Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results

The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can supply significant amounts of energy to the interface region and corona. In recent years an abundance of high-resolution observations from state-of-the-art facilities have provided new and exciting ways of disentangling the characteristics of oscillatory phenomena propagating through the dynamic chromosphere. Coupled with rapid advancements in magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly investigate the role waves play in supplying energy to sustain chromospheric and coronal heating. Here, we review the recent progress made in characterising, categorising and interpreting oscillations manifesting in the solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review

Crop Updates - 2003 Pulses

This session covers fifty one papers from different authors 2002 PULSE INDUSTRY HIGHLIGHTS CONTRIBUTORS BACKGROUND 2002 REGIONAL ROUNDUP 1.Northern Agricultural Region, M. Harries, Department of Agriculture 2.Central agricultural Region, R. French and I. Pritchard, Department of Agriculture 3.Great Southern and Lakes, R. Beermier, N. Poulish and S. White, Department of Agriculture 4.Esperance Mallee, M. Seymour, Department of Agriculture PULSE PRODUCTION ECONOMY AND GENETIC IMPROVEMENT 5.Faba Bean, P. White, Department of Agriculture 6.Germplasm evaluation, P. White, T. Pope, M. Harries and M. Seymour, Department of Agriculture 7.Row spacing and sowing rate, M. Seymour, Department of Agriculture 8.Tolerance to post emergent herbicides, M. Seymour, M. Harries, R. Beermier, M. Blyth and L. Young, Department of Agriculture 9.Investigation of environmental staining and storage discolouration, N. Abbas1,2, J. Plummer1, P. White3, D. Harris4 and K. Siddique1,2, 1Plant Biology, The University of Western Australia, 2CLIMA, The University of Western Australia, 3Department of Agriculture, 4Chemistry Centre of Western Australia. Desi chickpea 10.Breeding highlights, T. Khan1,2 and K. Siddique2 1Department of Agriculture, 2CLIMA, The University of Western Australia 11. Variety evaluation, T. Khan and K. Regan, Department of Agriculture 12. Residual effect of chickpea row spacing and sowing rate on wheat yield, G. Riethmuller and B. MacLeod, Department of Agriculture 13. Genotype x environmental interaction studies to help explain adaptation, J. Berger1, N. Turner1,2, K. Siddique1, 1CLIMA, The University of Western Australia, 2CSIRO Plant Industry 14. Genetic characterisation of wild relatives, F. Shan and H. Clarke, CLIMA, The University of Western Australia 15. Tolerance to chilling at flowering, H. Clarke, CLIMA, The University of Western Australia 16. Kabuli chickpea, K. Regan, Department of Agriculture 17. Premium quality varieties for the Ord River Irrigation Area, K. Siddique1, K. Regan2 and P. Smith2 1CLIMA, The University of Western Australia, 2Department of Agriculture 18. Development of aschochyta resistant varieties for Australia, K. Siddique1, K. Regan2 and M. Baker2 1CLIMA, University of Western Australia, 2Department of Agriculture Field pea 19. Breeding highlights, T. Khan and B. French, Department of Agriculture 20. Variety evaluation, T. Khan, Department of Agriculture 21. Specialty types for the high rainfall regions, P. White and T. Khan, Department of Agriculture 22. Are new varieties more sensitive to delayed sowing than Dundale? R. French, M. Seymour and R. Beermier, Department of Agriculture 23. Does the size of sown seed affect seed size and yield at harvest? R. Beermier and N. Poulish, Department of Agriculture 24. Tolerance to post emergent herbicides, H. Dhammu, T. Piper and D. Nicholson, Department of Agriculture 25. Lentil, K. Regan, Department of Agriculture 26. Variety evaluation, K. Regan and M. Harries, Department of Agriculture 27. Interstate evaluation of advanced breeding lines, K. Regan1 and M. Materne2 1Department of Agriculture, 2Victorian Institute for Dryland Agriculture, Agriculture Victoria 28. Timing of harvest for the best seed yield, M. Harries and M. Blyth, Department of Agriculture 29. Tolerance to post emergent herbicides, M. Harries and D. Nicholson, Department of Agriculture, H. Dhammu, T. Piper and L. Young, Department of Agriculture 30. Row spacing and stubble, G. Riethmuller, Department of Agriculture Pulse species 31. High value pulses for the high rainfall areas, N. Poulish1, P. White1,2 and K. Siddique1,2 , 1Department of Agriculture, 2CLIMA, The University of Western Australia 32. Alternative Rhizobium inoculant carrier technologies, J. Howieson and R. Yates, Centre for Rhizobium Studies (CRS), Murdoch University 33. Time of harvest to improve seed yield and quality of pulses, G. Riethmuller and R. French, Department of Agriculture 34. Phosphorus and zinc responses in pulses, S. Loss1, Z. Rengel2, B. Bowden3, M. Bolland3 and K. Siddique4 , 1Wesfarmers CSBP, 2Soil Science and Plant Nutrition, The University of Western Australia, 3Department of Agriculture, 4CLIMA, The University of Western Australia 35. Robust protocols for doubled haploid production in field pea and chickpea, J. Croser and K. Siddique, CLIMA, The University of Western Australia DEMONSTRATION OF PULSES IN THE FARMING SYSTEM 36. Field pea and lentil on clayed sandplain, M. Seymour, Department of Agriculture 37. Field pea variety demonstration, M. Harries and M. Blyth, Department of Agriculture 38. The benefit of field peas compared to lupins, R. Beermier, Department of Agriculture DISEASE AND PEST MANAGEMENT 39. Ascochyta blight of chickpea, B. MacLeod, Department of Agriculture 40. Management of chickpeas with improved ascochyta resistance, B. Macleod, A. Harrod, M. Harries and M. Blyth, Department of Agriculture 41. Chlorothalonil provides the most effective control, B. Macleod, A. Harrod, M. Harries and M. Blyth, Department of Agriculture 42. Importance of early sprays and value of seed dressing (post emergence), B. Macleod and A. Harrod, Department of Agriculture 43. A windborne stage of ascochyta blight in WA, J. Galloway and B. MacLeod, Department of Agriculture Ascochyta disease of pulses 44. Geographic location effects ascochyta spore maturation on pulse stubble, J. Galloway and B. MacLeod, Department of Agriculture Blackspot of field pea 45. Rapid recurrent selection to improve resistance to black spot, C. Beeck1, J. Wroth1, W. Cowling1 and T. Khan2, 1Plant Science, The University of Western Australia, 2Department of Agriculture 46. Survival of blackspot on old field pea stubble, J. Galloway and B. MacLeod, Department of Agriculture 47. Blackspot spores mature earlier in the southern regions, M. Salam, J. Galloway, A. Diggle and B. MacLeod, Department of Agriculture Viruses in pulses 48. Early insecticide application suppresses spread of Beet Western Yellows virus in field pea, R. Jones, B. Coutts and L. Smith, Department of Agriculture, and CLIMA, The University of Western Australia Insect pests and nematodes 49. Incorporation of pea weevil resistance from Pisum fulvum into field pea, O. Byrne1 and D. Hardie2, 1CLIMA, The University of Western Australia 2Department of Agriculture 50. Resistance to Helicoverpa in wild species of chickpea, J. Ridsdill-Smith1, H. Sharma2 and K. Mann1, 1CSIRO Entomology, Western Australia, 2 ICRISAT, Hyderabad, India 51. Relative hosting ability of field pea genotypes to root lesion nematode, S. Kelly, S. Sharma, H. Hunter and V. Vanstone, Department of Agriculture ACKNOWLEDGEMENTS APPENDIX I: Publications by Pulse Productivity Project Staff 2002 APPENDIX II: Summary of previous results APPENDIX III: List of common acronym

NS2 Protein of Hepatitis C Virus Interacts with Structural and Non-Structural Proteins towards Virus Assembly

Growing experimental evidence indicates that, in addition to the physical virion components, the non-structural proteins of hepatitis C virus (HCV) are intimately involved in orchestrating morphogenesis. Since it is dispensable for HCV RNA replication, the non-structural viral protein NS2 is suggested to play a central role in HCV particle assembly. However, despite genetic evidences, we have almost no understanding about NS2 protein-protein interactions and their role in the production of infectious particles. Here, we used co-immunoprecipitation and/or fluorescence resonance energy transfer with fluorescence lifetime imaging microscopy analyses to study the interactions between NS2 and the viroporin p7 and the HCV glycoprotein E2. In addition, we used alanine scanning insertion mutagenesis as well as other mutations in the context of an infectious virus to investigate the functional role of NS2 in HCV assembly. Finally, the subcellular localization of NS2 and several mutants was analyzed by confocal microscopy. Our data demonstrate molecular interactions between NS2 and p7 and E2. Furthermore, we show that, in the context of an infectious virus, NS2 accumulates over time in endoplasmic reticulum-derived dotted structures and colocalizes with both the envelope glycoproteins and components of the replication complex in close proximity to the HCV core protein and lipid droplets, a location that has been shown to be essential for virus assembly. We show that NS2 transmembrane region is crucial for both E2 interaction and subcellular localization. Moreover, specific mutations in core, envelope proteins, p7 and NS5A reported to abolish viral assembly changed the subcellular localization of NS2 protein. Together, these observations indicate that NS2 protein attracts the envelope proteins at the assembly site and it crosstalks with non-structural proteins for virus assembly

The CD81 Partner EWI-2wint Inhibits Hepatitis C Virus Entry

Two to three percent of the world's population is chronically infected with hepatitis C virus (HCV) and thus at risk of developing liver cancer. Although precise mechanisms regulating HCV entry into hepatic cells are still unknown, several cell surface proteins have been identified as entry factors for this virus. Among these molecules, the tetraspanin CD81 is essential for HCV entry. Here, we have identified a partner of CD81, EWI-2wint, which is expressed in several cell lines but not in hepatocytes. Ectopic expression of EWI-2wint in a hepatoma cell line susceptible to HCV infection blocked viral entry by inhibiting the interaction between the HCV envelope glycoproteins and CD81. This finding suggests that, in addition to the presence of specific entry factors in the hepatocytes, the lack of a specific inhibitor can contribute to the hepatotropism of HCV. This is the first example of a pathogen gaining entry into host cells that lack a specific inhibitory factor

Aging and Visual Counting

Much previous work on how normal aging affects visual enumeration has been focused on the response time required to enumerate, with unlimited stimulus duration. There is a fundamental question, not yet addressed, of how many visual items the aging visual system can enumerate in a "single glance", without the confounding influence of eye movements.We recruited 104 observers with normal vision across the age span (age 21-85). They were briefly (200 ms) presented with a number of well- separated black dots against a gray background on a monitor screen, and were asked to judge the number of dots. By limiting the stimulus presentation time, we can determine the maximum number of visual items an observer can correctly enumerate at a criterion level of performance (counting threshold, defined as the number of visual items at which ≈63% correct rate on a psychometric curve), without confounding by eye movements. Our findings reveal a 30% decrease in the mean counting threshold of the oldest group (age 61-85: ∼5 dots) when compared with the youngest groups (age 21-40: 7 dots). Surprisingly, despite decreased counting threshold, on average counting accuracy function (defined as the mean number of dots reported for each number tested) is largely unaffected by age, reflecting that the threshold loss can be primarily attributed to increased random errors. We further expanded this interesting finding to show that both young and old adults tend to over-count small numbers, but older observers over-count more.Here we show that age reduces the ability to correctly enumerate in a glance, but the accuracy (veridicality), on average, remains unchanged with advancing age. Control experiments indicate that the degraded performance cannot be explained by optical, retinal or other perceptual factors, but is cortical in origin

A Common Left Occipito-Temporal Dysfunction in Developmental Dyslexia and Acquired Letter-By-Letter Reading?

We used fMRI to examine functional brain abnormalities of German-speaking dyslexics who suffer from slow effortful reading but not from a reading accuracy problem. Similar to acquired cases of letter-by-letter reading, the developmental cases exhibited an abnormal strong effect of length (i.e., number of letters) on response time for words and pseudowords.Corresponding to lesions of left occipito-temporal (OT) regions in acquired cases, we found a dysfunction of this region in our developmental cases who failed to exhibit responsiveness of left OT regions to the length of words and pseudowords. This abnormality in the left OT cortex was accompanied by absent responsiveness to increased sublexical reading demands in phonological inferior frontal gyrus (IFG) regions. Interestingly, there was no abnormality in the left superior temporal cortex which--corresponding to the onological deficit explanation--is considered to be the prime locus of the reading difficulties of developmental dyslexia cases.The present functional imaging results suggest that developmental dyslexia similar to acquired letter-by-letter reading is due to a primary dysfunction of left OT regions

Holistic Processing of Words Modulated by Reading Experience

Perceptual expertise has been studied intensively with faces and object categories involving detailed individuation. A common finding is that experience in fulfilling the task demand of fine, subordinate-level discrimination between highly similar instances is associated with the development of holistic processing. This study examines whether holistic processing is also engaged by expert word recognition, which is thought to involve coarser, basic-level processing that is more part-based. We adopted a paradigm widely used for faces – the composite task, and found clear evidence of holistic processing for English words. A second experiment further showed that holistic processing for words was sensitive to the amount of experience with the language concerned (native vs. second-language readers) and with the specific stimuli (words vs. pseudowords). The adoption of a paradigm from the face perception literature to the study of expert word perception is important for further comparison between perceptual expertise with words and face-like expertise

Grounding Word Learning in Space

Humans and objects, and thus social interactions about objects, exist within space. Words direct listeners' attention to specific regions of space. Thus, a strong correspondence exists between where one looks, one's bodily orientation, and what one sees. This leads to further correspondence with what one remembers. Here, we present data suggesting that children use associations between space and objects and space and words to link words and objects—space binds labels to their referents. We tested this claim in four experiments, showing that the spatial consistency of where objects are presented affects children's word learning. Next, we demonstrate that a process model that grounds word learning in the known neural dynamics of spatial attention, spatial memory, and associative learning can capture the suite of results reported here. This model also predicts that space is special, a prediction supported in a fifth experiment that shows children do not use color as a cue to bind words and objects. In a final experiment, we ask whether spatial consistency affects word learning in naturalistic word learning contexts. Children of parents who spontaneously keep objects in a consistent spatial location during naming interactions learn words more effectively. Together, the model and data show that space is a powerful tool that can effectively ground word learning in social contexts