A Monte Carlo experiment for measuring acoustic properties of macroalgae living tissue

A methodology is developed to measure ex situ ultrasonic velocity of submerged aquatic vegetation tissue, in particular, macroalgae, in a nondestructive and efficient manner. An entire thallus is submerged in artificial seawater-filled tank through which many ultrasonic pulse-echo measurements are recorded while thallus parts are randomly displaced. Average sound speed of tissue is estimated from normal fit to extracted travel times given measured total volume fraction of tissue and travel time in water alone. For species Ecklonia radiata the resulting values for sound speed 1573.4?±?4.8 m s-1 and adiabatic compressibility 3.134?×10-10?±?1.34?×10-11 Pa-1 at 18?°C agree with more laborious and destructive methods

The embedding of the spacetime in five-dimensional spaces with arbitrary non-degenerate Ricci tensor

We discuss and prove a theorem which asserts that any n-dimensional semi-Riemannian manifold can be locally embedded in a (n+1)-dimensional space with a non-degenerate Ricci tensor which is equal, up to a local analytic diffeomorphism, to the Ricci tensor of an arbitrary specified space. This may be regarded as a further extension of the Campbell-Magaard theorem. We highlight the significance of embedding theorems of increasing degrees of generality in the context of higher dimensional spacetimes theories and illustrate the new theorem by establishing the embedding of a general class of Ricci-flat spacetimes

Effects of Local Conspecific Density on Reproductive Success in Penstemon Digitalis and Hesperis Matronalis

Author Institution: Department of Biology, University of AkronWe investigated the effects of plant density on reproductive success for two insect-pollinated plant species—the native North American wildflower Penstemon digitalis (Foxglove-leaved Penstemon), and the showy introduced weed Hesperis matronalis (Dame's Rocket). We found no indication that local density (within 3.0 m) affected reproductive success (seeds per fruit, proportion fruit set, total seeds per plant) for either species. Penstemon digitalis suffered heavy fruit predation from micro-lepidopterans, and such damage tended non-significantly to increase with density. We discuss the reasons for our results, and suggest that an understanding of those causes is important for conservation

"Community Development Banking, A Proposal to Establish a Nationwide System of Community Development Banks"

This brief proposes that the establishment of a nationwide system of community development banks (CDBs) would advance the capital development of the economy. The proposal is based on the notion that a critical function of the financial system is not being adequately performed by existing institutions for low-income citizens, inner-city minorities, and entrepreneurs who seek modest financing for small businesses. The primary goals of the CDBs are to deliver credit, payment, and savings opportunities to communities not well served by banks and to provide financing throughout a designated area for businesses too small to attract the interest of the investment banking and normal commercial banking communities.

Current and future graphics requirements for LaRC and proposed future graphics system

The findings of an investigation to assess the current and future graphics requirements of the LaRC researchers with respect to both hardware and software are presented. A graphics system designed to meet these requirements is proposed

Results of an aqueous source term model for a radiological risk assessment of the Drigg LLW Site, U.K.

A radionuclide source term model has been developed which simulates the biogeochemical evolution of the Drigg low level waste (LLW) disposal site. The DRINK (DRIgg Near field Kinetic) model provides data regarding radionuclide concentrations in groundwater over a period of 100,000 years, which are used as input to assessment calculations for a groundwater pathway. The DRINK model also provides input to human intrusion and gaseous assessment calculations through simulation of the solid radionuclide inventory. These calculations are being used to support the Drigg post closure safety case. The DRINK model considers the coupled interaction of the effects of fluid flow, microbiology, corrosion, chemical reaction, sorption and radioactive decay. It represents the first direct use of a mechanistic reaction-transport model in risk assessment calculations

Comparison of patient satisfaction after uncomplicated cataract surgery between the silicone AMO SI-30/40 and the acrylic Alcon MA30BA and MA60BA foldable intraocular lenses

Journal ArticlePURPOSE: To compare patient satisfaction with vision 12 months after implantation of a silicone or acrylic foldable intraocular lens (IOL). SETTING: John A. Moran Eye Center, University of Utah Medical Center, Salt Lake City, Utah, USA. METHODS: Selection criteria included patients who had uneventful cataract extraction by phacoemulsification with a temporal clear corneal incision or superior scleral tunnel incision, a curvilinear capsulorhexis, and in-the-bag IOL placement. One hundred sixty-two patients surveyed had a mean follow-up of approximately 15 months (range 12 to 18 months). Patients were divided into 3 groups of 54 each based on IOL type: AMO SI-30/40, Alcon MA30BA, and Alcon MA60BA. All patients were surveyed over the telephone using a standardized questionnaire protocol. They were questioned about their perception of vision with best optical correction in relation to visual blurring symptoms, glare symptoms, night vision, near vision, and overall vision. RESULTS: There were no significant differences in patient satisfaction among the 3 IOL groups in visual blurring or night vision. Patients in the SI-30/40 and MA60BA groups reported significantly higher satisfaction with glare symptoms, near vision, and overall satisfaction than patients in the MA30BA group. CONCLUSION: The SI-30/SI-40 and the MA60BA IOLs received significantly higher patient satisfaction scores than the MA30BA IOL in glare symptoms, near vision, and overall satisfaction

The effects of nitrogen and potassium nutrition on the growth of nonembryogenic and embryogenic tissue of sweet orange (Citrus sinensis (L.) Osbeck)

<p>Abstract</p> <p>Background</p> <p>Mineral nutrients are one of the most basic components of plant tissue culture media. Nitrogen in the form of NH₄⁺and NO₃^-is the dominant mineral nutrient in most plant tissue culture formulations, with effects dependent on both the proportion and the amount of NH₄⁺and NO₃^-. The effects of nitrogen nutrition on the growth of nonembryogenic and embryogenic cell lines of sweet orange (<it>C. sinensis </it>(L.) Osbeck cv. 'Valencia'), tissues routinely used in citrus horticultural and plant improvement research, was explored using an experimental approach free of ion confounding that included a 2-component mixture (NH₄⁺:K⁺) and a quantitative factor [NO₃^-] crossed by the mixture, thereby providing ion-specific estimates of proportional and amount effects.</p> <p>Results</p> <p>First, the linear mixture component, though only a comparison of the design space vertices, was highly significant for both tissue types and showed that NH₄⁺was required by both tissues. Second, the NH₄⁺* K⁺mixture term was highly significant for both tissue types, revealing that NH₄⁺and K⁺exhibit strong synergistic blending and showed that growth was substantially greater at certain blends of these two ions. Third, though the interaction between the NH₄⁺:K⁺mixture and NO₃^-amount on fresh weight accumulation for both tissue types was significant, it was substantially less than the main effect of the NH₄⁺:K⁺mixture. Fourth, a region of the design space was identified where fresh weight growth was increased 198% and 67% over the MS medium controls for nonembryogenic and embryogenic tissues.</p> <p>Conclusion</p> <p>By designing a mineral nutrient experiment free of ion confounding, a direct estimation of ion-specific proportional and amount effects on plant tissue growth is possible. When the ions themselves are the independent factors and/or mixture components, the resulting design space can be systematically explored to identify regions where the response(s) is substantially improved over current media formulations. In addition, because the response is over a defined experimental region, a specific medium formulation is more accurately interpreted as a coordinate in the specified design geometry.</p

Comparison of thermal features associated with 2 phacoemulsification machines

Journal ArticlePURPOSE: To determine the thermal characteristics of the Legacy Advantec and Sovereign WhiteStar phacoemulsification machines during different clinically relevant scenarios. SETTING: In vitro study. METHODS: In water, temperature was recorded continuously on the sleeve in an artificial chamber, and the increase in temperature over baseline after 60 seconds of ultrasound was determined. This was done for continuous ultrasound, 50 ms on and 50 ms off (pulse), 6 ms on and 12 ms off (WhiteStar; Sovereign only) with aspiration blocked and not blocked, and with 100 g and 200 g weights suspended from the sleeve. RESULTS: Comparing temperature increase per 20% machine power increments, Sovereign ran hotter than Legacy Advantec for continuous ultrasound (2.31x) and pulse (2.23x). Blocking aspiration increased temperature over the unblocked state. Pulsing decreased temperature by 51% (Legacy Advantec, pulse), 52% (Sovereign, pulse), and 64% (WhiteStar). Weights had much more effect on the Legacy Advantec: 3.5 times more going from baseline to 100 g weights and 3.2 times more going from 100 to 200 g weights. For all these comparisons, the P value was less than 0.0001. CONCLUSIONS: The machines behaved fundamentally differently, with the Legacy Advantec controlling stroke length and Sovereign controlling a fixed power at any setting. Therefore, workload had a much bigger impact on Legacy Advantec thermal characteristics. Pulsing decreased heat produced directly related to the duty cycle. The most dangerous incision burn scenario is with continuous ultrasound, aspiration blocked, and a heavy workload