333 research outputs found
Influence of reed beds (Phragmites australis) and submerged vegetation on pike (Esox lucius)
Eutrophication and reduced grazing have led to an expansion of the common reed (Phragmites australis) in ar-chipelago areas in the Baltic Sea, while at the same time the composition of submerged vegetation has changed. Although reed is important as nursery habitat for many fish species, extensive emergent vegetation may reduce biodiversity and abundance of predatory fish. Pike (Esox lucius) is a predatory fish whose larvae and young-of -the-year find both food and shelter in reed but use different micro-habitats during different life-stages. Here we investigate the influence of reed and submerged vegetation on abundance and body size of adult pike during the spawning season. We predicted that coastal bays with extensive but heterogeneous reed beds with higher cover of submerged vegetation would have more and larger pike than bays with smaller, homogenous reed belts or with less submerged vegetation. To test these predictions, we estimated abundance and size-structure of adult pike from catches in angling fishing among 22 bays in the Stockholm archipelago at the Swedish Baltic Sea coast. Our analyses show that catches of adult pike were positively associated with both extensive reed beds and cover of rooted submerged vegetation. However, pike size was not correlated with any vegetation variable, but instead increased with wave exposure and bay area. Our study suggests that reed beds and submerged vegetation are important for adult pike during the spawning season, and even the most extensive reed beds had no evident negative effect on pike populations. We could not see any clear relationship between emergent reed habitat and cover of submerged vegetation among the studied bays, and conclude that to maintain pike population during the spawning season it is important that coastal bays have sufficient amounts of both reed beds and rooted submerged vegetation
Temperature effects on dislocation core energies in silicon and germanium
Temperature effects on the energetics of the 90-degree partial dislocation in
silicon and germanium are investigated, using non-equilibrium methods to
estimate free energies, coupled with Monte Carlo simulations. Atomic
interactions are described by Tersoff and EDIP interatomic potentials. Our
results indicate that the vibrational entropy has the effect of increasing the
difference in free energy between the two possible reconstructions of the
90-degree partial, namely, the single-period and the double-period geometries.
This effect further increases the energetic stability of the double-period
reconstruction at high temperatures. The results also indicate that anharmonic
effects may play an important role in determining the structural properties of
these defects in the high-temperature regime.Comment: 8 pages in two-column physical-review format with six figure
Fraction of Inspired Oxygen During General Anesthesia for Non-Cardiac Surgery:Systematic Review and Meta-Analysis
BACKGROUND: Controversy exists regarding the effects of a high versus a low intraoperative fraction of inspired oxygen (FiO(2)) in adults undergoing general anesthesia. This systematic review and metaâanalysis investigated the effect of a high versus a low FiO(2) on postoperative outcomes. METHODS: PubMed and Embase were searched on March 22, 2022 for randomized clinical trials investigating the effect of different FiO(2) levels in adults undergoing general anesthesia for nonâcardiac surgery. Two investigators independently reviewed studies for relevance, extracted data, and assessed risk of bias. Metaâanalyses were performed for relevant outcomes, and potential effect measure modification was assessed in subgroup analyses and metaâregression. The evidence certainty was evaluated using GRADE. RESULTS: This review included 25 original trials investigating the effect of a high (mostly 80%) versus a low (mostly 30%) FiO(2). Risk of bias was intermediate for all trials. A high FiO(2) did not result in a significant reduction in surgical site infections (OR: 0.91, 95% CI 0.81â1.02 [p = .10]). No effect was found for all other included outcomes, including mortality (OR = 1.27, 95% CI: 0.90â1.79 [p = .18]) and hospital length of stay (mean difference = 0.03âdays, 95% CI â0.25 to 0.30 [p = .84). Results from subgroup analyses and metaâregression did not identify any clear effect modifiers across outcomes. The certainty of evidence (GRADE) was rated as low for most outcomes. CONCLUSIONS: In adults undergoing general anesthesia for nonâcardiac surgery, a high FiO(2) did not improve outcomes including surgical site infections, length of stay, or mortality. However, the certainty of the evidence was assessed as low
Goal-directed haemodynamic therapy during general anaesthesia for noncardiac surgery:a systematic review and meta-analysis
BACKGROUND: During general anaesthesia for noncardiac surgery, there remain knowledge gaps regarding the effect of goal-directed haemodynamic therapy on patient-centred outcomes. METHODS: Included clinical trials investigated goal-directed haemodynamic therapy during general anaesthesia in adults undergoing noncardiac surgery and reported at least one patient-centred postoperative outcome. PubMed and Embase were searched for relevant articles on March 8, 2021. Two investigators performed abstract screening, full-text review, data extraction, and bias assessment. The primary outcomes were mortality and hospital length of stay, whereas 15 postoperative complications were included based on availability. From a main pool of comparable trials, meta-analyses were performed on trials with homogenous outcome definitions. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). RESULTS: The main pool consisted of 76 trials with intermediate risk of bias for most outcomes. Overall, goal-directed haemodynamic therapy might reduce mortality (odds ratio=0.84; 95% confidence interval [CI], 0.64 to 1.09) and shorten length of stay (mean difference=â0.72 days; 95% CI, â1.10 to â0.35) but with low certainty in the evidence. For both outcomes, larger effects favouring goal-directed haemodynamic therapy were seen in abdominal surgery, very high-risk surgery, and using targets based on preload variation by the respiratory cycle. However, formal tests for subgroup differences were not statistically significant. Goal-directed haemodynamic therapy decreased risk of several postoperative outcomes, but only infectious outcomes and anastomotic leakage reached moderate certainty of evidence. CONCLUSIONS: Goal-directed haemodynamic therapy during general anaesthesia might decrease mortality, hospital length of stay, and several postoperative complications. Only infectious postoperative complications and anastomotic leakage reached moderate certainty in the evidence
Tracking uncertainties in the causal chain from human activities to climate
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95537/1/grl25489.pd
ISO's Contribution to the Study of Clusters of Galaxies
Starting with nearby galaxy clusters like Virgo and Coma, and continuing out
to the furthest galaxy clusters for which ISO results have yet been published
(), we discuss the development of knowledge of the infrared and
associated physical properties of galaxy clusters from early IRAS observations,
through the "ISO-era" to the present, in order to explore the status of ISO's
contribution to this field. Relevant IRAS and ISO programmes are reviewed,
addressing both the cluster galaxies and the still-very-limited evidence for an
infrared-emitting intra-cluster medium. ISO made important advances in
knowledge of both nearby and distant galaxy clusters, such as the discovery of
a major cold dust component in Virgo and Coma cluster galaxies, the elaboration
of the correlation between dust emission and Hubble-type, and the detection of
numerous Luminous Infrared Galaxies (LIRGs) in several distant clusters. These
and consequent achievements are underlined and described. We recall that, due
to observing time constraints, ISO's coverage of higher-redshift galaxy
clusters to the depths required to detect and study statistically significant
samples of cluster galaxies over a range of morphological types could not be
comprehensive and systematic, and such systematic coverage of distant clusters
will be an important achievement of the Spitzer Observatory.Comment: 22 pages, 7 figures. Accepted for publication in Space Science
Reviews ISO Special Issue "ISO science legacy - a compact review of ISO major
achievements", Ed.C.Cesarky & A.Salama Updated 23 Aug. 2005 in order to
change some citations from astro-ph nos. to full Journal references after
they were publishe
Learn2Reg: comprehensive multi-task medical image registration challenge, dataset and evaluation in the era of deep learning
Image registration is a fundamental medical image analysis task, and a wide
variety of approaches have been proposed. However, only a few studies have
comprehensively compared medical image registration approaches on a wide range
of clinically relevant tasks. This limits the development of registration
methods, the adoption of research advances into practice, and a fair benchmark
across competing approaches. The Learn2Reg challenge addresses these
limitations by providing a multi-task medical image registration data set for
comprehensive characterisation of deformable registration algorithms. A
continuous evaluation will be possible at
https://learn2reg.grand-challenge.org. Learn2Reg covers a wide range of
anatomies (brain, abdomen, and thorax), modalities (ultrasound, CT, MR),
availability of annotations, as well as intra- and inter-patient registration
evaluation. We established an easily accessible framework for training and
validation of 3D registration methods, which enabled the compilation of results
of over 65 individual method submissions from more than 20 unique teams. We
used a complementary set of metrics, including robustness, accuracy,
plausibility, and runtime, enabling unique insight into the current
state-of-the-art of medical image registration. This paper describes datasets,
tasks, evaluation methods and results of the challenge, as well as results of
further analysis of transferability to new datasets, the importance of label
supervision, and resulting bias. While no single approach worked best across
all tasks, many methodological aspects could be identified that push the
performance of medical image registration to new state-of-the-art performance.
Furthermore, we demystified the common belief that conventional registration
methods have to be much slower than deep-learning-based methods
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