Many-body Effects in Angle-resolved Photoemission: Quasiparticle Energy and Lifetime of a Mo(110) Surface State

In a high-resolution photoemission study of a Mo(110) surface state various contributions to the measured width and energy of the quasiparticle peak are investigated. Electron-phonon coupling, electron-electron interactions and scattering from defects are all identified mechanisms responsible for the finite lifetime of a valence photo-hole. The electron-phonon induced mass enhancement and rapid change of the photo-hole lifetime near the Fermi level are observed for the first time.Comment: RevTEX, 4 pages, 4 figures, to be published in PR

Charge-imbalance effects in intrinsic Josephson systems

We report on two types of experiments with intrinsic Josephson systems made from layered superconductors which show clear evidence of nonequilibrium effects: 1. In 2-point measurements of IV-curves in the presence of high- frequency radiation a shift of the voltage of Shapiro steps from the canonical value hf/(2e) has been observed. 2. In the IV-curves of double-mesa structures an influence of the current through one mesa on the voltage measured on the other mesa is detected. Both effects can be explained by charge-imbalance on the superconducting layers produced by the quasi-particle current, and can be described successfully by a recently developed theory of nonequilibrium effects in intrinsic Josephson systems.Comment: 8pages, 9figures, submitted to Phys. Rev.

A comparative analysis of advanced techniques for skin reconstruction with autologous keratinocyte culture in severely burned children : own experience

Introduction: The local treatment in burns larger than 50% of total body surface area is still the great challenge for surgeons. Aim: This paper presents a review of different solutions for deep burn wound healing in children and the early outcomes of treatment with combined autologous cell culture technique. Material and methods: For this study, 20 children aged between 4 and 12 years with 55–65% of TBSA III grade burn injury were analyzed. A skin sample, 1 cm × 1 cm in size, for keratinocyte cultivation, was taken on the day of the burn. After necrotic tissue excision, the covering of the burned area with an isolated meshed skin graft was carried out between day 4 and 7. After 7 days of keratinocyte cultivation, the mentioned areas were covered with cells from the culture. We divided the burned regions, according to the way of wound closure, into 3 groups each consisting of 15 treated regions of the body. We used meshed split thickness skin grafts (SSG group), cultured autologous keratinocytes (CAC group), and both techniques applied in one stage (SSG + CAC group). Results: In the SSG group, the mean time for complete closure of wounds was 12.7 days. Wounds treated with CAC only needed a non-significantly longer time to heal – 14.2 days (p = 0.056) when compared to SSG. The shortest time to heal was observed in the group treated with SSG + CAC – 8.5 days, and it was significantly shorter when compared to the SSG and CAC groups (p < 0.001). Conclusions: This study suggests that cultured keratinocytes obtained after short-time multiplication, combined with meshed autologous split thickness skin grafts, constitute the optimal wound closure in burned children

Mating plugs in polyandrous giants: Which sex produces them, when, how and why?

10.1371/journal.pone.0040939PLoS ONE77

Benchmarking spike-based visual recognition: a dataset and evaluation

Today, increasing attention is being paid to research into spike-based neural computation both to gain a better understanding of the brain and to explore biologically-inspired computation. Within this field, the primate visual pathway and its hierarchical organisation have been extensively studied. Spiking Neural Networks (SNNs), inspired by the understanding of observed biological structure and function, have been successfully applied to visual recognition and classification tasks. In addition, implementations on neuromorphic hardware have enabled large-scale networks to run in (or even faster than) real time, making spike-based neural vision processing accessible on mobile robots. Neuromorphic sensors such as silicon retinas are able to feed such mobile systems with real-time visual stimuli. A new set of vision benchmarks for spike-based neural processing are now needed to measure progress quantitatively within this rapidly advancing field. We propose that a large dataset of spike-based visual stimuli is needed to provide meaningful comparisons between different systems, and a corresponding evaluation methodology is also required to measure the performance of SNN models and their hardware implementations. In this paper we first propose an initial NE (Neuromorphic Engineering) dataset based on standard computer vision benchmarks and that uses digits from the MNIST database. This dataset is compatible with the state of current research on spike-based image recognition. The corresponding spike trains are produced using a range of techniques: rate-based Poisson spike generation, rank order encoding, and recorded output from a silicon retina with both flashing and oscillating input stimuli. In addition, a complementary evaluation methodology is presented to assess both model-level and hardware-level performance. Finally, we demonstrate the use of the dataset and the evaluation methodology using two SNN models to validate the performance of the models and their hardware implementations. With this dataset we hope to (1) promote meaningful comparison between algorithms in the field of neural computation, (2) allow comparison with conventional image recognition methods, (3) provide an assessment of the state of the art in spike-based visual recognition, and (4) help researchers identify future directions and advance the field

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

A comparative analysis of advanced techniques for skin reconstruction with autologous keratinocyte culture in severely burned children: own experience

Introduction: The local treatment in burns larger than 50% of total body surface area is still the great challenge for surgeons. Aim: This paper presents a review of different solutions for deep burn wound healing in children and the early outcomes of treatment with combined autologous cell culture technique. Material and methods: For this study, 20 children aged between 4 and 12 years with 55–65% of TBSA III grade burn injury were analyzed. A skin sample, 1 cm × 1 cm in size, for keratinocyte cultivation, was taken on the day of the burn. After necrotic tissue excision, the covering of the burned area with an isolated meshed skin graft was carried out between day 4 and 7. After 7 days of keratinocyte cultivation, the mentioned areas were covered with cells from the culture. We divided the burned regions, according to the way of wound closure, into 3 groups each consisting of 15 treated regions of the body. We used meshed split thickness skin grafts (SSG group), cultured autologous keratinocytes (CAC group), and both techniques applied in one stage (SSG + CAC group). Results: In the SSG group, the mean time for complete closure of wounds was 12.7 days. Wounds treated with CAC only needed a non-significantly longer time to heal – 14.2 days (p = 0.056) when compared to SSG. The shortest time to heal was observed in the group treated with SSG + CAC – 8.5 days, and it was significantly shorter when compared to the SSG and CAC groups (p < 0.001). Conclusions: This study suggests that cultured keratinocytes obtained after short-time multiplication, combined with meshed autologous split thickness skin grafts, constitute the optimal wound closure in burned children

Mouse models of neurodegenerative disease: preclinical imaging and neurovascular component.

Neurodegenerative diseases represent great challenges for basic science and clinical medicine because of their prevalence, pathologies, lack of mechanism-based treatments, and impacts on individuals. Translational research might contribute to the study of neurodegenerative diseases. The mouse has become a key model for studying disease mechanisms that might recapitulate in part some aspects of the corresponding human diseases. Neurode- generative disorders are very complicated and multifacto- rial. This has to be taken in account when testing drugs. Most of the drugs screening in mice are very di cult to be interpretated and often useless. Mouse models could be condiderated a ‘pathway models’, rather than as models for the whole complicated construct that makes a human disease. Non-invasive in vivo imaging in mice has gained increasing interest in preclinical research in the last years thanks to the availability of high-resolution single-photon emission computed tomography (SPECT), positron emission tomography (PET), high eld Magnetic resonance, Optical Imaging scanners and of highly speci c contrast agents. Behavioral test are useful tool to characterize di erent ani- mal models of neurodegenerative pathology. Furthermore, many authors have observed vascular pathological features associated to the di erent neurodegenerative disorders. Aim of this review is to focus on the di erent existing animal models of neurodegenerative disorders, describe behavioral tests and preclinical imaging techniques used for diagnose and describe the vascular pathological features associated to these diseases

Novel method for the rapid establishment of antibiotic susceptibility profiles in bacterial strains linked to musculoskeletal infections using Scattered Light Integrated Collector technology

Funding: This study was funded by the collaborative research grant of the universities St Andrews and Bonn, the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy—EXC2151—390873048, and the John Templeton Foundation (grant #62214).Bacterial antibiotic resistance is an important challenge that the healthcare system is continually battling and a major problem in the treatment of musculoskeletal infections such as periprosthetic joint infections. Current methods to identify infectious microbes and define susceptibility to antibiotics require two to ten days from isolation to the establishment of an antibiogram. This slow process limits advances in antimicrobial drug discovery and, in the clinical context, delays the delivery of targeted treatments, with potentially devastating outcomes for patients. With this in mind, we strived to establish a quicker and more sensitive method to deliver antibiotic susceptibility profiles of clinically relevant microbes using Scattered Light Integrated Collector (SLIC) technology. We established antibiotic panels to obtain an approximate identification of a wide variety of microbes linked to periprosthetic joint infections and determine their susceptibility to antibiotics. We challenged microbes isolated from patients with our tailored antibiotic panels and found that SLIC detects perturbations in bacterial growth accurately and reproducibly within minutes of culture. Indeed, we could show that SLIC can be used to measure the dose-dependent inhibitory or bacteriolytic activity of broad classes of antibiotics. Our panel design enabled us to establish a profile similar to an antibiogram for the tested bacteria within 90 min. Our method can provide information on the class of bacteria tested and potential treatment avenues in parallel. Our proof-of-principle experiments using isolated clinical strains of bacteria demonstrate that SLIC, together with our specifically designed antibiotic panels, could be used to rapidly provide information on the identity of an infecting microbe, such as those associated with periprosthetic joint infections, and guide physicians to prescribe targeted antibiotic treatment early-on. The constant emergence of resistant strains of bacteria pushes the pharmaceutical industry to develop further effective drugs. Our optimized method could significantly accelerate this work by characterizing the efficacy of new classes of compounds against bacterial viability within minutes, a timeframe far shorter than the current standards.Peer reviewe