A minimum-time obstacle-avoidance path planning algorithm for unmanned aerial vehicles

In this article, we present a new strategy to determine an unmanned aerial vehicle trajectory that minimizes its flight time in presence of avoidance areas and obstacles. The method combines classical results from optimal control theory, i.e. the Euler-Lagrange Theorem and the Pontryagin Minimum Principle, with a continuation technique that dynamically adapts the solution curve to the presence of obstacles. We initially consider the two-dimensional path planning problem and then move to the three-dimensional one, and include numerical illustrations for both cases to show the efficiency of our approach

High concordance between trained nurses and gastroenterologists in evaluating recordings of small bowel video capsule endoscopy (VCE)

Background & Aims: The video capsule endoscopy (VCE) is an accurate and validated tool to investigate the entire small bowel mucosa, but VCE recordings interpretation by the gastroenterologist is time-consuming. A pre-reading of VCE recordings by an expert nurse could be accurate and cost saving. We assessed the concordance between nurses and gastroenterologists in detecting lesions on VCE examinations. Methods: This was a prospective study enrolling consecutive patients who had undergone VCE in clinical practice. Two trained nurses and two expert gastroenterologists participated in the study. At VCE pre-reading the nurses selected any abnormalities, saved them as “thumbnails” and classified the detected lesions as a vascular abnormality, ulcerative lesion, polyp, tumor mass, and unclassified lesion. Then, the gastroenterologist evaluated and interpreted the selected lesions and, successively, reviewed the entire video for potential missed lesions. The time for VCE evaluation was recorded. Results: A total of 95 VCE procedures performed on consecutive patients (M/F: 47/48; mean age: 63 ± 12 years, range: 27−86 years) were evaluated. Overall, the nurses detected at least one lesion in 54 (56.8%) patients. There was total agreement between nurses and gastroenterologists, no missing lesions being discovered at a second look of the entire VCE recording by the physician. The pre-reading procedure by nurse allowed a time reduction of medical evaluation from 49 (33-69) to 10 (8-16) minutes (difference:-79.6%). Conclusions: Our data suggest that trained nurses can accurately identify and select relevant lesions in thumbnails that subsequently were faster reviewed by the gastroenterologist for a final diagnosis. This could significantly reduce the cost of VCE procedure

Comparative analysis of Iron Age bronze archaeological objects from a Picenum necropolis of Centre Italy with Prompt Gamma Activation Analysis

An archaeological area from the 8th and 7th centuries B.C. has been recently discovered during a rescue excavation near Matelica site (Marche Region, Italy) in the period 1994-2005. Out of the treasures found in the graves, 18 bronze objects have been chosen for Prompt Gamma Activation Analysis (PGAA) at the Budapest Research Reactor (BRR), selected from the 7th century B.C. archaeological founds of Matelica and Fabriano sites. Various investigations, already performed in the same field, have confirmed the applicability of the considered technique and the feasibility of the proposed experiment. Besides determining the major components of the analyzed fragments, some trace elements, such as Sb, As and Ag, have also been identified. The compositions of the different samples have been also compared, in order to gain information regarding possible workshops and provenance. The comparative analysis will be useful, moreover, to establish an eventual classification according to the chemical composition. The obtained results are complementary to those already achieved for the considered objects, including atomic absorption, atomic emission and neutron diffraction

Climate and land-use change during the late Holocene at Lake Ledro (southern Alps, Italy)

International audienceThis paper investigates the relative influences of climatic and anthropogenic factors in explaining environmental and societal changes in the southern Alps, Italy. We investigate a deep sediment core (LL081) from Lake Ledro (652 m a.s.l.). Environmental changes are reconstructed through multiproxy analysis, that is, pollen-based vegetation and climate reconstruction, magnetic susceptibility (MS), lake level, and flood frequency, and the paper focuses on the climate and land-use changes which occurred during the late Holocene. For this time interval, Lake Ledro records high mean water table, increasing amount of pollen-based precipitation, and more erosive conditions. Therefore, while a more humid late Holocene in the southern Alps has the potential to reinforce the forest presence, pollen evidence suggests that anthropogenic activities changed the impact of this regional scenario. Land-use activity (forest clearance for pastoralism, farming, and arboriculture) opened up the large vegetated slopes in the catchment of Lake Ledro, which in turn magnified the erosion related to the change in the precipitation pattern. The record of an almost continuous human occupation for the last 4100 cal. BP is divided into several land-use phases. On the one hand, forest redevelopments on abandoned or less cultivated areas appear to be climatically induced as they occurred in relation with well-known events such as the 2.8-kyr cold event and the ‘Little Ice Age’. On the other hand, climatically independent changes in land use or habitat modes are observed, such as the late-Bronze-Age lake-dwellings abandonment, the human population migration at c. 1600 cal. BP, and the period of the Black Death and famines at 600 cal. BP

Development and Validation of a Computerized Assessment Form to Support Nursing Diagnosis

PURPOSE: Describe the development and validation of the Nursing Assessment Form (NAF), within a clinical nursing information system, to support nurses in the identification of nursing diagnoses. METHODS: Content validity and consensus on NAF contents were established using a panel of experts in nursing diagnosis and Delphi rounds. FINDINGS: Expert consensus was achieved to validate an instrument to support nurses in the process of nursing diagnoses identification. CONCLUSIONS: The use of the NAF can help nurses in diagnostic reasoning, facilitating the identification of the more suitable nursing diagnoses, and provide a basis for the best nursing interventions and outcomes. IMPLICATIONS FOR NURSING PRACTICE: The use of computerized decision support can improve the implementation of standardized terminology and the accuracy of nursing diagnosis