Experimental considerations of acute heat stress assays to quantify coral thermal tolerance

Understanding the distribution and abundance of heat tolerant corals across seascapes is imperative for predicting responses to climate change and to support novel management actions. Thermal tolerance is variable in corals and intrinsic and extrinsic drivers of tolerance are not well understood. Traditional experimental evaluations of coral heat and bleaching tolerance typically involve ramp-and-hold experiments run across days to weeks within aquarium facilities with limits to colony replication. Field-based acute heat stress assays have emerged as an alternative experimental approach to rapidly quantify heat tolerance in many samples yet the role of key methodological considerations on the stress response measured remains unresolved. Here, we quantify the effects of coral fragment size, sampling time point, and physiological measures on the acute heat stress response in adult corals. The effect of fragment size differed between species (Acropora tenuis and Pocillopora damicornis). Most physiological parameters measured here declined over time (tissue colour, chlorophyll-a and protein content) from the onset of heating, with the exception of maximum photosynthetic efficiency (Fv/Fm) which was surprisingly stable over this time scale. Based on our experiments, we identified photosynthetic efficiency, tissue colour change, and host-specific assays such as catalase activity as key physiological measures for rapid quantification of thermal tolerance. We recommend that future applications of acute heat stress assays include larger fragments (> 9 cm2) where possible and sample between 10 and 24 h after the end of heat stress. A validated high-throughput experimental approach combined with cost-effective genomic and physiological measurements underpins the development of markers and maps of heat tolerance across seascapes and ocean warming scenarios

Progress in the determination of the J/ψ−πJ/\psi-\pi cross section

Improving previous calculations, we compute the $J/\psi \pi\to {charmed mesons}$ cross section using QCD sum rules. Our sum rules for the $J/\psi \pi\to \bar{D} D^*$, $D \bar{D}^*$, ${\bar D}^* D^*$ and ${\bar D} D$ hadronic matrix elements are constructed by using vaccum-pion correlation functions, and we work up to twist-4 in the soft-pion limit. Our results suggest that, using meson exchange models is perfectly acceptable, provided that they include form factors and that they respect chiral symmetry. After doing a thermal average we get $\sim 0.3$ mb at T=150\MeV.Comment: 22 pages, RevTeX4 including 7 figures in ps file

Diffusion of Macromolecules across the Nuclear Pore Complex

Nuclear pore complexes (NPCs) are very selective filters that monitor the transport between the cytoplasm and the nucleoplasm. Two models have been suggested for the plug of the NPC. They are (i) it is a reversible hydrogel or (ii) it is a polymer brush. We propose a mesoscopic model for the transport of a protein through the plug, that is general enough to cover both. The protein stretches the plug and creates a local deformation. The bubble so created (prtoein+deformation) executes random walk in the plug. We find that for faster relaxation of the gel, the diffusion of the bubble is greater. Further, on using parameters appropriate for the brush, we find that the diffusion coefficient is much lower. Hence the gel model seems to be more likely explanation for the workings of the plug

CIP2A Inhibits PP2A in Human Malignancies

SummaryInhibition of protein phosphatase 2A (PP2A) activity has been identified as a prerequisite for the transformation of human cells. However, the molecular mechanisms by which PP2A activity is inhibited in human cancers are currently unclear. In this study, we describe a cellular inhibitor of PP2A with oncogenic activity. The protein, designated Cancerous Inhibitor of PP2A (CIP2A), interacts directly with the oncogenic transcription factor c-Myc, inhibits PP2A activity toward c-Myc serine 62 (S62), and thereby prevents c-Myc proteolytic degradation. In addition to its function in c-Myc stabilization, CIP2A promotes anchorage-independent cell growth and in vivo tumor formation. The oncogenic activity of CIP2A is demonstrated by transformation of human cells by overexpression of CIP2A. Importantly, CIP2A is overexpressed in two common human malignancies, head and neck squamous cell carcinoma (HNSCC) and colon cancer. Thus, our data show that CIP2A is a human oncoprotein that inhibits PP2A and stabilizes c-Myc in human malignancies

On the dual structure of the auditory brainstem response in dogs

Objective: To use the over-complete discrete wavelet transform (OCDWT) to further examine the dual structure of auditory brainstem response (ABR) in the dog. Methods: ABR waveforms recorded from 20 adult dogs at supra-threshold (90 and 70 dBnHL) and threshold (0-15 dBSL) levels were decomposed using a six level OCDWT and reconstructed at individual scales (frequency ranges) A6 (0-391 Hz), D6 (391-781 Hz), and D5 (781-1563 Hz). Results: At supra-threshold stimulus levels, the A6 scale (0-391 Hz) showed a large amplitude waveform with its prominent wave corresponding in latency with ABR waves II/III; the D6 scale (391-781 Hz) showed a small amplitude waveform with its first four waves corresponding in latency to ABR waves I, II/III, V, and VI; and the D5 scale (781-1563 Hz) showed a large amplitude, multiple peaked waveform with its first six waves corresponding in latency to ABR waves I, II, III, IV, V, and VI. At threshold stimulus levels (0-15 dBSL), the A6 scale (0-391 Hz) continued to show a relatively large amplitude waveform, but both the D6 and D5 scales (391781 and 781-1563 Hz, respectively) now showed relatively small amplitude waveforms. Conclusions: A dual structure exists within the ABR of the dog, but its relative structure changes with stimulus level. Significance: The ABR in the dog differs from that in the human both in the relative contributions made by its different frequency components, and the way these components change with stimulus level. (c) 2006 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved

Viking Age garden plants from southern Scandinavia: diversity, taphonomy and cultural aspects

Plant finds recovered from archaeological sites in southern Scandinavia dated to the Viking Age reflect the diversity of useful plants that were cultivated and collected. This review presents the results of 14 investigations of deposits that are dated between AD 775 and 1050. The site types are categorized as agrarian, urban, military and burials. Garden plants are unevenly distributed, as the greatest diversity is recorded in features from urban contexts. We argue that taphonomic processes played an important role in the picture displayed. Archaeobotanical research results from neighbouring regions suggest that Viking Age horticulture has its roots in older traditions, and that the spectrum of garden plants is influenced by central and north-western European horticultural customs, which were to a great extent shaped by Roman occupation