2,516 research outputs found
Are we overusing IVF?
Peer reviewedPublisher PD
Some Observations and Comments on Birdsfoot Trefoil
Farmer\u27s Bulletin No. 2191, TREFOIL PRODUCTION FOR PASTURE AND HAY, was released by the U.S. Department of Agriculture in July, 1967. This publication noted that acreages of trefoil in the U.S. increased from 770,000 in 1957 to over 2 million acres in 1967. This bulletin is an excellent guide to kinds of trefoils, to the different varieties available, and to general production practices in obtaining stands and in managing this legume. It is stated in the bulletin that birdsfoot trefoil is not recommended south of a line drawn from the Nebraska-Kansas border to the east coast, except at higher elevations. (The very northern tip of Kentucky is about 70 miles south of the Nebraska-Kansas line.
A New Atomic Force Microscopy Technique for the Measurement of the Elastic Properties of Biological Materials
We developed a new technique to measure elastic properties by using the atomic force microscope (AFM) tip to press samples into grooves etched in a GaAs substrate.
We measured the Young\u27s modulus of Ī²-chitin fibres with cross-sections less than 40 nm X 20 nm to be 1-2 X 1011 N/m2. In the isotropic approximation, the Young\u27s modulus of the S-layer sheath of the archaeobacterium Methanospirillum hungatei was 1-3 X 1010 N/m2. By testing the sheath to breaking strength we estimated the bacterium can sustain an internal pressure as high as 100-200 atmospheres (1-2 x 107 N/m2)
New ADS Functionality for the Curator
In this paper we provide an update concerning the operations of the NASA
Astrophysics Data System (ADS), its services and user interface, and the
content currently indexed in its database. As the primary information system
used by researchers in Astronomy, the ADS aims to provide a comprehensive index
of all scholarly resources appearing in the literature. With the current effort
in our community to support data and software citations, we discuss what steps
the ADS is taking to provide the needed infrastructure in collaboration with
publishers and data providers. A new API provides access to the ADS search
interface, metrics, and libraries allowing users to programmatically automate
discovery and curation tasks. The new ADS interface supports a greater
integration of content and services with a variety of partners, including ORCID
claiming, indexing of SIMBAD objects, and article graphics from a variety of
publishers. Finally, we highlight how librarians can facilitate the ingest of
gray literature that they curate into our system.Comment: Submitted to the Proceedings of Library and Information Services in
Astronomy VIII, Strasbourg, Franc
Compositional Analysis of Lignocellulosic Feedstocks. 2. Method Uncertainties
The most common procedures for characterizing the chemical components
of lignocellulosic feedstocks use a two-stage sulfuric acid hydrolysis
to fractionate biomass for gravimetric and instrumental analyses.
The uncertainty (i.e., dispersion of values from repeated measurement)
in the primary data is of general interest to those with technical
or financial interests in biomass conversion technology. The composition
of a homogenized corn stover feedstock (154 replicate samples in 13
batches, by 7 analysts in 2 laboratories) was measured along with
a National Institute of Standards and Technology (NIST) reference
sugar cane bagasse, as a control, using this laboratory's suite of
laboratory analytical procedures (LAPs). The uncertainty was evaluated
by the statistical analysis of these data and is reported as the standard
deviation of each component measurement. Censored and uncensored versions
of these data sets are reported, as evidence was found for intermittent
instrumental and equipment problems. The censored data are believed
to represent the ābest caseā results of these analyses,
whereas the uncensored data show how small method changes can strongly
affect the uncertainties of these empirical methods. Relative standard
deviations (RSD) of 1ā3% are reported for glucan, xylan, lignin,
extractives, and total component closure with the other minor components
showing 4ā10% RSD. The standard deviations seen with the corn
stover and NIST bagasse materials were similar, which suggests that
the uncertainties reported here are due more to the analytical method
used than to the specific feedstock type being analyzed
What lies beneath? The role of informal and hidden networks in the management of crises
Crisis management research traditionally focuses on the role of formal communication networks in the escalation and management of organisational crises. Here, we consider instead informal and unobservable networks. The paper explores how hidden informal exchanges can impact upon organisational decision-making and performance, particularly around inter-agency working, as knowledge distributed across organisations and shared between organisations is often shared through informal means and not captured effectively through the formal decision-making processes. Early warnings and weak signals about potential risks and crises are therefore often missed. We consider the implications of these dynamics in terms of crisis avoidance and crisis management
ACCUMULATION AND RETENTION OF TRITIUM (TRITIATED WATER) IN EMBRYONIC AND LARVAL FISH, AND RADIATION EFFECT.
This report addresses the accumulation and retention of tritium in embryonic and larval fish, and radiation effec
- ā¦