713 research outputs found
Two-dimensional echocardiographic spectrum of univentricular atrioventricular connection
The spectrum of anomalies in hearts having a univentricular atrioventricular (AV) connection was examined by two-dimensional echocardiography in 183 patients and the anatomic findings were compared with angiography. The mode of AV connection was found to be of three types: 1) double inletvia two A V valves; 2) singleinlet via one AV valve with absence of the other (left or right AV valve atresia); and 3) common inletvia a common AV valve. Identification of an accessory chamber by two-dimensional echocardiography was possible with 90% sensitivity, but it was limited compared with angiography in patients with severely hypoplastic anterior Chambers and pulmonary valve atresia. All patients with subaortic outlet foramen obstruction were detected. Great artery position and the presence of obstruction to pulmonary flow were correctly predicted in all but one patient. Two-dimensional echocardiography was superior to angiography for the detection of AV valve abnormalities which were present in 27% and included abnormal chordae, hypoplasia or dysplasia of either valve. Two-dimensional echocardiography should play an essential role in the complete preoperative assessment of patients with univentricular AV connection
Quantum Monte Carlo calculations of nuclei
We report on quantum Monte Carlo calculations of the ground and low-lying
excited states of nuclei using realistic Hamiltonians containing the
Argonne two-nucleon potential alone or with one of several
three-nucleon potentials, including Urbana IX and three of the new Illinois
models. The calculations begin with correlated many-body wave functions that
have an -like core and multiple p-shell nucleons, -coupled to the
appropriate quantum numbers for the state of interest. After
optimization, these variational trial functions are used as input to a Green's
function Monte Carlo calculation of the energy, using a constrained path
algorithm. We find that the Hamiltonians that include Illinois three-nucleon
potentials reproduce ten states in Li, Be, Be, and B with
an rms deviation as little as 900 keV. In particular, we obtain the correct
3 ground state for B, whereas the Argonne alone or with
Urbana IX predicts a 1 ground state. In addition, we calculate isovector
and isotensor energy differences, electromagnetic moments, and one- and
two-body density distributions.Comment: 28 pages, 12 tables, 7 figure
Level structure of 99Nb
The β decay of 97Sr to 97Y has been investigated using ion-guide on-line mass separation and a 10 Ge-detector array to record γ−γ coincidences to a detection limit well below that of former studies. Similarities are found in the β-decay patterns of 99Zr and of its isotone 97Sr and also in the γ-ray decay rates and branchings of the corresponding levels in their respective daughters 99Nb and 97Y. This indicates a persisting influence of the d5/2 neutron shell closure for 99Nb. The level structure of 99Nb and the β-feeding pattern are discussed in the frame of the interacting boson-fermion plus broken pair model and the microscopic quasiparticle phonon model
No Adverse Effect of Genetically Modified Antifungal Wheat on Decomposition Dynamics and the Soil Fauna Community – A Field Study
The cultivation of genetically modified (GM) plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b) and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C∶N ratio, lignin, cellulose, hemicellulose) were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina), springtails (Isotomidae), annelids (Enchytraeidae) and Diptera (Cecidomyiidae larvae). Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM wheat on the composition and the activity of the soil fauna community
Increased Resistance of Bt Aspens to Phratora vitellinae (Coleoptera) Leads to Increased Plant Growth under Experimental Conditions
One main aim with genetic modification (GM) of trees is to produce plants that are resistant to various types of pests. The effectiveness of GM-introduced toxins against specific pest species on trees has been shown in the laboratory. However, few attempts have been made to determine if the production of these toxins and reduced herbivory will translate into increased tree productivity. We established an experiment with two lines of potted aspens (Populus tremula×Populus tremuloides) which express Bt (Bacillus thuringiensis) toxins and the isogenic wildtype (Wt) in the lab. The goal was to explore how experimentally controlled levels of a targeted leaf beetle Phratora vitellinae (Coleoptera; Chrysomelidae) influenced leaf damage severity, leaf beetle performance and the growth of aspen. Four patterns emerged. Firstly, we found clear evidence that Bt toxins reduce leaf damage. The damage on the Bt lines was significantly lower than for the Wt line in high and low herbivory treatment, respectively. Secondly, Bt toxins had a significant negative effect on leaf beetle survival. Thirdly, the significant decrease in height of the Wt line with increasing herbivory and the relative increase in height of one of the Bt lines compared with the Wt line in the presence of herbivores suggest that this also might translate into increased biomass production of Bt trees. This realized benefit was context-dependent and is likely to be manifested only if herbivore pressure is sufficiently high. However, these herbivore induced patterns did not translate into significant affect on biomass, instead one Bt line overall produced less biomass than the Wt. Fourthly, compiled results suggest that the growth reduction in one Bt line as indicated here is likely due to events in the transformation process and that a hypothesized cost of producing Bt toxins is of subordinate significance
Research Methodologies and Business Discourse Teaching
This chapter will:; ; ; Define English for specific purposes and indicate the specific ways in which it has been influential on business discourse teaching;; ; ; Discuss the most relevant approaches to genre analysis that have been used in business discourse teaching;; ; ; Explore the most relevant approaches to critical discourse analysis and organizational rhetoric for business discourse teaching;; ; ; Identify the most relevant aspects of multimodal discourse analysis for business discourse teaching;; ; ; Provide a case study that illustrates the use of one approach to business discourse teaching, showing how practitioners can incorporate it into their classroom- or consultancy-based ideas
Inconsistent impacts of decomposer diversity on the stability of aboveground and belowground ecosystem functions
The intensive discussion on the importance of biodiversity for the stability of essential processes in ecosystems has prompted a multitude of studies since the middle of the last century. Nevertheless, research has been extremely biased by focusing on the producer level, while studies on the impacts of decomposer diversity on the stability of ecosystem functions are lacking. Here, we investigate the impacts of decomposer diversity on the stability (reliability) of three important aboveground and belowground ecosystem functions: primary productivity (shoot and root biomass), litter decomposition, and herbivore infestation. For this, we analyzed the results of three laboratory experiments manipulating decomposer diversity (1–3 species) in comparison to decomposer-free treatments in terms of variability of the measured variables. Decomposer diversity often significantly but inconsistently affected the stability of all aboveground and belowground ecosystem functions investigated in the present study. While primary productivity was mainly destabilized, litter decomposition and aphid infestation were essentially stabilized by increasing decomposer diversity. However, impacts of decomposer diversity varied between plant community and fertility treatments. There was no general effect of the presence of decomposers on stability and no trend toward weaker effects in fertilized communities and legume communities. This indicates that impacts of decomposers are based on more than effects on nutrient availability. Although inconsistent impacts complicate the estimation of consequences of belowground diversity loss, underpinning mechanisms of the observed patterns are discussed. Impacts of decomposer diversity on the stability of essential ecosystem functions differed between plant communities of varying composition and fertility, implicating that human-induced changes of biodiversity and land-use management might have unpredictable effects on the processes mankind relies on. This study therefore points to the necessity of also considering soil feedback mechanisms in order to gain a comprehensive and holistic understanding of the impacts of current global change phenomena on the stability of essential ecosystem functions
Landscape homogenization due to agricultural intensification disrupts the relationship between reproductive success and main prey abundance in an avian predator
Selecting high-quality habitat and the optimal time to reproduce can increase individual fitness and is a strong evolutionary factor shaping animal populations. However, few studies have investigated the interplay between land cover heterogeneity, limitation in food resources, individual quality and spatial variation in fitness parameters. Here, we explore how individuals of different quality respond to possible mismatches between a cue for prey availability (land cover heterogeneity) and the actual fluctuating prey abundance.Peer reviewe
Performance of the electromagnetic and hadronic prototype segments of the ALICE Forward Calorimeter
We present the performance of a full-length prototype of the ALICE Forward
Calorimeter (FoCal). The detector is composed of a silicon-tungsten
electromagnetic sampling calorimeter with longitudinal and transverse
segmentation (FoCal-E) of about 20 and a hadronic
copper-scintillating-fiber calorimeter (FoCal-H) of about 5.
The data were taken between 2021 and 2023 at the CERN PS and SPS beam lines
with hadron (electron) beams up to energies of 350 (300) GeV. Regarding
FoCal-E, we report a comprehensive analysis of its response to minimum ionizing
particles across all pad layers. The longitudinal shower profile of
electromagnetic showers is measured with a layer-wise segmentation of 1.
As a projection to the performance of the final detector in electromagnetic
showers, we demonstrate linearity in the full energy range, and show that the
energy resolution fulfills the requirements for the physics needs.
Additionally, the performance to separate two-showers events was studied by
quantifying the transverse shower width. Regarding FoCal-H, we report a
detailed analysis of the response to hadron beams between 60 and 350 GeV. The
results are compared to simulations obtained with a Geant4 model of the test
beam setup, which in particular for FoCal-E are in good agreement with the
data. The energy resolution of FoCal-E was found to be lower than 3% at
energies larger than 100 GeV. The response of FoCal-H to hadron beams was found
to be linear, albeit with a significant intercept that is about factor 2 larger
than in simulations. Its resolution, which is non-Gaussian and generally larger
than in simulations, was quantified using the FWHM, and decreases from about
16% at 100 GeV to about 11% at 350 GeV. The discrepancy to simulations, which
is particularly evident at low hadron energies, needs to be further
investigated.Comment: 55 pages (without acronyms), 45 captioned figure
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