1,658 research outputs found
A Conversation with Alan Gelfand
Alan E. Gelfand was born April 17, 1945, in the Bronx, New York. He attended
public grade schools and did his undergraduate work at what was then called
City College of New York (CCNY, now CUNY), excelling at mathematics. He then
surprised and saddened his mother by going all the way across the country to
Stanford to graduate school, where he completed his dissertation in 1969 under
the direction of Professor Herbert Solomon, making him an academic grandson of
Herman Rubin and Harold Hotelling. Alan then accepted a faculty position at the
University of Connecticut (UConn) where he was promoted to tenured associate
professor in 1975 and to full professor in 1980. A few years later he became
interested in decision theory, then empirical Bayes, which eventually led to
the publication of Gelfand and Smith [J. Amer. Statist. Assoc. 85 (1990)
398-409], the paper that introduced the Gibbs sampler to most statisticians and
revolutionized Bayesian computing. In the mid-1990s, Alan's interests turned
strongly to spatial statistics, leading to fundamental contributions in
spatially-varying coefficient models, coregionalization, and spatial boundary
analysis (wombling). He spent 33 years on the faculty at UConn, retiring in
2002 to become the James B. Duke Professor of Statistics and Decision Sciences
at Duke University, serving as chair from 2007-2012. At Duke, he has continued
his work in spatial methodology while increasing his impact in the
environmental sciences. To date, he has published over 260 papers and 6 books;
he has also supervised 36 Ph.D. dissertations and 10 postdocs. This interview
was done just prior to a conference of his family, academic descendants, and
colleagues to celebrate his 70th birthday and his contributions to statistics
which took place on April 19-22, 2015 at Duke University.Comment: Published at http://dx.doi.org/10.1214/15-STS521 in the Statistical
Science (http://www.imstat.org/sts/) by the Institute of Mathematical
Statistics (http://www.imstat.org
A d-Amino Acid at the N-Terminus of a Protein Abrogates Its Degradation by the N-End Rule Pathway
Eukaryotes have evolved the ubiquitin (Ub)/proteasome system to degrade polypeptides. The Ub/proteasome system is one way that cells regulate cytosolic protein and amino acids levels through the recognition and ubiquitination of a protein’s N-terminus via E1, E2, and E3 enzymes. The process by which the N-terminus stimulates intracellular protein degradation is referred to as the N-end rule. Characterization of the N-end rule has been limited to only the natural l-amino acids. Using a cytosolic delivery platform derived from anthrax lethal toxin, we probed the stability of mixed chirality proteins, containing one d-amino acid on the N-terminus of otherwise all l-proteins. In all cases, we observed that one N-terminal d-amino acid stabilized the cargo protein to proteasomal degradation with respect to the N-end rule. We found that since the mixed chirality proteins were not polyubiquitinated, they evaded N-end-mediated proteasomal degradation. Evidently, a subtle change on the N-terminus of a natural protein can enhance its intracellular lifetime.MIT Faculty Start-up FundMassachusetts Institute of Technology. Charles E. Reed Faculty Initiative FundNational Science Foundation (U.S.) (CAREER Award CHE-1351807)Damon Runyon Cancer Research FoundationNational Science Foundation (U.S.). Graduate Research Fellowship Progra
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Changes in the Organization of Paternal Behavior during Early and Middle Childhood
Out With the Old, In With the New: Are Western Commodity Producers Ready for Buyouts?
Agricultural and Food Policy,
Comparative in vitro evaluation of contact activity of fluralaner, spinosad, phoxim, propoxur, permethrin and deltamethrin against the northern fowl mite, Ornithonyssus sylviarum.
BackgroundNorthern fowl mites (Ornithonyssus sylviarum) are obligate hematophagous ectoparasites of both feral birds and poultry, particularly chicken layers and breeders. They complete their entire life-cycle on infested birds while feeding on blood. Infestations of O. sylviarum are difficult to control and resistance to some chemical classes of acaricides is a growing concern. The contact susceptibility of O. sylviarum to a new active ingredient, fluralaner, was evaluated, as well as other compounds representative of the main chemical classes commonly used to control poultry mite infestations in Europe and the USA.MethodsSix acaricides (fluralaner, spinosad, phoxim, propoxur, permethrin, deltamethrin) were dissolved and serially diluted in butanol:olive oil (1:1) to obtain test solutions used for impregnation of filter paper packets. A carrier-only control was included. Thirty adult northern fowl mites, freshly collected from untreated host chickens, were inserted into each packet for continuous compound exposure. Mite mortality was assessed after incubation of the test packets for 48 h at 75% relative humidity and a temperature of 22 °C.ResultsAdult mite LC50 /LC99 values were 2.95/8.09 ppm for fluralaner, 1587/3123 ppm for spinosad, 420/750 ppm for phoxim and 86/181 ppm for propoxur. Permethrin and deltamethrin LC values could not be calculated due to lack of mortality observed even at 1000 ppm.ConclusionsNorthern fowl mites were highly sensitive to fluralaner after contact exposure. They were moderately sensitive to phoxim and propoxur, and less sensitive to spinosad. Furthermore, the tested mite population appeared to be resistant to the pyrethroids, permethrin and deltamethrin, despite not being exposed to acaricides for at least 10 years
Professional Services Offered in Rural, Mixed-Animal Veterinary Practices
Rural, mixed animal veterinary practices offer a variety of professional services to their clientele. Practitioners must decide which services to offer and how much time to dedicate to each offering. These decisions are influenced by the perceived need for each service in the area and the potential income that can be generated from the specific service
Automated Mobile System for Accurate Outdoor Tree Crop Enumeration Using an Uncalibrated Camera.
This paper demonstrates an automated computer vision system for outdoor tree crop enumeration in a seedling nursery. The complete system incorporates both hardware components (including an embedded microcontroller, an odometry encoder, and an uncalibrated digital color camera) and software algorithms (including microcontroller algorithms and the proposed algorithm for tree crop enumeration) required to obtain robust performance in a natural outdoor environment. The enumeration system uses a three-step image analysis process based upon: (1) an orthographic plant projection method integrating a perspective transform with automatic parameter estimation; (2) a plant counting method based on projection histograms; and (3) a double-counting avoidance method based on a homography transform. Experimental results demonstrate the ability to count large numbers of plants automatically with no human effort. Results show that, for tree seedlings having a height up to 40 cm and a within-row tree spacing of approximately 10 cm, the algorithms successfully estimated the number of plants with an average accuracy of 95.2% for trees within a single image and 98% for counting of the whole plant population in a large sequence of images
Blueprint for the Dissemination of Evidence-Based Practices in Health Care
Proposes strategies for better dissemination of best practices through quality improvement campaigns, including campaigns aligned with adopting organizations' goals, practical implementation tools and guides, and networks to foster learning opportunities
The Rich Get Richer: Enabling Conditions for Knowledge Use in Organizational Work Teams
Individuals on the periphery of organizational knowledge sharing networks, due to inexperience, location, or lack of social capital, may struggle to access useful knowledge at work. An electronic knowledge repository (KR) has the potential to help peripheral individuals gain access to valuable knowledge because a KR is universally and constantly available and can be used without social interaction. However, for it to serve this equalizing function, those on the periphery of the organization must actually use it, possibly overcoming barriers to doing so. In this paper, we develop a multi-level model of knowledge use in teams and show that individuals whose experience and position already provide them access to vital knowledge use a KR more frequently than individuals on the organizational periphery. We argue that this occurs because the KR – despite its appearance of equivalent accessibility to all – is actually more accessible to central than peripheral players due to their greater experience and access to colleagues. Thus, KR use is not driven primarily by the need to overcome limited access to other knowledge sources. Rather KR use is enabled when actors know how to reap value from the KR, which ironically improves with increasing access to other sources of knowledge. Implications for both team effectiveness and knowledge management research are offered. We conclude that KRs are unlikely to serve as a knowledge equalizer without intervention
Examining 4-H Robotics in the Learning of Science, Engineering and Technology Topics and the Related Student Attitudes
Youths’ natural fascination and identification with robots make them an ideal teaching and learning platform. Robots would seem to be excellent hands-on tools to teach science, engineering and technology (SET) concepts. However, while research supports their use to increase interest and motivation, the effectiveness of robots to directly teach science, engineering, and technology concepts is less clear. The purpose of this study was to measure the effectiveness of a 4-H robotics program to support the learning of specific SET concepts and to examine related student attitudes towards science. This study compared the pretest and posttest scores on an assessment of basic SET concepts and attitudes of youth who participated in the 4-H robotics intervention with the scores of youth in a control group.
Analysis of covariance (ANCOVA) results revealed that youth in the robotics intervention scored better on a SET concepts posttest. Student attitudes toward science were also investigated. The results suggested that educational robotics can engage youth in activities that support their learning of SET topics, but that it may have more limited impact on general student attitudes towards science, as measured by the study\u27s attitudinal instrument
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