323 research outputs found
Automated delineation of roof planes from LIDAR data
In this paper, we describe an algorithm for roof line delineation from LIDAR data which aims at achieving models of a high level of detail. Roof planes are initially extracted by segmentation based on the local homogeneity of surface normal vectors of a digital surface model (DSM). A case analysis then reveals which of these roof planes intersect and which of them are separated by a step edge. The positions of the step edges are determined precisely by a new algorithm taking into account domain specific information. Finally, all step edges and intersection lines are combined to form consistent polyhedral models. In all phases of this workflow, decision making is based upon statistical reasoning about geometrical relations between neighbouring entities in order to reduce the number of control parameters and to increase the robustness of the method
Evaluation of a method for fusing LIDAR data and multispectral images for building detection
In this paper, we describe the evaluation of a method for building detection by the Dempster-Shafer fusion of LIDAR data and multispectral images. For that purpose, ground truth was digitised for two test sites with quite different characteristics. Using these data sets, the heuristic model for the probability mass assignments of the method is validated, and rules for the tuning of the parameters of this model are discussed. Further we evaluate the contributions of the individual cues used in the classification process to the quality of the classification results. Our results show the degree to which the overall correctness of the results can be improved by fusing LIDAR data with multispectral images
Fusing airborne laser scanner data and aerial imagery for the automatic extraction of buildings in densely built-up areas
Building Detection by Dempster-Shafer Fusion of LIDAR Data and Multispectral Aerial Imagery
A method for the classification of land cover in urban areas by the fusion of first and last pulse LIDAR data and multi-spectral images is presented. Apart from buildings, the classes "tree", "grass land", and "bare soil" are also distinguished by a classification method based on the theory of Dempster-Shafer for data fusion. Examples are given for a test site in Germany
Classification of non-indigenous species based on their impacts: Considerations for application in marine management
Assessment of the ecological and economic/societal impacts of the introduction of non-indigenous species (NIS) is one of the primary focus areas of bioinvasion science in terrestrial and aquatic environments, and is considered essential to management. A classification system of NIS, based on the magnitude of their environmental impacts, was recently proposed to assist management. Here, we consider the potential application of this classification scheme to the marine environment, and offer a complementary framework focussing on value sets in order to explicitly address marine management concerns. Since existing data on marine NIS impacts are scarce and successful marine removals are rare, we propose that management of marine NIS adopt a precautionary approach, which not only would emphasise preventing new incursions through pre-border and at-border controls but also should influence the categorisation of impacts. The study of marine invasion impacts requires urgent attention and significant investment, since we lack the luxury of waiting for the knowledge base to be acquired before the window of opportunity closes for feasible management
Apresentação Pélvica: Parto Vaginal Versus Cesariana, Qual a Melhor Intervenção?
INTRODUCTION:
The best route of delivery for the term breech fetus is still controversial. We aim to compare maternal and neonatal outcomes between vaginal and cesarean term breech deliveries.
MATERIAL AND METHODS:
Multicentric retrospective cohort study of singleton term breech fetuses delivered vaginally or by elective cesarean section from January 2012 - October 2014. Primary outcomes were maternal and neonatal morbidity or mortality.
RESULTS:
Sixty five breech fetuses delivered vaginally were compared to 1262 delivered by elective cesarean. Nulliparous women were more common in the elective cesarean group (69.3% vs 24.6%; p < 0.0001). Gestational age at birth was significantly lower in the vaginal delivery group (38 ± 1 weeks vs 39 ± 0.8 weeks; p = 0.0029) as was birth weight (2928 ± 48.4 g vs 3168 ± 11.3 g; p < 0.0001). Apgar scores below seven on the first and fifth minutes were more likely in the vaginal delivery group (1st minute: 18.5% vs 5.9%; p = 0.0006; OR 3.6 [1.9 - 7.0]; 5th minute: 3.1% vs 0.2%; p = 0.0133; OR 20.0 [2.8 - 144.4]), as was fetal trauma (3.1% vs 0.3%: p = 0.031; OR 9.9 [1.8-55.6]). Neither group had cases of fetal acidemia. Admission to the Neonatal Intensive Care Unit, maternal postpartum hemorrhage and the incidence of other obstetric complications were similar between groups.
DISCUSSION:
Although vaginal breech delivery was associated with lower Apgar scores and higher incidence of fetal trauma, overall rates of such events were low. Admission to the neonatal intensive care unit and maternal outcomes were similar.
CONCLUSION:
Both delivery routes seem equally valid, neither posing high maternal or neonatal complications' incidence.info:eu-repo/semantics/publishedVersio
Threat-sensitive anti-predator defence in precocial wader, the northern lapwing Vanellus vanellus
Birds exhibit various forms of anti-predator behaviours to avoid reproductive failure, with mobbing—observation, approach and usually harassment of a predator—being one of the most commonly observed. Here, we investigate patterns of temporal variation in the mobbing response exhibited by a precocial species, the northern lapwing (Vanellus vanellus). We test whether brood age and self-reliance, or the perceived risk posed by various predators, affect mobbing response of lapwings. We quantified aggressive interactions between lapwings and their natural avian predators and used generalized additive models to test how timing and predator species identity are related to the mobbing response of lapwings. Lapwings diversified mobbing response within the breeding season and depending on predator species. Raven Corvus corax, hooded crow Corvus cornix and harriers evoked the strongest response, while common buzzard Buteo buteo, white stork Ciconia ciconia, black-headed gull Chroicocephalus ridibundus and rook Corvus frugilegus were less frequently attacked. Lapwings increased their mobbing response against raven, common buzzard, white stork and rook throughout the breeding season, while defence against hooded crow, harriers and black-headed gull did not exhibit clear temporal patterns. Mobbing behaviour of lapwings apparently constitutes a flexible anti-predator strategy. The anti-predator response depends on predator species, which may suggest that lapwings distinguish between predator types and match mobbing response to the perceived hazard at different stages of the breeding cycle. We conclude that a single species may exhibit various patterns of temporal variation in anti-predator defence, which may correspond with various hypotheses derived from parental investment theory
‘A flying start’: Wildlife trypanosomes in tissues of Australian tabanids (Diptera: Tabanidae)
Tabanids (syn. horse flies) are biting-flies of medical and veterinary significance because of their ability to transmit a range of pathogens including trypanosomes – some species of which carry a combined health and biosecurity risk. Invertebrate vectors responsible for transmitting species of Trypanosoma between Australian wildlife remains unknown, thus establishing the role of potential vector candidates such as tabanids is of utmost importance. The current study aimed to investigate the presence of indigenous trypanosomes in tabanids from an endemic area of south-west Australia. A total of 148 tabanids were collected, with morphological analysis revealing two subgenera: Scaptia (Pseudoscione) and S. (Scaptia) among collected flies. A parasitological survey using an HRM-qPCR and sequencing approach revealed a high (105/148; 71%) prevalence of trypanosomatid DNA within collected tabanids. Individual tissues - proboscis (labrum, labium and mandibles, hypopharynx), salivary glands, proventriculus, midgut, and hindgut and rectum - were also tested from a subset of 20 tabanids (n = 140 tissues), confirming the presence of Trypanosoma noyesi in 31% of screened tissues, accompanied by T. copemani (3%) and T. vegrandis/T.gilletti (5%). An unconfirmed trypanosomatid sp. was also detected (9%) within tissues. The difference between tissues infected with T. noyesi compared with tissues infected with other trypanosome species was statistically significant (p < 0.05), revealing T. noyesi as the more frequent species detected in the tabanids examined. Fluorescence in situ hybridisation (FISH) and scanning electron microscopy (SEM) confirmed intact parasites within salivary glands and the proboscis respectively, suggesting that both biological and mechanical modes of transmission could occur. This study reveals the presence of Australian Trypanosoma across tabanid tissues and confirms intact parasites within tabanid salivary glands and the proboscis for the first time. Further investigations are required to determine whether tabanids have the vectorial competence to transmit Australian trypanosomes between wildlife
The emergent rhizosphere: imaging the development of the porous architecture at the root-soil interface
The rhizosphere is the zone of soil infuenced by a plant root and is critical for plant health and nutrient acquisition. All below ground resources must pass through this dynamic zone prior to their capture by plant roots. However, researching the undisturbed rhizosphere has proved very challenging. Here we compare the temporal changes to the intact rhizosphere pore structure during the emergence of a developing root system in diferent soils. High resolution X-ray Computed Tomography (CT) was used to quantify the impact of root development on soil structural change, at scales relevant to individual micro-pores and aggregates (µm). A comparison of micro-scale structural evolution in homogenously packed soils highlighted the impacts of a penetrating root system in changing the surrounding porous architecture and morphology. Results indicate the structural zone of infuence of a root can be more localised than previously reported (µm scale rather than mm scale). With time, growing roots signifcantly alter the soil physical environment in their immediate vicinity through reducing root-soil contact and crucially increasing porosity at the root-soil interface and not the converse as has often been postulated. This ‘rhizosphere pore structure’ and its impact on associated dynamics are discussed
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