1,098 research outputs found

    Interleaved Parton Showers and Tuning Prospects

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    General-purpose Monte Carlo event generators have become important tools in particle physics, allowing the simulation of exclusive hadronic final states. In this article we examine the Pythia 8 generator, in particular focusing on its parton-shower algorithms. Some relevant new additions to the code are introduced, that should allow for a better description of data. We also implement and compare with 2 to 3 real-emission QCD matrix elements, to check how well the shower algorithm fills the phase space away from the soft and collinear regions. A tuning of the generator to Tevatron data is performed for two PDF sets and the impact of first new LHC data is examined

    Bi-allelic JAM2 Variants Lead to Early-Onset Recessive Primary Familial Brain Calcification.

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    Primary familial brain calcification (PFBC) is a rare neurodegenerative disorder characterized by a combination of neurological, psychiatric, and cognitive decline associated with calcium deposition on brain imaging. To date, mutations in five genes have been linked to PFBC. However, more than 50% of individuals affected by PFBC have no molecular diagnosis. We report four unrelated families presenting with initial learning difficulties and seizures and later psychiatric symptoms, cerebellar ataxia, extrapyramidal signs, and extensive calcifications on brain imaging. Through a combination of homozygosity mapping and exome sequencing, we mapped this phenotype to chromosome 21q21.3 and identified bi-allelic variants in JAM2. JAM2 encodes for the junctional-adhesion-molecule-2, a key tight-junction protein in blood-brain-barrier permeability. We show that JAM2 variants lead to reduction of JAM2 mRNA expression and absence of JAM2 protein in patient's fibroblasts, consistent with a loss-of-function mechanism. We show that the human phenotype is replicated in the jam2 complete knockout mouse (jam2 KO). Furthermore, neuropathology of jam2 KO mouse showed prominent vacuolation in the cerebral cortex, thalamus, and cerebellum and particularly widespread vacuolation in the midbrain with reactive astrogliosis and neuronal density reduction. The regions of the human brain affected on neuroimaging are similar to the affected brain areas in the myorg PFBC null mouse. Along with JAM3 and OCLN, JAM2 is the third tight-junction gene in which bi-allelic variants are associated with brain calcification, suggesting that defective cell-to-cell adhesion and dysfunction of the movement of solutes through the paracellular spaces in the neurovascular unit is a key mechanism in CNS calcification

    Heavy Quarkonium Physics

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    This report is the result of the collaboration and research effort of the Quarkonium Working Group over the last three years. It provides a comprehensive overview of the state of the art in heavy-quarkonium theory and experiment, covering quarkonium spectroscopy, decay, and production, the determination of QCD parameters from quarkonium observables, quarkonia in media, and the effects on quarkonia of physics beyond the Standard Model. An introduction to common theoretical and experimental tools is included. Future opportunities for research in quarkonium physics are also discussed.Comment: xviii + 487 pages, 260 figures. The full text is also available at the Quarkonium Working Group web page: http://www.qwg.to.infn.i

    First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

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    Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

    Crop Updates 2009 - Cereals

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    This session covers twenty seven papers from different authors: PLENARY 1. Building soil carbon for productivity and implications for carbon accounting, Jeff Baldock, CSIRO Land and Water, Adelaide, SA 2. Fact or Fiction: Who is telling the truth and how to tell the difference, Doug Edmeades, agKnowledge Ltd, Hamilton 3. Four decades of crop sequence trials in Western Australia, Mark Seymour,Department of Agriculture and Food BREAK CROPS 4. 2008 Break Crops survey Report, Paul Carmody,Development Officer, Department of Agriculture and Food 5. Attitudes of Western Australian wheatbelt growers to ‘Break Crops’, Paul Carmody and Ian Pritchard, Development Officers, Department of Agriculture and Food 6. The value of organic nitrogen from lupins, Alan Meldrum, Pulse Australia 7.The area of break crops on farm: What farmers are doing compared to estimates based on maximising profit, Michael Robertson and Roger Lawes,CSIRO Floreat, Rob Sands,FARMANCO Farm Consultants, Peter White,Department of Agriculture and Food, Western Australia, Felicity Byrne and Andrew Bathgate,Farming Systems Analysis CROP SPECIFIC Breeding 8. Identification of WALAB2014 as a potential albus lupin variety for northern agricultural region of Western Australia, Kedar Adhikari, Department of Agriculture and Food 9. Enhancement of black spot resistance in field pea, Kedar Adhikari, Tanveer Khan, Stuart Morgan and Alan Harris, Department of Agriculture and Food 10. Desi chickpea breeding: Evaluation of advanced line, Khan, TN1, Harris, A1, Gaur, P2, Siddique, KHM3, Clarke, H4, Turner, NC4, MacLeod, W1, Morgan, S1 1Department of Agriculture and Food, Western Australia, 2International Crop Research Institute for the Semi Arid Tropics (ICRISAT), 3The University of Western Australia, 4Centre for Legumes in Mediterranean Agriculture 11. Pulse Breeding Australia-Australian Field Pea Improvement Program (AFPIP), Ian Pritchard1, Chris Veitch1, Stuart Morgan1, Alan Harris1 and Tony Leonforte 2 1 Department of Agriculture and Food, Western Australia, 2 Department off Primary Industries, Victoria Disease 12. Interaction between wheat varieties and fungicides to control stripe rust for grain and quality, Kith Jayasena, Geoff Thomas, Rob Loughman, Kazue Tanaka and Bill MacLeod, Department of Agriculture and Food 13. Findings of canola disease survey 2008 and its implications for better disease management in 2009, Ravjit Khangura, WJ MacLeod, P White, P Carmody and M Amjad, Department of Agriculture and Food 14. Combating wheat leaf diseases using genome sequencing and functional genomics, Richard Oliver, Australian Centre for Necrotrophic Fungal Pathogens, Murdoch University 15. Distribution and survival of wheat curl mite (Aceria tosichella), vector of Wheat Streak Mosaic Virus, in the WA grainbelt during 2008, Dusty Severtson, Peter Mangano, John Botha and Brenda Coutts, Department of Agriculture and Food 16. Partial resistance to Stagonspora (Septoria) Partial resistance to Stagonospora (Septoria) nodorum blotch and response to fungicide in a severe epidemic scenario, Manisha Shankar1, Richard Oliver2, Kasia Rybak2and Rob Loughman1 1Department of Agriculture and Food, Western Australia, 2Australian Centre for Necrotrophic Fungal Pathogens, Murdoch University, Western Australia 17. Black pod syndrome in lupins can be reduced by regular insecticide sprays, Peter White and Michael Baker,Department of Agriculture and Food Variety performance 18. Incorporating new herbicide tolerant juncea canola into low rainfall cropping systems in Western Australia, Mohammad Amjad, Department of Agriculture and Food 19. Varietal differences in germ end staining of barley, Andrea Hills,Department of Agriculture and Food 20. Wheat variety performance in the Central Agricultural Region in 2008, Shahajahan Miyan, Department of Agriculture and Food 21. Barley variety identification using DNA fingerprinting, Peter Portmann, Agriconnect, Perth WA Dr Nicole Rice, Southern Cross University, Lismore NSW Prof Robert Henry, Southern Cross University, Lismore NSW 22. Forecast disease resistance profile for the Western Australian barley crop over the next three years, Jeff J. Russell, Department of Agriculture and Food 23. Malting barley varieties differ in their flowering date and their response to changes in sowing date, BH Paynter and Jeff J. Russell,Department of Agriculture and Food 24. Market development for new barley varieties, Linda Price,Barley Australia 25. Response of wheat varieties to sowing time at Mt Barker, Katanning and Newdegate in 2008, Brenda Shackley and Vicki Scanlan,Department of Agriculture and Food 26. Flowering dates of wheat varieties in 2008 at three locations in Western Australia, Darshan Sharma, Brenda Shackley and Christine Zaicou-Kunesch, Department of Agriculture and Food 27. Agronomic responses of new wheat varieties in the norther agricultural region in 2008, Christine Zaicou-Kunesch, Department of Agriculture and Foo

    Parton distribution benchmarking with LHC data

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    We present a detailed comparison of the most recent sets of NNLO PDFs from the ABM, CT, HERAPDF, MSTW and NNPDF collaborations. We compare parton distributions at low and high scales and parton luminosities relevant for LHC phenomenology. We study the PDF dependence of LHC benchmark inclusive cross sections and differential distributions for electroweak boson and jet production in the cases in which the experimental covariance matrix is available. We quantify the agreement between data and theory by computing the χ 2 for each data set with all the various PDFs. PDF comparisons are performed consistently for common values of the strong coupling. We also present a benchmark comparison of jet production at the LHC, comparing the results from various available codes and scale settings. Finally, we discuss the implications of the updated NNLO PDF sets for the combined PDF+α s uncertainty in the gluon fusion Higgs production cross section

    Inhibition of G-protein signalling in cardiac dysfunction of intellectual developmental disorder with cardiac arrhythmia (IDDCA) syndrome

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    Background: Pathogenic variants of GNB5 encoding the ÎČ5 subunit of the guanine nucleotide-binding protein cause IDDCA syndrome, an autosomal recessive neurodevelopmental disorder associated with cognitive disability and cardiac arrhythmia, particularly severe bradycardia. Methods: We used echocardiography and telemetric ECG recordings to investigate consequences of Gnb5 loss in mouse. Results: We delineated a key role of Gnb5 in heart sinus conduction and showed that Gnb5-inhibitory signalling is essential for parasympathetic control of heart rate (HR) and maintenance of the sympathovagal balance. Gnb5-/- mice were smaller and had a smaller heart than Gnb5+/+ and Gnb5+/-, but exhibited better cardiac function. Lower autonomic nervous system modulation through diminished parasympathetic control and greater sympathetic regulation resulted in a higher baseline HR in Gnb5-/- mice. In contrast, Gnb5-/- mice exhibited profound bradycardia on treatment with carbachol, while sympathetic modulation of the cardiac stimulation was not altered. Concordantly, transcriptome study pinpointed altered expression of genes involved in cardiac muscle contractility in atria and ventricles of knocked-out mice. Homozygous Gnb5 loss resulted in significantly higher frequencies of sinus arrhythmias. Moreover, we described 13 affected individuals, increasing the IDDCA cohort to 44 patients. Conclusions: Our data demonstrate that loss of negative regulation of the inhibitory G-protein signalling causes HR perturbations in Gnb5-/- mice, an effect mainly driven by impaired parasympathetic activity. We anticipate that unravelling the mechanism of Gnb5 signalling in the autonomic control of the heart will pave the way for future drug screening
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