Comparison of proximal isovelocity surface area method with pressure half-time and planimetry in evaluation of mitral stenosis

AbstractObjectives. This study sought to 1) compare the accuracy of the proximal isovelocity surface area (PISA) and Doppler pressure half-time methods and planimetry for echocardiographic estimation of mitral valve area; 2) evaluate the effect of atrial fibrillation on the accuracy of the PISA method; and 3) assess factors used to correct PISA area estimates for leaflet angulation.Background. Despite recognized limitations of traditional echocardiographic methods for estimating mitral valve area, there has been no systematic comparison with the PISA method in a single cohort.Methods. Area estimates were obtained in patients with mitral stenosis by the Gorlin hydraulic formula, PISA and pressure half-time method in 48 patients and by planimetry in 36. Two different factors were used to correct PISA estimates for leaflet angle (θ): 1) plane-angle factor (θ/180 [θ in degrees]); and 2) solid-angle factor [1 — cos(θ/2)].Results. After exclusion of patients with significant mitral regurgitation, the correlation between Gorlin and PISA areas (0.88) was significantly greater (p < 0.04) than that between Gorlin and pressure half-time (0.78) or Gorlin and planimetry (0.72). The correlation between Gorlin and PISA area estimates was lower in atrial fibrillation than sinus rhythm (0.69 vs. 0.93), but the standard error of the estimate was only slightly greater (0.24 vs. 0.19 cm2). The average ratio of the solid- to the plane-angle correction factors was approximately equal to previously reported values of the orifice contraction coefficient for tapering stenosis.Conclusions. 1) The accuracy of PISA area estimates in mitral stenosis is at least comparable to those of planimetry and pressure half-time. 2) Reasonable accuracy of the PISA method is possible in irregular rhythms. 3) A simple leaflet angle correction factor, θ/180 (θ in degrees), yields the physical orifice area because it overestimates the vena contracta area by a factor approximately equal to the contraction coefficient for a tapering stenosis

The American Upper Ordovician Standard. XIX. A Middle And Upper Ordovician Reference Standard for the Eastern Cincinnati Region

Author Institution: Department of Geology and Mineralogy, The Ohio State UniversityA 1,200-foot core (designated CA-38) drilled by Cominco American, Inc., just east of Minerva, Mason County, Kentucky, provides an essentially complete section from near the top of the Fairview Formation (Upper Ordovician, Maysvillian) to the base of the Middle Ordovician High Bridge Group. The lowest 850 feet of the core penetrates a part of the Ordovician section that is not exposed in the eastern Cincinnati region, and the uppermost 350 feet provides a more nearly complete stratigraphic record than is exposed in a single surface section. Thus we suggest that core CA-38 be a primary reference standard for stratigraphic units in the eastern Cincinnati region. As a first step in establishing such a standard, we present for the uppermost 665 feet of the core a shale-percentage log, a clastic-ratio log, and a log showing the ranges and relative abundances of important conodont species. This portion of the core represents the stratigraphic interval above the base of the Lexington Limestone. Correlation and nomenclature of units in the uppermost 665 feet of core CA-38 is effected by comparing the logs with similar ones for important surface and subsurface sections elsewhere in the Cincinnati region

Comparative hazard analysis and toxicological modeling of diverse nanomaterials using the embryonic zebrafish (EZ) metric of toxicity

The integration of rapid assays, large datasets, informatics, and modeling can overcome current barriers in understanding nanomaterial structure–toxicity relationships by providing a weight-of-the-evidence mechanism to generate hazard rankings for nanomaterials. Here, we present the use of a rapid, low-cost assay to perform screening-level toxicity evaluations of nanomaterials in vivo. Calculated EZ Metric scores, a combined measure of morbidity and mortality in developing embryonic zebrafish, were established at realistic exposure levels and used to develop a hazard ranking of diverse nanomaterial toxicity. Hazard ranking and clustering analysis of 68 diverse nanomaterials revealed distinct patterns of toxicity related to both the core composition and outermost surface chemistry of nanomaterials. The resulting clusters guided the development of a surface chemistry-based model of gold nanoparticle toxicity. Our findings suggest that risk assessments based on the size and core composition of nanomaterials alone may be wholly inappropriate, especially when considering complex engineered nanomaterials. Research should continue to focus on methodologies for determining nanomaterial hazard based on multiple sub-lethal responses following realistic, low-dose exposures, thus increasing the availability of quantitative measures of nanomaterial hazard to support the development of nanoparticle structure–activity relationships.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Springer. The published article can be found at: http://link.springer.com/journal/11051Keywords: Zebrafish, Nanoparticle, Surface chemistry, Informatics, ToxicityKeywords: Zebrafish, Nanoparticle, Surface chemistry, Informatics, Toxicit

Australian bat lyssavirus infection in two horses

In May 2013, the first cases of Australian bat lyssavirus infections in domestic animals were identified in Australia. Two horses (filly-H1 and gelding-H2) were infected with the Yellow-bellied sheathtail bat (YBST) variant of Australian bat lyssavirus (ABLV). The horses presented with neurological signs, pyrexia and progressing ataxia. Intra-cytoplasmic inclusion bodies (Negri bodies) were detected in some Purkinje neurons in haematoxylin and eosin (H&amp;E) stained sections from the brain of one of the two infected horses (H2) by histological examination. A morphological diagnosis of sub-acute moderate non-suppurative, predominantly angiocentric, meningo-encephalomyelitis of viral aetiology was made. The presumptive diagnosis of ABLV infection was confirmed by the positive testing of the affected brain tissue from (H2) in a range of laboratory tests including fluorescent antibody test (FAT) and real-time PCR targeting the nucleocapsid (N) gene. Retrospective testing of the oral swab from (H1) in the real-time PCR also returned a positive result. The FAT and immunohistochemistry (IHC) revealed an abundance of ABLV antigen throughout the examined brain sections. ABLV was isolated from the brain (H2) and oral swab/saliva (H1) in the neuroblastoma cell line (MNA). Alignment of the genome sequence revealed a 97.7% identity with the YBST ABLV strain

Feeding strategies for improving ruminant productivity in the post-COVID 19 pandemic era particularly for small holders

COVID-19 has highlighted the need for robust cattle supply chains using local feed resources. Higher Income Over Food Costs (IOFC) are usually achieved when live weight gains are high and the cost of the ingredients are low. There is a need to formulate rations with high metabolisable energy (ME) and crude protein (CP) to achieve the high live weight gain. Rations can be formulated locally by farmer co-operatives, entrepreneurs and local commercial enterprises to take advantage of cheaper prices for local ingredients. To do this, rations need to be altered quickly to take advantage of local fluctuations in prices and availability of ingredients. A recent ACIAR funded project has developed a least cost ration (ACIAR LCR) system to formulate rations to meet minimum ME and CP contents for beef cattle using locally available ingredients. The use of cassava and its various products in combination with protein sources, such as tree legumes and high protein by-products, have markedly improved IOFC

ISA-TAB-Nano: A Specification for Sharing Nanomaterial Research Data in Spreadsheet-based Format

BACKGROUND AND MOTIVATION: The high-throughput genomics communities have been successfully using standardized spreadsheet-based formats to capture and share data within labs and among public repositories. The nanomedicine community has yet to adopt similar standards to share the diverse and multi-dimensional types of data (including metadata) pertaining to the description and characterization of nanomaterials. Owing to the lack of standardization in representing and sharing nanomaterial data, most of the data currently shared via publications and data resources are incomplete, poorly-integrated, and not suitable for meaningful interpretation and re-use of the data. Specifically, in its current state, data cannot be effectively utilized for the development of predictive models that will inform the rational design of nanomaterials. RESULTS: We have developed a specification called ISA-TAB-Nano, which comprises four spreadsheet-based file formats for representing and integrating various types of nanomaterial data. Three file formats (Investigation, Study, and Assay files) have been adapted from the established ISA-TAB specification; while the Material file format was developed de novo to more readily describe the complexity of nanomaterials and associated small molecules. In this paper, we have discussed the main features of each file format and how to use them for sharing nanomaterial descriptions and assay metadata. CONCLUSION: The ISA-TAB-Nano file formats provide a general and flexible framework to record and integrate nanomaterial descriptions, assay data (metadata and endpoint measurements) and protocol information. Like ISA-TAB, ISA-TAB-Nano supports the use of ontology terms to promote standardized descriptions and to facilitate search and integration of the data. The ISA-TAB-Nano specification has been submitted as an ASTM work item to obtain community feedback and to provide a nanotechnology data-sharing standard for public development and adoption

Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: a case study of Irish Sea beaches

In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the publicwho may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16 l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq 137Cs within large areas (10–20 km2 h−1), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15 m whilst maintaining speeds covering 1–2 km2 h−1 can detect buried 137Cs sources of 0.5 MBq or greater activity. A survey design to detect 100 kBq 137Cs sources at 10 cm depth has also been defined, requiring surveys at b15 m ground clearance and b2 m s−1 ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed

Stochastic population growth in spatially heterogeneous environments

Classical ecological theory predicts that environmental stochasticity increases extinction risk by reducing the average per-capita growth rate of populations. To understand the interactive effects of environmental stochasticity, spatial heterogeneity, and dispersal on population growth, we study the following model for population abundances in $n$ patches: the conditional law of $X_{t+dt}$ given $X_t=x$ is such that when $dt$ is small the conditional mean of $X_{t+dt}^i-X_t^i$ is approximately $[x^i\mu_i+\sum_j(x^j D_{ji}-x^i D_{ij})]dt$, where $X_t^i$ and $\mu_i$ are the abundance and per capita growth rate in the $i$-th patch respectivly, and $D_{ij}$ is the dispersal rate from the $i$-th to the $j$-th patch, and the conditional covariance of $X_{t+dt}^i-X_t^i$ and $X_{t+dt}^j-X_t^j$ is approximately $x^i x^j \sigma_{ij}dt$. We show for such a spatially extended population that if $S_t=(X_t^1+...+X_t^n)$ is the total population abundance, then $Y_t=X_t/S_t$, the vector of patch proportions, converges in law to a random vector $Y_\infty$ as $t\to\infty$, and the stochastic growth rate $\lim_{t\to\infty}t^{-1}\log S_t$ equals the space-time average per-capita growth rate \sum_i\mu_i\E[Y_\infty^i] experienced by the population minus half of the space-time average temporal variation \E[\sum_{i,j}\sigma_{ij}Y_\infty^i Y_\infty^j] experienced by the population. We derive analytic results for the law of $Y_\infty$, find which choice of the dispersal mechanism $D$ produces an optimal stochastic growth rate for a freely dispersing population, and investigate the effect on the stochastic growth rate of constraints on dispersal rates. Our results provide fundamental insights into "ideal free" movement in the face of uncertainty, the persistence of coupled sink populations, the evolution of dispersal rates, and the single large or several small (SLOSS) debate in conservation biology.Comment: 47 pages, 4 figure

Biostratigraphy, paleomagnetism and sedimentology of Late Cenozoic sediments in northwestern Hokkaido, Japan

Four Neogene sedimentary basins in northwestern Hokkaido (latitudes 44°-45° N.), the northernmost island of Japan, were studied to establish a combined microfossil-paleomagnetic sedimentologic stratigraphy. The measured section near Atsuta encompasses a shoaling depositional sequence from upper bathyal depths in the lower part to stagnant, nearshore conditions near the top of the sequence. Magnetostratigraphic evidence and age-diagnostic diatoms indicate the section to be Late Miocene age covering the interval from early Epoch 5 through Epoch 6, and possibly to late Epoch 7. The second measured section located north of Shosanbetsu exposes sediments derived from a volcano-clastic source and deposited on a continental slope with oversteepened slopes. Rich diatom floras from the sequence are assignable to the Denticula seminae var. fossilis-D. kamtschatica and D. kamtschatica Zones. A magnetic signature containing one reversal was observed in the upper part of the section, although the data seem to indicate the lower section to be dominantly normally magnetized. In the northwest Pacific deep-sea sequences, the zonal boundary of these two diatom zones lies between the Nunivak ( = "b") and "c" Events of the Gilbert Epoch, thus the distinct magnetic reversal observed in the upper part of the sequence is correlated with the top of the Nunivak Event. Neogene strata developed near Wakkanai City, the northwestern tip of Hokkaido, appear to have been deposited during a time interval of predominantly reversed geomagnetic polarity. Diatom floras suggest a correlation of these strata with the Denticula kamtschatica Zone which in turn corresponds, in the northwest Pacific deep-sea sequences, to the lower Gilbert Series below a horizon midway between the Nunivak and "c" Events. Diatom rich sediments of the Shimo-Ebekorobetsu area belong to the Yuchi Formation and comprise two assemblages assignable to the D. kamtschatica Zone and the superjacent Denticula seminae var.fossilis-D. kamtschatica Zone. From northern Honshu through Hokkaido to Sakhalin, in the western Pacific coastal region, beds containing the large pecten Fortipecten takahashii (YOKOYAMA) constitute a marker horizon useful for inter-regional correlation. In its southern range of distribution, F. takahashii is a diagnostic species in the lower part of the Tatsunokuchi Formation from which diatom floras assignable to the D. seminae var. fossilis-D. kamtschatica Zone are described. The F. takahashii bed occurs in the Shosanbetsu section, lying within the same diatom zone as the Tastunokuchi Formation and is in a reversely magnetized interval above the Nunivak Event (3.9 m.y. B.P.). The Neogene marine sediments of northwestern Hokkaido were deposited in the back-arc basin and reveal evidence of active arc magmatism at the time of deposition. In this tectonically active back-arc region, sediment-collecting basins shifted from area to area, accumulating sediments only for a relatively short period of time when spurts of active subsidence occurred in a given sedimentary basin