5,563 research outputs found
The Sulzer Hip Replacement Recall Crisis: A Patient\u27s Perspective
This case discusses a product recall that resulted from a manufacturing defect and the degree to which the company distributed accurate and timely information to affected patients. More specifically, the case examines the crisis communication of Sulzer Orthopedics and its efforts to negotiate the interests of various stakeholders, while limiting liability. Written from the perspective of a patient, the case raises interesting questions regarding organizational duties related to product liability. It also provides valuable insights into how organizational communication may have both short- and long-term effects on its relationship with patients and physicians, among others
Interferometric Observations of High-Mass Star-Forming Clumps with Unusual N2H+/HCO+ Line Ratios
The Millimetre Astronomy Legacy Team 90 GHz (MALT90) survey has detected
high-mass star-forming clumps with anomalous NH/HCO(1-0) integrated
intensity ratios that are either unusually high ("NH rich") or
unusually low ("NH poor"). With 3 mm observations from the Australia
Telescope Compact Array (ATCA), we imaged two NH rich clumps,
G333.234-00.061 and G345.144-00.216, and two NH poor clumps,
G351.409+00.567 and G353.229+00.672. In these clumps, the NH rich
anomalies arise from extreme self-absorption of the HCO line.
G333.234-00.061 contains two of the most massive protostellar cores known with
diameters of less than 0.1 pc, separated by a projected distance of only 0.12
pc. Unexpectedly, the higher mass core appears to be at an earlier evolutionary
stage than the lower mass core, which may suggest that two different epochs of
high-mass star formation can occur in close proximity. Through careful analysis
of the ATCA observations and MALT90 clumps (including the G333, NGC 6334, and
NGC 6357 star formation regions), we find that NH poor anomalies arise
at clump-scales and are caused by lower relative abundances of NH due
to the distinct chemistry of H II regions or photodissociation regions.Comment: 18 pages, 18 figures, accepted to Ap
The Drought Monitor
There is a need for improved drought monitoring and assessment methods in the United States. Drought is the most costly natural disaster [Federal Emergency Management Agancy (FEMA 1995; Wilhite 2000)], but it is often neglected by developers of assessment and forecast products. Drought is more nebulous than other disasters and does not lend itself to traditional assessments or forecast methods. Its relatively slow onset and the complexity of its impacts are reasons for the new assessment methodology. Improvements in drought monitoring and forecasting techniques will allow for better preparation, lead to better management practices, and reduce the vulnerability of society to drought and its subsequent impacts.
The Drought Monitor (additional information available online at http://drought.unl/edu/dm) was created with the goal of tracking and displaying the magnitude and spatial extent of drought and its impacts across the United States. The Drought Monitor is produced weekly and classifies drought severity into four major categories, with a fifth category threshold assigned to locations on a map are determined from a number of indicators, or tools, blended with subjective interpretation
Recommended from our members
Highly Speciated Measurements of Terpenoids Emitted from Laboratory and Mixed-Conifer Forest Prescribed Fires
Microbial and metabolic succession on common building materials under high humidity conditions.
Despite considerable efforts to characterize the microbial ecology of the built environment, the metabolic mechanisms underpinning microbial colonization and successional dynamics remain unclear, particularly at high moisture conditions. Here, we applied bacterial/viral particle counting, qPCR, amplicon sequencing of the genes encoding 16S and ITS rRNA, and metabolomics to longitudinally characterize the ecological dynamics of four common building materials maintained at high humidity. We varied the natural inoculum provided to each material and wet half of the samples to simulate a potable water leak. Wetted materials had higher growth rates and lower alpha diversity compared to non-wetted materials, and wetting described the majority of the variance in bacterial, fungal, and metabolite structure. Inoculation location was weakly associated with bacterial and fungal beta diversity. Material type influenced bacterial and viral particle abundance and bacterial and metabolic (but not fungal) diversity. Metabolites indicative of microbial activity were identified, and they too differed by material
Efficient bio-production of citramalate using an engineered Escherichia coli strain
Citramalic acid is a central intermediate in a combined biocatalytic and chemocatalytic route to produce bio-based methylmethacrylate, the monomer used to manufacture Perspex and other high performance materials. We developed an engineered E. coli strain and a fed-batch bioprocess to produce citramalate at concentrations in excess of 80 g l-1 in only 65 h. This exceptional efficiency was achieved by designing the production strain and the fermentation system to operate synergistically. Thus, a single gene encoding a mesophilic variant of citramalate synthase from Methanococcus jannaschii, CimA3.7, was expressed in E. coli to convert acetyl-CoA and pyruvate to citramalate, and the ldhA and pflB genes were deleted. By using a bioprocess with a continuous, growth-limiting feed of glucose, these simple interventions diverted substrate flux directly from central metabolism towards formation of citramalate, without problematic accumulation of acetate. Furthermore, the nutritional requirements of the production strain could be satisfied through the use of a mineral salts medium supplemented only with glucose (172 g l-1 in total) and 1.4 g l-1 yeast extract. Using this system, citramalate accumulated to 82±1.5 g l-1, with a productivity of 1.85 g l-1 h-1 and a conversion efficiency of 0.48 gcitramalate g-1 glucose. The new bioprocess forms a practical first step for integrated bio- and chemocatalytic production of methylmethacrylate
Muscle Recruitment of Upper Trapezius for Computer Workers with Chronic Neck Pain
Muscle Recruitment of Upper Trapezius for Computer Workers with Chronic Neck Pain
aHannah Cline, aMarQiesha Stephens, bDavid Flynn, aScott Marzilli, aX. Neil Dong
aBiomechanics Laboratory, Department of Health and Kinesiology, The University of Texas at Tyler, Tyler, Texas
bEast Texas Doctors of Chiropractic, Tyler, Texas
The lifetime prevalence of chronic neck pain has been reported to be greater than 80% for office computer workers with intensive computer work. Despite the fact that prevention strategies may have reduced the incidence of chronic neck pain, they don’t provide rehabilitation or prevent disease progression for computer workers who already have a symptomatic disease. By providing the means to detect tension that may otherwise go unnoticed of computer workers through the use of intervention strategies, the desire to prevent and reduce muscle tension for symptomatic computer workers can be accomplished. The central hypothesis is that changes in the motor response of symptomatic workers are manifested with abnormally higher muscle activities at rest postures and such modifications in muscle recruitment can be reversed by retraining muscles to be at a more relaxed state by attention of audio or visual biofeedback in motor learning. To test the central hypothesis, differences of muscle activation patterns between normal controls and symptomatic subjects were established by collecting EMG activity of bilateral upper trapezius muscles during a thirty-minute typing task. To meet the criteria for the symptomatic group, our subject has to have neck discomfort related to computer use which has lasted more than three months in the past year and is present in the past seven days. Muscle activities during the typing task were analyzed in terms of Amplitude Probability Distribution Function (APDF) for normalized percentages of reference voluntary contraction. By comparing average muscle activity (50% of APDF), preliminary data from this study indicated that symptomatic workers had higher muscle activities in upper trapezius muscles than asymptomatic workers. Such results may help to establish a preset threshold level of muscle activity to differentiate symptomatic and asymptomatic workers. Based on these preliminary results, a portable EMG-based biofeedback system may be developed to alleviate chronic neck pain of symptomatic computer workers by testing the latter part of our hypothesis that motor learning strategies can be used to reverse the changes in muscle recruitment of these patients
The Mothball, Sustainment, and Proposed Reactivation of the Hypersonic Tunnel Facility (HTF) at NASA Glenn Research Center Plum Brook Station
The Hypersonic Tunnel Facility (HTF) located at the NASA Glenn Research Center s Plum Brook Station in Sandusky, Ohio, is the nation s only large-scale, non-vitiated, hypersonic propulsion test facility. The HTF, with its 4-story graphite induction heater, is capable of duplicating Mach 5, 6, and 7 flight conditions. This unique propulsion system test facility has experienced several standby and reactivation cycles. The intent of the paper is to overview the HTF capabilities to the propulsion community, present the current status of HTF, and share the lessons learned from putting a large-scale facility into mothball status for a later restar
- …
