925 resultados para Picture and Image Generation
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The spread of antibiotic-resistant bacteria through food has become a major public health concern because some important human pathogens may be transferred via the food chain. Acinetobacter baumannii is one of the most life-threatening gram-negative pathogens; multidrug-resistant (MDR) clones of A. baumannii are spreading worldwide, causing outbreaks in hospitals. However, the role of raw meat as a reservoir of A. baumannii remains unexplored. In this study, we describe for the first time the antibiotic susceptibility and fingerprint (repetitive extragenic palindromic PCR [rep-PCR] profile and sequence types [STs]) of A. baumannii strains found in raw meat retailed in Switzerland. Our results indicate that A. baumannii was present in 62 (25.0%) of 248 (CI 95%: 19.7 to 30.9%) meat samples analyzed between November 2012 and May 2013, with those derived from poultry being the most contaminated (48.0% [CI 95%: 37.8 to 58.3%]). Thirty-nine strains were further tested for antibiotic susceptibility and clonality. Strains were frequently not susceptible (intermediate and/or resistant) to third- and fourth-generation cephalosporins for human use (i.e., ceftriaxone [65%], cefotaxime [32%], ceftazidime [5%], and cefepime [2.5%]). Resistance to piperacillin-tazobactam, ciprofloxacin, colistin, and tetracycline was sporadically observed (2.5, 2.5, 5, and 5%, respectively), whereas resistance to carbapenems was not found. The strains were genetically very diverse from each other and belonged to 29 different STs, forming 12 singletons and 6 clonal complexes (CCs), of which 3 were new (CC277, CC360, and CC347). RepPCR analysis further distinguished some strains of the same ST. Moreover, some A. baumannii strains from meat belonged to the clonal complexes CC32 and CC79, similar to the MDR isolates responsible for human infections. In conclusion, our findings suggest that raw meat represents a reservoir of MDR A. baumannii and may serve as a vector for the spread of these pathogens into both community and hospital settings.
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AIMS In this work, we provide novel insight into the morphology of dissecting abdominal aortic aneurysms in angiotensin II-infused mice. We demonstrate why they exhibit a large variation in shape and, unlike their human counterparts, are located suprarenally rather than infrarenally. METHODS AND RESULTS We combined synchrotron-based, ultra-high resolution ex vivo imaging (phase contrast X-Ray tomographic microscopy) with in vivo imaging (high-frequency ultrasound and contrast-enhanced micro-CT) and image-guided histology. In all mice, we observed a tear in the tunica media of the abdominal aorta near the ostium of the celiac artery. Independently we found that, unlike the gradual luminal expansion typical for human aneurysms, the outer diameter increase of angiotensin II-induced dissecting aneurysms in mice was related to one or several intramural haematomas. These were caused by ruptures of the tunica media near the ostium of small suprarenal side branches, which had never been detected by the established small animal imaging techniques. The tear near the celiac artery led to apparent luminal dilatation, while the intramural haematoma led to a dissection of the tunica adventitia on the left suprarenal side of the aorta. The number of ruptured branches was higher in those aneurysms that extended into the thoracic aorta, which explained the observed variability in aneurysm shape. CONCLUSION Our results are the first to describe apparent luminal dilatation, suprarenal branch ruptures, and intramural haematoma formation in dissecting abdominal aortic aneurysms in mice. Moreover, we validate and demonstrate the vast potential of phase contrast X-ray tomographic microscopy in cardiovascular small animal applications.
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Accurate three-dimensional (3D) models of lumbar vertebrae are required for image-based 3D kinematics analysis. MRI or CT datasets are frequently used to derive 3D models but have the disadvantages that they are expensive, time-consuming or involving ionizing radiation (e.g., CT acquisition). In this chapter, we present an alternative technique that can reconstruct a scaled 3D lumbar vertebral model from a single two-dimensional (2D) lateral fluoroscopic image and a statistical shape model. Cadaveric studies are conducted to verify the reconstruction accuracy by comparing the surface models reconstructed from a single lateral fluoroscopic image to the ground truth data from 3D CT segmentation. A mean reconstruction error between 0.7 and 1.4 mm was found.
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Automated identification of vertebrae from X-ray image(s) is an important step for various medical image computing tasks such as 2D/3D rigid and non-rigid registration. In this chapter we present a graphical model-based solution for automated vertebra identification from X-ray image(s). Our solution does not ask for a training process using training data and has the capability to automatically determine the number of vertebrae visible in the image(s). This is achieved by combining a graphical model-based maximum a posterior probability (MAP) estimate with a mean-shift based clustering. Experiments conducted on simulated X-ray images as well as on a low-dose low quality X-ray spinal image of a scoliotic patient verified its performance.
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In clinical practice, traditional X-ray radiography is widely used, and knowledge of landmarks and contours in anteroposterior (AP) pelvis X-rays is invaluable for computer aided diagnosis, hip surgery planning and image-guided interventions. This paper presents a fully automatic approach for landmark detection and shape segmentation of both pelvis and femur in conventional AP X-ray images. Our approach is based on the framework of landmark detection via Random Forest (RF) regression and shape regularization via hierarchical sparse shape composition. We propose a visual feature FL-HoG (Flexible- Level Histogram of Oriented Gradients) and a feature selection algorithm based on trace radio optimization to improve the robustness and the efficacy of RF-based landmark detection. The landmark detection result is then used in a hierarchical sparse shape composition framework for shape regularization. Finally, the extracted shape contour is fine-tuned by a post-processing step based on low level image features. The experimental results demonstrate that our feature selection algorithm reduces the feature dimension in a factor of 40 and improves both training and test efficiency. Further experiments conducted on 436 clinical AP pelvis X-rays show that our approach achieves an average point-to-curve error around 1.2 mm for femur and 1.9 mm for pelvis.
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A search for squarks and gluinos in final states containing high-pT jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in √s = 8TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 20.3 fb−1. Results are interpreted in a variety of simplified and specific supersymmetry-breaking models assuming that R-parity is conserved and that the lightest neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1330GeV for a simplified model incorporating only a gluino and the lightest neutralino. For a simplified model involving the strong production of first- and second-generation squarks, squark masses below 850GeV (440GeV) are excluded for a massless lightest neutralino, assuming mass degenerate (single light-flavour) squarks. In mSUGRA/CMSSM models with tan β = 30, A0 = −2m0 and μ > 0, squarks and gluinos of equal mass are excluded for masses below 1700GeV. Additional limits are set for non-universal Higgs mass models with gaugino mediation and for simplified models involving the pair production of gluinos, each decaying to a top squark and a top quark, with the top squark decaying to a charm quark and a neutralino. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector.
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An autonomous energy source within a human body is of key importance in the development of medical implants. This work deals with the modelling and the validation of an energy harvesting device which converts the myocardial contractions into electrical energy. The mechanism consists of a clockwork from a commercially available wrist watch. We developed a physical model which is able to predict the total amount of energy generated when applying an external excitation. For the validation of the model, a custom-made hexapod robot was used to accelerate the harvesting device along a given trajectory. We applied forward kinematics to determine the actual motion experienced by the harvesting device. The motion provides translational as well as rotational motion information for accurate simulations in three-dimensional space. The physical model could be successfully validated.
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The Tibetan Plateau has a significant role with regard to atmospheric circulation and the monsoon in particular. Changes between a closed plant cover and open bare soil are one of the striking effects of land use degradation observed with unsustainable range management or climate change, but experiments investigating changes of surface properties and processes together with atmospheric feedbacks are rare and have not been undertaken in the world's two largest alpine ecosystems, the alpine steppe and the Kobresia pygmaea pastures of the Tibetan Plateau. We connected measurements of micro-lysimeter, chamber, 13C labelling, and eddy covariance and combined the observations with land surface and atmospheric models, adapted to the highland conditions. This allowed us to analyse how three degradation stages affect the water and carbon cycle of pastures on the landscape scale within the core region of the Kobresia pygmaea ecosystem. The study revealed that increasing degradation of the Kobresia turf affects carbon allocation and strongly reduces the carbon uptake, compromising the function of Kobresia pastures as a carbon sink. Pasture degradation leads to a shift from transpiration to evaporation while a change in the sum of evapotranspiration over a longer period cannot be confirmed. The results show an earlier onset of convection and cloud generation, likely triggered by a shift in evapotranspiration timing when dominated by evaporation. Consequently, precipitation starts earlier and clouds decrease the incoming solar radiation. In summary, the changes in surface properties by pasture degradation found on the highland have a significant influence on larger scales.
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This thesis covers a broad part of the field of computational photography, including video stabilization and image warping techniques, introductions to light field photography and the conversion of monocular images and videos into stereoscopic 3D content. We present a user assisted technique for stereoscopic 3D conversion from 2D images. Our approach exploits the geometric structure of perspective images including vanishing points. We allow a user to indicate lines, planes, and vanishing points in the input image, and directly employ these as guides of an image warp that produces a stereo image pair. Our method is most suitable for scenes with large scale structures such as buildings and is able to skip the step of constructing a depth map. Further, we propose a method to acquire 3D light fields using a hand-held camera, and describe several computational photography applications facilitated by our approach. As the input we take an image sequence from a camera translating along an approximately linear path with limited camera rotations. Users can acquire such data easily in a few seconds by moving a hand-held camera. We convert the input into a regularly sampled 3D light field by resampling and aligning them in the spatio-temporal domain. We also present a novel technique for high-quality disparity estimation from light fields. Finally, we show applications including digital refocusing and synthetic aperture blur, foreground removal, selective colorization, and others.
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Image-guided surgery systems are increasingly being used during orthopaedic interventions. The aim of this chapter is to present the basic elements of these image-guided orthopaedic surgery (IGOS) devices and to review examples of preoperative or intra-operative imaging modalities, of trackers for navigation systems, of different surgical robots, and of methods for registration as well as referencing. IGOS modules that have been realised for different surgical procedures will be presented.
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Question: Low back pain is an increasing global health problem, which is associated with intervertebral disc (IVD) damage and de- generation. Major changes occur in the nucleus pulposus (NP), with the degradation of the extracellular matrix (ECM) [1]. Further studies showed that growth factors from the transforming growth factor (TGF) and bone morphogenic proteins (BMP) family may induce chondrogenic differentiation of mesenchymal stem cells (MSC) [2]. Focusing on non-viral gene therapies and their possible translation into the clinics, we investigated if GDF6 (syn. BMP13 or CDMP2) can induce regeneration of degraded NP. We hypothesized that IVD transfected with plasmid over-expressing GDF6 also up-regulates other NP- and chondrogenic cell markers and enhances ECM deposition. Methods: Bovine IVD cells were isolated by pronase/collagenase II overnight digestion. After monolayer expansion up to passage 3, cells were transfected with the plasmid pGDF6 (RG211366, Origene, SF) or with green fluorescence protein (GFP) control using the NeonÒ transfection system (Invitrogen, Basel), both equipped with a Cy- tomegalovirus (CMV) promotor to induce over-expression. We tested a range of yet unpublished parameters for each of the primary disc cells to optimize efficiency. To test a non-viral gene therapy applied directly to 3D whole organ culture, bovine IVDs were harvested from fresh tails obtained from the abattoir within 5 h post-mortem [3]. Discs were then pre-incubated for 24 h in high glucose Dulbecco’s Modified Eagle Medium and 5 % fetal calf serum. Each disc was transfected by injection of 5 lg of plasmid GDF6 (Origene, RG211366) into the center by 25G needle and using Hamilton sy- ringe. Electroporation was performed using 2-needle array electrode or tweezertrodes; 8 pulses at 200mv/cm with an interval of 10 ms were applied using ECM830 Square Wave Electroporation System (Harvard Apparatus, MA) (Fig. 1). After transfection discs were cultured for 72 h to allow expression of GFP or GDF6. Discs were then fixed, cryosectioned and analysed by immunofluorescence against GDF6. Results: We successfully transfected bovine NP and AF cells in monolayer culture with the two plasmids using a 1,400 V, 20 ms and 2 pulses with a *25 % efficiency using 0.15 M cells and 3 lg DNA (Fig. 1). Organ IVD culture transfection revealed GFP6 positive staining in the centre of the disc using 2-needle array electrode. Results from tweezertrodes did not show any GFP posi- tive cells. Conclusions: We identified novel parameters to successfully transfect primary bovine IVD cells. For transfection of whole IVD explants electroporation parameters need to be further optimized. Acknowledgments: This study was supported by the Lindenhof Foundation ‘‘Forschung und Lehre’’ (Project no. 13-02-F). References 1. Roughly PJ (2004) Spine (Phila) 29:2691–2699 2. 3. Clarke LE, McConell JC, Sherratt MJ, Derby B, Richardson SM, Hoyland JA (2014) Arthritis Res Ther 16:R67 Chan SC, Gantenbein-Ritter B (2012) J Vis Exp 60(60):e3490
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The joint European Society of Cardiology and European Association of Cardio-Thoracic Surgery (ESC/EACTS) guidelines on myocardial revascularization collect and summarize the evidence regarding decision-making, diagnostics, and therapeutics in various clinical scenarios of coronary artery disease, including elective, urgent, and emergency settings. The 2014 document updates and extends the effort started in 2010, year of the first edition of these guidelines. Importantly, this latest edition provides a systematic review of all randomized clinical trials performed since 1980, comparing different strategies of myocardial revascularization, including coronary artery bypass graft (CABG), balloon angioplasty, percutaneous coronary intervention (PCI) with bare-metal stents (BMS) and first- and second-generation drug-eluting stents (DES). This review aims to highlight the most relevant novelties introduced by the 2014 edition of the ESC/EACTS myocardial revascularization guidelines as compared with the previous edition and to describe similarities and differences with the American societies' guidelines.
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Compromised skin integrity of farmed Atlantic salmon, commonly occurring under low temperature and stressful conditions, has major impacts on animal welfare and economic productivity. Even fish with minimal scale loss and minor wounds can suffer from secondary infections, causing downgrading and mortalities. Wound healing is a complex process, where water temperature and nutrition play key roles. In this study, Atlantic salmon (260 g) were held at different water temperatures (4 or 12 °C) and fed three different diets for 10 weeks, before artificial wounds were inflicted and the wound healing process monitored for 2 weeks. The fish were fed either a control diet, a diet supplemented with zinc (Zn) or a diet containing a combination of functional ingredients in addition to Zn. The effect of diet was assessed through subjective and quantitative skin histology and the transcription of skin-associated chemokines. Histology confirmed that wound healing was faster at 12 °C. The epidermis was more organised, and image analyses of digitised skin slides showed that fish fed diets with added Zn had a significantly larger area of the epidermis covered by mucous cells in the deeper layers after 2 weeks, representing more advanced healing progression. Constitutive levels of the newly described chemokines, herein named CK 11A, B and C, confirmed their preferential expression in skin compared to other tissues. Contrasting modulation profiles at 4 and 12 °C were seen for all three chemokines during the wound healing time course, while the Zn-supplemented diets significantly increased the expression of CK 11A and B during the first 24 h of the healing phase.
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Ninety-one Swiss veal farms producing under a label with improved welfare standards were visited between August and December 2014 to investigate risk factors related to antimicrobial drug use and mortality. All herds consisted of own and purchased calves, with a median of 77.4% of purchased calves. The calves' mean age was 29±15days at purchasing and the fattening period lasted at average 120±28 days. The mean carcass weight was 125±12kg. A mean of 58±33 calves were fattened per farm and year, and purchased calves were bought from a mean of 20±17 farms of origin. Antimicrobial drug treatment incidence was calculated with the defined daily dose methodology. The mean treatment incidence (TIADD) was 21±15 daily doses per calf and year. The mean mortality risk was 4.1%, calves died at a mean age of 94±50 days, and the main causes of death were bovine respiratory disease (BRD, 50%) and gastro-intestinal disease (33%). Two multivariable models were constructed, for antimicrobial drug treatment incidence (53 farms) and mortality (91 farms). No quarantine, shared air space for several groups of calves, and no clinical examination upon arrival at the farm were associated with increased antimicrobial treatment incidence. Maximum group size and weight differences >100kg within a group were associated with increased mortality risk, while vaccination and beef breed were associated with decreased mortality risk. The majority of antimicrobial treatments (84.6%) were given as group treatments with oral powder fed through an automatic milk feeding system. Combination products containing chlortetracycline with tylosin and sulfadimidine or with spiramycin were used for 54.9%, and amoxicillin for 43.7% of the oral group treatments. The main indication for individual treatment was BRD (73%). The mean age at the time of treatment was 51 days, corresponding to an estimated weight of 80-100kg. Individual treatments were mainly applied through injections (88.5%), and included administration of fluoroquinolones in 38.3%, penicillines (amoxicillin or benzylpenicillin) in 25.6%, macrolides in 13.1%, tetracyclines in 12.0%, 3th and 4th generation cephalosporines in 4.7%, and florfenicol in 3.9% of the cases. The present study allowed for identifying risk factors for increased antimicrobial drug treatment and mortality. This is an important basis for future studies aiming at reducing treatment incidence and mortality in veal farms. Our results indicate that improvement is needed in the selection of drugs for the treatment of veal calves according to the principles of prudent use of antibiotics.
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Increasing attention has been given to the connection between metabolism and cancer. Under aerobic conditions, normal cells predominantly use oxidative phosphorylation for ATP generation. In contrast, increase of glycolytic activity has been observed in various tumor cells, which is known as Warburg effect. Cancer cells, compared to normal cells, produce high levels of Reactive Oxygen Species (ROS) and hence are constantly under oxidative stress. Increase of oxidative stress and glycolytic activity in cancer cells represent major biochemical alterations associated with malignant transformation. Despite prevalent upregulation of ROS production and glycolytic activity observed in various cancer cells, underlying mechanisms still remain to be defined. Oncogenic signals including Ras has been linked to regulation of energy metabolism and ROS production. Current study was initiated to investigate the mechanism by which Ras oncogenic signal regulates cellular metabolism and redox status. A doxycycline inducible gene expression system with oncogenic K-ras transfection was constructed to assess the role played by Ras activation in any given studied parameters. Data obtained here reveals that K-ras activation directly caused mitochondrial dysfunction and ROS generation, which appeared to be mechanistically associated with translocation of K-ras to mitochondria and the opening of the mitochondrial permeability transition pore. K-ras induced mitochondrial dysfunction led to upregulation of glycolysis and constitutive activation of ROS-generating NAD(P)H Oxidase (NOX). Increased oxidative stress, upregulation of glycolytic activity, and constitutive activated NOX were also observed in the pancreatic K-ras transformed cancer cells compared to their normal counterparts. Compared to non-transformed cells, the pancreatic K-ras transformed cancer cells with activated NOX exhibited higher sensitivity to capsaicin, a natural compound that appeared to target NOX and cause preferential accumulation of oxidative stress in K-ras transformed cells. Taken together, these findings shed new light on the role played by Ras in the road to cancer in the context of oxidative stress and metabolic alteration. The mechanistic relationship between K-ras oncogenic signals and metabolic alteration in cancer will help to identify potential molecular targets such as NAD(P)H Oxidase and glycolytic pathway for therapeutic intervention of cancer development. ^