602 research outputs found

    University of Colorado: 1970 Summer Field Season in East Baffin Island

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    ... Field work continued on [the late glacial and neoglacial chronology and recent crustal movements] program with the main emphasis being shifted to Narpaing Fiord and outer Okoa Bay. Marine limits were measured at many localities in the two areas and some samples of marine shells were collected for dating ... Studies continued on the task of subdividing the glacial deposits on the basis of a number of weathering criteria such as: depth of pitting, surface texture of boulders, soil development, X-ray analysis for clay minerals and Free-iron content. The combined results suggest several episodes of glaciation with a general decrease of glacier area and volume throughout the Wisconsin. ... A tentative lichen growth-curve is being developed based on a variety of evidence, and it is considered that the graph may usefully be extended back to 8,000 or 10,000 years ago. Work on a series of corrie moraines at the heads of Narpaing and Quajon fiords suggests that the outermost south-facing moraines at 600 m.a.s.l. may be 15,000 years old whereas the north-facing moraines at 550 m.a.s.l. are 8,000 to 10,000 years old. ... A series of 7 weather stations were established at different exposures and elevations in the area between the head of Quajon and Narpaing fiords. ... Mass budgets were measured in early June and mid-August using a variety of methods. Stakes, probing and pits were used to detail the progress of melting during the ablation season. In early June the specific net budget was + 0.42 cm ± 0.06 and in mid-August was + 0.38 ± 0.06 cm water equivalent. In complete contrast to 1969, no ice was showing on the glacier and the summer melt had been compensated by snowfalls throughout the "ablation" season. Surface lowering amounted to about 45 cm of snow and this was nearly identical to the mass added in the growth of superimposed ice. Because of low temperatures the glacier was acting nearly as a closed system. ..

    University of Colorado 1974 Field Season in Eastern Baffin Island

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    The summer of 1974 saw one of the largest research parties the University of Colorado has been able to mount operating along the eastern coast of Baffin Island. The early and widespread break-up of sea ice greatly assisted in the completion of the field programme in which a total of sixteen persons were involved. In addition to members of the University staff, the following individuals from other institutions also participated. In the programme: a member of the Department of Micropalaeontology of the University of Aarhus, Denmark; a soil scientist from the University of Pennsylvania, U.S.A.; a Quaternary geologist from Brock University, Ontario, Canada; and a Quaternary geologist from Grand Valley State College, Michigan, U.S.A. ... Raised marine sediments and tills were investigated on Broughton Island and northwards along the coast to Quajon Fiord. Specific attention was focused on collecting samples for micro-faunal analysis and delimiting different marine episodes. In addition, a number of sites were revisited on Broughton Island and northwards along the coast to Kivitoo and Quajon Fiord. Large (1000-g and over) samples of marine shells were collected from sites previously given dates of over 30,000 years BP. ... One field party mapped the southern part of the Baffin Island National Park, giving particular attention to (a) the delimitation of glacial periods on the basis of surface weathering of boulders, and (b) determining the elevation of local marine limits and lower strandlines. The latter research was concentrated on the mapping of the southern shore of Cumberland Peninsula, from outer Kingnait Fiord westward to the head of Cumberland Sound. ... Soil scientists established a soil chronosequence, and investigated the range of soil types existing within the southern part of Cumberland Peninsula. They sent samples south from laboratory analysis. Plant collection: Specimens of vascular plants, mosses and lichens were collected from Broughton Island and from the head of Maktak Fiord, and sent to the University of Colorado Museum. By December 1974, a total of 86 vascular plants had been identified. Climatological studies in relation to fast ice: Work done during the summer of 1974 concludes the field-measurement phase of the University of Colorado's study of the surface energy budgets of fast ice at Broughton Island. A micrometeorological station was operated at a site approximately one kilometre south of Broughton settlement, from late May until local break-up in early July. The programme of observation consisted of the periodic taking of profiles of wind, temperature and relative humidity; the continuous measurement of temperature at two metres, and net radiation over both saturated and unsaturated surfaces; and transects of surface short-wave albedo. Salinity and temperature profiles in the ice and water were taken every 304 days. Comparative analysis of the data for 1972-74 is now in progress in relation to the observed ice regime. The 1974 data should provide better estimates of the turbulent flux components of the energy budget than it was possible to make in previous summers. Meteorological observations were continued near the base of the Broughton Island operations through mid-August. Results are now available of four summers and two winters of standard meteorological observations, and global solar and net radiation measurements as well. The Atmospheric Environment Service Cooperative Observer station, with its twice-daily measurements of maximum and minimum temperatures and of precipitation, is now into its fourth calendar year of operation. The summer of 1974 was unusually mild. The mean ablation seasonal temperature was 3.9°C at the Broughton DEW line weather station. In contrast, 1972 was the coldest (-1.2 C°). The early part of June 1974 was dominated by anticyclonic synoptic weather patterns which greatly accelerated the fast ice ablation rate to give the earliest break-up in five years. Satellite-observed conce ntrations of pack ice in Davis Strait in late May were less than at the same time in 1973. With the resurvey of the "Boas" Glacier (67 35 N, 65 16 W) in August 1974, the mass balance measurements were extended to five balance years. Accurate measurements were not possible, because most ablation poles melted out during the warm summer of 1974. However, it is estimated that the net specific balance for the 1973-74 budget year was approximately -0.5 m water equivalent (w.e.). ... Analysis of the past five budget years shows that (a) the "Boas" Glacier exhibited a two-year alternation of large mass gains and losses during the first four years, and (b) the estimated net specific mass balance for the five-year period was -0.16 m w.e., in spite of the total net mass gains of 0.38 m w.e. during the first four years. ..

    Assessment of Discordance Between Physicians and Family Members Regarding Prognosis in Patients With Severe Acute Brain Injury.

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    Shared decision-making requires key stakeholders to align in perceptions of prognosis and likely treatment outcomes. For patients with severe acute brain injury, the objective of this study was to better understand prognosis discordance between physicians and families by determining prevalence and associated factors. This mixed-methods cross-sectional study analyzed a cohort collected from January 4, 2018, to July 22, 2020. This study was conducted in the medical and cardiac intensive care units of a single neuroscience center. Participants included families, physicians, and nurses of patients admitted with severe acute brain injury. Severe acute brain injury was defined as stroke, traumatic brain injury, or hypoxic ischemic encephalopathy with a Glasgow Coma Scale score less than or equal to 12 points after hospital day 2. Prognosis discordance was defined as a 20% or greater difference between family and physician prognosis predictions; misunderstanding was defined as a 20% or greater difference between physician prediction and the family's estimate of physician prediction; and optimistic belief difference was defined as any difference (>0%) between family prediction and their estimate of physician prediction. Logistic regression was used to identify associations with discordance. Optimistic belief differences were analyzed as a subgroup of prognosis discordance. Among 222 enrolled patients, prognostic predictions were available for 193 patients (mean [SD] age, 57 [19] years; 106 men [55%]). Prognosis discordance occurred for 118 patients (61%) and was significantly more common among families who identified with minoritized racial groups compared with White families (odds ratio [OR], 3.14; CI, 1.40-7.07, P = .006); among siblings (OR, 4.93; 95% CI, 1.35-17.93, P = .02) and adult children (OR, 2.43; 95% CI, 1.10-5.37; P = .03) compared with spouses; and when nurses perceived family understanding as poor compared with good (OR, 3.73; 95% CI, 1.88-7.40; P < .001). Misunderstanding was present for 80 of 173 patients (46%) evaluated for this type of prognosis discordance, and optimistic belief difference was present for 94 of 173 patients (54%). In qualitative analysis, faith and uncertainty emerged as themes underlying belief differences. Nurse perception of poor family understanding was significantly associated with misunderstanding (OR, 2.06; 95% CI, 1.07-3.94; P = .03), and physician perception with optimistic belief differences (OR, 2.32; 95% CI, 1.10-4.88; P = .03). Results of this cross-sectional study suggest that for patients with severe acute brain injury, prognosis discordance between physicians and families was common. Efforts to improve communication and decision-making should aim to reduce this discordance and find ways to target both misunderstanding and optimistic belief differences

    Exile Vol. XXVI No. 1

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    Photo: Untitled by Jamie Bailey 3 Poem: Hi, My Name Is by Kathy Andrews 4 Poem: Untitled by Willi Haworth 5 Photo: Stratified Snow by Jim Lundy 6 Poem: Untitled by A. Pence 7 Poem: Akua\u27ba by Tona Dickerson 8 Photo: Untitled by Jim Lundy 9 Story: The Dogcatchers of Portimao by Debora Papierski 10-13 Photo: Untitled by Holly Hall 14 Poem: Tocopold Bloom: A Working Class Hero by Mary Ladky 15 Photo: Untitled by Cory Easter 16 Poem: A Mortal Wound by Peter Fish 17 Poem: Let Me Sleep by R. G. Trub 18-19 Photo: Modified Cube by Jim Lundy 20 Story: Untitled by Kathy Desmond 21-23 Photo: Untitled by Holly Hall 24 Poem: Untitled by Sharon McCartney 25 Photo: Untitled by Him Lundy 26 Poem: Every Morning I Wake by Peter Fish 27 Photo: Untitled by Rof Smith 28 Poem: For Mark Some Words by Bonny Lowe 29 Photo: Untitled by Jim Lundy 30 Poem: A Flash of Crooked Light by Lisa Minacci 31 Photo: Untitled by Jim Lundy 32 Poem: Paper Hearts by W. Dulles 33 Drawing: Untitled by Roger Weisman 34 Story: Untitled by Dane Lavin 35-42 Photo: Untitled by Jim Lundy 43 Special Thanks To Laurie Howard -

    Noise Filtering Strategies of Adaptive Signaling Networks: The Case of E. Coli Chemotaxis

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    Two distinct mechanisms for filtering noise in an input signal are identified in a class of adaptive sensory networks. We find that the high frequency noise is filtered by the output degradation process through time-averaging; while the low frequency noise is damped by adaptation through negative feedback. Both filtering processes themselves introduce intrinsic noises, which are found to be unfiltered and can thus amount to a significant internal noise floor even without signaling. These results are applied to E. coli chemotaxis. We show unambiguously that the molecular mechanism for the Berg-Purcell time-averaging scheme is the dephosphorylation of the response regulator CheY-P, not the receptor adaptation process as previously suggested. The high frequency noise due to the stochastic ligand binding-unbinding events and the random ligand molecule diffusion is averaged by the CheY-P dephosphorylation process to a negligible level in E.coli. We identify a previously unstudied noise source caused by the random motion of the cell in a ligand gradient. We show that this random walk induced signal noise has a divergent low frequency component, which is only rendered finite by the receptor adaptation process. For gradients within the E. coli sensing range, this dominant external noise can be comparable to the significant intrinsic noise in the system. The dependence of the response and its fluctuations on the key time scales of the system are studied systematically. We show that the chemotaxis pathway may have evolved to optimize gradient sensing, strong response, and noise control in different time scalesComment: 15 pages, 4 figure

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

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    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

    Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

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    A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

    Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

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    The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.Comment: Submitted to Physics Letters

    Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV

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    A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femtobarns. Two complementary search strategies are employed. The first probes models with a specific dilepton production mechanism that leads to a characteristic kinematic edge in the dilepton mass distribution. The second strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO
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