6,235 research outputs found
Obstruction of biodiversity conservation by minimum patch size criteria.
Minimum patch size criteria for habitat protection reflect the conservation principle that a single large (SL) patch of habitat has higher biodiversity than several small (SS) patches of the same total area (SL > SS). Nonetheless, this principle is often incorrect, and biodiversity conservation requires placing more emphasis on protection of large numbers of small patches (SS > SL). We used a global database reporting the abundances of species across hundreds of patches to assess the SL > SS principle in systems where small patches are much smaller than the typical minimum patch size criteria applied for biodiversity conservation (i.e., ∼85% of patches <100 ha). The 76 metacommunities we examined included 4401 species in 1190 patches. From each metacommunity, we resampled species-area accumulation curves to evaluate how biodiversity responded to habitat existing as a few large patches or as many small patches. Counter to the SL > SS principle and consistent with previous syntheses, species richness accumulated more rapidly when adding several small patches (45.2% SS > SL vs. 19.9% SL > SS) to reach the same cumulative area, even for the very small patches in our data set. Responses of taxa to habitat fragmentation differed, which suggests that when a given total area of habitat is to be protected, overall biodiversity conservation will be most effective if that habitat is composed of as many small patches as possible, plus a few large ones. Because minimum patch size criteria often require larger patches than the small patches we examined, our results suggest that such criteria hinder efforts to protect biodiversity
Outcomes of conjunctival compression sutures for hypotony after glaucoma filtering surgery
3openopenQuaranta L.; Riva I.; Floriani I.C:Quaranta, Luciano; Riva, Ivano; Floriani I., C
Microbial assisted phytodepuration for water reclamation: Environmental benefits and threats
Climate changes push for water reuse as a priority to counteract water scarcity and minimize water footprint especially in agriculture, one of the highest water consuming human activities. Phytodepuration is indicated as a promising technology for water reclamation, also in the light of its economic and ecological sustainability, and the use of specific bacterial inocula for microbial assisted phytodepuration has been proposed as a further advance for its implementation. Here we provided an overview on the selection and use of plant growth promoting bacteria in Constructed Wetland (CW) systems, showing their advantages in terms of plant growth support and pollutant degradation abilities. Moreover, CWs are also proposed for the removal of emerging organic pollutants like antibiotics from urban wastewaters. We focused on this issue, still debated in the literature, revealing the necessity to deepen the knowledge on the antibiotic resistance spread into the environment in relation to treated wastewater release and reuse. In addition, given the presence in the plant system of microhabitats (e.g. rhizosphere) that are hot spot for Horizontal Gene Transfer, we highlighted the importance of gene exchange to understand if these events can promote the diffusion of antibiotic resistance genes and antibiotic resistant bacteria, possibly entering in the food production chain when treated wastewater is used for irrigation. Ideally, this new knowledge will lead to improve the design of phytodepuration systems to maximize the quality and safety of the treated effluents in compliance with the 'One Health' concept
Outcomes of using a sutureless bovine pericardial patch graft for Ahmed glaucoma valve implantation
Los saurios y anfisbénidos de Bolivia (Reptilia, Squamata): lista patrón, localidades y bibliografía
The number of Bolivian lizards and amphisbaenids is increased from 79 (Fugler, 1989) to 102 in this updated and comprehensive list, which includes all new species and taxonomic changes published recently, as well as locality data. Coordinates for the localities are provided in a locality list. Three species are reported herein for the first time: Kentropyx pelviceps, Liolaemus schmidti, and Uranoscodon superciliosus.El número de saurios y anfisbénidos conocidos en Bolivia se incrementa de 79 especies (Fugler, 1989) a 102 en la presente lista actualizada, que incorpora todas las especies nuevas, los cambios taxonómicos recientes y todas las localidades de colecta conocidas con sus coordenadas. Tres especies son citadas para Bolivia por primera vez en este trabajo: Kentropyx pelviceps, Liolaemus schmidti y Uranoscodon superciliosus
Landscape and Environmental Impact Evaluation of Roundabouts
The interest of researchers and practitioners on roundabout solutions has been growing increasingly
in the last decades. The often large areas occupied by this type of intersections require special attention on
the use of ground and the preservation of the natural, environmental and architectural heritage. This aim also
presents the opportunity for evaluating their impact on the landscape and environment. The paper proposes a
new method developed for roundabout evaluation (but generalizable to other infrastructures and fields) borrowed
from building technology and based on the needs, requirements and performance expected from an object rather
than on prescriptions for and descriptions of its dimensions and quality. Applications on two roundabouts are
presented in order to highlight practical developments. Their final evaluation sheets are presented and through
them it is relatively easy to single out the problems and drawbacks of the roundabouts from the landscape point
of view
Case studies of landscape and environmental impact evaluation of roundabouts
This paper is a follow-up to a previous one that presented a new method for evaluating the landscape and environmental impact of roundabouts borrowed from building technology and based on the needs, requirements and performance expected from an object rather than on prescriptions for and descriptions of its dimensions and quality. The proposed method aims at defining criteria to set up an information structure based on a need and performance approach capable of evaluating impacts on the landscape and environmental integration. After a brief résumé of the above-mentioned principles, two applications are presented in order to highlight two practical developments. The roundabouts on which the applications are focused are located in an urban and in a rural environment respectively in the Northern part of Italy. Obviously their analysis cannot be considered comprehensive of all possible cases but it covers a large proportion of them. Differences between the two roundabouts are many and they concern, besides the landscape and environment, geometrical dimensions, type of flow, presence of weekday users (pedestrians and bikers). The final evaluation sheets are presented and through them it is relatively easy to single out the problems and drawbacks of the roundabouts from the landscape point of view
Additive manufacturing of PLA to mimic the thrust force of mandibular bone during drilling
Edentulism is a condition that results in the partial or total loss of teeth. It may lead to problems during chewing and be a cause of self-isolation and low self-esteem. Edentulism can be resolved both with removable prostheses (dentures) and fixed implants, with the latter being more efficient. The installation of a fixed implant involves a real surgical operation in which the jaw/mandibular bone is drilled through a special drill. One of the main cautions the surgeon must have during the operation is not to sever the nerves during the drilling. Given the composition of the bone is different in each person, the drilling thrust force is variable and controlling its movement can sometimes be complicated. Therefore, being able to test the operation on a dummy may reduce the number of errors. Additive manufacturing with its high degree of customization and ability to produce objects with almost no geometrical limitations could provide the required features to realize the dummy. In this work, the drilling properties of samples made in PLA through Fused Filament Fabrication (FFF) were studied. The samples were designed to mimic the composition of the bone. Specifically, a thin, hard, and denser outer layer and a 25% internal filling were adopted. The samples were drilled with a dental drill properly connected to a collaborative robot
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