First investigation on the applicability of an active noise control system on a tracked tractor without cab

In last years, several research teams pointed their attention on the application of active noise control systems (ANC) inside the cabs of agricultural tractor, with the purpose of reducing the driver exposition to noise, that is only partially controlled by the frame of the cab. This paper reports the results of a first experience that aimed at verifying the applicability of an ANC on a medium-high power, tracked tractor without cab. The tested tractor was a Fiat Allis 150 A, equipped with rear power take off, used in the execution of deep primary tillage in compact soils. It is a tracked tractor without cab, with maximum power of 108.8 kW at 1840 min–1 of the engine. The ANC consists of a control unit box based on a digital signal processor (DPS), two microphones, two speakers and a power amplifier. The instrumentation used in noise data collecting and processing consisted of a multichannel signal analyzer (Sinus - Soundbook), a ½” microphone capsule and an acoustic calibrator, both Bruel & Kjaer. The study aimed at evaluating the behaviour of the ANC by means of tests carried out under repeatable conditions, characterized by pre-defined engine speed values. Three replications have been made for each engine speed. The sampling time was 30 s. Two series of tests were performed in order to compare the results observed with the ANC on and off. The engine speed adopted in the study ranged from 600 min– 1, up to 2000 min–1 (maximum speed) with steps of 100 min–1. The ANC proved to be effective in the interval of speed between 1400 and 1700 min–1, where the samplings have been intensified, adopting steps of 50 min–1. In such an interval, the attenuation observed with the ANC system on appeared evident both as weighed A sound pressure level (from 1.29 up to 2.46 dB(A)) and linear (from 4.54 up to 8.53 dB). The best performance has been observed at the engine speed of 1550 min–1, with attenuations, respectively of 2.46 dB(A) and 7.67 dB. Outside of the engine speed interval 1400 - 1700 min–1, the attenuations always resulted lower than 1 dB(A) for the weighed A sound pressure level and between 0.66 and 7.72 dB

Magnetic Resonance Imaging in Primary and Secondary Septorhinoplasty

The authors emphasize the importance of MRI as a means to functionally evaluate patients in primary (PR) and secondary (SR) rhinoseptoplasty. Forty-eight subjects were appraised who underwent various types of corrective nose surgery: 31 PR, 12 SR, 4 introgenic perforations, and 1 dermoid cyst of the nasal dorsum. MRI allows the nasal structures at the level of the valve to be visualized, as well as the medial and lateral walls of the nasal fossa in all of its components. MRI studies improve pre-surgical evaluation (alar cartilages, iaterdomal distance, and valvular configuration), and the exam of structures and anomalies which are hard to evaluate by the rhinoscopy (turbino-septal-synchias, perforations, losses of bone-cartilaginous substance). Moreover, through MRI the nasal respiratory surface (NRS) is determined and used by the authors to quantify the improvement of the postsurgical nasal respiratory function. All of these points gain importance during the planning of primary, secondary, and/or corrective surgery

Early white matter involvement in an infant carrying a novel mutation in ACOX1

We describe the clinical findings and MRI features observed in a child who presented a two-step disease course: he was hypotonic at birth and soon afterwards developed seizures, which were partially responsive to treatment; he subsequently showed developmental delay and a progressive neurological deterioration with the onset of severe seizures at around three years of age. Head MRI at age 20 days was unremarkable, whereas at 25 months it showed bilateral hyperintensity of the deep cerebellar nuclei; five months later, the signal hyperintensity was also present in the cerebellar white matter and ventral pontine fibre tracts. Molecular analysis revealed a novel ACOX1 mutation, predicting a largely truncated protein. The white matter involvement, which followed an ascending trajectory from cerebellar and brainstem structures to the cerebral hemispheres, seemed to originate from the perinuclear white matter of the deep cerebellar nuclei

Multimodality approach in presurgical evaluation of epilepsy

Introduction: Both Electroencephalography-functional Magnetic Resonance Imaging (EEG-fMRI) coregistration and high density EEG (hdEEG) map abnormal brain activation elicited by epileptic processes. EEG-fMRI is an imaging technique which provides localizing Blood Oxygenation Level Dependent (BOLD) information of irritative regions. Conversely, the source analysis estimates the current density of the source that generates a measured electric potential. Objectives: Clinical assessment of these techniques is done in patients with focal epilepsy who subsequently underwent epilepsy surgery. Methods: The standard EEG (32 electrodes) and the fMRI data were acquired during a scanning session (1.5T). The hdEEG recording was performed using 256 channels. Each patient underwent to a 3T scan to create a constraint for the source localization. The analysis of EEG-fMRI data was performed by using both the conventional (General Linear Model, GLM) and a novel method, which integrates in the conventional one two new modules: individual-based hemodynamic response function, and EEG protocol. Source localization of interictal epileptiform discharges (IEDs) using 32 (EEG acquired inside the magnet) and 256 EEG channels was calculated. Results: Changes in BOLD signal were observed in 22 out of 30 patients in whom IEDs are recorded. In 82%, these are concordant with expected epileptic activity defined by EEG and clinical outcome. The remaining 8 patients had no significant BOLD activity because of either technical prob- lems or no interictal epileptiform EEG activity inside the scanner. Three patients with activation were selected to underwent a hdEEG and showed significant source localization correlating with the EEG-fMRI activation. Conclusions: The combination of multimodality techniques such as EEG- fMRI coregistration and hdEEG is a useful tool of a presurgical workup of epilepsy providing two different methods of localization of the same epileptic foci

Fossa navicularis magna

A notchlike bone defect in the basiocciput due to a prominent fossa navicularis was incidentally discovered in a patient referred for radiologic evaluation of sinusitis. MR images showed that the osseous defect was filled with lymphoid tissue of the pharyngeal tonsil. The occurrence of this anatomic variant is discussed, with reference to ancient anatomic works