Seagrass can mitigate negative ocean acidification effects on calcifying algae

The ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions between coexisting species may have on local seawater chemistry and the concurrent effect of OA. Here, we manipulated CO2 and temperature to evaluate the physiological responses of two common photoautotrophs from shallow tropical marine coastal ecosystems in Brazil: the calcifying alga Halimeda cuneata, and the seagrass Halodule wrightii. We tested whether or not seagrass presence can influence the calcification rate of a widespread and abundant species of Halimeda under OA and warming. Our results demonstrate that under elevated CO2, the high photosynthetic rates of H. wrightii contribute to raise H. cuneata calcification more than two-fold and thus we suggest that H. cuneata populations coexisting with H. wrightii may have a higher resilience to OA conditions. This conclusion supports the more general hypothesis that, in coastal and shallow reef environments, the metabolic interactions between calcifying and non-calcifying organisms are instrumental in providing refuge against OA effects and increasing the resilience of the more OA-susceptible species.E.B. would like to thank the Coordenação de Aperfeiçoamento de Pessoas de Nível Superior (CAPES) for Masters funding. Funding for this project came from the Synergism grant (CNPq 407365/2013-3). We extend our thanks to the Brazil-based Projeto Coral Vivo and its sponsor PetroBras Ambiental for providing the Marine Mesocosm structure and experimental assistance.info:eu-repo/semantics/publishedVersio

Grisel’s syndrome, a rare cause of anomalous head posture in children: a case report

BACKGROUND: Anomalous head posture (AHP) or torticollis is a relatively common condition in children. Torticollis is not a diagnosis, but it is a sign of underlying disease. Grisel’s syndrome (GS) is a rare condition of uncertain etiology characterized by a nontraumatic atlanto-axial subluxation (AAS), secondary to an infection in the head and neck region. It has not been considered, in ophthalmological papers, as a possible cause of AHP. CASE PRESENTATION: A case of AAS secondary to an otitis media is studied. The children showed neck pain, head tilt, and reduction in neck mobility. The patient had complete remission with antibiotic and anti-inflammatory therapy and muscle relaxants. Signs of GS should always be taken into account during ophthalmological examination (recent history of upper airway infections and/or head and neck surgeries associated to a new onset of sudden, painful AHP with normal ocular exam). In such cases it is necessary to require quick execution of radiological examinations (computer tomography and/or nuclear magnetic resonance), which are essential to confirm the diagnosis. CONCLUSION: GS is a multidisciplinary disease. We underline the importance of an accurate orthoptic and ophthalmological examination. Indeed, early detection and diagnosis are fundamental to achieve proper management, avoid neurological complications and lead to a good prognosis

Carbon sequestration via wood burial

To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink

Irrelevant deformations and the holographic Callan-Symanzik equation

We discuss the systematics of obtaining the Callan-Symanzik equation within the framework of the gauge/gravity dualities. We present a completely general formula which in particular takes into account the new holographic renormalization results of arXiv:1102.2239. Non-trivial beta functions are obtained from new logarithmic terms in the radial expansion of the fields. The appearance of multi-trace counterterms is also discussed in detail and we show that mixing between single- and multi-trace operators leads to very specific non-linearities in the Callan-Symanzik equation. Additionally, we compute the conformal anomaly for a scalar three-point function in a CFT.Comment: 40 page

Corrigendum: Whole genome analysis of a schistosomiasis-transmitting freshwater snail

This corrects the article DOI: 10.1038/ncomms15451

Dynamic Tunneling of Ultra-Cold Atoms

The divergence of quantum and classical descriptions of particle motion is clearly apparent in quantum tunnelling1, 2 between two regions of classically stable motion. An archetype of such non-classical motion is tunnelling through an energy barrier. In the 1980s, a new process, 'dynamical' tunnelling1, 2, 3, was predicted, involving no potential energy barrier; however, a constant of the motion (other than energy) still forbids classically the quantum-allowed motion. This process should occur, for example, in periodically driven, nonlinear hamiltonian systems with one degree of freedom4, 5, 6. Such systems may be chaotic, consisting of regions in phase space of stable, regular motion embedded in a sea of chaos. Previous studies predicted4 dynamical tunnelling between these stable regions. Here we observe dynamical tunnelling of ultracold atoms from a Bose-Einstein condensate in an amplitude-modulated optical standing wave. Atoms coherently tunnel back and forth between their initial state of oscillatory motion (corresponding to an island of regular motion) and the state oscillating 180° out of phase with the initial state