Enduring Legacy: Rhetoric and Ritual of the Lost Cause

Exploring the Lost Cause Arriving as it does well after celebrated works on the same general subject by Charles Reagan Wilson, Gaines M. Foster, William C. Davis, David Blight, David Goldfield, and a raft of historians of scarcely less talent and repute, W. Stuart Towns’s Enduring Leg...

Experimental Investigation into Unsteady Force Transients on Rapidly Maneuvering Wings

Small-scale aircraft, such as biological fliers and micro air vehicles, typically operate in a low Reynolds number flight regime, Re ~ O(10^2 - 10^5), that is known to contain massive flow separation and unsteady force production. This work conducts comprehensive experimental campaigns on a flat plate undergoing three simple wing motions typical of low Reynolds number flight: surging from rest, pitching in a constant free stream, and deflection of a large trailing edge flap. Water tunnel tests were performed in collaboration between the University of Maryland (UMD) and the Air Force Research Laboratory (AFRL). Unsteady force measurements and time-resolved velocity fields were obtained for a wide range of incidence angles and motion rates, spanning cases of fully attached flow to those of massively separated flow. Experiments were conducted at Reynolds number Re = 20,000 over an extensive breadth of reduced frequencies (0.06 < k < 3) representative of the conditions found in small biological fliers. Detailed investigations into rapidly surging and pitching wings illustrated the direct relationship between observable vortex dynamics and force/moment coefficients during the transient acceleration and subsequent relaxation to steady state. It was shown that circulation strength is proportional to motion rate, and faster acceleration transients produce stronger, more coherent leading edge vortices. Experiments were also performed on a hinged wing with a 50%-chord trailing edge flap. Dynamically pitching the wing was shown to generate instantaneous lift response upon motion onset regardless of initial flow attachment. Additionally, direct measurement of wing component forces and numerical simulations using an unsteady panel method confirmed the production of considerable unsteady forces on the stationary fore element of the hinged wing. Using a modified aerodynamic model that accurately predicts force histories on the hinged wing, it was determined that the largest discrepancy between Theodorsen's classical solution and the measured forces is due to its over-prediction of steady circulatory lift

Fast emulation of anisotropies induced in the cosmic microwave background by cosmic strings

Cosmic strings are linear topological defects that may have been produced during symmetry-breaking phase transitions in the very early Universe. In an expanding Universe the existence of causally separate regions prevents such symmetries from being broken uniformly, with a network of cosmic string inevitably forming as a result. To faithfully generate observables of such processes requires computationally expensive numerical simulations, which prohibits many types of analyses. We propose a technique to instead rapidly emulate observables, thus circumventing simulation. Emulation is a form of generative modelling, often built upon a machine learning backbone. End-to-end emulation often fails due to high dimensionality and insufficient training data. Consequently, it is common to instead emulate a latent representation from which observables may readily be synthesised. Wavelet phase harmonics are an excellent latent representations for cosmological fields, both as a summary statistic and for emulation, since they do not require training and are highly sensitive to non-Gaussian information. Leveraging wavelet phase harmonics as a latent representation, we develop techniques to emulate string induced CMB anisotropies over a 7.2 degree field of view, with sub-arcminute resolution, in under a minute on a single GPU. Beyond generating high fidelity emulations, we provide a technique to ensure these observables are distributed correctly, providing a more representative ensemble of samples. The statistics of our emulations are commensurate with those calculated on comprehensive Nambu-Goto simulations. Our findings indicate these fast emulation approaches may be suitable for wide use in, e.g., simulation based inference pipelines. We make our code available to the community so that researchers may rapidly emulate cosmic string induced CMB anisotropies for their own analysis

Fighting the Obesity Pandemic During the COVID-19 Pandemic

BACKGROUND: The COVID-19 pandemic created delays in surgical care. The population with obesity has a high risk of death from COVID-19. Prior literature shows the most effective way to combat obesity is by weight loss surgery. At different times throughout the COVID-19 pandemic, elective inpatient surgeries have been halted due to bed availability. Recognizing that major complications following bariatric surgery are extremely low (bleeding 0-4%, anastomotic leaks 0.8%), we felt outpatient bariatric surgery would be safe for low-risk patients. Complications such as DVT, PE, infection, and anastomotic leaks typically present after 7 days postoperatively, well outside the usual length of stay. Bleeding events, severe postoperative nausea, and dehydration typically occur in the first few days postoperatively. We designed a pathway focused on detecting and preventing these early post-op complications to allow safe outpatient bariatric surgery. METHODS: We used a preoperative evaluation tool to risk stratify bariatric patients. During a 16-month period, 89 patients were identified as low risk for outpatient surgery. We designed a postoperative protocol that included IV hydration and PO intake goals to meet a safe discharge. We sent patients home with a pulse oximeter and had them self-monitor their pulse and oxygen saturation. We called all patients at 10 pm for a postoperative assessment and report of their vitals. Patients returned to clinic the following day and were seen by a provider, received IV hydration, and labs were drawn. RESULTS: 80 of 89 patients (89.8%) were successfully discharged on POD 0. 3 patients were readmitted within 30 days. We had zero deaths in our study cohort and no morbidity that would have been prevented with postoperative admission. CONCLUSION: We demonstrate that by identifying low-risk patients for outpatient bariatric surgery and by implementing remote monitoring of vitals early outpatient follow-up, we were able to safely perform outpatient bariatric surgery

Seeing the body distorts tactile size perception

Vision of the body modulates somatosensation, even when entirely non-informative about stimulation. For example, seeing the body increases tactile spatial acuity, but reduces acute pain. While previous results demonstrate that vision of the body modulates somatosensory sensitivity, it is unknown whether vision also affects metric properties of touch, and if so how. This study investigated how non-informative vision of the body modulates tactile size perception. We used the mirror box illusion to induce the illusion that participants were directly seeing their stimulated left hand, though they actually saw their reflected right hand. We manipulated whether participants: (a) had the illusion of directly seeing their stimulated left hand, (b) had the illusion of seeing a non-body object at the same location, or (c) looked directly at their non-stimulated right-hand. Participants made verbal estimates of the perceived distance between two tactile stimuli presented simultaneously to the dorsum of the left hand, either 20, 30, or 40 mm apart. Vision of the body significantly reduced the perceived size of touch, compared to vision of the object or of the contralateral hand. In contrast, no apparent changes of perceived hand size were found. These results show that seeing the body distorts tactile size perception

Impaired mitochondrial biogenesis is a common feature to myocardial hypertrophy and end-stage ischemic heart failure

Mitochondrial (mt) DNA depletion and oxidative mtDNA damage have been implicated in the process of pathological cardiac remodeling. Whether these features are present in the early phase of maladaptive cardiac remodeling, that is, during compensated cardiac hypertrophy, is still unknown. We compared the morphologic and molecular features of mt biogenesis and markers of oxidative stress in human heart from adult subjects with compensated hypertrophic cardiomyopathy and heart failure. We have shown that mtDNA depletion is a constant feature of both conditions. A quantitative loss of mtDNA content was associated with significant down-regulation of selected modulators of mt biogenesis and decreased expression of proteins involved in mtDNA maintenance. Interestingly, mtDNA depletion characterized also the end-stage phase of cardiomyopathies due to a primary mtDNA defect. Oxidative stress damage was detected only in failing myocardium

Implicit body representations and tactile spatial remapping

To perceive the location of a tactile stimulus in external space (external tactile localisation), information about the location of the stimulus on the skin surface (tactile localisation on the skin) must be combined with proprioceptive information about the spatial location of body parts (position sense) - a process often referred to as ‘tactile spatial remapping’. Recent research has revealed that both of these component processes rely on highly distorted implicit body representations. For example, on the dorsal hand surface position sense relies on a squat, wide hand representation. In contrast, tactile localisation on the same skin surface shows large biases towards the knuckles. These distortions can be seen as behavioural ‘signatures’ of these respective perceptual processes. Here, we investigated the role of implicit body representation in tactile spatial remapping by investigating whether the distortions of each of the two component processes (tactile localisation and position sense) also appear when participants localise the external spatial location of touch. Our study reveals strong distortions characteristic of position sense (i.e., overestimation of distances across vs along the hand) in tactile spatial remapping. In contrast, distortions characteristic of tactile localisation on the skin (i.e., biases towards the knuckles) were not apparent in tactile spatial remapping. These results demonstrate that a common implicit hand representation underlies position sense and external tactile localisation. Furthermore, the present findings imply that tactile spatial remapping does not require mapping the same signals in a frame of reference centered on a specific body part

Phosphorus mobilizing consortium Mammoth P enhances plant growth

Global agricultural productivity may be constrained by the finite and limited supply of phosphorus (P), adding to the challenges in meeting the projected needs of a growing human population in the coming decades. In addition, when P fertilizers are added to soils, they can become bound to soils resulting in low fertilizer efficiency. However, P-mobilizing bacteria could potentially liberate soil-bound P, resulting in a higher plant P uptake and increased yield. Bacteria can mobilize P through several mechanisms, suggesting that consortia of P-bacteria may be more effective than single species. Species diversity can have a synergistic, or non-additive, effect on ecosystem functioning (&quot;the whole is more than the sum of its parts&quot;) but rarely is the microbial community structure intentionally managed to improve plant nutrient uptake. We investigated whether inoculation of soils with a four-species bacterial community developed to mobilize soil P could increase plant productivity. In wheat and turf trials, we found that Mammoth P was able to deliver yields equivalent to those achieved using conventional fertilizer applications. Herbs and fruits showed that the combination of fertilizer with Mammoth P significantly increased productivity -in some cases productivity doubled. Metabolites produced by the Mammoth P consortium led to increased yields in some cases, suggesting that microbial products (produced in the absence of plants) played a role in enhancing plant productivity. Results from these trials indicate substantial potential of Mammoth P to enhance P supply to plants, improving P fertilizer use-efficiency and increasing agricultural productivity. 19 Agricultural productivity may be constrained in the 21 st Century by the finite supply of global a 20 phosphorus (P), adding to the challenges in meeting the projected needs of a growing human population 21 in the coming decades. In addition, when P fertilizers are added to soils, they can become bound to soils 22 resulting in low fertilizer efficiency. However, bacteria have the ability to mobilize soil bound P through 23 several mechanisms potentially resulting in a higher plant P uptake and increased yield. Furthermore, 24 species diversity can have a synergistic effect on ecosystem functioning (&quot;the whole is more than the sum 25 of its parts&quot;) suggesting that bacterial communities, or consortia, may be more effective than single 26 species. However, in agriculture management practices, rarely is the soil microbial community structure 27 effectively manipulated to improve plant nutrient uptake. We investigated whether inoculation of soils 28 with a bacterial consortium developed to mobilize soil P named Mammoth P could increase plant 29 productivity. In turf, herbs and fruits, we showed that the combination of conventional inorganic fertilizer 30 combined with Mammoth P increased productivity up to twofold compared to the fertilizer treatments 31 without the Mammoth P inoculant. In wheat trials, we found that Mammoth P by itself was able to deliver 32 yields equivalent to those achieved with conventional inorganic fertilizer applications. The metabolites 33 produced by the consortium in Mammoth P likely played a role in enhancing plant productivity. Results 34 from this study indicate the substantial potential of Mammoth P to enhance P supply to plants, improving 35 P fertilizer use-efficiency and increasing agricultural productivity. 3

Rapid enhancement of touch from non-informative vision of the hand

Processing in one sensory modality may modulate processing in another. Here we investigate how simply viewing the hand can influence the sense of touch. Previous studies showed that non-informative vision of the hand enhances tactile acuity, relative to viewing an object at the same location. However, it remains unclear whether this Visual Enhancement of Touch (VET) involves a phasic enhancement of tactile processing circuits triggered by the visual event of seeing the hand, or more prolonged, tonic neuroplastic changes, such as recruitment of additional cortical areas for tactile processing. We recorded somatosensory evoked potentials (SEPs) evoked by electrical stimulation of the right middle finger, both before and shortly after viewing either the right hand, or a neutral object presented via a mirror. Crucially, and unlike prior studies, our visual exposures were unpredictable and brief, in addition to being non-informative about touch. Viewing the hand, as opposed to viewing an object, enhanced tactile spatial discrimination measured using grating orientation judgements, and also the P50 SEP component, which has been linked to early somatosensory cortical processing. This was a trial-specific, phasic effect, occurring within a few seconds of each visual onset, rather than an accumulating, tonic effect. Thus, somatosensory cortical modulation can be triggered even by a brief, non-informative glimpse of one’s hand. Such rapid multisensory modulation reveals novel aspects of the specialised brain systems for functionally representing the body

A supramodal representation of the body surface

The ability to accurately localize both tactile and painful sensations on the body is one of the most important functions of the somatosensory system. Most accounts of localization refer to the systematic spatial relation between skin receptors and cortical neurons. The topographic organization of somatosensory neurons in the brain provides a map of the sensory surface. However, systematic distortions in perceptual localization tasks suggest that localizing a somatosensory stimulus involves more than simply identifying specific active neural populations within a somatotopic map. Thus, perceptual localization may depend on both afferent inputs and other unknown factors. In four experiments, we investigated whether localization biases vary according to the specific skin regions and subset of afferent fibers stimulated. We represented localization errors as a ‘perceptual map’ of skin locations. We compared the perceptual maps of stimuli that activate Aβ (innocuous touch), Aδ (pinprick pain), and C fibers (non-painful heat) on both the hairy and glabrous skin of the left hand. Perceptual maps exhibited systematic distortions that strongly depended on the skin region stimulated. We found systematic distal and radial (i.e., towards the thumb) biases in localization of touch, pain, and heat on the hand dorsum. A less consistent proximal bias was found on the palm. These distortions were independent of the population of afferent fibers stimulated, and also independent of the response modality used to report localization. We argue that these biases are likely to have a central origin, and result from a supramodal representation of the body surface