92 research outputs found

    Cross-correlation image analysis for real-time particle tracking

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    Accurately measuring translations between images is essential in many fields, including biology, medicine, geography, and physics. Existing methods, including the popular FFT-based cross-correlation, are not suitable for real-time analysis, which is especially vital in feedback control systems. To fill this gap, we introduce a new algorithm which approaches shot-noise limited displacement detection and a GPU-based implementation for real-time image analysis.Comment: 4 pages, 3 figures, submitted to Optics Letter

    Placing the Common Era in a Holocene context: millennial to centennial patterns and trends in the hydroclimate of North America over the past 2000 years

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    A synthesis of 93 hydrologic records from across North and Central America, and adjacent tropical and Arctic islands, reveals centennial to millennial trends in the regional hydroclimates of the Common Era (CE; past 2000 years). The hydrological records derive from materials stored in lakes, bogs, caves, and ice from extant glaciers, which have the continuity through time to preserve low-frequency ( \u3e 100 year) climate signals that may extend deeper into the Holocene. The most common pattern, represented in 46 (49 %) of the records, indicates that the centuries before 1000 CE were drier than the centuries since that time. Principal component analysis indicates that millennial-scale trends represent the dominant pattern of variance in the southwestern US, northeastern US, mid-continent, Pacific Northwest, Arctic, and tropics, although not all records within a region show the same direction of change. The Pacific Northwest and the southernmost tier of the tropical sites tended to dry toward present, as many other areas became wetter than before. In 22 records (24 %), the Medieval Climate Anomaly period (800–1300 CE) was drier than the Little Ice Age (1400–1900 CE), but in many cases the difference was part of the longer millennial-scale trend, and, in 25 records (27 %), the Medieval Climate Anomaly period represented a pluvial (wet) phase. Where quantitative records permitted a comparison, we found that centennial-scale fluctuations over the Common Era represented changes of 3–7% in the modern interannual range of variability in precipitation, but the accumulation of these long-term trends over the entirety of the Holocene caused recent centuries to be significantly wetter, on average, than most of the past 11 000 years

    Nocturnal dipping of heart rate and blood pressure in people with HIV in Tanzania.

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    People with HIV (PWH) have a >2-fold greater risk for development of cardiovascular disease (CVD), which may be associated with abnormalities in 24-h ambulatory blood pressure measurement (ABPM) profile. We conducted a nested case-control study of ABPM in 137 PWH and HIV-uninfected controls with normal and high clinic blood pressure (BP) in Tanzania. Nocturnal non-dipping of heart rate (HR) was significantly more common among PWH than HIV-uninfected controls (p = .01). Nocturnal non-dipping of BP was significantly more common in PWH with normal clinic BP (p = .048). Clinical correlates of nocturnal non-dipping were similar in PWH and HIV-uninfected adults and included higher BMI, higher CD4+ cell count, and high C-reactive protein for HR and markers of renal disease for BP. In conclusion, nocturnal non-dipping of both BP and HR was more common in PWH but further research is needed to determine causes and consequences of this difference

    The lncRNA CASC15 regulates SOX4 expression in RUNX1-rearranged acute leukemia

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    Abstract Background Long non-coding RNAs (lncRNAs) play a variety of cellular roles, including regulation of transcription and translation, leading to alterations in gene expression. Some lncRNAs modulate the expression of chromosomally adjacent genes. Here, we assess the roles of the lncRNA CASC15 in regulation of a chromosomally nearby gene, SOX4, and its function in RUNX1/AML translocated leukemia. Results CASC15 is a conserved lncRNA that was upregulated in pediatric B-acute lymphoblastic leukemia (B-ALL) with t (12; 21) as well as pediatric acute myeloid leukemia (AML) with t (8; 21), both of which are associated with relatively better prognosis. Enforced expression of CASC15 led to a myeloid bias in development, and overall, decreased engraftment and colony formation. At the cellular level, CASC15 regulated cellular survival, proliferation, and the expression of its chromosomally adjacent gene, SOX4. Differentially regulated genes following CASC15 knockdown were enriched for predicted transcriptional targets of the Yin and Yang-1 (YY1) transcription factor. Interestingly, we found that CASC15 enhances YY1-mediated regulation of the SOX4 promoter. Conclusions Our findings represent the first characterization of this CASC15 in RUNX1-translocated leukemia, and point towards a mechanistic basis for its action

    Student Recital (December 8, 2015)

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    Four Rotations for Solo Marimba / Eric Sammut I. Spencer Lusignan, marimba Trombone Concerto / Nicolai Rimsky-Korsakov Allegro vivace Andante cantabile Sarah Emanuel, trombone When I think upon the maidens / Michael Head O del mio dolce ardor / Christoph Willibald Gluck Robert Gariepy, bass Sonatina to David Russell / Jorge Morel Allegretto Nicholas Moreira, guitar Goodnight Moon / Eric Whitacre Taylor Eckstrom, soprano Sonate I for Flute / Paul Hindemith Heiter bewegt Ian Maguire, flute Etude No. 4 des Accords rĂ©pĂ©tĂ©s, W 235 / Heitor Villa-Lobos Sean Donovan, guitar Sonata I / Johann Ernst Galliard Cantabile Spiritoso e staccato Largo e staccato Hornpipe a l’Inglese Vivace Cody O’Toole, trombone Berta’s Aria (The Barber of Seville) / Gioachino Rossini Justine Smigel, soprano When I have sung my songs / Ernest Charles Emily Mills, soprano Romanze, Opus 13, No. 1 / Johann Kaspar Mertz Lieblied, Opus 13, No. 4 Nolan Driscoll, guitar Hommage a Villa-Lobos / Roland Dyens Andantinostalgie Prelude No. 5, W 419 / Heitor Villa-Lobos Austin DeAndrade, guitar Gretchen am Spinnrade, D. 118 / Franz Schubert Volta la terra (Un Ballo in Maschera) / Giuseppe Verdi Angela Maloney, sopranohttps://vc.bridgew.edu/student_concerts/1102/thumbnail.jp

    Do the size and landscape context of forest openings influence the abundance and breeding success of shrubland songbirds in southern New England?

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    Early successional birds have declined in the northeastern United States due to the regeneration of forest on abandoned farm fields and the suppression of natural disturbances that once provided appropriate habitat. These species have become increasingly dependent on early successional habitats generated by such activities as timber harvesting. Recent approaches of timber harvesting, which range from single-tree harvesting to clearcutting, create forest openings of different sizes and configurations embedded in landscapes with different land use patterns. To assess the importance of forest openings created by timber harvesting for shrubland birds, we surveyed birds on 50m radius plots in 34 harvest sites (0.5–21ha). We collected data on multi-scaled habitat variables ranging from plot-level vegetation characteristics to land use patterns within 1km of each study site. We also monitored mating and nesting success of Blue-winged Warblers (Vermivora pinus) in 10 forest openings. The abundance of most shrubland species was influenced by plot-level habitat variables, such as tree density and vegetation height, rather than shrubland area or the composition of land uses in the surrounding landscape. Only Eastern Towhees (Pipilo erythrophthalmus) were more frequent in survey plots in larger forest openings. In contrast, neither abundance nor reproductive activity of Blue-winged Warblers was correlated with the size of the forest opening. Their abundance was negatively related to vegetation height, however. Only 54% of the territorial male Blue-winged Warblers in forest openings were mated. We documented relatively low nest success rates of 21.1% during the egg laying and incubation nest stages, but increased success rates during the later stages of nesting. Our results indicate that even small forest openings with low vegetation provide habitat for Blue-winged Warblers and other shrubland birds. The overall reproductive rate of territorial male Blue-winged Warblers in forests openings was low during the 2 years of the study, however. Further studies are needed to assess the long-term value of this type of habitat for sustaining shrubland bird populations

    A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars

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    The Curiosity rover discovered fine-grained sedimentary rocks, inferred to represent an ancient lake, preserve evidence of an environment that would have been suited to support a Martian biosphere founded on chemolithoautotrophy. This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both iron and sulfur species. C, H, O, S, N, and P were measured directly as key biogenic elements, and by inference N and P are assumed to have been available. The environment likely had a minimum duration of hundreds to tens of thousands of years. These results highlight the biological viability of fluvial-lacustrine environments in the post-Noachian history of Mars

    Volatile and Organic Compositions of Sedimentary Rocks in Yellowknife Bay, Gale crater, Mars

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    H₂O, CO₂, SO₂, O₂, H₂, H₂S, HCl, chlorinated hydrocarbons, NO and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H₂O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO₂. Concurrent evolution of O₂ and chlorinated hydrocarbons suggest the presence of oxychlorine phase(s). Sulfides are likely sources for S-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic C sources may be preserved in the mudstone; however, the C source for the chlorinated hydrocarbons is not definitively of martian origin
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