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Analysis of human vergence dynamics
Disparity vergence is commonly viewed as being controlled by at least two mechanisms, an open-loop vergence-specific burst mechanism analogous to the ballistic drive of saccades, and a closed-loop feedback mechanism controlled by the disparity error. We show that human vergence dynamics for disparity jumps of a large textured field have a typical time course consistent with predominant control by the open-loop vergence-specific burst mechanism, although various subgroups of the population show radically different vergence behaviors. Some individuals show markedly slow divergence responses, others slow convergence responses, others slow responses in both vergence directions, implying that the two vergence directions have separate control mechanisms. The faster time courses usually had time-symmetric velocity waveforms implying open-loop burst control, while the slow response usually had time-asymmetric velocity waveforms implying closed-loop feedback control. A further type of behavior in a distinct subpopulation is a compound anomalous divergence response consisting of an initial convergence movement followed by a large corrective divergence movement with time courses implying closed-loop feedback control. The closed-loop response for slow responses to disparity steps exhibited pronounced oscillations in the velocity trace, implying the involvement of a sampled-data system with a rate of about 3 samples/s. This analysis of the variety of human vergence responses thus contributes substantially to the understanding of the oculomotor control mechanisms underlying the generation of vergence movements
An idealized numerical study of tropical cyclogenesis and evolution at the Equator
Tropical cyclone formation and evolution at, or near, the Equator is explored using idealized threeâdimensional model simulations, starting from a prescribed, initial, weak counterclockwise rotating vortex in an otherwise quiescent, nonrotating environment. Three simulations are carried out in which the maximum tangential wind speed (5âmâsurn:x-wiley:qj:media:qj3701:qj3701-math-0001) is specified at an initial radius of 50, 100, or 150âkm. After a period of gestation lasting between 30 and 60âhr, the vortices intensify rapidly, the evolution being similar to that for vortices away from the Equator. In particular, the larger the initial vortex size, the longer the gestation period, the larger the maximum intensity attained, and the longer the vortex lifetime. Beyond a few days, the vortices decay as the cyclonic vorticity source provided by the initial vortex is depleted and negative vorticity surrounding the vortex core is drawn inwards by the convectively driven overturning circulation. In these negative vorticity regions, the flow is inertially/centrifugally unstable. The vortex evolution during the mature and decay phases differs from that in simulations away from the Equator, where inertially unstable regions are much more limited in area. Vortex decay in the simulations appears to be related intimately to the development of inertial instability, which is accompanied by an outwardâpropagating band of deep convection. The degree to which this band of deep convection is realistic is unknown
The construction of masculinities and femininities in the Church of England:the case of the male clergy spouse
The ordination of women to the priesthood in the Church of England in 1994 signified great change. The impact of the new priests was well documented, and their integration became the focus of much research in the following years. One important area of change was the altered dynamics of gender identity. New roles had opened up for women, but new identities had also emerged for men. While women priests were a new historical emergence, so too were clergy husbands. This paper will consider the historical construction of masculinities and femininities within the church and will go on to look at this in the context of clergy spouses, specifically focusing on men occupying this role. Some provisional findings, acting as work in progress, will be considered
Measurement of the cardiac time intervals of the fetal ECG utilising a computerised algorithm: A retrospective observational study
.ObjectiveEstablish whether the reliable measurement of cardiac time intervals of the fetal ECG can be automated and to address whether this approach could be used to investigate large datasets.DesignRetrospective observational study.SettingTeaching hospitals in London UK, Nottingham UK and New York USA.ParticipantsSingleton pregnancies with no known fetal abnormality.MethodsArchived fetal ECG's performed using the MonicaAN24 monitor. A single ECG (PQRST) complex was generated from 5000 signal-averaged beats and electrical cardiac time intervals measured in an automated way and manually.Main Outcome measureValidation of a newly developed algorithm to measure the cardiac time intervals of the fetal ECG.Results188/236 (79.7%) subjects with fECGs of suitable signal:noise ratio were included for analysis comparing manual with automated measurement. PR interval was measured in 173/188 (92%), QRS complex in 170/188 (90%) and QT interval in 123/188 (65.4%). PR interval was 107.6 (12.07) ms [mean(SD)] manual vs 109.11 (14.7) ms algorithm. QRS duration was 54.72(6.35) ms manual vs 58.34(5.73) ms algorithm. QT-interval was 268.93 (21.59) ms manual vs 261.63 (36.16) ms algorithm. QTc was 407.5(32.71) ms manual vs 396.4 (54.78) ms algorithm. The QRS-duration increased with gestational age in both manual and algorithm measurements.ConclusionAccurate measurement of fetal ECG cardiac time intervals can be automated with potential application to interpretation of larger datasets
Extrapolating SMBH correlations down the mass scale: the case for IMBHs in globular clusters
Empirical evidence for both stellar mass black holes M_bh<10^2 M_sun) and
supermassive black holes (SMBHs, M_bh>10^5 M_sun) is well established.
Moreover, every galaxy with a bulge appears to host a SMBH, whose mass is
correlated with the bulge mass, and even more strongly with the central stellar
velocity dispersion sigma_c, the `M-sigma' relation. On the other hand,
evidence for "intermediate-mass" black holes (IMBHs, with masses in the range
1^2 - 10^5 M_sun) is relatively sparse, with only a few mass measurements
reported in globular clusters (GCs), dwarf galaxies and low-mass AGNs. We
explore the question of whether globular clusters extend the M-sigma
relationship for galaxies to lower black hole masses and find that available
data for globular clusters are consistent with the extrapolation of this
relationship. We use this extrapolated M-sigma relationship to predict the
putative black hole masses of those globular clusters where existence of
central IMBH was proposed. We discuss how globular clusters can be used as a
constraint on theories making specific predictions for the low-mass end of the
M-sigma relation.Comment: 14 pages, 3 figures, accepted for publication in Astrophysics and
Space Science; fixed typos and a quote in Sec.
Secondary education reform in Lesotho and Zimbabwe and the needs of rural girls: Pronouncements, policy and practice
Analysis of the educational needs of rural girls in Lesotho and Zimbabwe suggests a number of shortcomings in the current form of secondary education, and ways in which it might be modified so as to serve this sizeable group of students better. Several of the shortcomings, notably in relation to curricular irrelevance and excessive focus on examinations, have long been recognised, including by politicians. Yet political pronouncements are seldom translated into policy, and even where policy is formulated, reforms are seldom implemented in schools. This paper makes use of interviews with educational decision-makers in the two southern African countries and a range of documentary sources to explore why, despite the considerable differences between the two contexts, much needed educational reforms have been implemented in neither
Imagination, Hope and the Migrant Journey : Iraqi Asylum Seekers Looking for a Future in Europe
Europe received an unprecedented number of asylum seekers in 2015. This article examines Iraqi asylum seekers who journeyed through Europe in search of an idealized version of Finland, which they had imagined based on word-of-mouth and social media information. Through cognitive migration, the act of pre-experiencing futures in different locations, Finland was seen to offer both subjective hope of personal growth and advancement and objective hope of safety and physical security. This hope motivated them to embark on a journey of 6,000 kilometers to the European North. Based on interview data and relevant studies, the article concludes that hope of a better, imagined future abroad acts as a powerful magnet for persons with poor prospects in their countries of origin. Hope is a kind of critical emotion strongly shaped by beliefs and real-time opportunities; and as such, beliefs are notoriously difficult to change. Imagination, therefore, should not be overlooked when planning and implementing migration policies.Europe received an unprecedented number of asylum seekers in 2015. This article examines Iraqi asylum seekers who journeyed through Europe in search of an idealized version of Finland, which they had imagined based on word-of-mouth and social media information. Through cognitive migration, the act of pre-experiencing futures in different locations, Finland was seen to offer both subjective hope of personal growth and advancement and objective hope of safety and physical security. This hope motivated them to embark on a journey of 6,000 kilometers to the European North. Based on interview data and relevant studies, the article concludes that hope of a better, imagined future abroad acts as a powerful magnet for persons with poor prospects in their countries of origin. Hope is a kind of critical emotion strongly shaped by beliefs and real-time opportunities; and as such, beliefs are notoriously difficult to change. Imagination, therefore, should not be overlooked when planning and implementing migration policies.Peer reviewe
The trade-off between tidal-turbine array yield and environmental impact: a habitat suitability modelling approach
In the drive towards a carbon-free society, tidal energy has the potential to become a valuable part of the UK energy supply. Developments are subject to intense scrutiny, and potential environmental impacts must be assessed. Unfortunately many of these impacts are still poorly understood, including the implications that come with altering the hydrodynamics. Here, methods are proposed to quantify ecological impact and to incorporate its minimisation into the array design process. Four tidal developments in the Pentland Firth are modelled with the array optimisation tool OpenTidalFarm, that designs arrays to generate the maximum possible profit. Maximum entropy modelling is used to create habitat suitability maps for species that respond to changes in bedshear stress. Changes in habitat suitability caused by an altered tidal regime are assessed. OpenTidalFarm is adapted to simultaneously optimise array design to maximise both this habitat suitability and to maximise the profit of the array. The problem is thus posed as a multi-objective optimisation problem, and a set of Pareto solutions found, allowing trade-offs between these two objectives to be identified. The methods proposed generate array designs that have reduced negative impact, or even positive impact, on the habitat suitability of specific species or habitats of interest
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
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
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
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