1,885 research outputs found
Comment on "Regularizing capacity of metabolic networks"
In a recent paper, Marr, Muller-Linow and Hutt [Phys. Rev. E 75, 041917
(2007)] investigate an artificial dynamic system on metabolic networks. They
find a less complex time evolution of this dynamic system in real networks,
compared to networks of reference models. The authors argue that this suggests
that metabolic network structure is a major factor behind the stability of
biochemical steady states. We reanalyze the same kind of data using a dynamic
system modeling actual reaction kinetics. The conclusions about stability, from
our analysis, are inconsistent with those of Marr et al. We argue that this
issue calls for a more detailed type of modeling
Investigating the Effect of Stratospheric Radiation on Seed Germination and Growth
Three seed types: bean (Phaseolus vulgaris), corn (Zea mays) and radish (Raphanus sativus) were flown in a high altitude weather balloon into the mid-stratosphere to investigate the effects of high altitude radiation on germination success and seedling growth. After recovering and planting the seeds, the bean seeds showed lower germination success with exposure to high altitude radiation, and consequently stunted seedling growth. Cord and radish seeds experienced a statistically significant positive effect on germination success form radiation exposure compared to control seeds, but negative effect on seedling growth. Overall, the field experiments presented here support laboratory studies that show radiation exposure on vegetable seeds has a mixed effect on the germination success and negative effect on seedling growth on investigated seed types
Clinical and functional characterisation of a novel TNFRSF1A c.605T > A/V173D cleavage site mutation associated with tumour necrosis factor receptor-associated periodic fever syndrome (TRAPS), cardiovascular complications and excellent response to etanercept treatment.
Objectives: To study the clinical outcome, treatment
response, T-cell subsets and functional consequences of a
novel tumour necrosis factor (TNF) receptor type 1
(TNFRSF1A) mutation affecting the receptor
cleavage site.
Methods: Patients with symptoms suggestive of tumour
necrosis factor receptor-associated periodic syndrome
(TRAPS) and 22 healthy controls (HC) were screened for
mutations in the TNFRSF1A gene. Soluble TNFRSF1A and
inflammatory cytokines were measured by ELISAs.
TNFRSF1A shedding was examined by stimulation of
peripheral blood mononuclear cells (PBMCs) with phorbol
12-myristate 13-acetate followed by flow cytometric
analysis (FACS). Apoptosis of PBMCs was studied by
stimulation with TNFa in the presence of cycloheximide
and annexin V staining. T cell phenotypes were monitored
by FACS.
Results: TNFRSF1A sequencing disclosed a novel V173D/
p.Val202Asp substitution encoded by exon 6 in one
family, the c.194–14G.A splice variant in another and
the R92Q/p.Arg121Gln substitution in two families.
Cardiovascular complications (lethal heart attack and
peripheral arterial thrombosis) developed in two V173D
patients. Subsequent etanercept treatment of the V173D
carriers was highly effective over an 18-month follow-up
period. Serum TNFRSF1A levels did not differ between
TRAPS patients and HC, while TNFRSF1A cleavage from
monocytes was significantly reduced in V173D and R92Q
patients. TNFa-induced apoptosis of PBMCs and T-cell
senescence were comparable between V173D patients
and HC.
Conclusions: The TNFRSF1A V173D cleavage site
mutation may be associated with an increased risk for
cardiovascular complications and shows a strong
response to etanercept. T-cell senescence does not seem
to have a pathogenetic role in affected patients
First report of bacterial spot caused by Xanthomonas cucurbitae on pumpkin in Italy
In 2018, a disease outbreak was observed on pumpkin (Cucurbita moschata cv. Violina) in the municipality of Reggio Emilia (Northern Italy). Symptoms were observed on leaves and fruits
Ice thickness measurements and volume estimates for glaciers in Norway
Glacier volume and ice thickness distribution are important variables for water resource management in Norway and the assessment of future glacier changes. We present a detailed assessment of thickness distribution and total glacier volume for mainland Norway based on data and modelling. Glacier outlines from a Landsat-derived inventory from 1999 to 2006 covering an area of 2692 ± 81 km² were used as input. We compiled a rich set of ice thickness observations collected over the past 30 years. Altogether, interpolated ice thickness measurements were available for 870 km² (32%) of the current glacier area of Norway, with a total ice volume of 134 ± 23 km³. Results indicate that mean ice thickness is similar for all larger ice caps, and weakly correlates with their total area. Ice thickness data were used to calibrate a physically based distributed model for estimating the ice thickness of unmeasured glaciers. The results were also used to calibrate volume–area scaling relations. The calibrated total volume estimates for all Norwegian glaciers ranged from 257 to 300 km³
Genetic relationships between chondrules, rims and matrix.
Published versio
NNLO QCD corrections to event orientation in e+e- annihilation
We present a new implementation of the NNLO QCD corrections to three-jet final states and related event-shape observables in electron–positron annihilation. Our implementation is based on the antenna subtraction method, and is performed in the NNLOjet framework. The calculation improves upon earlier results by taking into account the full kinematical information on the initial state momenta, thereby allowing the event orientation to be computed to NNLO accuracy. We find the event-orientation distributions at LEP and SLC to be very robust under higher order QCD corrections
Constraining regional glacier reconstructions using past ice thickness of deglaciating areas – a case study in the European Alps
In order to assess future glacier evolution and
meltwater runoff, accurate knowledge on the volume and the ice thickness
distribution of glaciers is crucial. However, in situ observations of
glacier thickness are sparse in many regions worldwide due to the difficulty
of undertaking field surveys. This lack of in situ measurements can be
partially overcome by remote-sensing information. Multi-temporal and
contemporaneous data on glacier extent and surface elevation provide past
information on ice thickness for retreating glaciers in the newly
deglacierized regions. However, these observations are concentrated near the
glacier snouts, which is disadvantageous because it is known to introduce
biases in ice thickness reconstruction approaches. Here, we show a strategy
to overcome this generic limitation of so-called retreat thickness
observations by applying an empirical relationship between the ice viscosity
at locations with in situ observations and observations from digital elevation model (DEM) differencing at the glacier margins. Various datasets from the European
Alps are combined to model the ice thickness distribution of Alpine glaciers
for two time steps (1970 and 2003) based on the observed thickness in regions
uncovered from ice during the study period. Our results show that the
average ice thickness would be substantially underestimated (∼ 40 %) when relying solely on thickness observations from previously
glacierized areas. Thus, a transferable topography-based viscosity scaling
is developed to correct the modelled ice thickness distribution. It is shown
that the presented approach is able to reproduce region-wide glacier
volumes, although larger uncertainties remain at a local scale, and thus might
represent a powerful tool for application in regions with sparse
observations.</p
Grapevine fanleaf virus detection in various grapevine organs using polyclonal and monoclonal antibodies
Monoclonal antibodies prepared with grapevine fanleaf virus (GFV) are useful for detecting the virus in plant extracts. In this paper we describe comparisons between different ELISA techniques using rabbit and chicken immunoglobulins as weil as monoclonal antibodies (MCA). The technique using chicken immunoglobulins for coating the plates followed by MCA and goat anti-mouse phosphatase conjugate was the best one for detecting GFV in plant sap. In this technique, ascitic fluids containing MCA could be diluted up to 10-6. Our experiments clearly demonstrate that the detection of GFV is possible in grapevine not only from leaves or rootlets, but also from wood shavings, without grinding them. We replaced the classical nicotine containing extraction medium by a harmless phosphate or Tris-HCl buffer. To detect GFV with these media it is essential that the buffer should contain polyvinylpyrrolidone and that its molarity should not be less than 0.1 M
Can Action Research Strengthen District Health Management and Improve Health Workforce Performance? A Research Protocol.
The single biggest barrier for countries in sub-Saharan Africa (SSA) to scale up the necessary health services for addressing the three health-related Millennium Development Goals and achieving Universal Health Coverage is the lack of an adequate and well-performing health workforce. This deficit needs to be addressed both by training more new health personnel and by improving the performance of the existing and future health workforce. However, efforts have mostly been focused on training new staff and less on improving the performance of the existing health workforce. The purpose of this paper is to disseminate the protocol for the PERFORM project and reflect on the key challenges encountered during the development of this methodology and how they are being overcome. The overall aim of the PERFORM project is to identify ways of strengthening district management in order to address health workforce inadequacies by improving health workforce performance in SSA. The study will take place in three districts each in Ghana, Tanzania and Uganda using an action research approach. With the support of the country research teams, the district health management teams (DHMTs) will lead on planning, implementation, observation, reflection and redefinition of the activities in the study. Taking into account the national and local human resource (HR) and health systems (HS) policies and practices already in place, 'bundles' of HR/HS strategies that are feasible within the context and affordable within the districts' budget will be developed by the DHMTs to strengthen priority areas of health workforce performance. A comparative analysis of the findings from the three districts in each country will add new knowledge on the effects of these HR/HS bundles on DHMT management and workforce performance and the impact of an action research approach on improving the effectiveness of the DHMTs in implementing these interventions. Different challenges were faced during the development of the methodology. These include the changing context in the study districts, competing with other projects and duties for the time of district managers, complexity of the study design, maintaining the anonymity and confidentiality of study participants as well as how to record the processes during the study. We also discuss how these challenges are being addressed. The dissemination of this research protocol is intended to generate interest in the PERFORM project and also stimulate discussion on the use of action research in complex studies such as this on strengthening district health management to improve health workforce performance
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