Intermediate Axis Theorem with Shifting Weights

Almost anything can rotate — from gymnasts to satellites — but not everything can rotate stably. The stability of a rotation depends on its axis and moment of inertia. We are developing an apparatus for a simple demonstration of this concept in 0g. Every object has three principal moments of inertia. The first principal moment, with the greatest inertia, and the third principal moment, with the least inertia, are both considered stable. The second principal moment, however, is not stable, and will undergo chaotic rotations. Attempting to rotate an object around this so-called intermediate axis of rotation can cause the object to tumble chaotically, which for objects like satellites or gymnasts, can be catastrophic. Using this principle, we aimed to design a device that takes advantage of the inertial centrifugal force resulting from the unstable rotations in order to shift weights within the device. As a result, the device’s second and third principal moments of inertia switch during the unstable rotation. This experiment is made to the standards of equipment on board the International Space Station (ISS), including concerns over material off-gassing, flammability, and overall size, as we hope to test this experiment on board the ISS

Structures of Meaning: Popular Music and Society

The sociology of music has a long history and has attracted theorists because, although music has obvious effects on people which appear to be socially and culturally constrained, there is no 'meaning' which can be held accountable. Likewise, certain types of popular music, in particular 'rock' and 'reggae', are associated with identifiable social groups and yet homologies tying musical types with social structures are not easy to identify. Nevertheless, a feature of this field of study, which has been well received for some two decades, is to announce 'links' between certain popular musical styles and social structures. These 'links' are based on description and assumption rather than rigorous analysis. They are, however, an important feature of the myths which surround popular music, and an analysis of one group of myths in particular is offered. This thesis works with two main propositions: first, that popular music can be addressed sociologically in the same way as 'serious' or 'classical' music; and second, that the musical analysis should be consistent with the musical type concerned as well as descriptive of the music itself. Popular music, even if formally notated, has considerable degrees of freedom, far more than are available to 'serious' music. The presence of these degrees of freedom makes formal notation an inappropriate document for popular music and might explain why its main method of distribution and reproduction this century has been in the form of recorded artefacts - discs, tapes, compact discs, etc. Although these aural records could be used, the disadvantage of these media is the lack of generalisation. For this reason appropriate written documents can be utilised. These are offered here in the form of charts which identify general rather than specific elements in the music and are here employed to demonstrate overall structures in musical texts. It is from this position that it is possible to identify trends and similarities in popular music and this allows conclusions to be drawn concerning musical structures and social structures which are tied firmly to the musical texts involved. This both satisfies the musicological and sociological demands of such analyses by the identification of specific homologies. This thesis offers studies illustrating the method

The role of l-arabinose metabolism for <i>Escherichia coli</i> O157:H7 in edible plants

International audienceArabinose is a major plant aldopentose in the form of arabinans complexed in cell wall polysaccharides or glycoproteins (AGP), but comparatively rare as a monosaccharide. l -arabinose is an important bacterial metabolite, accessed by pectolytic micro-organisms such as Pectobacterium atrosepticum via pectin and hemicellulose degrading enzymes. However, not all plant-associated microbes encode cell-wall-degrading enzymes, yet can metabolize l -arabinose, raising questions about their use of and access to the glycan in plants. Therefore, we examined l -arabinose metabolism in the food-borne pathogen Escherichia coli O157:H7 (isolate Sakai) during its colonization of plants. l -arabinose metabolism ( araBA ) and transport ( araF ) genes were activated at 18 °C in vitro by l -arabinose and expressed over prolonged periods in planta . Although deletion of araBAD did not impact the colonization ability of E. coli O157:H7 (Sakai) on spinach and lettuce plants (both associated with STEC outbreaks), araA was induced on exposure to spinach cell-wall polysaccharides. Furthermore, debranched and arabinan oligosaccharides induced ara metabolism gene expression in vitro , and stimulated modest proliferation, while immobilized pectin did not. Thus, E. coli O157:H7 (Sakai) can utilize pectin/AGP-derived l -arabinose as a metabolite. Furthermore, it differs fundamentally in ara gene organization, transport and regulation from the related pectinolytic species P. atrosepticum , reflective of distinct plant-associated lifestyles

Antecedent hypertension and heart failure after myocardial infarction

AbstractObjectivesWe sought to assess the relationship of antecedent hypertension to neurohormones, ventricular remodeling and clinical heart failure (HF) after myocardial infarction (MI).BackgroundHeart failure is a probable contributor to the increased mortality observed after MI in those with antecedent hypertension. Hence, neurohormonal activation, adverse ventricular remodeling and a higher incidence of clinical HF may be expected in this group. However, no previous report has documented serial postinfarction neurohumoral status, serial left ventricular imaging and clinical outcomes over prolonged follow-up in a broad spectrum of patients with and without antecedent hypertension.MethodsInpatient events were documented in 1,093 consecutive patients (436 hypertensive and 657 normotensive) with acute MI. In 68% (282 hypertensive, 465 normotensive) serial neurohormonal sampling and radionuclide ventriculography were performed one to four days and three to five months after infarction. Clinical outcomes were recorded over a mean follow-up of two years.ResultsPlasma neurohormones were significantly higher in hypertensives than in normotensives one to four days and three to five months after infarction. From similar initial values, left ventricular volumes increased significantly in hypertensives, compared with normotensives. Left ventricular ejection fraction rose significantly in normotensive but not hypertensive patients. Together with higher inpatient (8.1% vs. 4.4%, p < 0.002) and post-discharge mortality (9.5% vs. 5.5%, p = 0.043), hypertensive patients incurred more inpatient HF (33% vs. 24%, p < 0.001) and more late HF requiring readmission to hospital (12.4% vs. 5.5%, p < 0.001). Antecedent hypertension predicted late HF in patients >64 years of age with neurohormonal activation and early left ventricular dilation.ConclusionsAntecedent hypertension interacts with age, neurohumoral activation and early ventricular remodeling to confer greater risk of HF after MI

Persistence of anticancer activity in berry extracts after simulated gastrointestinal digestion and colonic fermentation

Fruit and vegetable consumption is associated at the population level with a protective effect against colorectal cancer. Phenolic compounds, especially abundant in berries, are of interest due to their putative anticancer activity. After consumption, however, phenolic compounds are subject to digestive conditions within the gastrointestinal tract that alter their structures and potentially their function. However, the majority of phenolic compounds are not efficiently absorbed in the small intestine and a substantial portion pass into the colon. We characterized berry extracts (raspberries, strawberries, blackcurrants) produced by in vitro-simulated upper intestinal tract digestion and subsequent fecal fermentation. These extracts and selected individual colonic metabolites were then evaluated for their putative anticancer activities using in vitro models of colorectal cancer, representing the key stages of initiation, promotion and invasion. Over a physiologically-relevant dose range (0–50 µg/ml gallic acid equivalents), the digested and fermented extracts demonstrated significant anti-genotoxic, anti-mutagenic and anti-invasive activity on colonocytes. This work indicates that phenolic compounds from berries undergo considerable structural modifications during their passage through the gastrointestinal tract but their breakdown products and metabolites retain biological activity and can modulate cellular processes associated with colon cancer

Clinical grade ACE2 as a universal agent to block SARS-CoV-2 variants

The recent emergence of multiple SARS-CoV-2 variants has caused considerable concern due to both reduced vaccine efficacy and escape from neutralizing antibody therapeutics. It is, therefore, paramount to develop therapeutic strategies that inhibit all known and future SARS-CoV-2 variants. Here, we report that all SARS-CoV-2 variants analyzed, including variants of concern (VOC) Alpha, Beta, Gamma, Delta, and Omicron, exhibit enhanced binding affinity to clinical grade and phase 2 tested recombinant human soluble ACE2 (APN01). Importantly, soluble ACE2 neutralized infection of VeroE6 cells and human lung epithelial cells by all current VOC strains with markedly enhanced potency when compared to reference SARS-CoV-2 isolates. Effective inhibition of infections with SARS-CoV-2 variants was validated and confirmed in two independent laboratories. These data show that SARS-CoV-2 variants that have emerged around the world, including current VOC and several variants of interest, can be inhibited by soluble ACE2, providing proof of principle of a pan-SARS-CoV-2 therapeutic

Being Ready to Treat Ebola Virus Disease Patients

As the outbreak of Ebola virus disease (EVD) in West Africa continues, clinical preparedness is needed in countries at risk for EVD (e.g., United States) and more fully equipped and supported clinical teams in those countries with epidemic spread of EVD in Africa. Clinical staff must approach the patient with a very deliberate focus on providing effective care while assuring personal safety. To do this, both individual health care providers and health systems must improve EVD care. Although formal guidance toward these goals exists from the World Health Organization, Medecin Sans Frontières, the Centers for Disease Control and Prevention, and other groups, some of the most critical lessons come from personal experience. In this narrative, clinicians deployed by the World Health Organization into a wide range of clinical settings in West Africa distill key, practical considerations for working safely and effectively with patients with EVD

Persistence of Ebola virus in ocular fluid during convalescence

Please note: A correction to the original article has been published. “From New England Journal of Medicine, Jay B. Varkey, Jessica G. Shantha, Ian Crozier, Colleen S. Kraft, G. Marshall Lyon, Aneesh K. Mehta, Gokul Kumar, Justine R. Smith, Markus H. Kainulainen, Shannon Whitmer, Ute Ströher, Timothy M. Uyeki, Bruce S. Ribner, and Steven Yeh, Persistence of Ebola Virus in Ocular Fluid during Convalescence, 2015; 372:2423-2427. Copyright © (2015) Massachusetts Medical Society. Reprinted with permission.Among the survivors of Ebola virus disease (EVD), complications that include uveitis can develop during convalescence, although the incidence and pathogenesis of EVD-associated uveitis are unknown. We describe a patient who recovered from EVD and was subsequently found to have severe unilateral uveitis during convalescence. Viable Zaire ebolavirus (EBOV) was detected in aqueous humor 14 weeks after the onset of EVD and 9 weeks after the clearance of viremia.Supported by a grant from the National Center for Advancing Translational Sciences of the National Institutes of Health (UL1TR000454, to the Atlanta Clinical and Translational Science Institute), an unrestricted grant from Research to Prevent Blindness and a grant from the National Eye Institute (P30-EY06360, to the Department of Ophthalmology, Emory University School of Medicine), and a fellowship grant from the Australian Research Council (FT130101648, to Dr. Smith). Favipiravir was provided by the Department of Defense Joint Project Manager Medical Countermeasure Systems

Sudden cardiac death due to deficiency of the mitochondrial inorganic pyrophosphatase PPA2

We have used whole exome sequencing to identify biallelic missense mutations in the nuclearencoded mitochondrial inorganic pyrophosphatase (PPA2) in ten individuals from four unrelated pedigrees that are associated with mitochondrial disease. These individuals show a range of severity, indicating that PPA2 mutations may cause a spectrum of mitochondrial disease phenotypes. Severe symptoms include seizures, lactic acidosis and cardiac arrhythmia and death within days of birth. In the index family, presentation was milder and manifested as cardiac fibrosis and an exquisite sensitivity to alcohol, leading to sudden arrhythmic cardiac death in the second decade of life. Comparison of normal and mutated PPA2 containing mitochondria from fibroblasts showed the activity of inorganic pyrophosphatase significantly reduced in affected individuals. Recombinant PPA2 enzymes modeling hypomorphic missense mutations had decreased activity that correlated with disease severity. These findings confirm the pathogenicity of PPA2 mutations, and suggest that PPA2 is a new cardiomyopathy-associated protein, which has a greater physiological importance in mitochondrial function than previously recognized