1,209 research outputs found
Use of satellite images for broad-scale modelling of conservation areas for wolves in the Carpathian Mountains, central Europe
This study analysed the spatial structure of the Carpathian Mountains, in Central Europe, considering it a unit that extends across national boundaries, and assessing the suitability of areas were wolves could be conserved. Physical characteristics of the area were extracted from NOAA-AVHRR NDVI. A set of 9 images from different periods of the year was used to parameterise the phenological variability of the area. Digital maps of road networks, human settlements and a DEM were integrated in a GIS. Locations of wolf presence
were used to extract “optimal” environmental characteristics that served as reference for estimating the degree of suitability over the whole area. Results show that most of the Carpathian Mountains are highly suitable for the wolf and that highly suitable areas are actually inhabited by the present population of wolf. These are also the area most phenologically stable
One-loop effective potential in M4 x T2 with and without 't Hooft flux
We review the basic notions of compactification in the presence of a
background flux. In extra-dimentional models with more than five dimensions,
Scherk and Schwarz boundary conditions have to satisfy 't Hooft consistency
conditions. Different vacuum configurations can be obtained, depending whether
trivial or non-trivial 't Hooft flux is considered. The presence of the
"magnetic" background flux provide, in addition, a mechanism for producing
four-dimensional chiral fermions. Particularizing to the six-dimensional case,
we calculate the one-loop effective potential for a U(N) gauge theory on M4 x
T2. We firstly review the well known results of the trivial 't Hooft flux case,
where one-loop contributions produce the usual Hosotani dynamical symmetry
breaking. Finally we applied our result for describing, for the first time, the
one-loop contributions in the non-trivial 't Hooft flux case
P2O5-free cerium containing glasses: Bioactivity and cytocompatibility evaluation
(1) Background: valuation of the bioactivity and cytocompatibility of P2O5-free and CeO2 doped glasses. (2) Methods: all glasses are based on the Kokubo (K) composition and prepared by a melting method. Doped glassed, K1.2, K3.6 and K5.3 contain 1.2, 3.6, and 5.3 mol% of CeO2. Bioactivity and cytotoxicity tests were carried out in simulated body fluid (SBF) solution and murine osteocyte (MLO-Y4) cell lines, respectively. Leaching of ions concentration in SBF was determined by inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). The surface of the glasses were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. (3) Results: P2O5-free cerium doped glasses are proactive according to European directives. Cerium increases durability and retards, but does not inhibit, (Ca10(PO4)6(OH)2, HA) formation at higher cerium amounts (K3.6 and K5.3); however, cell proliferation increases with the amount of cerium especially evident for K5.3. (4) Conclusions: These results enforce the use of P2O5-free cerium doped bioactive glasses as a new class of biomaterials
Recommended from our members
A role for independent peer review: reflections on the gateway review process
Healthcare organisations face constant pressure to change in order to pursue quality and performance improvements. As a result, professionals are often said to be experiencing change fatigue. This can be problematic for policy implementation initiatives. This paper reflects on an informal Gateway Review of Leicester, Leicestershire and Rutland's Integrated Point of Access Programme to make the case for independent peer review of healthcare management change programmes in order to work towards reducing change fatigue and its impacts. Peer review has been identified as an effective but underused process across health and social care provision and management. With this in mind, the Gateway Review outlined here is used to exemplify some of the practical benefits and challenges of external peer review. Based on this experience, a number of learning points and recommendations are outlined for those undertaking or thinking about undertaking peer review in healthcare management
Non-vascular interventional procedures: effective dose to patient and equivalent dose to abdominal organs by means of dicom images and Monte Carlo simulation
This study evaluates X-ray exposure in patient undergoing abdominal extra-vascular interventional procedures by means of Digital Imaging and COmmunications in Medicine (DICOM) image headers and Monte Carlo simulation. The main aim was to assess the effective and equivalent doses, under the hypothesis of their correlation with the dose area product (DAP) measured during each examination. This allows to collect dosimetric information about each patient and to evaluate associated risks without resorting to in vivo dosimetry. The dose calculation was performed in 79 procedures through the Monte Carlo simulator PCXMC (A PC-based Monte Carlo program for calculating patient doses in medical X-ray examinations), by using the real geometrical and dosimetric irradiation conditions, automatically extracted from DICOM headers. The DAP measurements were also validated by using thermoluminescent dosimeters on an anthropomorphic phantom. The expected linear correlation between effective doses and DAP was confirmed with an R(2) of 0.974. Moreover, in order to easily calculate patient doses, conversion coefficients that relate equivalent doses to measurable quantities, such as DAP, were obtained
Inflammatory Responses and Barrier Function of Endothelial Cells Derived from Human Induced Pluripotent Stem Cells
Several studies have reported endothelial cell (EC) derivation from human induced pluripotent stem cells (hiPSCs). However, few have explored their functional properties in depth with respect to line-to-line and batch-to-batch variability and how they relate to primary ECs. We therefore carried out accurate characterization of hiPSC-derived ECs (hiPSC-ECs) from multiple (non-integrating) hiPSC lines and compared them with primary ECs in various functional assays, which included barrier function using real-time impedance spectroscopy with an integrated assay of electric wound healing, endothelia-leukocyte interaction under physiological flow to mimic inflammation and angiogenic responses in in vitro and in vivo assays. Overall, we found many similarities but also some important differences between hiPSC-derived and primary ECs. Assessment of vasculogenic responses in vivo showed little difference between primary ECs and hiPSC-ECs with regard to functional blood vessel formation, which may be important in future regenerative medicine applications requiring vascularization. In this article, Orlova and colleagues show that hiPSC-ECs have similar features to primary ECs but also show some differences. hiPSC-ECs exhibited higher barrier function, lower expression of pro-inflammatory adhesive receptors, and more stringent stromal cell requirements. Importantly, healthy control CD31+ hiPSC-ECs showed high consistency between different batches and lines, forming a good basis for disease modeling applications
Innovative strategy for polyhydroxyalkanoates recovery from mixed microbial cultures. Effects of aqueous phase and solvent extraction on polymer properties
This work aimed to investigate various methods of polyhydroxyalkanoates (PHA) extraction and to optimize the recovery in the view of reducing solvents’ use and waste. The extraction tests were applied on PHA-rich biomass collected at the end of the accumulation step, conducted both at pilot and lab scale. PHA-rich biomass obtained from the lab scale process was produced from synthetic feedstock (mixture of acetic and propionic acids), while fermented organic waste was used for PHA production at pilot scale. In the extraction tests, different solutions of NaOH, also in combination with a surfactant (sodium dodecyl sulfate, SDS), were used to recover the polymer from the non-polymeric cellular material (NPCM). Different times (3, 6 and 24 h) and concentrations (0.05 – 1 M) were tested, evaluating also the effect of adding SDS (0.1 % w/v). As a benchmark, solvent extraction with chloroform and oxidation with NaClO were also conducted. Finally, extracted samples were characterized through several techniques: DSC, TGA, GC-FID, capillary viscosimetry. Alkaline treatment at short times and low concentrations resulted to be more efficient in terms of purity (85 – 99 % w/w PHA) and recovery (higher than 80 % w/w), than higher concentration. On the other hand, the presence of SDS had dramatic effects on the recovery (lower than 50 % w/w) and also on the molecular weight, which was two folds lower than that obtained from alkaline extraction. Overall, extraction with aqueous phase reagents had no effects on thermal properties, which resulted to be in the range of those reported in literature
Tissue-specific deregulation of selected HDACs characterizes ALS progression in mouse models: pharmacological characterization of SIRT1 and SIRT2 pathways
Acetylation homeostasis is thought to play a role in amyotrophic lateral sclerosis, and treatment with inhibitors of histone deacetylases has been considered a potential and attractive therapeutic approach, despite the lack of a thorough study of this class of proteins. In this study, we have considerably extended previous knowledge on the expression of 13 histone deacetylases in tissues (spinal cord and muscle) from mice carrying two different ALS-linked SOD1 mutations (G93A-SOD1 and G86R-SOD1). We have then focused on class III histone deacetylases SIRT1 and SIRT2 that are considered relevant in neurodegenerative diseases. SIRT1 decreases in the spinal cord, but increases in muscle during the progression of the disease, and a similar expression pattern is observed in the corresponding cell models (neuroblastoma and myoblasts). SIRT2 mRNA expression increases in the spinal cord in both G93A-SOD1 and G86R-SOD1 mice but protein expression is substantially unchanged in all the models examined. At variance with other sirtuin modulators (sirtinol, AGK2 and SRT1720), the well-known SIRT1 inhibitor Ex527 has positive effects on survival of neuronal cells expressing mutant SOD1, but this effect is neither mediated by SIRT1 inhibition nor by SIRT2 inhibition. These data call for caution in proposing sirtuin modulation as a target for treatment
Next-to-leading-order QCD Corrections to Higgs Production in association with a Jet
We compute the next-to-leading-order (NLO) QCD corrections to the Higgs pT
distribution in Higgs production in association with a jet via gluon fusion at
the LHC, with exact dependence on the mass of the quark circulating in the
heavy-quark loops. The NLO corrections are presented including the top-quark
mass, and for the first time, the bottom-quark mass as well. Further, besides
the on-shell mass scheme, we consider for the first time a running mass
renormalisation scheme. The computation is based on amplitudes which are valid
for arbitrary heavy-quark masses.Comment: LaTeX, 7 pages, 5 figure
- …