1,804 research outputs found

    Acting without being in control: Exploring volition in Parkinson's disease with impulsive compulsive behaviours.

    Get PDF
    BACKGROUND: Several aspects of volitional control of action may be relevant in the pathophysiology of impulsive-compulsive behaviours (ICB) in Parkinson's disease (PD). We aimed to explore multiple aspects of action control, assessing reward-related behaviour, inhibition (externally and internally triggered) and sense of agency in PD patients, with and without ICB compared to healthy subjects. METHODS: Nineteen PD patients with ICB (PD-ICB), 19 PD without ICB (PD-no-ICB) and 19 healthy controls (HC) underwent a battery of tests including: Intentional Binding task which measures sense of agency; Stop Signal Reaction Time (SSRT) measuring capacity for reactive inhibition; the Marble task, assessing intentional inhibition; Balloon Analog Risk Task for reward sensitivity. RESULTS: One-way ANOVA showed significant main effect of group for action binding (p = 0.004, F = 6.27). Post hoc analysis revealed that PD-ICB had significantly stronger action binding than HC (p = 0.004), and PD-no-ICB (p = 0.04). There was no difference between PD-no-ICB and HC. SSRT did not differ between PD groups, whereas a significant difference between PD-no-ICB and HC was detected (p = 0.01). No other differences were found among groups in the other tasks. CONCLUSIONS: PD patients with ICB have abnormal performance on a psychophysical task assessing sense of agency, which might be related to a deficit in action representation at cognitive/experiential level. Yet, they have no deficit on tasks evaluating externally and internally triggered inhibitory control, or in reward-based decision-making. We conclude that impaired sense of agency may be a factor contributing to ICB in PD patients

    Planck Low Frequency Instrument: Beam Patterns

    Full text link
    The Low Frequency Instrument on board the ESA Planck satellite is coupled to the Planck 1.5 meter off-axis dual reflector telescope by an array of 27 corrugated feed horns operating at 30, 44, 70, and 100 GHz. We briefly present here a detailed study of the optical interface devoted to optimize the angular resolution (10 arcmin at 100 GHz as a goal) and at the same time to minimize all the systematics coming from the sidelobes of the radiation pattern. Through optical simulations, we provide shapes, locations on the sky, angular resolutions, and polarization properties of each beam.Comment: On behalf of the Planck collaboration. 3 pages, 1 figure. Article published in the Proceedings of the 2K1BC Experimental Cosmology at millimetre wavelength

    The Planck Low Frequency Instrument

    Get PDF
    The Low Frequency Instrument (LFI) of the "Planck Surveyor" ESA mission will perform high-resolution imaging of the Cosmic Microwave Background anisotropies at four frequencies in the 30-100 GHz range. We review the LFI main scientific objectives, the current status of the instrument design and the on-going effort to develop software simulations of the LFI observations. In particular we discuss the design status of the PLANCK telescope, which is critical for reaching adequate effective angular resolution.Comment: 10 pages, Latex (use epsfig.sty); 4 Postscript figures; Astrophys. Lett & Comm, in press. Proc. of the Conference: "The Cosmic Microwave Background and the Planck Mission", Santander, Spain, 22-25 June 199

    Sex of offspring influences metabolism during early transition period in dairy cows

    Get PDF
    Abstract. A study using 20 Holstein Friesian cows was conducted to investigate the influence of calf gender on metabolism during the transition period in dairy cattle. Blood samples were collected at three time points: 2–4 days prepartum (time 1), and 1 week and 2 weeks postpartum (time 2 and time 3 respectively). Serum samples obtained were analysed for total proteins, albumin, urea, glucose, non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB). Depending on the sex of the offspring, cows were divided into two groups: Group 1 consisted of cows with heifer offspring (n = 12) and Group 2 consisted of cows with bull offspring (n = 8). A two-way repeated measures ANOVA and t tests for unpaired data were used to analyse the pattern of studied parameters and differences between the two groups. The results indicate differences in metabolic parameters between the two groups. These results highlight the importance of considering fetal sex as a factor that influences maternal metabolism during the early transition period in dairy cows

    The use of thermography on the slaughter-line for the assessment of pork and raw ham quality

    Get PDF
    The left and right hams of forty heavy pig carcasses were thermographed to evaluate whether surface temperature differences were related to meat and ham quality. Thermal imaging analysis showed no differences in average surface temperature among classes of pH or of L* colour co-ordinate nor among classes of ham defects such as veining and red skin. However, hams with a lower fat cover displayed a significantly warmer average temperature surface. Infrared thermography seems to be a practical and non-invasive method to detect hamswith a fat cover below the minimum requested to be submitted to the dry-curing process

    Impaired temporal processing of tactile and proprioceptive stimuli in cerebellar degeneration.

    Get PDF
    Performance of timed motor sequences relies on the cerebellum and basal ganglia, which integrate proprioceptive information during the motor task and set internal timing mechanisms. Accordingly, these structures are also involved in other temporal processes, such as the discrimination of the different afferent information in the domain of time. In the present study we tested temporal processing of proprioceptive and tactile stimuli in 20 patients with neurodegenerative cerebellar ataxia and 20 age- and sex-matched healthy subjects. Tactile temporal discrimination threshold was defined as the value at which subjects recognized the two stimuli as asynchronous. Temporal discrimination movement threshold of the first dorsal interosseous and flexor carpi radialis was defined as the shortest interval between two paired electrical stimuli in which the subjects blindfolded perceived two separate index finger abductions and wrist flexions. Both tactile and movement temporal discrimination thresholds were higher in patients with cerebellar ataxia. No correlation was found with disease duration and severity. Our study demonstrates that temporal processing of tactile and proprioceptive stimuli is impaired in patients with cerebellar neurodegeneration and highlights the involvement of cerebellum in temporal processing of somatosensory stimuli of different type

    Thermal susceptibility of the Planck-LFI receivers

    Get PDF
    This paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jinst . This paper describes the impact of the Planck Low Frequency Instrument front end physical temperature fluctuations on the output signal. The origin of thermal instabilities in the instrument are discussed, and an analytical model of their propagation and impact on the receivers signal is described. The experimental test setup dedicated to evaluate these effects during the instrument ground calibration is reported together with data analysis methods. Finally, main results obtained are discussed and compared to the requirements.Comment: This is an author-created, un-copyedited version of an article accepted for publication in Journal of Instrumentation. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at 10.1088/1748-0221/4/12/T1201

    Dynamic validation of the Planck/LFI thermal model

    Get PDF
    The Low Frequency Instrument (LFI) is an array of cryogenically cooled radiometers on board the Planck satellite, designed to measure the temperature and polarization anisotropies of the cosmic microwave backgrond (CMB) at 30, 44 and 70 GHz. The thermal requirements of the LFI, and in particular the stringent limits to acceptable thermal fluctuations in the 20 K focal plane, are a critical element to achieve the instrument scientific performance. Thermal tests were carried out as part of the on-ground calibration campaign at various stages of instrument integration. In this paper we describe the results and analysis of the tests on the LFI flight model (FM) performed at Thales Laboratories in Milan (Italy) during 2006, with the purpose of experimentally sampling the thermal transfer functions and consequently validating the numerical thermal model describing the dynamic response of the LFI focal plane. This model has been used extensively to assess the ability of LFI to achieve its scientific goals: its validation is therefore extremely important in the context of the Planck mission. Our analysis shows that the measured thermal properties of the instrument show a thermal damping level better than predicted, therefore further reducing the expected systematic effect induced in the LFI maps. We then propose an explanation of the increased damping in terms of non-ideal thermal contacts.Comment: Planck LFI technical papers published by JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/1748-022

    Vitamin B12 and homocysteine levels in blood of dairy cows during subacute ruminal acidosis

    Get PDF
    Abstract. The aim of this study was to investigate the variations of vitamin B12 and homocysteine in blood of dairy cows during subacute ruminal acidosis (SARA). On 228 subjects ruminal liquid was collected through rumenocentesis technique and rumen pH was immediately measured by a portable pH-meter. On the basis of pH values all cows were classified (bovine class) in Group A (animals with rumen pH>5.7), Group B (animals with rumen pH between 5.6 and 5.7) and Group C (animals with rumen pH<5.6). In relation to the acidosis risk depending on the rumen pH (herd class), the herds were classified in Group 1 (normal herds: less than 33 % cows with rumen pH<5.8), Group 2 (critical herds: more than 33 % cows with rumen pH between 5.5 and 5.8) and Group 3 (acidosis herds: more than 33 % cows with rumen pH<5.5). On blood samples, collected by jugular venipuncture, vitamin B12 and homocysteine were measured by chemiluminescent immunological tests. One-way analysis of variance (ANOVA), followed by Bonferroni test, showed significant differences (P<0.05) for vitamin B12 in bovine class and significant differences (P<0.05) for homocysteine in herd class. The influence of rumen pH values resulted in adequate vitamin B12 and homocysteine levels to meet microbial and cow requirements and fatty acids modifications in dairy cows affected by SARA. Moreover, the increase of vitamin B12 could be due to the presence of analogues which interfere with the transport of the vitamin. These findings provide more information on blood modifications during SARA
    • …
    corecore