264 research outputs found
Apathy and impulsivity in frontotemporal lobar degeneration syndromes
Apathy and impulsivity are common and disabling consequences of frontotemporal lobar degeneration. They cause substantial carer distress, but their aetiology remains elusive. There are critical limitations to previous studies in this area including (i) the assessment of either apathy or impulsivity alone, despite their frequent co-existence; (ii) the assessment of behavioural changes within single diagnostic groups; and (iii) the use of limited sets of tasks or questions that relate to just one aspect of these multifactorial constructs. We proposed an alternative, dimensional approach that spans behavioural and language variants of frontotemporal dementia, progressive supranuclear palsy and corticobasal syndrome. This accommodates the commonalities of apathy and impulsivity across disorders and reveals their cognitive and anatomical bases. The ability to measure the components of apathy and impulsivity and their associated neural correlates across diagnostic groups would provide better novel targets for pharmacological manipulations, and facilitate new treatment strategies and strengthen translational models. We therefore sought to determine the neurocognitive components of apathy and impulsivity in frontotemporal lobar degeneration syndromes. The frequency and characteristics of apathy and impulsivity were determined by neuropsychological and behavioural assessments in 149 patients and 50 controls from the PIck’s disease and Progressive supranuclear palsy Prevalence and INcidence study (PiPPIN). We derived dimensions of apathy and impulsivity using principal component analysis and employed these in volumetric analyses of grey and white matter in a subset of 70 patients (progressive supranuclear palsy, n = 22; corticobasal syndrome, n = 13; behavioural variant, n = 14; primary progressive aphasias, n = 21) and 27 control subjects. Apathy and impulsivity were present across diagnostic groups, despite being criteria for behavioural variant frontotemporal dementia alone. Measures of apathy and impulsivity frequently loaded onto the same components reflecting their overlapping relationship. However, measures from objective tasks, patient-rated questionnaires and carer-rated questionnaires loaded onto separate components and revealed distinct neurobiology. Corticospinal tracts correlated with patients’ self-ratings. In contrast, carer ratings correlated with atrophy in established networks for goal-directed behaviour, social cognition, motor control and vegetative functions, including frontostriatal circuits, orbital and temporal polar cortex, and the brainstem. Components reflecting response inhibition deficits correlated with focal frontal cortical atrophy. The dimensional approach to complex behavioural changes arising from frontotemporal lobar degeneration provides new insights into apathy and impulsivity, and the need for a joint therapeutic strategy against them. The separation of objective tests from subjective questionnaires, and patient from carer ratings, has important implications for clinical trial design
Spin-Parity Analysis of the Centrally produced KsKs system at 800 GeV
Results are presented of the spin-parity analysis on a sample of centrally
produced mesons in the reaction (p p -> p_{slow} K_s K_s p_{fast}) with 800 GeV
protons on liquid hydrogen. The spin-parity analysis in the mass region between
threshold and 1.58 GeV/c^2 shows that the (K_s K_s) system is produced mainly
in S-wave. The f_0(1500) is clearly observed in this region. Above 1.58 GeV/c^2
two solutions are possible, one with mainly S-wave and another with mainly
D-wave. This ambiguity prevents a unique determination of the spin of the
f_J(1710) meson.Comment: 6 pages, including 6 figures. LaTex, uses 'espcrc2.sty'. To appear in
LEAP'96 proceeding
Recommended from our members
3Q120 Low Gradient Behaviour
Three 3Q120 magnets--representative of those in the AP 1 line--have been measured with a harmonics probe at MDTF at both low (0-48 A) and high (to >= 400 A). The intent of the measurements was to learn their behavior at the low gradients necessary to transport 8 Gev antiprotons back through the AP 1 line for injection into the Main Ring (and subsequently the superconducting ring--see Ref. 1). Many of the measurements have been preceded by remnant field biasing ramps to 148, 270, 295, or 405 amps to set the remnant field to a standard value. The measurement sequence is then 0,4,8,... 48 amperes (in 4 A steps). The amplitude vs current graph for 0-48 A is visually a straight line and can be fitted via linear regression to a straight line--obtaining a slope and intercept. The residual differences from a straight line can again be plotted vs current and can be reasonably well fit to a second degree polynomial. The smallest set of information that is necessary to tabulate for the operation of AP 1 quadrupoles is the set of currents that correspond to the desired focusing strengths as stipulated by the beam design. Given the parametrization described above, it is straightforward to extract a current corresponding to a given gradient strength for either of the two types of 3Q120
Testing Lorentz Invariance and CPT Conservation with NuMI Neutrinos in the MINOS Near Detector
A search for a sidereal modulation in the MINOS near detector neutrino data
was performed. If present, this signature could be a consequence of Lorentz and
CPT violation as predicted by a class of extensions to the Standard Model. No
evidence for a sidereal signal in the data set was found, implying that there
is no significant change in neutrino propagation that depends on the direction
of the neutrino beam in a sun-centered inertial frame. Upper limits on the
magnitudes of the Lorentz and CPT violating terms in these extensions to the
Standard Model lie between 0.01-1% of the maximum expected, assuming a
suppression of these signatures by factor of .
Recommended from our members
A proposal for a preliminary beam survey in the 3.5 mrad beam
We propose to measure the yields of positive and negative pions, kaons, and nucleons at 200 GeV/c from several target materials in the 3.5 mrad beam of the Meson Laboratory
Recommended from our members
A measurement of the pion radius
We propose a wire spark chamber experiment to measure the pion electromagnetic radius accurate to {+-}0.03f by measuring the scattering cross section for 50-80 GeV pions from electrons in a liquid hydrogen target. The data will distinguish between the {rho} dominance prediction of 0.64f and the ''proton-like'' radius to 0.81f
Upgrades to the Fermilab Numi Beamline
The NuMI beamline at Fermilab has been delivering high-intensity muon neutrino beams to the MINOS experiment since the spring of 2005. A total of 3.4 x 10{sup 20} protons has been delivered to the NuMI target and a maximum beam power of 320 kW has been achieved. An upgrade of the NuMI facility increasing the beam power capability to 700 kW is planned as part of the NOvA experiment. The plans for this upgrade are presented and the possibility of upgrading the NuMI beamline to handle 1.2 MW is considered
- …
