessment signals occur in a diverse array of animals, including humans. Age-related decline in vocal quality in humans is known to affect perceived attractiveness by potential mates and voters, but whether such changes have functional implications for nonhuman animals is poorly understood. Most studies of age-related change in animal signals focus on increases in signal quality that occur soon after the age of first breeding (“delayed maturation”), but a few have shown that signal quality declines in older individuals after a mid-life peak (“behavioral senescence”). Whether other individuals are able to detect this senescent decline of assessment signals has not previously been tested. Here we use playback experiments to show that wild male swamp sparrows (Melospiza georgiana) respond more aggressively to songs from 2-year-old males as compared with songs from the same males when they are 10 years old. Senescence in signals that, like birdsong, affect reproductive success through intrasexual competition or mate choice may be of evolutionary significance. Lay Summary: Using playback experiments with wild swamp sparrows (Melospiza georgiana), we demonstrate that listeners both detect and respond to age-related declines in vocal quality. Two previous studies have shown that some song characteristics deteriorate with age later in life in songbirds, but to our knowledge this is the first demonstration outside of humans that such deterioration affects receiver response. Discrimination of songs from males of different ages may have evolutionary implications
Macrophage NFATC2 mediates angiogenic signaling during mycobacterial infection.
No full textDuring mycobacterial infections, pathogenic mycobacteria manipulate both host immune and stromal cells to establish and maintain a productive infection. In humans, non-human primates, and zebrafish models of infection, pathogenic mycobacteria produce and modify the specialized lipid trehalose 6,6'-dimycolate (TDM) in the bacterial cell envelope to drive host angiogenesis toward the site of forming granulomas, leading to enhanced bacterial growth. Here, we use the zebrafish-Mycobacterium marinum infection model to define the signaling basis of the host angiogenic response. Through intravital imaging and cell-restricted peptide-mediated inhibition, we identify macrophage-specific activation of NFAT signaling as essential to TDM-mediated angiogenesis in vivo. Exposure of cultured human cells to Mycobacterium tuberculosis results in robust induction of VEGFA, which is dependent on a signaling pathway downstream of host TDM detection and culminates in NFATC2 activation. As granuloma-associated angiogenesis is known to serve bacterial-beneficial roles, these findings identify potential host targets to improve tuberculosis disease outcomes
General Anesthesia Activates an Anxiolytic Neuronal Group in the Bed Nucleus of the Stria Terminalis
No full textGeneral anesthesia and anesthetics, in addition to the well-known properties of unconsciousness, amnesia, analgesia, and akinesia, also have anxiolytic properties. Albeit successfully used clinically to treat patients with various anxiety disorders, the common underlying mechanisms that these drugs and compounds rely on to attenuate anxiety largely remain unclear, partially due to the difficulties in investigating neuropsychological disorders in rodent models, and in comprehensively studying both behavioral and physiological aspects of anxiety. Using transgenic mouse models and a variety of histochemistry, behavioral, and physiological recording methods, we aimed to decipher the brain regions and circuit mechanisms of anesthesia-induced anxiolysis. We discovered a unique population of neurons in the mouse ovBNST to be commonly activated by multiple anesthetics and anxiolytics, to innervate brain regions critical for the regulation of emotional and autonomic responses to stressors, and to express peptides and markers previously known to be associated with anxiolysis. We further showed that optogenetic activation of these neurons could attenuate anxiety-like behaviors, while the inhibitions of these neurons had opposite behavioral effects. Lastly, we showed that optogenetic activation of these neurons led to changes in heart rate, heart rate variability, and other bodily reactions involved in stress management. Our study indicates ovBNST to be a potential therapeutic target for anxiolysis.</p
Motivational States Shape the Process of Information Seeking
No full textSeeking information is fundamental not only for making adaptive choices but also for extending our knowledge both individually and as a collective society. Understanding how people organize and carry out seeking information, remains an open and critical challenge for the field of psychology and neuroscience. In this dissertation, I approach this challenge by examining the organization of information seeking through the lens of the motivational states of an individual. I leverage behavioral, computational modeling, and neuroimaging methods to provide a multi-faceted understanding of the relationship amongst motivation, information seeking, and memory formation. In the first study, I used computational models to examine latent sampling strategies as people gathered information to guide subsequent action. These results demonstrated that unlike the optimal strategy, people perform simple accumulations instead of computing expected values, and that unlike a simple heuristic strategy, people dynamically integrate multiple sources of information in lieu of using only one source, highlighting a computationally efficient strategy that balances competing motivations for accuracy and cost minimization. In the second study, I explore how curiosity evaluates information as it unfolds over time, reporting that curiosity can promote the patience to prolong uncertainty and such patience culminates in experiencing discovery. In the third study, I extend these findings to capture the rewarding process of discovery and its impact on memory using functional magnetic resonance imaging. In the fourth study, I investigate how distinct motivational forces can drive information seeking and learning through distinct mechanisms. Collectively, the work presented in this dissertation reveals that our motivational states play a significant role in shaping our information seeking behaviors, working to balance competing goal states, and pushing us to confront and even enjoy the experience of uncertainty.</p
Recent advances in lung organoid development and applications in disease modeling.
No full textOver the last decade, several organoid models have evolved to acquire increasing cellular, structural, and functional complexity. Advanced lung organoid platforms derived from various sources, including adult, fetal, and induced pluripotent stem cells, have now been generated, which more closely mimic the cellular architecture found within the airways and alveoli. In this regard, the establishment of novel protocols with optimized stem cell isolation and culture conditions has given rise to an array of models able to study key cellular and molecular players involved in lung injury and repair. In addition, introduction of other nonepithelial cellular components, such as immune, mesenchymal, and endothelial cells, and employment of novel precision gene editing tools have further broadened the range of applications for these systems by providing a microenvironment and/or phenotype closer to the desired in vivo scenario. Thus, these developments in organoid technology have enhanced our ability to model various aspects of lung biology, including pathogenesis of diseases such as chronic obstructive pulmonary disease, pulmonary fibrosis, cystic fibrosis, and infectious disease and host-microbe interactions, in ways that are often difficult to undertake using only in vivo models. In this Review, we summarize the latest developments in lung organoid technology and their applicability for disease modeling and outline their strengths, drawbacks, and potential avenues for future development
Evaluation of monoenergetic imaging to reduce metallic instrumentation artifacts in computed tomography of the cervical spine.
No full textObjectMonoenergetic imaging with dual-energy CT has been proposed to reduce metallic artifacts in comparison with conventional polychromatic CT. The purpose of this study is to systematically evaluate and define the optimal dual-energy CT imaging parameters for specific cervical spinal implant alloy compositions.MethodsSpinal fixation rods of cobalt-chromium or titanium alloy inserted into the cervical spine section of an Alderson Rando anthropomorphic phantom were imaged ex vivo with fast-kilovoltage switching CT at 80 and 140 peak kV. The collimation width and field of view were varied between 20 and 40 mm and medium to large, respectively. Extrapolated monoenergetic images were generated at 70, 90, 110, and 130 kiloelectron volts (keV). The standard deviation of voxel intensities along a circular line profile around the spine was used as an index of the magnitude of metallic artifact.ResultsThe metallic artifact was more conspicuous around the fixation rods made of cobalt-chromium than those of titanium alloy. The magnitude of metallic artifact seen with titanium fixation rods was minimized at monoenergies of 90 keV and higher, using a collimation width of 20 mm and large field of view. The magnitude of metallic artifact with cobalt-chromium fixation rods was minimized at monoenergies of 110 keV and higher; collimation width or field of view had no effect.ConclusionsOptimization of acquisition settings used with monoenergetic CT studies might yield reduced metallic artifacts
Embryonic exposure to benzo[a]pyrene causes age-dependent behavioral alterations and long-term metabolic dysfunction in zebrafish.
No full textPolycyclic aromatic hydrocarbons (PAH) are products of incomplete combustion which are ubiquitous pollutants and constituents of harmful mixtures such as tobacco smoke, petroleum and creosote. Animal studies have shown that these compounds exert developmental toxicity in multiple organ systems, including the nervous system. The relative persistence of or recovery from these effects across the lifespan remain poorly characterized. These studies tested for persistence of neurobehavioral effects in AB* zebrafish exposed 5-120 h post-fertilization to a typical PAH, benzo[a]pyrene (BAP). Study 1 evaluated the neurobehavioral effects of a wide concentration range of BAP (0.02-10 μM) exposures from 5 to 120 hpf during larval (6 days) and adult (6 months) stages of development, while study 2 evaluated neurobehavioral effects of BAP (0.3-3 μM) from 5 to 120 hpf across four stages of development: larval (6 days), adolescence (2.5 months), adulthood (8 months) and late adulthood (14 months). Embryonic BAP exposure caused minimal effects on larval motility, but did cause neurobehavioral changes at later points in life. Embryonic BAP exposure led to nonmonotonic effects on adolescent activity (0.3 μM hyperactive, Study 2), which attenuated with age, as well as startle responses (0.2 μM enhanced, Study 1) at 6 months of age. Similar startle changes were also detected in Study 2 (1.0 μM), though it was observed that the phenotype shifted from reduced pretap activity to enhanced posttap activity from 8 to 14 months of age. Changes in the avoidance (0.02-10 μM, Study 1) and approach (reduced, 0.3 μM, Study 2) of aversive/social cues were also detected, with the latter attenuating from 8 to 14 months of age. Fish from study 2 were maintained into aging (18 months) and evaluated for overall and tissue-specific oxygen consumption to determine whether metabolic processes in the brain and other target organs show altered function in late life based on embryonic PAH toxicity. BAP reduced whole animal oxygen consumption, and overall reductions in total basal, mitochondrial basal, and mitochondrial maximum respiration in target organs, including the brain, liver and heart. The present data show that embryonic BAP exposure can lead to neurobehavioral impairment across the life-span, but that these long-term risks differentially emerge or attenuate as development progresses
The evolution of facial reanimation techniques.
No full textThis review article provides an updated discussion on evidence-based practices related to the evaluation and management of facial paralysis. Ultimately, the goals of facial reanimation include obtaining facial symmetry at rest, providing corneal protection, restoring smile symmetry and facial movement for functional and aesthetic purposes. The treatment of facial nerve injury is highly individualized, especially given the wide heterogeneity regarding the degree of initial neuronal insult and eventual functional outcome. Recent advancements in facial reanimation techniques have better equipped clinicians to approach challenging patient scenarios with reliable, effective strategies. We discuss how technology such as machine learning software has revolutionized pre- and post-intervention assessments and provide an overview of current controversies including timing of intervention, choice of donor nerve, and management of nonflaccid facial palsy with synkinesis. We highlight novel considerations to mainstay conservative management strategies and examine innovations in modern surgical techniques with a focus on gracilis free muscle transfer. Innervation sources, procedural staging, coaptation patterns, and multi-vector and multi-muscle paddle design are modifications that have significantly evolved over the past decade