State University of New York System

About: State University of New York System is a education organization based out in Albany, New York, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 54077 authors who have published 78070 publications receiving 2985160 citations.

Assimilation efficiencies of chemical contaminants in aquatic invertebrates: A synthesis

Abstract: Assimilation efficiencies of contaminants from ingested food are critical for understanding chemical accumulation and trophic transfer in aquatic invertebrates. Assimilation efficiency is a first-order physiological parameter that can be used to systematically compare the bioavailability of different contaminants from different foods. The various techniques used to measure contaminant assimilation efficiencies are reviewed. Pulse-chase feeding techniques and the application of gamma-emitting radiotracers have been invaluable in measuring metal assimilation efficiencies in aquatic animals. Uniform radiolabeling of food is required to measure assimilation, but this can be difficult when sediments are the food source. Biological factors that influence contaminant assimilation include food quantity and quality, partitioning of contaminants in the food particles, and digestive physiology of the animals. Other factors influencing assimilation include the behavior of the chemical within the animal's gut and its associations with different geochemical fractions in food particles. Assimilation efficiency is a critical parameter to determine (and to make predictions of) bioaccumulation of chemicals from dietary exposure. Robust estimates of assimilation efficiency coupled with estimates of aqueous uptake can be used to determine the relative importance of aqueous and dietary exposures. For bioaccumulation of metals from sediments, additional studies are required to test whether metals bound to the acid-volatile sulfide fraction of sediments can be available to benthic deposit-feeding invertebrates. Most assimilation efficiency studies have focused on chemical transfer in organisms at the bottom of the food chain; additional studies are required to examine chemical transfer at higher trophic levels.

Low-Level, High-Frequency Mechanical Signals Enhance Musculoskeletal Development of Young Women With Low BMD

Abstract: The potential for brief periods of low-magnitude, high-frequency mechanical signals to enhance the musculoskeletal system was evaluated in young women with low BMD. Twelve months of this noninvasive signal, induced as whole body vibration for at least 2 minutes each day, increased bone and muscle mass in the axial skeleton and lower extremities compared with controls. Introduction: The incidence of osteoporosis, a disease that manifests in the elderly, may be reduced by increasing peak bone mass in the young. Preliminary data indicate that extremely low-level mechanical signals are anabolic to bone tissue, and their ability to enhance bone and muscle mass in young women was inves- tigated in this study. Materials and Methods: A 12-month trial was conducted in 48 young women (15-20 years) with low BMD and a history of at least one skeletal fracture. One half of the subjects underwent brief (10 minutes requested), daily, low-level whole body vibration (30 Hz, 0.3g); the remaining women served as controls. Quantitative CT performed at baseline and at the end of study was used to establish changes in muscle and bone mass in the weight-bearing skeleton. Results: Using an intention-to-treat (ITT) analysis, cancellous bone in the lumbar vertebrae and cortical bone in the femoral midshaft of the experimental group increased by 2.1% ( p 0.025) and 3.4% ( p < 0.001), respectively, compared with 0.1% ( p 0.74) and 1.1% ( p 0.14), in controls. Increases in cancellous and cortical bone were 2.0% ( p 0.06) and 2.3% ( p 0.04) greater, respectively, in the experimental group compared with controls. Cross-sectional area of paraspinous musculature was 4.9% greater ( p 0.002) in the experimental group versus controls. When a per protocol analysis was considered, gains in both muscle and bone were strongly correlated to a threshold in compliance, where the benefit of the mechanical intervention compared with controls was realized once subjects used the device for at least 2 minute/day (n 18), as reflected by a 3.9% increase in cancellous bone of the spine ( p 0.007), 2.9% increase in cortical bone of the femur ( p 0.009), and 7.2% increase in musculature of the spine ( p 0.001) compared with controls and low compliers (n 30). Conclusions: Short bouts of extremely low-level mechanical signals, several orders of magnitude below that associated with vigorous exercise, increased bone and muscle mass in the weight-bearing skeleton of young adult females with low BMD. Should these musculoskeletal enhancements be preserved through adulthood, this intervention may prove to be a deterrent to osteoporosis in the elderly.

Observation of stimulated emission by direct three-photon excitation

Abstract: Multiphoton processes, predicted theoretically in 1931, were for a long time considered to be mainly of academic interest. This view changed when it was shown that a two-photon absorption process could, because of a quadratic dependence of excitation on intensity, produce a spatially confined excitation useful for three-dimensional data storage and imaging. Two-photon absorption has received considerable attention recently because of the development of highly efficient two-photon-sensitive materials, leading to numerous technological applications. These successes have created interest in exploring applications based on three-photon excitations. For a three-photon process, a longer excitation wavelength such as those common in optical communications can be used. Also, the cubic dependence of the three-photon process on the input light intensity provides a stronger spatial confinement, so that a higher contrast in imaging can be obtained. Here we report the observation of a highly directional and up-converted stimulated emission as an amplified spontaneous emission, produced in an organic chromophore solution by a strong simultaneous three-photon absorption at 1.3 microm. This achievement suggests opportunities for a three-photon process in frequency-upconversion lasing, short-pulse optical communications, and the emerging field of biophotonics.

Temporomandibular joint: diagnostic accuracy with sagittal and coronal MR imaging.

Abstract: To determine the diagnostic accuracy, sensitivity, and specificity of magnetic resonance (MR) imaging of the temporomandibular joint (TMJ) in the assessment of disk position, disk form, and changes in the osseous components, 55 fresh cadaver joints were imaged. A 1.5-T imager was used in the sagittal and coronal planes. After MR imaging, the joints were cryosectioned in the coronal plane corresponding to the coronal image through the center of the joint. The joints were then remounted and sectioned serially in the sagittal plane from lateral to medial, corresponding to the sagittal MR images. MR images were interpreted by the two authors together, without knowledge about cryosectional findings. The cryosections were interpreted by the authors together, without knowledge of the MR imaging findings. MR imaging was 95% accurate in the assessment of disk position and disk form and 93% accurate in the assessment of osseous changes. Coronal images helped avoid a false-negative diagnosis in 13% (n = 7) of the jo...