Search results for "GIST"
showing 10 items of 3463 documents
Grasslands provide diverse opportunities for bird species along an urban-rural gradient
2021
Urbanisation is a major cause of biodiversity loss but careful habitat management and provision of green space within cities can help to mitigate its negative effects. Grasslands occupy large surface areas and have many functions but only a few studies have begun to explore how birds exploit these habitats in urban contexts. We hypothesized that the value of grasslands for nesting and feeding birds is likely to depend both on landscape context, and on local characteristics (grassland size, use and vegetation structure). We surveyed local habitat characteristics, breeding bird presence, abundance and foraging activity in 47 grassland sites, distributed along an urban-rural gradient in two Fr…
Are alternative food networks winning strategies to increase organic SMEs profitability? Evidence from a case study
2020
The aim of this study was to understand how and how much alternative food networks (AFNs) contribute to increasing the profitability of the organic SMEs, compared to traditional organic sales channels. For this purpose, an economic analysis and an in-depth interview were carried out in a case study located in the Sicilian northern coast. Findings showed a clear convenience of the participation to alternative food networks compared to the case in which all farm production was conferred to traditional sales channels, highlighting an increase both of farm profit (+76.9%) and net income (+72.1%). However, the in-depth interview revealed that AFNs are a mean, not only to have economic benefits, …
The preference and costs of sleeping under light at night in forest and urban great tits
2019
Artificial light at night (ALAN) is an increasing phenomenon associated with worldwide urbanization. In birds, broad-spectrum white ALAN can have disruptive effects on activity patterns, metabolism, stress response and immune function. There has been growing research on whether the use of alternative light spectra can reduce these negative effects, but surprisingly, there has been no study to determine which light spectrum birds prefer. To test such a preference, we gave urban and forest great tits (Parus major) the choice where to roost using pairwise combinations of darkness, white light or green dim light at night (1.5 lux). Birds preferred to sleep under artificial light instead of dar…
Synergistic reduction of a native key herbivore performance by two non-indigenous invasive algae
2019
Abstract Native generalist grazers can control the populations of non-indigenous invasive algae (NIIA). Here, it was found that the simultaneous consumption of two co-occurring NIIA, Caulerpa cylindracea and C. taxifolia var. distichophylla, hinders the grazing ability of the main Mediterranean herbivorous, the native sea urchin Paracentrotus lividus. The ingestion of any of the two NIIA alone did not produce any difference in sea urchin righting time with respect to usual algal diet. In contrast, the simultaneous consumption of both NIIA, which grow intermingled in nature and are consumed by P. lividus, retarded its righting behavior. Such result reveals substantial physiological stress in…
Cyclic hantavirus epidemics in humans--predicted by rodent host dynamics.
2009
Wildlife-originated zoonotic diseases are a major contributor to emerging infectious diseases. Hantaviruses cause thousands of human disease cases annually worldwide, and understanding and predicting human hantavirus epidemics still poses unsolved challenges. Here we studied the three-level relationships between the human disease nephropathia epidemica (NE), its etiological agent Puumala hantavirus (PUUV) and the rodent host of the virus, the bank vole (Myodes glareolus). A large and long-term data set (14 years, 2583 human NE cases and 4751 trapped bank voles) indicates that the number of human infections shows both seasonal and multi-annual fluctuations, is influenced by the phase of vole…
Seed Bank in Annuals: Competition Between Banker and Non-banker Morphs
2002
Seed bank is a plant life history strategy against the unpredictability of the biotic and the abiotic environment. We simulated competition between a seed banking and a non-banking morph of an annual plant. A constant fraction of the banker morph seeds was allocated to the seed bank, where they had a constant mortality and germination rate. All surviving seeds of the non-banker morph germinated in the next generation. The seedlings of both morphs experienced similar density-dependent mortality. Whether one of the morphs wins or the morphs coexist was evaluated from parameter space plots and statistically with logistic regression analysis. All parameters of the model had a significant, nonli…
Presence of uradenia in male adults of the genus Dismegistus (Hemiptera: Heteroptera: Parastrachiidae)
2018
Uradenia, often referred to as paragenital glands, are usually voluminous paired exocrine glands located ventrally in the abdomen mostly on the intersegmental membrane between abdominal segments (= urites) VII-VIII or VIII-IX, depending on sex or the taxon. They have been previously recorded from eight pentatomomorphan families belonging to Coreoidea, Lygaeoidea and Pyrrhocoroidea (Hemiptera: Heteroptera), found either in males, females or both sexes, and were thought to be absent in Pentatomoidea. We report here the first instance of uradenia in a pentatomoid genus, the African Dismegistus Amyot & Serville, 1843 (Parastrachiidae). Only the male adult possesses uradenia located on the i…
Image retrieval system for citizen services using penalized logistic regression models
2020
This paper describes a procedure to deal with large image collections obtained by smart city services based on interaction with citizens providing pictures. The semantic gap between the low-level image features and represented concepts and situations has been addressed using image retrieval techniques. A relevance feedback procedure is proposed for Content-Based Image Retrieval (CBIR) based on the modelling of user responses. One of the novelties of the proposal is that the feedback learning procedure can use the information that citizens themselves can provide when using these services.The proposed algorithm considers the probability of an image belonging to the set of those sought by the …
“Natural wine” consumers and interest in label information: An analysis of willingness to pay in a new Italian wine market segment
2019
Abstract Increasing public attention to issues of health and environmental sustainability has contributed to a growing consumer demand for “natural” food and drinks. As has been observed, this trend has also affected the wine market, leading to the spread of so-called “natural wine”. According to the literature, consumers who are aware of the social and environmental impact of their consumption choices pay more attention to the information displayed on the label as a tool to reduce the risk associated with their purchase. This study seeks to identify which consumers are willing to pay for natural wine and to understand what information on the label influences their choice. This study is one…
LMI-based 2D-3D Registration: from Uncalibrated Images to Euclidean Scene
2015
International audience; This paper investigates the problem of registering a scanned scene, represented by 3D Euclidean point coordinates , and two or more uncalibrated cameras. An unknown subset of the scanned points have their image projections detected and matched across images. The proposed approach assumes the cameras only known in some arbitrary projective frame and no calibration or autocalibration is required. The devised solution is based on a Linear Matrix Inequality (LMI) framework that allows simultaneously estimating the projective transformation relating the cameras to the scene and establishing 2D-3D correspondences without triangulating image points. The proposed LMI framewo…