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To use diffusion tensor MRI to quantify and compare degeneration of the pons and cerebellar peduncles in multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and Parkinson disease (PD) and to relate changes in diffusion measures to clinical features and localized atrophy.

Alzheimer's disease is a common and devastating disease for which there is no readily available biomarker to aid diagnosis or to monitor disease progression. Biomarkers have been sought in CSF but no previous study has used two-dimensional gel electrophoresis coupled with mass spectrometry to seek biomarkers in peripheral tissue. We performed a case–control study of plasma using this proteomics approach to identify proteins that differ in the disease state relative to aged controls. For discovery-phase proteomics analysis, 50 people with Alzheimer's dementia were recruited through secondary services and 50 normal elderly controls through primary care. For validation purposes a total of 511 subjects with Alzheimer's disease and other neurodegenerative diseases and normal elderly controls were examined. Image analysis of the protein distribution of the gels alone identifies disease cases with 56% sensitivity and 80% specificity. Mass spectrometric analysis of the changes observed in two-dimensional electrophoresis identified a number of proteins previously implicated in the disease pathology, including complement factor H (CFH) precursor and α-2-macroglobulin (α-2M). Using semi-quantitative immunoblotting, the elevation of CFH and α-2M was shown to be specific for Alzheimer's disease and to correlate with disease severity although alternative assays would be necessary to improve sensitivity and specificity. These findings suggest that blood may be a rich source for biomarkers of Alzheimer's disease and that CFH, together with other proteins such as α-2M may be a specific markers of this illness.

To identify predictors of psychological distress (measured by anxiety and depression) and low self-esteem and to determine whether these change over time in people with ALS.

To determine whether patients with Alzheimer disease (AD) compensate for neuropathologic changes when performing a mnemonic task by recruiting 1) the same brain regions as age-matched, healthy controls, but to a greater extent; 2) additional brain regions not activated by controls; or 3) both.

The ability to acquire and act upon serial order information is fundamental to almost all forms of adaptive behaviour. There is growing evidence that such knowledge may be acquired through a number of different means, each perhaps with its own neuronal substrate. One major distinction is between serial order information acquired intentionally and leading to explicit conscious knowledge of the sequence structure, and information acquired incidentally through experience. While this latter form of knowledge influences behaviour, it may do so without the participant being aware of the sequential information, i.e. it is acquired implicitly. Evidence from physiological and lesion studies in animals and imaging studies in humans suggests that these two forms of learning may have dissociable neuronal substrates. Specifically, the striato-thalamo-cortical circuit centred on the caudate nucleus is proposed to be involved in intentional sequence learning and that based on the putamen on incidental learning. The present study tested one part of this proposed dissociation by assessing patients with Huntington's disease on tasks of the two forms of learning. On the test of trial-and-error intentional learning there were marked deficits, which were closely related to disease progression and to measures of executive cognitive dysfunction. This finding was in contrast to the finding from the incidental learning task. Performance of the Huntington's disease group was essentially normal and unrelated to measures of disease progression and cognitive status. The results, although supportive of the proposed dual-system hypothesis, offer only partial confirmation. Further direct study is required using similar tasks in patients with putamenal disorder or lesions within the skeletomotor striato-thalamo-cortical circuit.

The ability to acquire and act upon serial order information is fundamental to almost all forms of adaptive behaviour. There is growing evidence that such knowledge may be acquired through a number of different means, each perhaps with its own neuronal substrate. One major distinction is between serial order information acquired intentionally and leading to explicit conscious knowledge of the sequence structure, and information acquired incidentally through experience. While this latter form of knowledge influences behaviour, it may do so without the participant being aware of the sequential information, i.e. it is acquired implicitly. Evidence from physiological and lesion studies in animals and imaging studies in humans suggests that these two forms of learning may have dissociable neuronal substrates. Specifically, the striato-thalamo-cortical circuit centred on the caudate nucleus is proposed to be involved in intentional sequence learning and that based on the putamen on incidental learning. The present study tested one part of this proposed dissociation by assessing patients with Huntington's disease on tasks of the two forms of learning. On the test of trial-and-error intentional learning there were marked deficits, which were closely related to disease progression and to measures of executive cognitive dysfunction. This finding was in contrast to the finding from the incidental learning task. Performance of the Huntington's disease group was essentially normal and unrelated to measures of disease progression and cognitive status. The results, although supportive of the proposed dual-system hypothesis, offer only partial confirmation. Further direct study is required using similar tasks in patients with putamenal disorder or lesions within the skeletomotor striato-thalamo-cortical circuit.

Ultrafast pump−probe studies of room-temperature solutions of 3-hydroxyflavone (3-HF) and some 4‘-substituted derivatives have been undertaken. Transient absorption attributable to the two zwitterionic forms of the excited tautomer arising from excited-state intramolecular proton transfer (ESIPT) was observed across most of the visible spectral region. For 3-HF in methylcyclohexane and acetonitrile, the ESIPT was found to be so rapid that it was only possible to assign a time constant of 35 fs to the process. In ethanol, however, a time constant of 60 fs was determined. The slower ESIPT in this solvent was attributed to the greater strength of the solute−solvent interactions. For the derivatives of 3-HF in all three solvents, the ESIPT step was also found to be instrument-limited. In addition to the femtosecond kinetics, there was also a picosecond component of the kinetics that is attributed to ESPT in molecules that are intermolecularly hydrogen bonded to the solvent.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or the internal segment of the globus pallidus (GPi) improves Parkinson's disease and increases frontal blood flow. We assessed the effects of bilateral DBS on executive function in Parkinson's disease patients, seven with electrodes implanted in the STN and six in the GPi. Patients were assessed off medication with stimulators off, on and off again. The groups showed differential change with stimulation on the Reitan Trail-Making test (TMT B) (STN more improved) and on some measures of random number generation and Wisconsin Card Sorting (STN improved, GPi worse with stimulation). Across the groups, stimulation speeded up responding (Stroop control trial, TMT A) and improved performance on paced serial addition and missing digit tests. Conversely, conditional associative learning became more errorful with stimulation across the two groups. In general, change in performance with stimulation was significant for the STN but not the GPi group. These results support two opposite predictions. In support of current models of Parkinson's disease, `releasing the brake' on frontal function with DBS improved aspects of executive function. Conversely, disruption of basal ganglia outflow during DBS impaired performance on tests requiring changing behaviour in novel contexts as predicted by Marsden and Obeso in 1994

Abstract.: Localization is the process of determining the robot's location within its environment. More precisely, it is a procedure which takes as input a geometric map, a current estimate of the robot's pose, and sensor readings, and produces as output an improved estimate of the robot's current pose (position and orientation). We describe a combinatorially precise algorithm which performs mobile robot localization using a geometric model of the world and a point-and-shoot ranging device. We also describe a rasterized version of this algorithm which we have implemented on a real mobile robot equipped with a laser rangefinder we designed. Both versions of the algorithm allow for uncertainty in the data returned by the range sensor. We also present experimental results for the rasterized algorithm, obtained using our mobile robots at Cornell.

Recent pathophysiological models of Parkinson's disease have led to new surgical approaches to treatment including deep brain stimulation (DBS) and lesioning of basal ganglia structures. Various measures of upper limb akinesia were assessed in 6 patients with bilateral DBS of the internal pallidum and 6 with DBS of the subthalamic nucleus. Stimulation improved a number of aspects of motor function, and particularly movement time, and force production. Time to initiate movements, and to perform repetitive movements also improved but less dramatically. Processes indicating preparatory motor processes showed no significant change. Few significant differences were found between the internal pallidum and subthalamic nucleus groups. In general, the effects of DBS closely parallel previous reports of the effects of dopaminergic medication. It is suggested that disrupted pallidal output in Parkinson's disease interferes with the rate, level, and coordination of force production but has little effect on preparatory processes. The similarity of the effects of subthalamic nucleus and internal pallidum stimulation suggests this disrupted outflow is the most important determinant of upper limb akinesia in Parkinson's disease. The effects of DBS were similar to the effects of unilateral pallidal lesions reported elsewhere. Ann Neurol 1999;45:473–488

Recent pathophysiological models of Parkinson's disease have led to new surgical approaches to treatment including deep brain stimulation (DBS) and lesioning of basal ganglia structures. Various measures of upper limb akinesia were assessed in 6 patients with bilateral DBS of the internal pallidum and 6 with DBS of the subthalamic nucleus. Stimulation improved a number of aspects of motor function, and particularly movement time, and force production. Time to initiate movements, and to perform repetitive movements also improved but less dramatically. Processes indicating preparatory motor processes showed no significant change. Few significant differences were found between the internal pallidum and subthalamic nucleus groups. In general, the effects of DBS closely parallel previous reports of the effects of dopaminergic medication. It is suggested that disrupted pallidal output in Parkinson's disease interferes with the rate, level, and coordination of force production but has little effect on preparatory processes. The similarity of the effects of subthalamic nucleus and internal pallidum stimulation suggests this disrupted outflow is the most important determinant of upper limb akinesia in Parkinson's disease. The effects of DBS were similar to the effects of unilateral pallidal lesions reported elsewhere. Ann Neurol 1999;45:473–488

The photophysics of two derivatives of 4-aminonaphthalimide have been studied in aqueous, ethanolic, and mixed aqueous/ethanolic solvents, including both normal and deuterated solvents. It is found that the fluorescence quantum yield and lifetime both decrease with increased water content of the solvent and that this is entirely due to increased nonradiative decay, the radiative rate constant being virtually independent of the solvent composition. It is proposed that a mechanism involving the formation of a hydrogen-bonded water cluster is responsible for the observed behavior with the excitation energy of the naphthalimide being distributed amongst the stretching vibrations of the water cluster. The increase in the rate of nonradiative decay is greatly reduced in deuterated solvent mixtures in accord with Siebrand's theory of radiationless processes.

Extracts of porcine pineal glands inhibited ovulation induced with gonadotropins (PMSG and HCG) in prepuberal mice. Ovulations in mice given gonadotropins plus .0, .125, .25, .5 and 1.0 dose units of crude pineal extract (1.0 dose unit to 1.1 mg extractable protein) averaged 14.0, 9.2, 6.8, 6.0 and 2.9 ovulations per mouse, respectively. This was a significant inhibition over the controls (P<.01). In some cases, ovulation was completely inhibited in mice given a dose unit ≥.25. Mice given similar crude extracts of brain ovulated fully at 12.2, 12.5, 11.5 and 13.9 ovulations per mouse, respectively. These findings indicate that the porcine pineal gland contains an antigonadotropin that is not present in the brain tissues sampled.Injection of saline, melatonin (150 /μg) or fractions of the pineal extract containing substances weighing over 20,000 daltons at .25, .5 and 1.0 dose units (1.0 purified dose unit ≈ 3.6 g fresh pineal tissue) resulted in 13.4, 13.6, 15.1 13.0 and 11.8 ovulations per mouse, respectively. Lack of inhibition of ovulation indicated that the pineal antigonadotropic substance was neither melatonin nor components of the pineal extract weighing in excess of 20,000 daltons.Fractions of pineal extracts devoid of small molecules including melatonin and other indole compounds, exhibited strong antigonadotropic activity. Effects were confined to components of 1,000 to 5,000 daltons. It appears that the active principle is a small peptide.

Two Hereford steers were adjusted to an environmental chamber which was maintained at 20 ± 1 C, 60 ± 2% relative humidity and 12-hr daily photoperiod. After a 3-week adjustment period, steers were exposed on 2 consecutive days to either an increase (from 20 to 40 C) or a decrease (from 20 to 4 C) in temperature at a rate of approximately 9 C/hr. Subsequently, four other Hereford steers were preconditioned to 20, 10 and 30 C. At the end of each period, steers were injected with either 2 mg of bovine prolactin or .85% NaCl and immediately infused for 2 hr with either prolactin (3.2 mg/16 ml/hr) or saline (16 ml/hr), respectively.Prolactin concentration in serum of steers averaged 23.2 ng/ml at 20 C and increased (P<.01) to 106.2 ng/ml at 40 C. Conversely, serum prolactin decreased (P<.001) from 34 ng/ml at 20 C to 4.4 ng/ml at 4 C. Stable serum prolactin concentrations were achieved within 30 min after infusions of exogenous prolactin were started. During this stable period serum prolactin concentration averaged 67.3, 82.4 and 114.3 ng/ml for steers infused at 10, 20 and 30 C, respectively. As ambient temperature increased from 10 to 30 C there was a reduction (P<.01) in the metabolic clearance rate and an increase (P<.01) in the secretion and disappearance rates of serum prolactin concentrations. It was concluded that changes in the metabolic clearance, secretion and disappearance rates of prolactin in cattle might account for at least a part of the inverse relationship between serum prolactin concentration and environmental temperature in this species.

Span A rapeseed meal was included in extruded dog foods at various levels to provide up to 25% to 30% of the protein in the product. Both Beagles and Alaskan Malamutes ate all such rations readily and grew normally. There were no abnormal changes in hematological or thyroid parameters of animals which were exposed to the experimental diets in either short or long-term experiments. The nitrogen digestibility of the rapeseed meal diets was from 75% to 85% in young dogs which was typical of that reported for canines fed commercial-type diets. Diets which contained 20% rapeseed meal were also fed in a kennel trial which lasted 1 year. This ration, in which rapeseed meal contributed 25% to 30% of the protein, was readily consumed and no problems with reproduction or long-term acceptance were encountered. The extrusion process used to produce the dog foods used in this study probably inactivated those toxic factors that may have been present thus allowing the addition of higher levels of rapeseed meal than those which are typical for most livestock feeds without deleterious effects.

Dissociations between different aspects of learning and memory in patients with amnesic syndromes and various neurodegenerative diseases has led to a fundamental revision of the taxonomy of human memory, and a greater understanding of its neurobiological basis. It has been suggested that, while lesions to temporal and diencephalic structures leave procedural learning intact, neurological disorders involving the striatum lead to deficits in this aspect of learning. However, as comparative evidence has accumulated on a variety of procedural tasks, it has become clear that different neurological diseases lead to varying patterns of impaired and intact performance. This has led to a revision of the concept of a unified procedural system in favour of parallel, independent systems, only some of which involve the striatum. There is a danger, however, that the effort to fit the patterns of functional association and dissociation into a neuroanatomical framework may be premature, It is suggested that the way forward lies in more comparative studies, but ones which (1) adopt a broader perspective, assessing other patient groups or single cases, (2) tackle the question of inter-subject variability, (3) adopt a more analytic approach to the assessment of individual performance, and which utilise theory-driven methods to assess the processes of learning at different stages, and (4) which employ complementary methods such as pharmacological manipulations in normal subjects to assess the neurochemical basis of procedural knowledge.

The results of an investigation of a long-seam welded low chrome pipe that failed in a high-temperature refinery piping system are presented in this paper. Based upon the results of a metallurgical investigation, which included a creep testing program and a detailed finite element stress analysis, the cause of the failure has been attributed to creep damage at the weld seam. The metallurgical investigation and creep testing program indicated that the 1-1/4 Cr-1/2 Mo pipe material was normalized and exhibited greater than average creep strength and creep ductility. The results of a piping stress analysis indicated that all pressure, weight, and thermal stresses were in compliance with the ASME B31.3 Piping Code (ASME, 1993a). Nonetheless, the pipe failed after only 100,000 h at a nominal hoop stress of 6 ksi (41.4 MPa) with an operating temperature range of 970°F (521°C) to 1000°F (538°C). Results from subsequent detailed finite element stress analyses of the failed pipe indicated that very high localized bending stresses were present in the pipe due to peaking at the long-seam weld. These stresses partially relax by creep, but after 100,000 h they were still approximately 38 percent higher than the nominal hoop stress. The creep strains resulting from stress relaxation and those associated with the long-term value of the sustained stresses cause severe creep damage at the weld seam. As a result of this damage, cracks initiated at the inside of the pipe and primarily grew through the HAZ/fusion line until an 18-in. through-wall crack developed. The pipe was produced to ASTM A691, Grade 1-1/4 Cr, Class 41 (ASTM, 1989), and the peaked geometry was found to satisfy the fabrication tolerances of this standard. The need for the development of an acceptable tolerance for peaking in addition to the outside diameter and out-of-roundness fabrication tolerances currently included in this standard is highlighted for long-seam welded pipe that is to operate in the creep range.

Laser transit anemometer cross-correlation functions acquired in the wakes of turbine blades in a linear transonic cascade have been observed to have an oscillatory form. Vortex shedding and spatially non-Poisson particle concentration arguments are proposed to account for this previously unobserved behaviour in the light scattering data.

THE STUDY OF GOVERNMENT, F. F. Ridley, Allen and Unwin, 1975, pp. 240, £6.50, £3.35 (paperback).LEISURE AND THE ARTS IN BIRMINGHAM, Barbara Weinberger, Centre for Urban and Regional Studies, University of Birmingham, 1975, £2.00.RATIONING HEALTH CARE, Michael H. Cooper, Croom Helm, 1975, pp. 109 plus bibliography and index, £4.50.COMMUNITY WORK: TWO, David Jones and Marjorie Mayo (ed.), Rout-ledge and Kegan Paul, 1975, pp. 202, £4.95.

The results of an investigation of a long-seam welded low chrome pipe that failed in a high-temperature refinery piping system are presented in this paper. Based upon the results of a metallurgical investigation, which included a creep testing program and a detailed finite element stress analysis, the cause of the failure has been attributed to creep damage at the weld seam. The metallurgical investigation and creep testing program indicated that the 1-1/4 Cr-1/2 Mo pipe material was normalized and exhibited greater than average creep strength and creep ductility. The results of a piping stress analysis indicated that all pressure, weight, and thermal stresses were in compliance with the ASME B31.3 Piping Code (ASME, 1993a). Nonetheless, the pipe failed after only 100,000 h at a nominal hoop stress of 6 ksi (41.4 MPa) with an operating temperature range of 970°F (521°C) to 1000°F (538°C). Results from subsequent detailed finite element stress analyses of the failed pipe indicated that very high localized bending stresses were present in the pipe due to peaking at the long-seam weld. These stresses partially relax by creep, but after 100,000 h they were still approximately 38 percent higher than the nominal hoop stress. The creep strains resulting from stress relaxation and those associated with the long-term value of the sustained stresses cause severe creep damage at the weld seam. As a result of this damage, cracks initiated at the inside of the pipe and primarily grew through the HAZ/fusion line until an 18-in. through-wall crack developed. The pipe was produced to ASTM A691, Grade 1-1/4 Cr, Class 41 (ASTM, 1989), and the peaked geometry was found to satisfy the fabrication tolerances of this standard. The need for the development of an acceptable tolerance for peaking in addition to the outside diameter and out-of-roundness fabrication tolerances currently included in this standard is highlighted for long-seam welded pipe that is to operate in the creep range.

Measurements of arterial pressure in 1045 representative men in the seventh decade are used to examine its relation to age, social class (as indicated by occupation), physical and mental demands of occupation, and smoking habits. It is shown that both systolic and diastolic pressures tend to rise as economic and social circumstances become progressively less favorable; they are lower in smokers than in non-smokers. There is no evidence that arterial pressures are related to the physical or mental demands of employment.

A 4‐year lysimeter study was conducted to determine the contribution of low to moderately saline, shallow static water tables to the total water use and yield of cotton grown on deep, permeable soils. Water tables controlled at 91‐, 183‐, and 274‐cm depths contributed 54.4, 26.4, and 17.3% of the total water use under the high moisture treatment and 60.6, 48.9, and 39.2% under the low moisture treatment. Total water use consisted of soil profile depletion, rainfall, irrigations, and additions of water to maintain the water tables. Water uptake from the 274‐cm water table was strongly related to the salinity level (electrical conductivity of saturated soil extract, ECe) of the capillary (183‐ to 274‐cm) zone. Lint cotton yields were related to the total amount of water obtained from the table as well as to the salinity level of the capillary zone. Moderate salinity (ECeof 10 to 14 mmhos/cm) of the capillary zone reduced monthly and seasonal water use from the water tables as compared with low salinity (ECeof 2 to 3 mmhos/cm) conditions. The high moisture treatment delayed significant use of water from 183‐ and 274‐cm water tables until late in the season, when irrigations were discontinued and the upper soil profile dried.

Average measured ETcurves and ET/RScurves were developed for estimating short‐period (7 to 14 days) or seasonal ETfor cotton grown under wet, moderate, and dry soil moisture regimes on a medium‐ and a fine‐textured soil in the Lower Rio Grande Valley of Texas. Maximum average ETrates ranged from 0.46 cm per day for the dry moisture regime to 0.74 cm per day on the wet moisture regime on the medium‐textured soil compared with 0.46 to 0.76 cm per day on the dry and wet moisture regimes, respectively, on the fine‐textured soil. Comparison of the two estimating methods indicated that cotton ETestimates made from average ETwere as reliable as estimates made from ET/RSand solar radiation.

Transmission loss in plastic optical fibers was investigated for axial, small numerical aperture input. The loss coefficient α was determined as a function of wavelength λ by varying sample length and using filters. More extensive information on α(λ) was obtained by use of a monochromator with transmission at a particular λ standardized by independent measurement. Measurement in white light of scattered intensity as a function of position along a fiber yielded α and an estimate of scattering power. Analyses of the scattering data and the variation of α with λ suggest that scattering is the principal loss mechanism.

Output intensity patterns and total throughput for plastic fiber optic systems were measured as a function of input direction. For increasingly oblique input, the output pattern approached a conical shell and total throughput decreased. The decrease of total throughput was faster than expected from geometrical considerations and was interpreted in terms of loss at reflection from the core–sheath interface. Analysis indicated (a) that the reflection loss was of the order of 10^−4 for angles of incidence ≥ 70°, (b) that interface quality was high and imperfections contributed relatively little to this loss except for angles of incidence near 90°, and (c) that this loss was principally due to sheath penetration at internal reflection for most angles of incidence greater than the critical angle. The effective absorption coefficient of the sheath derived from this analysis was larger than the absorption coefficient measured for bulk sheath polymer.

Measurements of arterial pressure in 1045 representative men in the seventh decade are used to examine its relation to age, social class (as indicated by occupation), physical and mental demands of occupation, and smoking habits. It is shown that both systolic and diastolic pressures tend to rise as economic and social circumstances become progressively less favorable; they are lower in smokers than in non-smokers. There is no evidence that arterial pressures are related to the physical or mental demands of employment.