248 research outputs found
Near-forward Raman selection rules of the phonon-polariton created by alloying in (Zn,Be)Se
The Raman selection rules of the (ZnSe, BeSe) mixed phonon polariton created
by alloying in the three mode (1ZnSe, 2BeSe) ZnBeSe system, whose dramatic S
like dispersion covers the large frequency gap between the ZnSe and BeSe
spectral ranges, is studied in its wave vector dependence by near forward
scattering. Both the collapse regime away from the Brillouin zone centre and
the reinforcement regime near the Brillouin zone centre are addressed, using
appropriate laser lines and Be contents. We find that in both regimes the
considered phonon polariton, in fact a transverse mode with mixed mechanical
and electrical character, obeys the same nominal Raman selection rules as its
purely mechanical variant commonly observed in the backscattering geometry.
Besides, marked differences in the phonon polariton Raman lineshapes in the two
regimes give a hint about how the phonon polariton electrical field E develops
while descending the S like dispersion towards the Brillouin zone centre. In
the reinforcement regime E is large, leading to intramode on top of intermode
transfers of oscillator strength mediated by E between the two BeSe modes, that
both exhibit a fine structure on account of the alloy disorder. In contrast, in
the collapse regime E remains weak, as testified by the absence of intramode
transfer. The discussion is supported by contour modeling of the multi phonon
polariton Raman lineshapes in their wave vector dependence within the linear
dielectric approach.Comment: 16 pages, 7 figure
Dynamic and volumetric variables reliably predict fluid responsiveness in a porcine model with pleural effusion
Background: The ability of stroke volume variation (SVV), pulse pressure variation (PPV) and global end-diastolic volume (GEDV) for prediction of fluid responsiveness in presence of pleural effusion is unknown. The aim of the present study was to challenge the ability of SVV, PPV and GEDV to predict fluid responsiveness in a porcine model with pleural effusions.
Methods: Pigs were studied at baseline and after fluid loading with 8 ml kg−1 6% hydroxyethyl starch. After withdrawal of 8 ml kg−1 blood and induction of pleural effusion up to 50 ml kg−1 on either side, measurements at baseline and after fluid loading were repeated. Cardiac output, stroke volume, central venous pressure (CVP) and pulmonary occlusion pressure (PAOP) were obtained by pulmonary thermodilution, whereas GEDV was determined by transpulmonary thermodilution. SVV and PPV were monitored continuously by pulse contour analysis.
Results: Pleural effusion was associated with significant changes in lung compliance, peak airway pressure and stroke volume in both responders and non-responders. At baseline, SVV, PPV and GEDV reliably predicted fluid responsiveness (area under the curve 0.85 (p<0.001), 0.88 (p<0.001), 0.77 (p = 0.007). After induction of pleural effusion the ability of SVV, PPV and GEDV to predict fluid responsiveness was well preserved and also PAOP was predictive. Threshold values for SVV and PPV increased in presence of pleural effusion.
Conclusions: In this porcine model, bilateral pleural effusion did not affect the ability of SVV, PPV and GEDV to predict fluid responsiveness
Behavior trees in action: A study of robotics applications
Autonomous robots combine a variety of skills to form increasingly complex
behaviors called missions. While the skills are often programmed at a
relatively low level of abstraction, their coordination is architecturally
separated and often expressed in higher-level languages or frameworks.
Recently, the language of Behavior Trees gained attention among roboticists for
this reason. Originally designed for computer games to model autonomous actors,
Behavior Trees offer an extensible tree-based representation of missions.
However, even though, several implementations of the language are in use,
little is known about its usage and scope in the real world. How do behavior
trees relate to traditional languages for describing behavior? How are behavior
tree concepts used in applications? What are the benefits of using them?
We present a study of the key language concepts in Behavior Trees and their
use in real-world robotic applications. We identify behavior tree languages and
compare their semantics to the most well-known behavior modeling languages:
state and activity diagrams. We mine open source repositories for robotics
applications that use the language and analyze this usage. We find that
Behavior Trees are a pragmatic language, not fully specified, allowing projects
to extend it even for just one model. Behavior trees clearly resemble the
models-at-runtime paradigm. We contribute a dataset of real-world behavior
models, hoping to inspire the community to use and further develop this
language, associated tools, and analysis techniques.Comment: 14 pages, 5 figures, 13rd ACM SIGPLAN International Conference on
Software Language Engineering (SLE) (SLE 2020
Less invasive methods of advanced hemodynamic monitoring: principles, devices, and their role in the perioperative hemodynamic optimization.
The monitoring of the cardiac output (CO) and other hemodynamic parameters, traditionally performed with the thermodilution method via a pulmonary artery catheter (PAC), is now increasingly done with the aid of less invasive and much easier to use devices. When used within the context of a hemodynamic optimization protocol, they can positively influence the outcome in both surgical and non-surgical patient populations. While these monitoring tools have simplified the hemodynamic calculations, they are subject to limitations and can lead to erroneous results if not used properly. In this article we will review the commercially available minimally invasive CO monitoring devices, explore their technical characteristics and describe the limitations that should be taken into consideration when clinical decisions are made
Development of an initiatives package to increase children’s vegetable intake in long day care centres using the Multiphase Optimisation Strategy (MOST) randomised factorial experiment
Abstract
Objective:
To inform a package of initiatives to increase children’s vegetable intake while in long day care (LDC) by evaluating the independent and combined effects of three initiatives targeting food provision, the mealtime environment and the curriculum.
Design:
Using the Multiphase Optimisation Strategy (MOST) framework, a 12-week, eight-condition (n 7 intervention, n 1 control) randomised factorial experiment was conducted. Children’s dietary intake data were measured pre- and post-initiative implementation using the weighed plate waste method (1× meal and 2× between-meal snacks). Vegetable intake (g/d) was calculated from vegetable provision and waste. The optimal combination of initiatives was determined using a linear mixed-effects model comparing between-group vegetable intake at follow-up, while considering initiative fidelity and acceptability.
Setting:
LDC centres in metropolitan Adelaide, South Australia.
Participants:
32 centres, 276 staff and 1039 children aged 2–5 years.
Results:
There were no statistically significant differences between any of the intervention groups and the control group for vegetable intake (all P > 0·05). The curriculum with mealtime environment group consumed 26·7 g more vegetables/child/day than control (ratio of geometric mean 3·29 (95 % CI 0·96, 11·27), P = 0·06). Completion rates for the curriculum (> 93 %) and mealtime environment (61 %) initiatives were high, and acceptability was good (4/5 would recommend), compared with the food provision initiative (0–50 % completed the menu assessment, 3/5 would recommend).
Conclusion:
A programme targeting the curriculum and mealtime environment in LDC may be useful to increase children’s vegetable intake. Determining the effectiveness of this optimised package in a randomised controlled trial is required, as per the evaluation phase of the MOST framework
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Hundreds of genetic barcodes of the species-rich hydroid superfamily Plumularioidea (Cnidaria, Medusozoa) provide a guide toward more reliable taxonomy
Marine hydroids are important benthic components of shallow and deep waters worldwide, but their taxonomy is controversial because diagnostic morphological characters to categorize taxa are limited. Their genetic relationships are also little investigated. We tested taxonomic hypotheses within the highly speciose superfamily Plumularioidea by integrating a classical morphological approach with DNA barcoding of the 16S and COI mitochondrial markers for 659 and 196 specimens of Plumularioidea, respectively. Adding Genbank sequences, we inferred systematic relationships among 1,114 plumularioids, corresponding to 123 nominal species and 17 novel morphospecies in five families of Plumularioidea. We found considerable inconsistencies in the systematics of nominal families, genera and species. The families Kirchenpaueriidae and Plumulariidae were polyphyletic and the Halopterididae paraphyletic. Most genera of Plumularioidea are not monophyletic. Species diversity is considerably underestimated. Within our study, at least 10% of the morphologically-distinctive morphospecies are undescribed, and about 40% of the overall species richness is represented by cryptic species. Convergent evolution and morphological plasticity therefore blur systematic relationships. Additionally, cryptic taxa occur frequently in sympatry or parapatry, complicating correspondence with type material of described species. Sometimes conspecificity of different morphotypes was found. The taxonomy of hydroids requires continued comprehensive revision.This work relied on several hydrozoan samples collected from various sites, with the aid of many people. Supplementary Table S1 refers many of the people involved in the collection and/or preservation of the samples. C.J.M. acknowledges his great buddy-divers Jaime N.-Ruiz (CIMAR, Univ. Costa Rica), Axel Calderon, Nathaniel Chu, Eleni Petrou (STRI, Smiths. Inst.), Hanae Spathias, Karen Koltes (at the Belize station, Smith. Inst.), Freya Sommer (Hopkins Marine Station), Remilson Ferreira ('Costa Norte', Sao Tome), Frederico Cardigos (DOP, Univ. Azores) and others that assisted the dives. C.J.M. also acknowledges Rita Castillo (CIMAR, Univ. Costa Rica), Plinio Gondola, Ligia Calderon, Laura Geyer, Maria Castillo (STRI, Smiths. Inst.), Gregory Ruiz (SERC, Smiths. Inst.), Paul Greenhall, William Keel (MSC, Smith. Inst.), Manuel Enes, Valentina Matos (IMAR/DOP, Univ. Azores), Filipe Porteiro, Joao Goncalves (OKEANOS/IMAR, Univ. Azores), Marina Cunha, Ascensao Ravara (CESAM, Univ. Aveiro), Shirley Pomponi (Harbor Branch, Florida Atlantic Univ.), Estrela Matilde (Fundacao Principe Trust), Monica Albuquerque, Ines Tojeira (EMEPC), Diana Carvalho (Nat. Mus. Nat. Hist., Lisbon) and many others colleagues that facilitated the morphologic classifications and deposition of the samples. Peter Schuchert (Mus. d'Hist. Nat. Geneve) kindly provided some DNA extractes. Todd Kincaid and his team of GUE divers (Project Baseline - Azores) collected valuable samples from unusual depths. Joana Boavida (CIIMAR, Univ. Algarve) facilitated some samples of the 'DeepReefs' project. Jim Drewery (Marine Scotland Science Inst.) also provided few samples. Dale Calder (Royal Ontario Museum) provided some bibliography to C.J.M. and discussed/resolved some dubios taxonomic classifications. Colleagues at the L.A.B. (NMNH, Smith. Inst.) were very supportive. The APC fees for open access publication were supported by a program of the Regional Government of the Azores ("Apoio ao funcionamento e gestao dos centros de I&D regionais: 2018 - DRCT-medida 1
Crescimento e acúmulo de fósforo pela soja cultivada em sucessão a diferentes gramíneas forrageiras adubadas com super fosfato triplo e fosfato reativo de arad
Identifying Where REDD+ Financially Out Competes Oil Palm in Floodplain Landscapes Using a Fine-Scale Approach
Reducing Emissions from Deforestation and forest Degradation (REDD+) aims to avoid forest conversion to alternative land-uses through financial incentives. Oil-palm has high opportunity costs, which according to current literature questions the financial competitiveness of REDD+ in tropical lowlands. To understand this more, we undertook regional finescale and coarse-scale analyses (through carbon mapping and economic modelling) to assess the financial viability of REDD+ in safeguarding unprotected forest (30,173 ha) in the Lower Kinabatangan floodplain in Malaysian Borneo. Results estimate 4.7 million metric tons of carbon (MgC) in unprotected forest, with 64% allocated for oil-palm cultivations. Through fine-scale mapping and carbon accounting, we demonstrated that REDD+ can outcompete oil-palm in regions with low suitability, with low carbon prices and low carbon stock. In areas with medium oil-palm suitability, REDD+ could outcompete oil palm in areas
with: very high carbon and lower carbon price; medium carbon price and average carbon stock; or, low carbon stock and high carbon price. Areas with high oil palm suitability, REDD + could only outcompete with higher carbon price and higher carbon stock. In the coarse-scale model, oil-palm outcompeted REDD+ in all cases. For the fine-scale models at the landscape level, low carbon offset prices (US 27 million to secure these areas for 25 years. Higher carbon offset price (US 380–416 million in carbon financing. REDD+ has been identified as a strategy to mitigate climate change by many countries (including Malaysia). Although REDD+ in certain scenarios cannot outcompete oil palm, this research contributes to the global REDD+ debate by: highlighting REDD+ competitiveness in tropical floodplain landscapes; and, providing a robust approach for identifying and targeting limited REDD+ funds
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