Spectral characterization and unmixing of intrinsic contrast in intact normal and diseased gastric tissues using hyperspectral two-photon microscopy

Background: Living tissues contain a range of intrinsic fluorophores and sources of second harmonic generation which provide contrast that can be exploited for fresh tissue imaging. Microscopic imaging of fresh tissue samples can circumvent the cost and time associated with conventional histology. Further, intrinsic contrast can provide rich information about a tissue\u27s composition, structure and function, and opens the potential for in-vivo imaging without the need for contrast agents. Methodology/Principal Findings: In this study, we used hyperspectral two-photon microscopy to explore the characteristics of both normal and diseased gastrointestinal (GI) tissues, relying only on their endogenous fluorescence and second harmonic generation to provide contrast. We obtained hyperspectral data at subcellular resolution by acquiring images over a range of two-photon excitation wavelengths, and found excitation spectral signatures of specific tissue types based on our ability to clearly visualize morphology. We present the two-photon excitation spectral properties of four major tissue types that are present throughout the GI tract: epithelium, lamina propria, collagen, and lymphatic tissue. Using these four excitation signatures as basis spectra, linear unmixing strategies were applied to hyperspectral data sets of both normal and neoplastic tissue acquired in the colon and small intestine. Our results show that hyperspectral unmixing with excitation spectra allows segmentation, showing promise for blind identification of tissue types within a field of view, analogous to specific staining in conventional histology. The intrinsic spectral signatures of these tissue types provide information relating to their biochemical composition. Conclusions/Significance: These results suggest hyperspectral two-photon microscopy could provide an alternative to conventional histology either for in-situ imaging, or intraoperative \u27instant histology\u27 of fresh tissue biopsies. © 2011 Grosberg et al

Effect of Catalyst Layer and Fuel Utilization on the Durability of Direct Methane SOFC

International audienceSolid oxide fuels cells with and without anodic catalytic layer and specific anodic current collectors were developed in order to be fueled by dry methane. Due to the cell architecture integrating a 0.1wt% Ir-CGO catalyst layer onto the anode, platinum, gold and cupper screen-printed meshes were designed and optimized to ensure efficient current collection between the anode surface and the catalyst membrane. Current density and ageing in H2 and in pure dry CH4 respectively were compared to conventional pressed grid collecting systems. Similar performances were achieved using bulk grids or gold, platinum and copper screen-printed meshes. Operation in pure dry methane is compared with and without the catalytic layer as a function of the fuel utilization. It is demonstrated that long term operation is possible provided that sufficient faradic efficiency is achieved

Low field vortex matter in YBCO: an atomic beam magnetic resonance study

We report measurements of the low field structure of the magnetic vortex lattice in an untwinned YBCO single-crystal platelet. Measurements were carried out using a novel atomic beam magnetic resonance (ABMR) technique. For a 10.7 G field applied parallel to the c-axis of the sample, we find a triangular lattice with orientational order extending across the entire sample. We find the triangular lattice to be weakly distorted by the a-b anisotropy of the material and measure a distortion factor, f = 1.16. Model-experiment comparisons determine a penetration depth, lambda_ab = 140 (+-20) nm. The paper includes the first detailed description of the ABMR technique. We discuss both technical details of the experiment and the modeling used to interpret the measurements.Comment: 44 pages, 13 figures, submitted to Phys. Rev. B Revision includes Postscript wrapped figures + minor typo

Is there still room to explore cyclodextrin glycosyltransferase-producers in Brazilian biodiversity?

In the present work, different Brazilian biomes aiming to identify and select cyclodextrin glycosyltransferase-producer bacteria are explored. This enzyme is responsible for converting starch to cyclodextrin, which are interesting molecules to carry other substances of economic interest applied by textile, pharmaceutical, food, and other industries. Based on the enzymatic index, 12 bacteria were selected and evaluated, considering their capacity to produce the enzyme in culture media containing different starch sources. It was observed that the highest yields were presented by the bacteria when grown in cornstarch. These bacteria were also characterized by sequencing of the 16S rRNA region and were classified as Bacillus, Paenibacillus, Gracilibacillus and Solibacillus.publishersversionpublishe

Social engagement with climate change: principles for effective visual representation on social media

Climate change communication on social media plays a prominent role in efforts undertaken by state agencies, NGOs, and international organizations, to make citizens aware of this phenomenon. The images used to communicate climate change are of great importance, since they can help to effectively raise citizen awareness. Building upon news values theory and the concept of availability heuristics, this research paper aims to identify principles that can be used for effective visual communication of climate change on social media on a cross-national scale, based upon analyses of characteristics of images that foster interaction on Twitter. We conducted a content analysis of a random selection of images (photographs, illustrations, and graphics, n = 380), posted on Twitter that were included in the so-called 'top tweets' about climate change. The results indicate that the types of images that are used on social media are relatively similar to those employed by conventional media, although images of identifiable people are less frequently shown on social media. We also deduced that four practical principles are especially relevant to foster user interaction on Twitter through images: (i) show 'real people' (i.e. non-staged images of people that transmit real emotions), (ii) tell a story, (iii) include a local connection, and (iv) show impacts or actions by people who are directly affected. These practical principles are based on the more general principles of meaningfulness and personification, two foundations that can help to overcome some of the main barriers to citizens' perception of climate change as a relevant issue with serious consequences in their lives. Campaigns on social media that use imagery based on these practical and general principles can be effective in communicating the shared responsibility to address climate change. This can have a relevant impact on social perception, since it can encourage citizens to care about climate, which is regarded as necessary to increase participation in climate action. Key policy insights Social media can play a prominent role in campaigns to make citizens aware of climate change. Images can help to effectively raise citizen awareness of climate change. Four practical principles can be effective in increasing user interaction on social media with images about climate: show 'real' people, tell a story, include a local connection, and show people who are directly affected. Visual campaigns based on the more general principles of meaningfulness and personification can be effective in representing climate change as a relevant issue in citizens' lives. These practical and more general principles can have a relevant impact on the social perception of climate change and increase citizen participation in climate debate and action

Understanding the influence of the head coach on soccer training drills—an 8 season analysis

Soccer players perform a variety of training drills to develop the physical, technical and tactical qualities required for match-play. The role of coaches in prescribing training suggests that players may not always meet physical targets set by conditioning staff. To quantify the physical outputs elicited by different training drill types, 183 professional soccer players were monitored over 8 seasons using Microelectromechanical Systems during normal training, yielding 65,825 drill observations [362 ± 341 observations·player−1]. Linear mixed models assessed the influence of drill type, head coach and playing position on physical output. Drills lasted ~14 min, eliciting total distances and high speed running of ~1000 m and 40 m, respectively. Conditioning drills elicited substantially greater relative high-speed running [18.8 ± 27.2 m.min−1] and Sprint [3.5 ± 9.4 m.min−1] distances than all other drill types. The proportion of training drill types used and external outputs elicited per drill were affected by the head coach. Midfielders recorded the highest total distance [77.3 ± 36.1 m.min] and PlayerLoad™ [8.29 ± 3.54] of any playing position, whilst the lowest outputs were recorded by goalkeepers. This study provides reference data for practitioners when seeking to manipulate training prescription to achieve physical output targets whilst also meeting the team’s technical and tactical objectives

Differential scanning calorimetry (DSC) and thermodynamic prediction of liquid fraction vs temperature for two high-performance alloys for semi-solid processing (Al-Si-Cu-Mg (319s) and Al-Cu-Ag (201))

There is a need to extend the application of semi-solid processing (SSP) to higher performance alloys such as 319s (Al-Si-Cu-Mg) and 201 (Al-Cu-Ag). The melting of these two alloys was investigated using differential scanning calorimetry (DSC) and thermodynamic prediction. The alloys had been processed by magneto-hydrodynamic (MHD) stirring before receipt to produce a microstructure suitable for SSP. The DSC results for the as-received MHD material were compared with those for material which has been taken through a complete DSC cycle and then reheated for a second DSC run. The effects of microsegregation were then analyzed. A higher liquid fraction for a particular temperature is found in the second DSC run than the first. Microstructural observations suggest this is because the intermetallics which form during the first cooling cycle tend to co-located. Quaternary and ternary reactions then occur during the second DSC heat and the co-location leads to enhanced peaks. The calculated liquid fraction is lower with 10 K/min DSC heating rate comparing with 3 K/min at a given temperature. The DSC scan rate must therefore be carefully considered if it is to be used to identify temperature parameters or the suitability of alloys for SSP. In addition, the starting material for DSC must represent the starting material for the SSP. With thermodynamic prediction, the equilibrium condition will provide better guidance for the thixoforming of MHD stirred starting material than the Scheil condition. The Scheil mode approximates more closely with a strongly microsegregated state

Prevalence of HIV and disease outcomes on the medical and surgical wards at Kamuzu Central Hospital, Lilongwe, Malawi

Introduction: The World Health Organization (WHO) recommends HIV Counseling and Testing (HCT) in a range of clinical settings. We describe the characteristics of patients diagnosed with HIV on the medical and surgical wards at a tertiary care hospital in Malawi. Methods: Under the universal opt-out HCT protocol we characterized the number of new HIV/AIDS infections and associated clinical features among hospitalized surgical and medical patients diagnosed during the course of admission. Results: All 2985 and 3959 medical and surgical patients, respectively, admitted between April 2012 and January 2013 were screened for HCT. 62% and 89% of medical and surgical patients, respectively, had an unknown status on admission and qualified for testing. Of the patients with an unknown status, a new HIV diagnosis was made in 20% and 7% of medical and surgical patients, respectively. Of the newly diagnosed patients with a CD4 count recorded, 91% and 67% of medical and surgical patients, respectively, had a count less than 350, qualifying for ART by Malawi ART guidelines. Newly HIV-diagnosed medical and surgical patients had an inpatient mortality of 20% and 2%, respectively. Discussion: While newly diagnosed HIV-positive medical patients had high inpatient mortality and higher rates of WHO stage 3 or 4 conditions, surgical patients presented with less advanced HIV, though still meeting ART initiation guidelines. The medical inpatient wards are an obvious choice for implementing voluntary counseling and testing (VCT), but surgical patients present with less advanced disease and starting treatment in this group could result in more years of life gained

Deconfining Phase Transition as a Matrix Model of Renormalized Polyakov Loops

We discuss how to extract renormalized from bare Polyakov loops in SU(N) lattice gauge theories at nonzero temperature in four spacetime dimensions. Single loops in an irreducible representation are multiplicatively renormalized without mixing, through a renormalization constant which depends upon both representation and temperature. The values of renormalized loops in the four lowest representations of SU(3) were measured numerically on small, coarse lattices. We find that in magnitude, condensates for the sextet and octet loops are approximately the square of the triplet loop. This agrees with a large $N$ expansion, where factorization implies that the expectation values of loops in adjoint and higher representations are just powers of fundamental and anti-fundamental loops. For three colors, numerically the corrections to the large $N$ relations are greatest for the sextet loop, $\leq 25$; these represent corrections of $\sim 1/N$ for N=3. The values of the renormalized triplet loop can be described by an SU(3) matrix model, with an effective action dominated by the triplet loop. In several ways, the deconfining phase transition for N=3 appears to be like that in the $N=\infty$ matrix model of Gross and Witten.Comment: 24 pages, 7 figures; v2, 27 pages, 12 figures, extended discussion for clarity, results unchange