Leveraging well-conditioned bases : streaming and distributed summaries in Minkowski p-norms

Work on approximate linear algebra has led to efficient distributed and streaming algorithms for problems such as approximate matrix multiplication, low rank approximation, and regression, primarily for the Euclidean norm ℓ2. We study other ℓp norms, which are more robust for p2. Unlike previous algorithms for such norms, we give algorithms that are (1) deterministic, (2) work simultaneously for every p≥1, including p=∞, and (3) can be implemented in both distributed and streaming environments. We study ℓp-regression, entrywise ℓp-low rank approximation, and versions of approximate matrix multiplication

The unusual UBZ domain of Saccharomyces cerevisiae polymerase η

Recent research has revealed the presence of ubiquitin-binding domains in the Y family polymerases. The ubiquitin-binding zinc finger (UBZ) domain of human polymerase η is vital for its regulation, localization, and function. Here, we elucidate structural and functional features of the non-canonical UBZ motif of Saccharomyces cerevisiae pol η. Characterization of pol η mutants confirms the importance of the UBZ motif and implies that its function is independent of zinc binding. Intriguingly, we demonstrate that zinc does bind to and affect the structure of the purified UBZ domain, but is not required for its ubiquitin-binding activity. Our finding that this unusual zinc finger is able to interact with ubiquitin even in its apo form adds support to the model that ubiquitin binding is the primary and functionally important activity of the UBZ domain in S. cerevisiae polymerase η. Putative ubiquitin-binding domains, primarily UBZs, are identified in the majority of known pol η homologs. We discuss the implications of our observations for zinc finger structure and pol η regulation.National Institute of Environmental Health Sciences (Grant ES-015818)National Institute of Environmental Health Sciences (Grant P30 ES-002109)American Cancer Society (Research Professorship

Subspace exploration : bounds on projected frequency estimation

Given an n×d dimensional dataset A, a projection query specifies a subset C⊆[d] of columns which yields a new n×|C| array. We study the space complexity of computing data analysis functions over such subspaces, including heavy hitters and norms, when the subspaces are revealed only after observing the data. We show that this important class of problems is typically hard: for many problems, we show 2Ω(d) lower bounds. However, we present upper bounds which demonstrate space dependency better than 2d. That is, for c,c′∈(0,1) and a parameter N=2d an Nc-approximation can be obtained in space min(Nc′,n), showing that it is possible to improve on the naïve approach of keeping information for all 2d subsets of d columns. Our results are based on careful constructions of instances using coding theory and novel combinatorial reductions that exhibit such space-approximation tradeoffs

Konverents "Digitaalraamatukogu ja selle kasutaja IV. ELNET Konsortsium 10"

● Kümme aastat hiljem / Mihkel Reial ● Millennium — what next??? / Graham Woodruff ● FinELib consortium supporting research, teaching and learning in Finland / Kristiina Hormia-Poutanen ● Infokirjaoskus ajavaimust kantuna / Taimi Nurmiste ● E-õpe - uus ühenduslüli raamatukogu ja ülikooli koostöös / Kärt Miil, Vilve Seiler ● Ühiselt hangitud e-väljaannete väärtusest / Marika Meltsas ● Autentimisest, printimisest jm TÜ raamatukogus / Kill Kas

Design of the Subpopulations and Intermediate Outcome Measures in COPD (SPIROMICS) AIR Study.

IntroductionPopulation-based epidemiological evidence suggests that exposure to ambient air pollutants increases hospitalisations and mortality from chronic obstructive pulmonary disease (COPD), but less is known about the impact of exposure to air pollutants on patient-reported outcomes, morbidity and progression of COPD.Methods and analysisThe Subpopulations and Intermediate Outcome Measures in COPD (SPIROMICS) Air Pollution Study (SPIROMICS AIR) was initiated in 2013 to investigate the relation between individual-level estimates of short-term and long-term air pollution exposures, day-to-day symptom variability and disease progression in individuals with COPD. SPIROMICS AIR builds on a multicentre study of smokers with COPD, supplementing it with state-of-the-art air pollution exposure assessments of fine particulate matter, oxides of nitrogen, ozone, sulfur dioxide and black carbon. In the parent study, approximately 3000 smokers with and without airflow obstruction are being followed for up to 3 years for the identification of intermediate biomarkers which predict disease progression. Subcohorts undergo daily symptom monitoring using comprehensive daily diaries. The air monitoring and modelling methods employed in SPIROMICS AIR will provide estimates of individual exposure that incorporate residence-specific infiltration characteristics and participant-specific time-activity patterns. The overarching study aim is to understand the health effects of short-term and long-term exposures to air pollution on COPD morbidity, including exacerbation risk, patient-reported outcomes and disease progression.Ethics and disseminationThe institutional review boards of all the participating institutions approved the study protocols. The results of the trial will be presented at national and international meetings and published in peer-reviewed journals

Calretinin positive neurons form an excitatory amplifier network in the spinal cord dorsal horn

Nociceptive information is relayed through the spinal cord dorsal horn, a critical area in sensory processing. The neuronal circuits in this region that underpin sensory perception must be clarified to better understand how dysfunction can lead to pathological pain. This study used an optogenetic approach to selectively activate spinal interneurons that express the calcium-binding protein calretinin (CR). We show that these interneurons form an interconnected network that can initiate and sustain enhanced excitatory signaling, and directly relay signals to lamina I projection neurons. Photoactivation of CR interneurons in vivo resulted in a significant nocifensive behavior that was morphine sensitive, caused a conditioned place aversion, and was enhanced by spared nerve injury. Furthermore, halorhodopsin-mediated inhibition of these interneurons elevated sensory thresholds. Our results suggest that dorsal horn circuits that involve excitatory CR neurons are important for the generation and amplification of pain and identify these interneurons as a future analgesic target