Burn wound classification model using spatial frequency-domain imaging and machine learning.

Accurate assessment of burn severity is critical for wound care and the course of treatment. Delays in classification translate to delays in burn management, increasing the risk of scarring and infection. To this end, numerous imaging techniques have been used to examine tissue properties to infer burn severity. Spatial frequency-domain imaging (SFDI) has also been used to characterize burns based on the relationships between histologic observations and changes in tissue properties. Recently, machine learning has been used to classify burns by combining optical features from multispectral or hyperspectral imaging. Rather than employ models of light propagation to deduce tissue optical properties, we investigated the feasibility of using SFDI reflectance data at multiple spatial frequencies, with a support vector machine (SVM) classifier, to predict severity in a porcine model of graded burns. Calibrated reflectance images were collected using SFDI at eight wavelengths (471 to 851 nm) and five spatial frequencies (0 to 0.2  mm  -  1). Three models were built from subsets of this initial dataset. The first subset included data taken at all wavelengths with the planar (0  mm  -  1) spatial frequency, the second comprised data at all wavelengths and spatial frequencies, and the third used all collected data at values relative to unburned tissue. These data subsets were used to train and test cubic SVM models, and compared against burn status 28 days after injury. Model accuracy was established through leave-one-out cross-validation testing. The model based on images obtained at all wavelengths and spatial frequencies predicted burn severity at 24 h with 92.5% accuracy. The model composed of all values relative to unburned skin was 94.4% accurate. By comparison, the model that employed only planar illumination was 88.8% accurate. This investigation suggests that the combination of SFDI with machine learning has potential for accurately predicting burn severity

Laparoscopic simulation training in gynaecology:Current provision and staff attitudes - a cross-sectional survey

<p>The objectives of this study were to explore current provision of laparoscopic simulation training, and to determine attitudes of trainers and trainees to the role of simulators in surgical training across the UK. An anonymous cross-sectional survey with cluster sampling was developed and circulated. All Royal College of Obstetricians and Gynaecologists (RCOG) Training Programme Directors (TPD), College Tutors (RCT) and Trainee representatives (TR) across the UK were invited to participate. One hundred and ninety-six obstetricians and gynaecologists participated. Sixty-three percent of hospitals had at least one box trainer, and 14.6% had least one virtual-reality simulator. Only 9.3% and 3.6% stated that trainees used a structured curriculum on box and virtual-reality simulators, respectively. Respondents working in a Large/Teaching hospital (<i>p</i> = 0.008) were more likely to agree that simulators enhance surgical training. Eighty-nine percent agreed that simulators improve the quality of training, and should be mandatory or desirable for junior trainees. Consultants (<i>p</i> = 0.003) and respondents over 40 years (<i>p</i> = 0.011) were more likely to hold that a simulation test should be undertaken before live operation. Our data demonstrated, therefore, that availability of laparoscopic simulators is inconsistent, with limited use of mandatory structured curricula. In contrast, both trainers and trainees recognise a need for greater use of laparoscopic simulation for surgical training.</p

Crystal structure and revised chemical formula for burckhardtite, Pb_2(Fe^(3+)Te^(6+))[AlSi_3O_8]O_6: a double-sheet silicate with intercalated phyllotellurate layers

The crystal structure of burckhardite from the type locality, Moctezuma, Sonora, Mexico, has been refined to R_1 = 0.0362 and wR_2 = 0.0370 for 215 reflections with I > 2σ(I). Burckhardtite is trigonal, space group P3lm, with the unit-cell parameters ɑ = 5.2566(5) Å, c = 13.0221(10) Å, V = 311.62(5) Å3 and Z = 1 for the ideal formula unit Pb_2(Fe^(3+)Te^(6+))[AlSi_3O_8]O_6. There is no long-range order of (Fe^(3+), Te^(6+)) or (Al^(3+), Si^(4+)). New microprobe data were used to estimate site scattering factors, and Raman spectroscopic data showed no evidence of O–H stretching bands. Burckhardtite is not closely related to the micas, as supposed previously, but is a double-sheet silicate in which the aluminosilicate anion resembles that of minerals such as cymrite and kampfite. The [(Fe^(3+)Te^(6+))O_6]^(3−) part of the structure is not bonded directly to the aluminosilicate layer, but forms a discrete anionic phyllotellurate layer that alternates with the [AlSi_3O_8]^− double sheets. Similar phyllotellurate layers are known from several synthetic phases. In burckhardtite, Pb^(2+) cations intercalate between phyllosilicate and phyllotellurate layers, forming a Pb_2[FeTeO_6] module that is topologically similar to a slab of the structure of rosiaite, Pb[Sb_2O_6]. The crystal symmetry, structure, classification as a double-sheet silicate and chemical formula, including the determination of the 6+ valence of Te and absence of essential H_2O, are all new findings for the mineral

The relationship between mineral composition, crystal structure and paragenetic sequence: the case of secondary Te mineralization at the Bird Nest drift, Otto Mountain, California, USA

An unusually diverse array of 25 secondary Te oxysalt minerals has been documented from Otto Mountain, California, and 18 of these from the Bird Nest drift sublocality. A paragenetic sequence for these minerals is proposed, using observed overgrowth relationships plus spatial association data and data from other localities. Apart from Te and O, the components Pb, Cu and H are essential in the majority of the minerals. The atomic Cu/Te ratio decreases through the paragenetic sequence. This, and the occurrence of minerals with additional components such as Cl^–, CO_3^(2–), SO_4^(2–) and Fe^(3+) at an intermediate stage, suggests nonmonotonic evolution of the parent fluids, reflecting differing access to or spatial distribution of various components. For the minerals with known crystal structures, two alternative 'structural units' were identified, one consisting only of the Te^(4+) or Te^(6+) oxyanion, while the other also included small, strongly-bound cations such as Cu^(2+). The degree of polymerization for the Te oxyanion correlated with the paragenetic sequence: the monomeric tellurate anions of early minerals were replaced progressively by dimers, chains and sheet structures, which may relate to a decreasing abundance of the 'network modifying' Cu^(2+) cation, analogous to Bowen's discontinuous reaction series in igneous rock-forming silicates. No relationship was seen between paragenetic order and the larger type of structural unit, or structural complexity as defined by information content. This contrasts with results in the literature for evaporite sulfates and pegmatite phosphates. While structure–paragenesis relationships may be widespread, the exact nature of such relationships may be different for different chemical systems and different paragenetic environments

Classical Cepheid Pulsation Models: IX. New Input Physics

We constructed several sequences of classical Cepheid envelope models at solar chemical composition ($Y=0.28, Z=0.02$) to investigate the dependence of the pulsation properties predicted by linear and nonlinear hydrodynamical models on input physics. To study the dependence on the equation of state (EOS) we performed several numerical experiments by using the simplified analytical EOS originally developed by Stellingwerf and the recent analytical EOS developed by Irwin. Current findings suggest that the pulsation amplitudes as well as the topology of the instability strip marginally depend on the adopted EOS. We also investigated the dependence of observables predicted by theoretical models on the mass-luminosity (ML) relation and on the spatial resolution across the Hydrogen and the Helium partial ionization regions. We found that nonlinear models are marginally affected by these physical and numerical assumptions. In particular, the difference between new and old models in the location as well as in the temperature width of the instability strip is on average smaller than 200 K. However, the spatial resolution somehow affects the pulsation properties. The new fine models predict a period at the center of the Hertzsprung Progression ($P_{HP}=9.65$$-$9.84 days) that reasonably agree with empirical data based on light curves ($P_{HP}=10.0\pm 0.5$ days; \citealt{mbm92}) and on radial velocity curves ($P_{HP}=9.95\pm 0.05$ days; \citealt{mall00}), and improve previous predictions by Bono, Castellani, and Marconi (2000, hereinafter BCM00).Comment: 35 pages, 7 figures. Accepted for publication in the Astrophysical Journa

Quantifying imperfect detection in an invasive pest fish and the implications for conservation management

In managing non-native species, surveillance programmes aim to minimise the opportunity for invasions to develop from initial introductions through early detection. However, this is dependent on surveillance methods being able to detect species at low levels of abundance to avoid false-negative recordings through imperfect detection. We investigated through field experimentation the ability to detect Pseudorasbora parva, a highly invasive pest fish in Europe, in relation to their known density and sampling method. Secure pond mesocosms of area 100 m2 contained P. parva densities from 0.02 to 5.0 m"122; each density was in triplicate. These were searched using point sampling electric fishing and deployment of fish traps (non-baited and baited). No fish were captured at densities 0.5 m"122, whereas for electric fishing it only exceeded 0.95 at 5.0 m"122 using high searching effort. These data reveal that small pest fishes such as P. parva may be prone to imperfect detection when at low densities and this is consistent with a number of other invasive species. This indicates the importance of designing surveillance programmes using methods of known statistical power to optimise conservation resource expenditure and enhance management outcomes

Hdelta-Selected Galaxies in the Sloan Digital Sky Survey I: The Catalog

[Abridged] We present here a new and homogeneous sample of 3340 galaxies selected from the Sloan Digital Sky Survey (SDSS) based solely on the observed strength of their Hdelta absorption line. These galaxies are commonly known as ``post-starburst'' or ``E+A'' galaxies, and the study of these galaxies has been severely hampered by the lack of a large, statistical sample of such galaxies. In this paper, we rectify this problem by selecting a sample of galaxies which possess an absorption Hdelta equivalent width of EW(Hdelta_max) - Delta EW(Hdelta_max) > 4A from 106682 galaxies in the SDSS. We have performed extensive tests on our catalog including comparing different methodologies of measuring the Hdelta absorption and studying the effects of stellar absorption, dust extinction, emission-filling and measurement error. The measured abundance of our Hdelta-selected (HDS) galaxies is 2.6 +/- 0.1% of all galaxies within a volume-limited sample of 0.05<z<0.1 and M(r*)<-20.5, which is consistent with previous studies of such galaxies in the literature. We find that only 25 of our HDS galaxies in this volume-limited sample (3.5+/-0.7%) show no evidence for OII and Halpha emission, thus indicating that true E+A (or k+a) galaxies are extremely rare objects at low redshift, i.e., only 0.09+/-0.02% of all galaxies in this volume-limited sample are true E+A galaxies. In contrast, 89+/-5% of our HDS galaxies in the volume-limited sample have significant detections of the OII and Halpha emission lines. We find 27 galaxies in our volume-limited HDS sample that possess no detectable OII emission, but do however possess detectable Halpha emission. These galaxies may be dusty star-forming galaxies. We provide the community with this new catalog of Hdelta-selected galaxies to aid in the understanding of these galaxies.Comment: Submitted to PASJ. Catalog of galaxies available at http://astrophysics.phys.cmu.edu/~tomo/ea

The Cutaneous Microbiome and Wounds: New Molecular Targets to Promote Wound Healing

The ecological community of microorganisms in/on humans, termed the microbiome, is vital for sustaining homeostasis. While culture-independent techniques have revealed the role of the gut microbiome in human health and disease, the role of the cutaneous microbiome in wound healing is less defined. Skin commensals are essential in the maintenance of the epithelial barrier function, regulation of the host immune system, and protection from invading pathogenic microorganisms. In this review, we summarize the literature derived from pre-clinical and clinical studies on how changes in the microbiome of various acute and chronic skin wounds impact wound healing tissue regeneration. Furthermore, we review the mechanistic insights garnered from model wound healing systems. Finally, in the face of growing concern about antibiotic-resistance, we will discuss alternative strategies for the treatment of infected wounds to improve wound healing and outcomes. Taken together, it has become apparent that commensals, symbionts, and pathogens on human skin have an intimate role in the inflammatory response that highlights several potential strategies to treat infected, non-healing wounds. Despite these promising results, there are some contradictory and controversial findings from existing studies and more research is needed to define the role of the human skin microbiome in acute and chronic wound healing