81 research outputs found
TOMOBFLOW: feature-preserving noise filtering for electron tomography
<p>Abstract</p> <p>Background</p> <p>Noise filtering techniques are needed in electron tomography to allow proper interpretation of datasets. The standard linear filtering techniques are characterized by a tradeoff between the amount of reduced noise and the blurring of the features of interest. On the other hand, sophisticated anisotropic nonlinear filtering techniques allow noise reduction with good preservation of structures. However, these techniques are computationally intensive and are difficult to be tuned to the problem at hand.</p> <p>Results</p> <p>TOMOBFLOW is a program for noise filtering with capabilities of preservation of biologically relevant information. It is an efficient implementation of the Beltrami flow, a nonlinear filtering method that locally tunes the strength of the smoothing according to an edge indicator based on geometry properties. The fact that this method does not have free parameters hard to be tuned makes TOMOBFLOW a user-friendly filtering program equipped with the power of diffusion-based filtering methods. Furthermore, TOMOBFLOW is provided with abilities to deal with different types and formats of images in order to make it useful for electron tomography in particular and bioimaging in general.</p> <p>Conclusion</p> <p>TOMOBFLOW allows efficient noise filtering of bioimaging datasets with preservation of the features of interest, thereby yielding data better suited for post-processing, visualization and interpretation. It is available at the web site <url>http://www.ual.es/%7ejjfdez/SW/tomobflow.html</url>.</p
Presence of depression and anxiety before and after coronary artery bypass graft surgery and their relationship to age
<p>Abstract</p> <p>Background</p> <p>Scientific literature on depression and anxiety in patients with coronary heart disease (CHD) consistently reports data of elevated anxiety and depression scores indicating clinically relevant quantities of these psychopathological conditions. Depression is considered to be a risk factor for the development of CHD and deteriorates the outcome after cardiac rehabilitation efforts. The aim of our study was to evaluate the presence of clinically relevant anxiety and depression in patients before and after coronary artery bypass grafting (CABG). Additionally we evaluated their relationship to age because of the increasing number of elderly patients undergoing CABG surgery.</p> <p>Methods</p> <p>One hundred and forty-two consecutive patients who underwent CABG in our hospital were asked to fill in the "Hospital Anxiety and Depression Scale – German Version (HADS)" to measure depression and anxiety scores two days before and ten days after CABG surgery. Differences between these pre- and post-surgical scores were then calculated as means for changes, and the amount of elevated scores were appraised. In order to investigate the relationship between age and anxiety and depression, respectively, Spearman correlations between age and the difference scores were calculated. In addition, ANOVA procedures with the factor "age group" and McNemar tests were calculated. Therefore the sample was divided into four equally sized age groups.</p> <p>Results</p> <p>25.8% of the patients were clinically depressed before and 17.5% after surgery; 34.0% of the patients were clinically anxious before and 24.7% after surgery. This overall change is not significant. We found a significant negative correlation between age and the difference between the two time points for anxiety (Spearman rho = -.218; p = 0.03), but not for depression (Spearman rho = -.128; p = 0.21). ANOVA and McNemar-Tests revealed that anxiety scores and the number of patients high in anxiety declined statistically meaningful only in the youngest patient group. Such a relationship could not be found for depression.</p> <p>Conclusion</p> <p>Our data show a relationship between age and anxiety. Younger patients are more anxious before CABG surgery than older ones and show a decline in symptoms while elderly patients show hardly any change.</p
Influence of Uranium on Bacterial Communities: A Comparison of Natural Uranium-Rich Soils with Controls
This study investigated the influence of uranium on the indigenous bacterial community structure in natural soils with high uranium content. Radioactive soil samples exhibiting 0.26% - 25.5% U in mass were analyzed and compared with nearby control soils containing trace uranium. EXAFS and XRD analyses of soils revealed the presence of U(VI) and uranium-phosphate mineral phases, identified as sabugalite and meta-autunite. A comparative analysis of bacterial community fingerprints using denaturing gradient gel electrophoresis (DGGE) revealed the presence of a complex population in both control and uranium-rich samples. However, bacterial communities inhabiting uraniferous soils exhibited specific fingerprints that were remarkably stable over time, in contrast to populations from nearby control samples. Representatives of Acidobacteria, Proteobacteria, and seven others phyla were detected in DGGE bands specific to uraniferous samples. In particular, sequences related to iron-reducing bacteria such as Geobacter and Geothrix were identified concomitantly with iron-oxidizing species such as Gallionella and Sideroxydans. All together, our results demonstrate that uranium exerts a permanent high pressure on soil bacterial communities and suggest the existence of a uranium redox cycle mediated by bacteria in the soil
Azacitidine front-line in 339 patients with myelodysplastic syndromes and acute myeloid leukaemia: comparison of French-American-British and World Health Organization classifications
A synthesis of past, current and future research for protection and management of papyrus (Cyperus papyrus L.) wetlands in Africa
Papyrus wetlands (dominated by the giant
sedge Cyperus papyrus L.) occur throughout eastern,
central and southern Africa and are important for
biodiversity, for water quality and quantity regulation
and for the livelihoods of millions of people. To draw
attention to the importance of papyrus wetlands, a
special session entitled ‘‘The ecology of livelihoods in
papyrus wetlands’’ was organized at the 9th INTECOL
Wetlands Conference in Orlando, Florida in June
2012. Papers from the session, combined with additional
contributions, were collected in a special issue
of Wetlands Ecology and Management. The current
paper reviews ecological and hydrological characteristics
of papyrus wetlands, summarizes their ecosystem
services and sustainable use, provides an
overview of papyrus research to date, and looks at
policy development for papyrus wetlands. Based on
this review, the paper provides a synthesis of research
and policy priorities for papyrus wetlands and introduces
the contributions in the special issue. Main
conclusions are that (1) there is a need for better
estimates of the area covered by papyrus wetlands.
Limited evidence suggests that the loss of papyrus
wetlands is rapid in some areas; (2) there is a need for a
better understanding and modelling of the regulating
services of papyrus wetlands to support trade-off
analysis and improve economic valuation; (3) research
on papyrus wetlands should include assessment of all
ecosystem services (provisioning, regulating, habitat,
cultural) so that trade-offs can be determined as the
basis for sustainable management strategies (‘wise
use’); (4) more research on the governance, institutional
and socio-economic aspects of papyrus wetlands
is needed to assist African governments in
dealing with the challenges of conserving wetlands in
the face of growing food security needs and climate
change. The papers in the special issue address a
number of these issues
A comprehensive overview of radioguided surgery using gamma detection probe technology
The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology
Contextualizing willingness to participate: recommendations for engagement, recruitment & enrolment of Kenyan MSM in future HIV prevention trials
A model of acceptance of augmented-reality interactive technology: the moderating role of cognitive innovativeness
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