Photonic processing at NASA Ames Research Center

The Photonic Processing group is engaged in applied research on optical processors in support of the Ames vision to lead the development of autonomous intelligent systems. Optical processors, in conjunction with numeric and symbolic processors, are needed to provide the powerful processing capability that is required for many future agency missions. The research program emphasizes application of analog optical processing, where free-space propagation between components allows natural implementations of algorithms requiring a large degree of parallel computation. Special consideration is given in the Ames program to the integration of optical processors into larger, heterogeneous computational systems. Demonstration of the effective integration of optical processors within a broader knowledge-based system is essential to evaluate their potential for dependable operation in an autonomous environment such as space. The Ames Photonics program is currently addressing several areas of interest. One of the efforts is to develop an optical correlator system with two programmable spatial light modulators (SLMs) to perform distortion invariant pattern recognition. Another area of research is optical neural networks, also for use in distortion-invariant pattern recognition

Comparing the Effects of Various Exercise Regimens on Anxiety Levels in College Aged Students

Generalized anxiety disorder is described as excessive and inappropriate worrying that is persistent and not restricted to particular circumstances. Anxiety has recently surpassed depression as the number one mental health disorder on college campuses. Multiple studies have shown that exercise reduces anxiety symptoms and feelings of stress. Many students enroll in physical activity courses due to college requirements, or as a way to engage in regular physical activity. On our campus, yoga and pilates are two of the most popular physical activity courses and require two 50-minute sessions each week. The purpose of this study was to determine whether participation in these courses has a significant impact in reducing anxiety in a traditional college population. We surveyed students enrolled in either a yoga or pilates class and compared their responses to a control group not enrolled in a physical activity course

Book review: mean girl: Ayn Rand and the culture of greed by Lisa Duggan

In Mean Girl: Ayn Rand and the Culture of Greed, Lisa Duggan offers a new thesis on the infamous literary, cultural and political icon, Ayn Rand, exploring how the adoption of many of her philosophical and political ideas and beliefs helped fuel the insidious shift towards neoliberalism. Duggan’s skills as a cultural historian and her sharp-witted socio-political commentary fuse seamlessly together in this short yet fascinating book that is a necessary read for students of culture and politics, as well as activists and organisers, writes Ellen Reid

Material poetics

quench: /kwen(t)SH/ a : put out, extinguish b : to put out the light or fire c : to cool suddenly by immersion d : to cause to lose heat or warmth e : to bring to an end typically by satisfying, damping, cooling, or decreasing f : to relieve or satisfy with liquid This is often how projects begin, a haunting idea, word, or experience inundates my consciousness and sub-consciousness. How could the body directly relate to an experience of quenching? This provoked the idea of the extreme sport: freediving. To adequately depict the definition of quenching, any ordinary depth would not suffice; it required being the world’s deepest dive by a human. Danger aside, the world record unassisted freedive would be the purest example of an experiential quenching imagined. After contacting William Trubridge, a world record holding freediver, the consequential physical dangers became secondary. In order to successfully execute his dive, it is imperative that Trubridge reaches an extreme quieted state of mind before and during a dive. Below the surface, at a maximum depth of three hundred and thirty four feet, he cannot allow physical stress or mental disturbances arise. He cannot waste the oxygen that such a heightened state of awareness burns. The mastering of this mental focus and such a profound state of calm is overwhelming. “At three hundred feet, we are profoundly changed. The pressure at these depths is nine times that of the surface. The organs collapse. The heart beats a quarter of its normal rate, slower that the rate of a person in a coma. Senses disappear. The brain enters a dream state”[1]. All of the components of a work are imagined as facets in a constellation. Continuously connecting one aspect to another, which might seem disparate allows for an exponential evolution of associations. The work is consistently larger that I am, and has capabilities to know more than I know. Gathering and choosing materials becomes an elaborate, idiosyncratic, and highly deliberate system. Ultimately, through my art, I am encountering ways to be affected. I am watching constellations expand into universes. Quench What am I to do now with my hands After the mouth stings of sumac, the way a split fish shines in its uncooperative ways. Bones suddenly stark of scales: a secret that is the entire story. This too shows a kind of pretend‑ these terms of deserving and not deserving play an omen and a stray Animalistic, unnamed. I believe there is no false ache, and no vowel held delicately in the mouth; bereft from the choice to veer towards or to retract from. [1] Nestor, James. Deep: Freediving, Renegade Science, and What The Ocean Tells Us About Ourselves. Boston, NY: Profile , 2015. Print

The effect of temperature and terrace geometry on carbonate precipitation rate in an experimental setting

textThrough flume experiments we demonstrate the calcite precipitation process seen at geothermal hot springs in the lab setting. A series of four experiments were run, varying temperature and terrace ridge height while all other experimental parameters, including initial substrate slope, spring water discharge, and CO₂ input were kept constant. The goal of the experiments was to measure the temperature and terrace height control quantitatively in terms of the amount of overall travertine aggradation, aggradation rate changes in time and downstream direction, as well as to observe the effect of these parameters on processes occurring during precipitation. Using the final deposit thickness measured manually at the end of each experiment and elevation data obtained from a laser topographic profiler, I conclude that high temperature and small terrace heights favor increased precipitation of travertine. However, the amount of precipitation also depends on location within a terrace pond. Flow velocity increases as it approaches a terrace lip, resulting in enhanced precipitation and greater thicknesses in the downstream direction through increased CO₂ degassing, a process called downstream coarsening.Geological Science

Patterns and mechanisms of the exploitation of mutualisms

Mutualisms are reciprocally exploitative interactions providing net benefits to both partners. These interactions can be exploited, in turn, by individuals that take advantage of benefits offered by one or both partners in a mutualism, while offering no benefits in return. For many mutualist-exploiter interactions the mechanisms allowing exploitation, and the maintenance of mutualisms in the face of exploitation, are still poorly understood. Here I describe manipulative field and laboratory experiments to investigate the mechanisms used by an exploiter to invade an ant-plant mutualism. I tested two non-mutually exclusive hypotheses for how a coreid (Mozena sp., Hemiptera: Coreidae) feeds on mymecophytic acacia trees (Vachellia spp.) while avoiding attack by resident ants: chemical defense and chemical mimicry. I found that chemical compounds produced by Mozena sp. in both the metathoracic gland and the cuticle reduced the number of ant attacks and cuticular compounds appeared to be essential in escaping recognition on ant-occupied Vachellia spp. trees. The compounds were effective on multiple colonies and for multiple ant species, thus they are not strictly host- or species-specific. In addition, gas chromatography and mass spectrometry analyses of cuticular compounds revealed a close match between chemical profiles of Mozena sp. and Pseudomyrmex spinicola ants, suggesting chemical mimicry is the primary mechanism by which Mozena sp. exploits the ant-acacia mutualism. To examine the prevalence of a cost of exploitation for plant partners in exploited mutualisms, I conducted a meta-analysis of studies from the published literature. I found that exploitation has a weak, negative, but insignificant impact on the reproductive success of mutualistic plants. Collectively, these analyses illuminated methods by which exploiters may succeed in infiltrating mutualisms and suggested that the relatively low costs of exploitation may account for the lack of destabilization and degradation by exploiters of some mutualistic interactions

Author Correction: Probiotics and prebiotics in intestinal health and disease: from biology to the clinic (Nature Reviews Gastroenterology & Hepatology, (2019), 16, 10, (605-616), 10.1038/s41575-019-0173-3)

© 2019, Springer Nature Limited. In the original article published online, the Competing Interests statement was incorrect and should have stated the following: M.E.S. declares personal fees related to probiotics from the following entities: California Dairy Research Foundation, Clorox, Danone, Danone USA, Dutch Mill, General Mills, JHeimbach, Kelley Drye & Warren, Kellogg, Kerry, Medscape, Nestle, New Chapter, Pepsico, Pfizer, Pharmavite, Probi, Procter & Gamble, Trouw Nutrition, Visalia Dairy Company, Williams Mullen, Winclove Probiotics and Yakult. D.J.M. declares personal fees for consulting for Bayer and Pharmavite. G.R. declares that he helped develop and commercialize probiotic strains GR-1 and RC-14, but has had no financial interest in them for over 10 years. He is Chief Scientific Officer for Seed, a company producing probiotic products. Over the past 3 years, he has consulted on probiotics with Acerus Pharmaceuticals, Altmann, Chr. Hansen, Danone, KGK Science, Kimberly-Clark, Metagenics and Seed. G.R.G. and R.A.R. declare no competing interests. This error has been corrected in the HTML and PDF versions of the article

Probiotics and prebiotics in intestinal health and disease: from biology to the clinic

Probiotics and prebiotics are microbiota-management tools for improving host health. They target gastrointestinal effects via the gut, although direct application to other sites such as the oral cavity, vaginal tract and skin is being explored. Here, we describe gut-derived effects in humans. In the past decade, research on the gut microbiome has rapidly accumulated and has been accompanied by increased interest in probiotics and prebiotics as a means to modulate the gut microbiota. Given the importance of these approaches for public health, it is timely to reiterate factual and supporting information on their clinical application and use. In this Review, we discuss scientific evidence on probiotics and prebiotics, including mechanistic insights into health effects. Strains of Lactobacillus, Bifidobacterium and Saccharomyces have a long history of safe and effective use as probiotics, but Roseburia spp., Akkermansia spp., Propionibacterium spp. and Faecalibacterium spp. show promise for the future. For prebiotics, glucans and fructans are well proven, and evidence is building on the prebiotic effects of other substances (for example, oligomers of mannose, glucose, xylose, pectin, starches, human milk and polyphenols)