\u27I Think I\u27m Gonna Hurl\u27: A Narrative Review of the Causes of Nausea and Vomiting in Sport

Exercise-associated gastrointestinal (GI) distress can negatively impact athletic performance and interfere with exercise training. Although there are a few universal underlying causes of GI distress, each symptom often has its own unique triggers and, therefore, its own prevention and management strategies. One of the most troubling GI symptoms an athlete can experience during training and competition is nausea/vomiting. The prevalence of nausea varies with several factors, two of the most important being exercise intensity and duration. Relatively brief, high-intensity exercise (e.g., sprinting, tempo runs) and ultra-endurance exercise are both associated with more frequent and severe nausea. The potential causes of nausea in sport are numerous and can include catecholamine secretion, hypohydration, heat stress, hyponatremia, altitude exposure, excessive fluid/food consumption, hypertonic beverage intake, pre-exercise intake of fatty- or protein-rich foods (especially in close proximity to exercise), prolonged fasting, various supplements (caffeine, sodium bicarbonate, ketones), certain drugs (antibiotics, opioids), GI infections, and competition-related anxiety. Beyond directly addressing these aforementioned causes, antiemetic drugs (e.g., ondansetron) may also be useful for alleviating nausea in some competitive situations. Given the commonness of nausea in sport and its potential impact on exercise performance, athletes and sports medicine practitioners should be aware of the origins of nausea and strategies for dealing with this troublesome gut complaint

Frequency of Chronic Gastrointestinal Distress in Runners: Validity and Reliability of a Retrospective Questionnaire

Gastrointestinal (GI) symptoms may affect up to 90% of competitors during endurance races. Studies have typically assessed GI symptoms retrospectively or only over an acute timeframe, and information on the validity and reliability of the questionnaires employed is lacking. This investigation aimed to estimate the frequency of GI distress experienced by runners over 30 days and to establish the validity and reliability of a retrospective GI symptom questionnaire. Runners (70 men, 75 women) recorded GI symptoms with a prospective journal for 30 days. Retrospective GI symptom data were then collected after the 30-day period on two occasions within one week. GI symptoms were rated on a 0-10 scale. Descriptive statistics for GI symptoms are reported as medians (interquartile ranges) because of nonnormal distributions. Men and women experienced at least one GI symptom on 84.0% (59.8-95.1%) and 78.3% (50.0-95.2%) of runs, respectively. Moderate-to-severe GI symptoms (score of \u3e= 5) were experienced on 13.8% (6.7-37.3%) and 21.7% (5.3-41.2%) of runs for men and women. Spearman\u27s rho correlations between journal ratings and retrospective questionnaire ratings ranged from 0.47 to 0.82 (all p \u3c.001), although they were highest when journal ratings were quantified as mean 30-day values (all rho \u3e= 0.59). Reliability of the retrospective questionnaire ratings was high (rho = 0.78-0.92; p \u3c.001). In comparison with tracking GI symptoms with a daily journal, retrospective questionnaires seem to offer a convenient and reasonably valid and reliable method of quantifying GI symptoms over 30 days

Misrepresentation of carbohydrate for exercise: ‘It is time to bust the myth of physical inactivity and obesity: you cannot outrun a bad diet’

The contention from Malhotra et al1 regarding the unimportance of carbohydrate for exercise is misguided. First, the reference they provide is an editorial2 that should not be viewed as high-quality evidence. Several oft-cited exercise studies showing benefits with high-fat diets simultaneously utilized carbohydrate restoration strategies,3 which involves “carbohydrate loading” after a high-fat diet. Thus, the evidence provided does not contradict the established belief that carbohydrate is an important fuel for endurance exercise. Second, the authors’ use of the term “carbohydrate loading” is misleading in this context. No public health organizations advocate a diet containing carbohydrate in amounts used in “carbohydrate loading” studies (often 10 g/kg of body weight).4 Indeed, the authors should not confuse public health recommendations to eat fruits, vegetables and whole grains with “carbohydrate loading” strategies. Finally, their statement that “fat … appears to be the ideal fuel for most exercise” is overly-simplistic and, again, is only supported by a referenced editorial.1 Ample evidence exists showing the importance of carbohydrate for high-intensity and intermittent exercise,5 activities commonly engaged in by athletes as well as the public

Practical Hidden Voice Attacks against Speech and Speaker Recognition Systems

Voice Processing Systems (VPSes), now widely deployed, have been made significantly more accurate through the application of recent advances in machine learning. However, adversarial machine learning has similarly advanced and has been used to demonstrate that VPSes are vulnerable to the injection of hidden commands - audio obscured by noise that is correctly recognized by a VPS but not by human beings. Such attacks, though, are often highly dependent on white-box knowledge of a specific machine learning model and limited to specific microphones and speakers, making their use across different acoustic hardware platforms (and thus their practicality) limited. In this paper, we break these dependencies and make hidden command attacks more practical through model-agnostic (blackbox) attacks, which exploit knowledge of the signal processing algorithms commonly used by VPSes to generate the data fed into machine learning systems. Specifically, we exploit the fact that multiple source audio samples have similar feature vectors when transformed by acoustic feature extraction algorithms (e.g., FFTs). We develop four classes of perturbations that create unintelligible audio and test them against 12 machine learning models, including 7 proprietary models (e.g., Google Speech API, Bing Speech API, IBM Speech API, Azure Speaker API, etc), and demonstrate successful attacks against all targets. Moreover, we successfully use our maliciously generated audio samples in multiple hardware configurations, demonstrating effectiveness across both models and real systems. In so doing, we demonstrate that domain-specific knowledge of audio signal processing represents a practical means of generating successful hidden voice command attacks

Phosphorylation of Spinophilin Modulates Its Interaction with Actin Filaments

Spinophilin is a protein phosphatase 1 (PP1)- and actin-binding protein that modulates excitatory synaptic transmission and dendritic spine morphology. We report that spinophilin is phosphorylated in vitro by protein kinase A (PKA). Phosphorylation of spinophilin was stimulated by treatment of neostriatal neurons with a dopamine D1 receptor agonist or with forskolin, consistent with spinophilin being a substrate for PKA in intact cells. Using tryptic phosphopeptide mapping, site-directed mutagenesis, and microsequencing analysis, we identified two major sites of phosphorylation, Ser-94 and Ser-177, that are located within the actin-binding domain of spinophilin. Phosphorylation of spinophilin by PKA modulated the association between spinophilin and the actin cytoskeleton. Following subcellular fractionation, unphosphorylated spinophilin was enriched in the postsynaptic density, whereas a pool of phosphorylated spinophilin was found in the cytosol. F-actin co-sedimentation and overlay analysis revealed that phosphorylation of spinophilin reduced the stoichiometry of the spinophilin-actin interaction. In contrast, the ability of spinophilin to bind to PP1 remained unchanged. Taken together, our studies suggest that phosphorylation of spinophilin by PKA modulates the anchoring of the spinophilin-PP1 complex within dendritic spines, thereby likely contributing to the efficacy and plasticity of synaptic transmission

Evaluation of Balance and a Timed Walk on Ankle Brachial Pressure Index and Potential Blood Measures of Cardiovascular Health

Clinicians are focused on ways to preserve function, independence, and quality of life in the aging adult population. Heart disease is the leading cause of death in the U.S.[1]. Thus, assessing the extent of this disease is a high priority in preserving health throughout the lifespan. When determining risk of cardiovascular (CV) disease, functional assessments are recognized as a way to embed function-focused care into assessing disease risk [2]. Ankle-brachial pressure index (ABPI) is a non-invasive reliable predictor for identifying cardiovascular disease risk and mortality [3]. Thus, the purpose was to evaluate the association between functional assessments and ankle brachial pressure index in an aged population. Data was collected from the 1999-2002 National Health and Nutrition Examination Survey, which included 1696 adults (age 40-70 years). Measurements evaluated were functional assessments of a vestibular balance test and a timed 20ft walking test, and laboratory measurements of right and left leg ABPI score. Results found poor balance associated with higher odds of being in a high-risk ABPI category when looking at both left ABPI (odds ratio [OR] = 1.70; 95%CI: 0.58, 5.0) and right ABPI (OR = 2.37; 95%CI: 0.76, 7.33). Slower timed walk scores were associated with increased odds of being in the high-risk ABPI category for the left (OR = 3.21; 95%CI: 1.73, 5.98) and right (OR = 3.44; 95%CI: 2.13, 5.58). When combined, those with poor balance and slower walking speed are at higher odds for being in the high-risk ABPI category for the left (OR = 1.97; 95% 0.80, 4.85) and right (OR = 2.55; 95% 1.23, 5.79). We conclude, functional assessments are associated with a commonly used measure of CV disease risk, ABPI. Specifically, functional assessments of balance and walking speed are suggestive of risk category of ABPI, which indicates risk category for CV disease [4].https://digitalcommons.odu.edu/gradposters2020_education/1003/thumbnail.jp

The central density of a neutron star is unaffected by a binary companion at linear order in μ/R\mu/R

Recent numerical work by Wilson, Mathews, and Marronetti [J. R. Wilson, G. J. Mathews and P. Marronetti, Phys. Rev. D 54, 1317 (1996)] on the coalescence of massive binary neutron stars shows a striking instability as the stars come close together: Each star's central density increases by an amount proportional to 1/(orbital radius). This overwhelms any stabilizing effects of tidal coupling [which are proportional to 1/(orbital radius)^6] and causes the stars to collapse before they merge. Since the claimed increase of density scales with the stars' mass, it should also show up in a perturbation limit where a point particle of mass $\mu$ orbits a neutron star. We prove analytically that this does not happen; the neutron star's central density is unaffected by the companion's presence to linear order in $\mu/R$. We show, further, that the density increase observed by Wilson et. al. could arise as a consequence of not faithfully maintaining boundary conditions.Comment: 3 pages, REVTeX, no figures, submitted to Phys Rev D as a Rapid Communicatio

Methane flux from the Central Amazonian Floodplain

A total of 186 methane measurements from the three primary Amazon floodplain environments of open water lakes, flood forests, and floating grass mats were made over the period 18 July through 2 September 1985. These data indicate that emissions were lowest over open water lakes. Flux from flooded forests and grass mats was significantly higher. At least three transport processes contribute to tropospheric emissions: ebullition from sediments, diffusion along the concentration gradient from sediment to overlaying water to air, and transport through the roots and stems of aquatic plants. Measurements indicate that the first two of these processes are most significant. It was estimated that on the average bubbling makes up 49% of the flux from open water, 54% of that from flooded forests, and 64% of that from floating mats. If the measurements were applied to the entire Amazonian floodplain, it is calculated that the region could supply up to 12% of the estimated global natural sources of methane

Infrared Variability of Two Dusty White Dwarfs

The most heavily polluted white dwarfs often show excess infrared radiation from circumstellar dust disks, which are modeled as a result of tidal disruption of extrasolar minor planets. Interaction of dust, gas, and disintegrating objects can all contribute to the dynamical evolution of these dust disks. Here, we report on two infrared variable dusty white dwarfs, SDSS J1228+1040 and G29-38. For SDSS J1228+1040, compared to the first measurements in 2007, the IRAC [3.6] and [4.5] fluxes decreased by 20% by 2014 to a level also seen in the recent 2018 observations. For G29-38, the infrared flux of the 10 $\mu$m silicate emission feature became 10% stronger between 2004 and 2007, We explore several scenarios that could account for these changes, including tidal disruption events, perturbation from a companion, and runaway accretion. No satisfactory causes are found for the flux drop in SDSS J1228+1040 due to the limited time coverage. Continuous tidal disruption of small planetesimals could increase the mass of small grains and concurrently change the strength of the 10 $\mu$m feature of G29-38. Dust disks around white dwarfs are actively evolving and we speculate that there could be different mechanisms responsible for the temporal changes of these disks.Comment: ApJ, in pres