A preliminary study of head-up display assessment techniques. 2: HUD symbology and panel information search time

Twelve commercial pilots were shown 50 high-fidelity slides of a standard aircraft instrument panel with the airspeed, altitude, ADI, VSI, and RMI needles in various realistic orientations. Fifty slides showing an integrated head-up display (HUD) symbology containing an equivalent number of flight parameters as above (with flight path replacing VSI) were also shown. Each subject was told what flight parameter to search for just before each slide was exposed and was given as long as needed (12 sec maximum) to respond by verbalizing the parameter's displayed value. The results for the 100-percent correct data indicated that: there was no significant difference in mean reaction time (averaged across all five flight parameters) between the instrument panel and HUD slides; and a statistically significant difference in mean reaction time was found in responding to different flight parameters

Electron beam melting of Ti-6Al-4V lattice structures: correlation between post heat treatment and mechanical properties

Additive manufacturing processes are considered advanced manufacturing methods. It would be possible to produce complex shape components from a computer-aided design model in a layer-by-layer manner. As one of the complex geometries, lattice structures could attract lots of attention for both medical and industrial applications. In these structures, besides cell size and cell type, the microstructure of lattice structures can play a key role in these structures’ mechanical performance. On the other hand, heat treatment has a significant influence on the mechanical properties of the material. Therefore, in this work, the effect of the heat treatments on the microstructure and mechanical behaviour of Ti-6Al-4V lattice structures manufactured by electron beam melting was analysed. The main mechanical properties were compared with the Ashby and Gibson model. It is very interesting to notice that a more homogeneous failure mode was found for the heat-treated samples. The structures’ relative density was the main factor influencing the mechanical performance of the heat-treated samples. It is also found that the heat treatments were able to preserve the stiffness and the compressive strength of the lattice structures. Besides, an increment of both the elongation at failure and the absorbed energy was obtained after the heat treatments. Microstructure analysis of the heat-treated samples confirms the increment of ductility of the heat-treated samples with respect to the as-built one

A simulation investigation of scout/attack helicopter directional control requirements for hover and low-speed tasks

A piloted simulator experiment was conducted to investigate directional axis handling qualities requirements for low speed and hover tasks performed by a Scout/Attack helicopter. Included were the directional characteristics of various candidate light helicopter family configurations. Also, the experiment focused on conventional single main/tail rotor configurations of the OH-58 series aircraft, where the first-order yaw-axis dynamic effects that contributed to the loss of tail rotor control were modeled. Five pilots flew 22 configurations under various wind conditions. Cooper-Harper handling quality ratings were used as the primary measure of merit of each configuration. The results of the experiment indicate that rotorcraft configurations with high directional gust sensitivity require greater minimum yaw damping to maintain satisfactory handling qualities during nap-of-the-Earth flying tasks. It was also determined that both yaw damping and control response are critical handling qualities parameters in performing the air-to-air target acquisition and tracking task. Finally, the lack of substantial yaw damping and larger values of gust sensitivity increased the possibility of loss of directional control at low airspeeds for the single main/tail rotor configurations

Mannheim Peritonitis Index (MPI) and elderly population: Prognostic evaluation in acute secondary peritonitis

Introduction. Acute Secondary Peritonitis due to abdominal visceral perforation is characterized by high mortality and morbidity risk. Risk stratification allows prognosis prediction to adopt the best surgical treatment and clinical care support therapy. In Western countries elderly people represent a significant percentage of population Aim. Evaluation of Mannheim Peritonitis Index (MPI) and consideration upon old people. Patients and methods. Retrospective study on 104 patients admitted and operated for \ue2\u80\u9cAcute Secondary Peritonitis due to visceral perforation\ue2\u80\u9d. MPI was scored. In our study we want to demonstrate efficacy of MPI and the possibility to consider older age an independent prognostic factor. Results. Mortality was 25.96%. Greatest sensitivity and specificity for the MPI score as a predictor of mortality was at the score of 20. MPI score of 22. Patients with MPI score 17-21 had 0.46 times lower risk of mortality compared to patients with MPI score >21. In the group of patients with MPI score of >20 the mortality rate was 48.5% for patients older than 80 years old and 12.1% for younger patients (p < 0.005); in the group with MPI score of < 20 mortality rate was respectively 8.4% and 1.4% (p < 0.005). Discussion and conclusions. Data confirm the accuracy of the test. MPI score and age over 80 years old resulted independent predictors of mortality at multivariate analysis

a cephalometric intercentre comparison of patients with unilateral cleft lip and palate at 5 and 10 years of age

SUMMARY The aim of this study was to evaluate any differences between the craniofacial growth of unilateral cleft lip and palate (UCLP) patients who underwent surgery in the Milan CLP centre with those from the Oslo CLP centre at 5 and 10 years of age. The Milan sample comprised 88 UCLP patients (60 males, 28 females) at 5 years of age and 26 patients (17 males, 9 females) at 10 years of age all operated on by the same surgeon. The Oslo sample consisted of 48 UCLP patients (26 males, 22 females) aged 5 years and 29 patients (20 males, 9 females) aged 10 years treated by four different surgeons. Lateral cephalometric radiographs obtained for both samples were analysed and angular measurements and ratios were calculated both for the hard and soft tissues. Statistical analysis was undertaken with an unpaired t -test. At 5 years of age, there were neither sagittal nor vertical hard tissue differences between the two groups. With regard to the soft tissues, only the naso-labial angle showed a statistically signifi cant difference (Milan greater than Oslo by 5 degrees, P 2.6 degrees, P 2.9 degrees, P < 0.001, respectively. At 5 years of age, the Milan UCLP sample had the same maxillary protrusion as the Oslo group, while at 10 years of age, the Milan sample were slightly less protruded than the Oslo group

Multiple dental inclusion in monozygotic twins with congenital visual impairment

The study presents two monozygotic twins (MZ) with multiple impacted teeth, affecting the upper canines and lower second molars, as well as congenital aniridia. The clinical aspect of the upper canines is peculiar because of the different positions - palatal in one and buccal in the other twin. Studies reporting different scenarios of impaction in monozygotic twins can contribute more data to the debate on tooth eruption aetiology and more so in this case because of the association with a genetic panocular disease. Patients' Concerns. The patients were referred by a general dentist, who diagnosed the presence of multiple inclusions. Diagnostic Study. Both patients showed severe malocclusion, classified as grade 5 of the Index of Orthodontic Treatment Need (IOTN). The MZ showed class I malocclusion, upper and lower crowding, and impacted lower right and left second molars. A Dentascan was prescribed for the canine impaction. The impaction of the upper canine was palatal of 2.3 in one of the MZ and buccal of 1.3 in the other one. The same altered pattern of eruption of the lower second molars was identified in both twins. The proposed treatment plan contemplated orthodontic surgical recovery of the impacted elements, followed by orthodontic treatment with multibracket appliance after the extraction of the first four premolars, given the crowding entity. The use of a retraction spring action was chosen for the recovery of the lower second molars. Many aspects of the possible genetic aetiology of tooth impaction are still under discussion. The study of diseases in twins offers decisive information. Finally, the possibility that alterations in the eruptive pattern of the dental elements may be associated with other congenital problems broadens the range of investigations related to the possible aetiological causes of the inclusions in humans

Nuove varianti di Bronchite Infettiva negli allevamenti avicoli siciliani

Avian Infectious Bronchitis (IB) is a disease caused by a Coronavirus, included in Coronaviridae family. The disease, endemic in Italy, affects both broilers and laying hens. It represents one of the main health issue in sicilian poultry farms. The presence of new antigenic variants makes problematic the implementation of an adequate prophylaxis through the use of appropriate vaccines. The present work aims to study the spread of IB strains in Sicily by serological and biomolecular tests in order to investigate the presence of "historical" strains as well as new strains and to carry out the genotyping of viruses isolated. The serological results show that the used vaccination protocols are able to develop an adequate antibody titre along all production steps both laying hens and broilers. The virological results underline the presence of QX strain in a broilers farm. This is a strain widespread in Italy but never reported in the regional territory

Incarcerated hernia in a trocar site following laparoscopic gastric bypass

This paper reports a case of small bowel occlusion due to the herniation of an ileal ansa at the site of the insertion of a 12-mm trocar. A 28-year-old obese female patient underwent laparoscopic surgery for gastric bypass, the skin incisions of the trocar insertion sites were closed with absorbable sutures. Small bowel occlusion occurred on post-operative day 6 and the patient again underwent laparoscopic surgery. Laparoscopic exploration confirmed the suspected presence of the incarcerated hernia of an ileal ansa at the site of the trocar insertion which was freed without any need for bowel resection. The fascial defect was successfully closed under direct vision with the use of a special system of fascial sutures