330 research outputs found
Mobile camera-space manipulation
The invention is a method of using computer vision to control systems consisting of a combination of holonomic and nonholonomic degrees of freedom such as a wheeled rover equipped with a robotic arm, a forklift, and earth-moving equipment such as a backhoe or a front-loader. Using vision sensors mounted on the mobile system and the manipulator, the system establishes a relationship between the internal joint configuration of the holonomic degrees of freedom of the manipulator and the appearance of features on the manipulator in the reference frames of the vision sensors. Then, the system, perhaps with the assistance of an operator, identifies the locations of the target object in the reference frames of the vision sensors. Using this target information, along with the relationship described above, the system determines a suitable trajectory for the nonholonomic degrees of freedom of the base to follow towards the target object. The system also determines a suitable pose or series of poses for the holonomic degrees of freedom of the manipulator. With additional visual samples, the system automatically updates the trajectory and final pose of the manipulator so as to allow for greater precision in the overall final position of the system
Making a market for Miscanthus: Can new contract designs solve the biofuel investment hold-up problem?
We present designs for optimal contracts to solve the investment hold-up problem for perennial crops for the biofuel industry. A fixed-price contract is ex-ante efficient but renegotiation-proof for a limited range of discount parameters. A perfectly- indexed contract is both renegotiation-proof and ex-post efficient. Provided long-run land prices are stationary, the expected cost for both contracts converges to the long-run expected price of land for a risk-neutral farmer.Biofuels, Miscanthus, contract theory, industrial organization, renegotiation-proof contract, Marketing,
Review of: \u3cem\u3eJohn D. Burkholder’s Diaries Written During His Civilian Public Service: Camp 45, Skyline Drive, Luray, Virginia – November 1, 1944 through May 1, 1946\u3c/em\u3e—John D. Burkholder
The book opens with a lengthy introduction by the editors to the history of the Civilian Public Service camps during the 1940s that came to be known simply as CPS camps. The diary begins November 1, 1944, a few months after John D. Burkholder started his service on July 4th at Camp 45. The diary ends abruptly on May 1, 1946. I cannot find exactly when his time of service ended but the editor reports that the camp closed at the end of June of the same year. [First paragraph.
Coherent Coupled Qubits for Quantum Annealing
Quantum annealing is an optimization technique which potentially leverages quantum tunneling to enhance computational performance. Existing quantum annealers use superconducting flux qubits with short coherence times limited primarily by the use of large persistent currents I[subscript p]. Here, we examine an alternative approach using qubits with smaller I[subscript p] and longer coherence times. We demonstrate tunable coupling, a basic building block for quantum annealing, between two flux qubits with small (approximately 50-nA) persistent currents. Furthermore, we characterize qubit coherence as a function of coupler setting and investigate the effect of flux noise in the coupler loop on qubit coherence. Our results provide insight into the available design space for next-generation quantum annealers with improved coherence.United States. Office of the Director of National IntelligenceUnited States. Intelligence Advanced Research Projects ActivityUnited States. Dept. of Defense. Assistant Secretary of Defense for Research & Engineering (FA8721-05-C-0002
Symposium Review: \u3cem\u3eFacing Infotainment Technologies: Evolution Beyond Human\u3c/em\u3e [2nd ed]
Daniel Mast offers a very detailed review of the ever-changing world of information technology and entertainment. The book opens by addressing the pleasure and entertainment aspects of technology and later focuses on how technology has become more advanced and has the potential to be used to monitor and control people. The intended audience is the plain Mennonite, Amish, and Brethren people. He writes from the perspective that the Bible is the final authority and cites many Biblical verses to make his case clear; the Bible gives reason for concern about the infotainment flood. As well as the Bible, the author cites many secular and Christian authors who share his concern. [First paragraph.
Identical probes on different high-density oligonucleotide microarrays can produce different measurements of gene expression
BACKGROUND: There are many potential sources of variability in a microarray experiment. Variation can arise from many aspects of the collection and processing of samples for gene expression analysis. Oligonucleotide-based arrays are thought to minimize one source of variability as identical oligonucleotides are expected to recognize the same transcripts during hybridization. RESULTS: We demonstrate that although the probes on the U133A GeneChip arrays are identical in sequence to probes designed for the U133 Plus 2.0 arrays the values obtained from an experimental hybridization can be quite different. Nearly half of the probesets in common between the two array types can produce slightly different values from the same sample. Nearly 70% of the individual probes in these probesets produced array specific differences. CONCLUSION: The context of the probe may also contribute some bias to the final measured value of gene expression. At a minimum, this should add an extra level of caution when considering the direct comparison of experiments performed in two microarray formats. More importantly, this suggests that it may not be possible to know which value is the most accurate representation of a biological sample when comparing two formats
Bmi1 Promotes Erythroid Development Through Regulating Ribosome Biogenesis
While Polycomb group protein Bmi1 is important for stem cell maintenance, its role in lineage commitment is largely unknown. We have identified Bmi1 as a novel regulator of erythroid development. Bmi1 is highly expressed in mouse erythroid progenitor cells and its deficiency impairs erythroid differentiation. BMI1 is also important for human erythroid development. Furthermore, we discovered that loss of Bmi1 in erythroid progenitor cells results in decreased transcription of multiple ribosomal protein genes and impaired ribosome biogenesis. Bmi1 deficiency stabilizes p53 protein, leading to upregulation of p21 expression and subsequent G0/G1 cell cycle arrest. Genetic inhibition of p53 activity rescues the erythroid defects seen in the Bmi1 null mice, demonstrating that a p53-dependent mechanism underlies the pathophysiology of the anemia. Mechanistically, Bmi1 is associated with multiple ribosomal protein genes and may positively regulate their expression in erythroid progenitor cells. Thus, Bmi1 promotes erythroid development, at least in part through regulating ribosome biogenesis. Ribosomopathies are human disorders of ribosome dysfunction, including Diamond-Blackfan anemia (DBA) and 5q− syndrome, in which genetic abnormalities cause impaired ribosome biogenesis, resulting in specific clinical phenotypes. We observed that BMI1 expression in human hematopoietic stem and progenitor cells from patients with DBA is correlated with the expression of some ribosomal protein genes, suggesting that BMI1 deficiency may play a pathological role in DBA and other ribosomopathies
Why Dose Frequency Affects Spoken Vocabulary in Preschoolers With Down Syndrome
In an earlier randomized clinical trial, daily communication and language therapy resulted in more favorable spoken vocabulary outcomes than weekly therapy sessions in a subgroup of initially nonverbal preschoolers with intellectual disabilities that included only children with Down syndrome (DS). In this reanalysis of the dataset involving only the participants with DS, we found that more therapy led to larger spoken vocabularies at posttreatment because it increased children’s canonical syllabic communication and receptive vocabulary growth early in the treatment phase
The Use of Mentored Inquiry Communities to Foster Scholarship of Teaching and Learning (SoTL): Outcomes of the American Occupational Therapy Association SoTL Program (2007-2017)
Scholarship of teaching and learning (SoTL) is recognized in Boyer’s model, along with discovery, integration, and application, as one of four essential scholarships and is the systematic study of teaching and learning. As such, in 2007, the American Occupational Therapy Foundation (AOTF), and later the American Occupational Therapy Association (AOTA), supported the development of a SoTL mentorship program in an effort to foster SoTL within the discipline of occupational therapy. This mixed-methods study describes AOTA SoTL Program outcomes across ten years, 2007-2017, gathered via survey of past program mentee (n = 50) and mentor (n = 12) participants. Results suggest that mentored inquiry communities are a useful approach to fostering SoTL collaborations. In the future, the AOTA SoTL Program and similar disciplinary-specific SoTL programs should consider additional strategies for supporting mentee participants to completion with their projects
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