3,062 research outputs found
Mosaic of submerged habitats in the Venice lagoon shows signs of marinization
The relationships between habitat patterns and ecosystem functioning have been widely explored in terrestrial ecosystems, but less in marine and coastal ecosystems, calling for further research in this direction. This work focuses on the mosaic of submerged habitats in the Venice lagoon, Italy. It aims to describe the habitatsâ spatial patterns at multiple spatial scales, and to explore their linkages with the ecological status defined according to the EU Water Framework Directive (WFD, 2000/60/EC). The submerged habitatsâ mosaic has been analysed by calculating a set of seascape metrics at different spatial scales. These metrics have been linked with the biological quality elements (BQEs) that are monitored in the lagoon in compliance to the WFD. The results show that the habitatsâ spatial patterns differ between the areas of the lagoon with marine-like features and the areas which still retain more lagoon characteristics. The similarity between the pattern found in the whole lagoon and those found in marine-like areas suggests a general loss of lagoon characteristics at the lagoon scale. Regarding the ecological status, every BQE seems to be associated with a different habitat configuration at the water body scale. This does not facilitate the joint improvement of the BQEs, as required by the Directive. If we cannot achieve that, at some point we will probably have to choose what to prioritize. On a broader perspective, this calls for a reflection on what lagoon we want for the future, a vision that should be shared and account for the lagoonâs complexity, current trends and challenges
TCP throughput guarantee in the DiffServ Assured Forwarding service: what about the results?
Since the proposition of Quality of Service architectures by the IETF, the
interaction between TCP and the QoS services has been intensively studied. This
paper proposes to look forward to the results obtained in terms of TCP
throughput guarantee in the DiffServ Assured Forwarding (DiffServ/AF) service
and to present an overview of the different proposals to solve the problem. It
has been demonstrated that the standardized IETF DiffServ conditioners such as
the token bucket color marker and the time sliding window color maker were not
good TCP traffic descriptors. Starting with this point, several propositions
have been made and most of them presents new marking schemes in order to
replace or improve the traditional token bucket color marker. The main problem
is that TCP congestion control is not designed to work with the AF service.
Indeed, both mechanisms are antagonists. TCP has the property to share in a
fair manner the bottleneck bandwidth between flows while DiffServ network
provides a level of service controllable and predictable. In this paper, we
build a classification of all the propositions made during these last years and
compare them. As a result, we will see that these conditioning schemes can be
separated in three sets of action level and that the conditioning at the
network edge level is the most accepted one. We conclude that the problem is
still unsolved and that TCP, conditioned or not conditioned, remains
inappropriate to the DiffServ/AF service
The First Year of the Large Hadron Collider: A Brief Review
The first year of LHC data taking provided an integrated luminosity of about
35/pb in proton-proton collisions at sqrt(s)=7 TeV. The accelerator and the
experiments have demonstrated an excellent performance. The experiments have
obtained important physics results in many areas, ranging from tests of the
Standard Model to searches for new particles. Among other results the physics
highlights have been the measurements of the W-, Z-boson and t t-bar production
cross-sections, improved limits on supersymmetric and other hypothetical
particles and the observation of jet-quenching, elliptical flow and J/Psi
suppression in lead-lead collisions at sqrt(sNN) = 2.76 TeV.Comment: 11 pages, 9 figures, invited brief review for Mod. Phys. Lett.
As cidades e o aquecimento global: desafios para o planejamento urbano, as engenharias e as ciĂȘncias sociais e bĂĄsicas
This article aims to present a transdisciplinary approach to the relationship between climate change and cities. Part of the recognition that the current form of urbanization in large metropolitan regions is a strong agent that promotes global warming, at the same time that it is the locus of the harmful manifestation of the effects of these changes. The change in rainfall patterns, with greater frequency and intensity, in the distribution of rainfall and the phenomenon of heat islands, particularly affects the most precarious settlement areas, where high social vulnerability exposes gigantic contingents of people to constant flood risks, landslides, lack of drinking water and basic sanitation, and diseases caused by excessive heat. The search for environmental sustainability involves this social dimension, requiring from sciences and techniques a transdisciplinary effort for integrated actions that can face the ethical challenge of social inequality among those affected by the harmful effects of climate change.Este artigo tem como objetivo apresentar uma abordagem transdisciplinar para a relação entre as mudanças climĂĄticas e as cidades. Parte do reconhecimento de que a atual forma da urbanização das grandes regiĂ”es metropolitanas Ă© forte agente promotor do aquecimento global, ao mesmo tempo que constitui lĂłcus da manifestação nociva dos efeitos dessas mudanças. A alteração dos regimes de chuva, com maior frequĂȘncia e intensidade, da distribuição das precipitaçÔes e do fenĂŽmeno das ilhas de calor afetam em especial as ĂĄreas de assentamentos mais precĂĄrios, onde a elevada vulnerabilidade social expĂ”e gigantescos contingentes de pessoas a riscos constantes de inundação, deslizamentos, falta de ĂĄgua potĂĄvel e saneamento bĂĄsico, e doenças geradas pelo calor excessivo. A busca por sustentabilidade ambiental envolve essa dimensĂŁo social, exigindo das ciĂȘncias e das tĂ©cnicas um esforço transdisciplinar para açÔes integradas que possa fazer frente ao desafio Ă©tico da desigualdade social entre os afetados pelos efeitos nocivos das mudanças climĂĄticas
A new proposal: A digital flow for the construction of a haas-inspired rapid maxillary expander (HIRME)
Maxillary expansion is a common orthodontic treatment used for the correction of posterior crossbite resulting from reduced maxillary width. Transverse maxillomandibular discrepancies are a major cause of several malocclusions and may be corrected in dierent manners; in particular, the rapid maxillary expansion (RME) performed in the early mixed dentition has now become a routine procedure in orthodontic practice. The aim of this study is to propose a procedure that reduces the patient cooperation as well as the lab work required in preparing a customized Haas-inspired rapid maxillary expander (HIRME) that can be anchored to deciduous teeth and can be utilized in mixed dentition with tubes on the molars and hooks and brackets on the canines. This article thus presents an expander that is completely digitally developed, from the first moment of taking the impression with an optical scanner to the final solidification phase by the use of a 3D printer. This digital flow takes place in a CAD environment and it starts with the creation of the appliance on the optical impression; this design is then exported as an stl extension and is sent to the print service to obtain a solid model of the device through a laser sintering process. This "rough" device goes through a post-processing procedure; finally, a commercial expansion screw is laser-welded. This expander has all the advantages of a cast-metal Haas-type RME that rests on deciduous teeth; moreover, it has the characteristic of being developed with a completely digitized and individualized process, for the mouth of the young patient, as well as being made completely of cobalt-chrome, thus ensuring greater adaptability and stability in the patient's mouth
Optical Link of the Atlas Pixel Detector
The on-detector optical link of the ATLAS pixel detector contains
radiation-hard receiver chips to decode bi-phase marked signals received on PIN
arrays and data transmitter chips to drive VCSEL arrays. The components are
mounted on hybrid boards (opto-boards). We present results from the irradiation
studies with 24 GeV protons up to 32 Mrad (1.2 x 10^15 p/cm^2) and the
experience from the production.Comment: 9th ICATPP Conference, Como, Ital
Arsenic movement and fractionation in agricultural soils which received wastewater from an adjacent industrial site for 50 years
Arsenic (As) is an element with important environmental and human health implications due to its toxic properties. It is naturally occurring since it is contained in minerals, but it can also be enriched and distributed in the environment by anthropogenic activities. This paper reports on the historic As contamination of agricultural soils in one of the most important national relevance site for contamination in Italy, the so-called SIN Brescia-Caffaro, in the city of Brescia, northern Italy. These agricultural areas received As through the use of irrigation waters from wastewater coming from a factory of As-based pesticides (lead and calcium arsenates, sodium arsenite). Pesticide production started in 1920 and ended in the '70. Concentrations in the areas are generally beyond the legal threshold values for different soil uses and are up to >200 mg/kg. Arsenic contamination was studied to assess the long-time trend and the dynamics related to the vertical movement of As down to 1 m depth and its horizontal diffusion with surface irrigation in the entire field. Arsenic fractionation analysis (solid phase speciation by sequential extraction procedure) was also performed on samples collected from these areas and employed in greenhouse experiments with several plant species to evaluate the long-term contamination and the role of plant species in modifying As availability in soil. The results of this work can help in the evaluation of the conditions controlling the vertical transfer of As towards surface aquifers, the bioaccumulation likelihood in the agricultural food chain and the selection of sustainable remediation techniques such as phytoextraction
Effect of oral consumption of capsules containing Lactobacillus paracasei LPC-S01 on the vaginal microbiota of healthy adult women: a randomized, placebo-controlled, double-blind crossover study
Oral consumption of probiotics is practical and can be an effective solution to preserve vaginal eubiosis. Here, we studied the ability of orally administered Lactobacillus paracasei LPC-S01 (DSM 26760) to affect the composition of the vaginal microbiota and colonize the vaginal mucosa in nondiseased adult women. A total of 40 volunteers took oral probiotic (24 billion CFU) or placebo capsules daily for 4 weeks, and after a 4-week washout, they switched to placebo or probiotic capsules according to the crossover design. A total of 23 volunteers completed the study according to the protocol. Before and after capsule ingestion, vaginal swabs were collected for qPCR quantification to detect L. paracasei LPC-S01 and for 16S rRNA gene sequencing. Vaginal swabs were grouped according to their bacterial taxonomic structure into nine community state types (CSTs), four of which were dominated by lactobacilli. Lactobacillus paracasei LPC-S01 was detected in the vagina of two participants. Statistical modeling (including linear mixed-effects model analysis) demonstrated that daily intake of probiotic capsules reduced the relative abundance of Gardnerella spp. Quantitative PCR with Gardnerella vaginalis primers confirmed this result. Considering the pathogenic nature of G. vaginalis, these results suggest a potential positive effect of this probiotic capsule on the vaginal microbial ecosystem
Measurement of neutron detection efficiency between 22 and 174 MeV using two different kinds of Pb-scintillating fiber sampling calorimeters
We exposed a prototype of the lead-scintillating fiber KLOE calorimeter to
neutron beam of 21, 46 and 174 MeV at The Svedberg Laboratory, Uppsala, to
study its neutron detection efficiency. This has been found larger than what
expected considering the scintillator thickness of the prototype. %To check our
method, we measured also the neutron %detection efficiency of a 5 cm thick
NE110 scintillator. We show preliminary measurement carried out with a
different prototype with a larger lead/fiber ratio, which proves the relevance
of passive material to neutron detection efficiency in this kind of
calorimeters
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