226 research outputs found
Analytical and Experimental Study of Transient-response Characteristics of a Turboprop Engine
Study of intermediate velocity products in the Ar+Ni collisions between 52 and 95 A.MeV
Intermediate velocity products in Ar+Ni collisions from 52 to 95 A.MeV are
studied in an experiment performed at the GANIL facility with the 4
multidetector INDRA. It is shown that these emissions cannot be explained by
statistical decays of the quasi-projectile and the quasi-target in complete
equilibrium. Three methods are used to isolate and characterize intermediate
velocity products. The total mass of these products increases with the violence
of the collision and reaches a large fraction of the system mass in mid-central
collisions. This mass is found independent of the incident energy, but strongly
dependent on the geometry of the collision. Finally it is shown that the
kinematical characteristics of intermediate velocity products are weakly
dependent on the experimental impact parameter, but strongly dependent on the
incident energy. The observed trends are consistent with a
participant-spectator like scenario or with neck emissions and/or break-up.Comment: 37 pages, 13 figure
Systematic review of factors influencing patient and practitioner delay in diagnosis of upper gastrointestinal cancer
As knowledge on the causation of cancers advances and new treatments are developed, early recognition and accurate diagnosis becomes increasingly important. This review focused on identifying factors influencing patient and primary care practitioner delay for upper gastrointestinal cancer. A systematic methodology was applied, including extensive searches of the literature published from 1970 to 2003, systematic data extraction, quality assessment and narrative data synthesis. Included studies were those evaluating factors associated with the time interval between a patient first noticing a cancer symptom and presenting to primary care, between a patient first presenting to primary care and being referred to secondary care, or describing an intervention designed to reduce those intervals. Twenty-five studies were included in the review. Studies reporting delay intervals demonstrated that the patient phase of delay was greater than the practitioner phase, whilst patient-related research suggests that recognition of symptom seriousness is more important than recognition of the presence of the symptom. The main factors related to practitioner delay were misdiagnosis, application and interpretation of tests, and the confounding effect of existing disease. Greater understanding of patient factors is required, along with evaluation of interventions to ensure appropriate diagnosis, examination and investigation
The Frequency Following Response (FFR) May Reflect Pitch-Bearing Information But is Not a Direct Representation of Pitch
The frequency following response (FFR), a scalp-recorded measure of phase-locked brainstem activity, is often assumed to reflect the pitch of sounds as perceived by humans. In two experiments, we investigated the characteristics of the FFR evoked by complex tones. FFR waveforms to alternating-polarity stimuli were averaged for each polarity and added, to enhance envelope, or subtracted, to enhance temporal fine structure information. In experiment 1, frequency-shifted complex tones, with all harmonics shifted by the same amount in Hertz, were presented diotically. Only the autocorrelation functions (ACFs) of the subtraction-FFR waveforms showed a peak at a delay shifted in the direction of the expected pitch shifts. This expected pitch shift was also present in the ACFs of the output of an auditory nerve model. In experiment 2, the components of a harmonic complex with harmonic numbers 2, 3, and 4 were presented either to the same ear (“mono”) or the third harmonic was presented contralaterally to the ear receiving the even harmonics (“dichotic”). In the latter case, a pitch corresponding to the missing fundamental was still perceived. Monaural control conditions presenting only the even harmonics (“2 + 4”) or only the third harmonic (“3”) were also tested. Both the subtraction and the addition waveforms showed that (1) the FFR magnitude spectra for “dichotic” were similar to the sum of the spectra for the two monaural control conditions and lacked peaks at the fundamental frequency and other distortion products visible for “mono” and (2) ACFs for “dichotic” were similar to those for “2 + 4” and dissimilar to those for “mono.” The results indicate that the neural responses reflected in the FFR preserve monaural temporal information that may be important for pitch, but provide no evidence for any additional processing over and above that already present in the auditory periphery, and do not directly represent the pitch of dichotic stimuli
Vitamin B12 deficiency in metformin-treated type-2 diabetes patients, prevalence and association with peripheral neuropathy
Prendersi cura della generatività,genitorialità e cogenitorialità con gli operatori socio-sanitari per una profilassi psicoeducativa
Prevalence of vitamin B12 deficiency in type 2 diabetic patients using metformin: a cross-sectional study
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