1,831 research outputs found
Narrative of Chain cruise #43 : February - August 1964
Originally issued as Reference No. 65-9, series later renamed WHOI-.On CHAIN Cruise 43, 15 February to 21 August 1964, geophysical
and geological observations were made in the North Atlantic Ocean, the
Mediterranean and Red Seas, and the Western part of the Indian Ocean,
along the track Woods Hole - Ceuta (Spanish Africa) - La Spezia - Port
Said - Aden - Victoria (Seychelles Islands) - Port Louis (Mauritius) -
Victoria (Seychelles Islands) - Port Said - Beirut - La Spezia - Monaco -
Plymouth (England) - Woods Hole. This report contains (1) a narrative
of the cruise, (2) a list of stations, (3) statements of the scientific
objectives of the cruise, (4) a summary of the geological and geophysical
observations, (5) end-of-cruise reports on equipment and some phases
of the research program, and (6) a selection of bottom photographs.
WHOI Ref. No. 64-51 contains a detailed navigational plot of the entire
cruise, including soundings and the locations of other observations.This cruise was supported by the National Science Foundation under Grant
GP-2370 and Submitted to the Office of Naval Research under Contract
Nonr-4029(00) NR 260-101
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How effective is eccentric viewing training? A systematic literature review
Purpose: The global prevalence of age-related macular degeneration (AMD) and associated central vision loss (CVL) is rising. CVL hinders the performance of many activities of daily living (ADLs). Adaptive strategies such as eccentric viewing (EV) and steady eye strategy (SES) may be used to compensate for CVL. In order to establish the potential of these rehabilitation strategies, this systematic review evaluates current literature regarding the effectiveness of EV and SES training in people with CVL.
Recent Findings: The search strategies identified 2605 publications, 36 of which met the inclusion criteria for the review, but only three of which were randomised controlled trials. This literature shows that EV and SES training can improve near visual acuity, reading speed, and performance of ADLs in people with CVL. However, there was insufficient literature to establish a relationship between training and distance visual acuity or quality-of-life. There is no conclusive evidence to show that a particular model of EV training is superior to another, little clear evidence of a relationship between participant characteristics and training outcomes and no data regarding the cost effectiveness of training.
Summary: This report highlights the need for further robust research to establish the true potential and cost effectiveness of EV and SES training as a rehabilitation strategy for individuals with CVL
Development of a core outcome set for effectiveness studies of breech birth at term (Breech-COS)-an international multi-stakeholder Delphi study: study protocol.
BACKGROUND: Women pregnant with a breech-presenting foetus at term are at increased risk of adverse pregnancy outcomes. The most common intervention used to improve neonatal outcomes is planned delivery by caesarean section. But this is not always possible, and some women prefer to plan a vaginal birth. A number of providers have proposed alternative interventions, such as delivery protocols or specialist teams, but heterogeneity in reported outcomes and their measurements prevents meaningful comparisons. The aim of this paper is to present a protocol for a study to develop a Breech Core Outcome Set (Breech-COS) for studies evaluating the effectiveness of interventions to improve outcomes associated with term breech birth. METHODS: The development of a Breech-COS includes three phases. First, a systematic literature review will be conducted to identify outcomes previously used in effectiveness studies of breech birth at term. A focus group discussion will be conducted with the study's pre-established Patient and Public Involvement (PPI) group, to enable service user perspectives on the results of the literature review to influence the design of the Delphi survey instrument. Second, an international Delphi survey will be conducted to prioritise outcomes for inclusion in the Breech-COS from the point of view of key stakeholders, including perinatal care providers and families who have experienced a term breech pregnancy. Finally, a consensus meeting will be held with stakeholders to ratify the Breech-COS and disseminate findings for application in future effectiveness studies. DISCUSSION: The expectation is that the Breech-COS will always be collected in all clinical trials, audits of practice and other forms of observation research that concern breech birth at term, along with other outcomes of interest. This will facilitate comparing, contrasting and combining studies with the ultimate goal of improved maternal and neonatal outcomes. TRIAL REGISTRATION: Core Outcome Measures in Effectiveness Trials (COMET) #1749
Discovery limits for a new contact interaction at future hadronic colliders with polarized beams
The production of high-transverse energy jets in hadron-hadroncollisions is
sensitive to the presence of new contact interactions between quarks. If proton
polarization were available, the measurement of some parity violating spin
asymmetries in one-jet production at large transverse energy would complement
the usual search for deviations from the expected QCD cross section. In the
same time, a unique information on the chirality structure of the new
interaction could be obtained. In this context, we compare the potentialities
of various and colliders that are planned or have been proposed,
with the additional requirement of beam polarization.Comment: Latex file, 9 pages and 1 ps fig, definition of the subprocess
variables and one example of the effect of new contact terms on the parity
violating spin asymmetry are added. Eq. 8 (now eq. 9) and the following
equation are changed, giving better bounds in the polarized pp case (new
figure
Cassini observations of ion and electron beams at Saturn and their relationship to infrared auroral arcs
We present Cassini Visual and Infrared Mapping Spectrometer observations of infrared auroral emissions from the noon sector of Saturn's ionosphere revealing multiple intense auroral arcs separated by dark regions poleward of the main oval. The arcs are interpreted as the ionospheric signatures of bursts of reconnection occurring at the dayside magnetopause. The auroral arcs were associated with upward field-aligned currents, the magnetic signatures of which were detected by Cassini at high planetary latitudes. Magnetic field and particle observations in the adjacent downward current regions showed upward bursts of 100â360 keV light ions in addition to energetic (hundreds of keV) electrons, which may have been scattered from upward accelerated beams carrying the downward currents. Broadband, upward propagating whistler waves were detected simultaneously with the ion beams. The acceleration of the light ions from low altitudes is attributed to wave-particle interactions in the downward current regions. Energetic (600 keV) oxygen ions were also detected, suggesting the presence of ambient oxygen at altitudes within the acceleration region. These simultaneous in situ and remote observations reveal the highly energetic magnetospheric dynamics driving some of Saturn's unusual auroral features. This is the first in situ identification of transient reconnection events at regions magnetically conjugate to Saturn's magnetopause
Magnetic Field Observations on Cassini's Proximal Periapsis Passes: Planetary Period Oscillations and Mean Residual Fields
We analyze periapsis pass magnetic field data from the final 23 orbits of the Cassini spacecraft at Saturn, uniquely encompassing auroral, subauroral, ring region, and intraâring field lines, to determine the planetary period oscillations (PPOs) and mean residual fields in these regions. Dual modulation by northern and southern PPO systems is found almost continuously, demonstrating for the first time the presence of PPOs on and inside ring region field lines. The azimuthal component displays the largest ~10â15nT PPO amplitudes on auroral field lines, falling across the subauroral region to ~3â5 nT on main ring field lines in the northern hemisphere, less in the southern hemisphere, while increasing to ~5â8 nT on D ring and intraâD ring field lines. Auroral and subauroral amplitudes mapped along field lines are in good agreement with previous analyses in regions of overlap. Colatitudinal and radial field oscillations generally have a half and a quarter the amplitude of the azimuthal component, respectively. Inner region oscillation phases are typically several tens of degrees âearlierâ than those of outer subauroral and auroral regions. Mean residual poloidal fields (internal and ring current fields subtracted) show quasiâsinusoidal latitude variations of ~2.5nT amplitude, with radial and colatitudinal fields approximately in quadrature. Mean azimuthal fields peaking at ~15 nT are approximately symmetrical about the equator on and inside D ring field lines as previously reported, but are unexpectedly superposed on ~3â5nT âlaggingâ fields which extend continuously through the ring region onto subauroral field lines north and south
The relevance of outsourcing and leagile strategies in performance optimization of an integrated process planning and scheduling
Over the past few years growing global competition has forced the manufacturing industries to upgrade their old production strategies with the modern day approaches. As a result, recent interest has been developed towards finding an appropriate policy that could enable them to compete with others, and facilitate them to emerge as a market winner. Keeping in mind the abovementioned facts, in this paper the authors have proposed an integrated process planning and scheduling model inheriting the salient features of outsourcing, and leagile principles to compete in the existing market scenario. The paper also proposes a model based on leagile principles, where the integrated planning management has been practiced. In the present work a scheduling problem has been considered and overall minimization of makespan has been aimed. The paper shows the relevance of both the strategies in performance enhancement of the industries, in terms of their reduced makespan. The authors have also proposed a new hybrid Enhanced Swift Converging Simulated Annealing (ESCSA) algorithm, to solve the complex real-time scheduling problems. The proposed algorithm inherits the prominent features of the Genetic Algorithm (GA), Simulated Annealing (SA), and the Fuzzy Logic Controller (FLC). The ESCSA algorithm reduces the makespan significantly in less computational time and number of iterations. The efficacy of the proposed algorithm has been shown by comparing the results with GA, SA, Tabu, and hybrid Tabu-SA optimization methods
Genetic diversity loss in a biodiversity hotspot: ancient DNA quantifies genetic decline and former connectivity in a critically endangered marsupial
The extent of genetic diversity loss and former connectivity between fragmented populations are often unknown factors when studying endangered species. While genetic techniques are commonly applied in extant populations to assess temporal and spatial demographic changes, it is no substitute for directly measuring past diversity using ancient DNA (aDNA). We analysed both mitochondrial DNA (mtDNA) and nuclear microsatellite loci from 64 historical fossil and skin samples of the critically endangered Western Australian woylie (Bettongia penicillata ogilbyi), and compared them with 231 (n = 152 for mtDNA) modern samples. In modern woylie populations 15 mitochondrial control region (CR) haplotypes were identified. Interestingly, mtDNA CR data from only 29 historical samples demonstrated 15 previously unknown haplotypes and detected an extinct divergent clade. Through modelling, we estimated the loss of CR mtDNA diversity to be between 46% and 91% and estimated this to have occurred in the past 2000-4000 years in association with a dramatic population decline. In addition, we obtained near-complete 11-loci microsatellite profiles from 21 historical samples. In agreement with the mtDNA data, a number of 'new' microsatellite alleles was only detected in the historical populations despite extensive modern sampling, indicating a nuclear genetic diversity loss >20%. Calculations of genetic diversity (heterozygosity and allelic rarefaction) showed that these were significantly higher in the past and that there was a high degree of gene flow across the woylie's historical range. These findings have an immediate impact on how the extant populations are managed and we recommend the implementation of an assisted migration programme to prevent further loss of genetic diversity. Our study demonstrates the value of integrating aDNA data into current-day conservation strategies
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