933 resultados para Course of study
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Glutamate transporters in the central nervous system are expressed in both neurons and glia, they mediate high affinity, electrogenic uptake of glutamate, and they are associated with an anion conductance that is stoichiometrically uncoupled from glutamate flux. Although a complete cycle of transport may require 50–100 ms, previous studies suggest that transporters can alter synaptic currents on a much faster time scale. We find that application of l-glutamate to outside-out patches from cerebellar Bergmann glia activates anion-potentiated glutamate transporter currents that activate in <1 ms, suggesting an efficient mechanism for the capture of extrasynaptic glutamate. Stimulation in the granule cell layer in cerebellar slices elicits all or none α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor and glutamate transporter currents in Bergmann glia that have a rapid onset, suggesting that glutamate released from climbing fiber terminals escapes synaptic clefts and reaches glial membranes shortly after release. Comparison of the concentration dependence of both α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor and glutamate transporter kinetics in patches with the time course of climbing fiber-evoked responses indicates that the glutamate transient at Bergmann glial membranes reaches a lower concentration than attained in the synaptic cleft and remains elevated in the extrasynaptic space for many milliseconds.
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Predominant usage of V beta 8.2 gene segments, encoding a T-cell receptor (TCR) beta chain variable region, has been reported for pathogenic Lewis rat T cells reactive to myelin basic protein (MBP). However, up to 75% of the alpha/beta T cells in a panel of MBP-specific T-cell lines did not display TCR V beta 8.2, V beta 8.5, V beta 10, or V beta 16 elements. To further investigate TCR usage, we sorted the T-cell lines for V beta 8.2- and V beta 10-positive T cells or depleted the lines of cells with these TCRs. V beta 8.2-positive T cells and one of the depleted T-cell lines strongly reacted against the MBP peptide MBP-(68-88). The depleted T-cell line caused marked experimental autoimmune encephalomyelitis (EAE) even in Lewis rats in which endogenous V beta 8.2-positive T cells had been eliminated by neonatal treatment with anti-V beta 8.2 monoclonal antibodies. T-cell hybridomas generated from this line predominantly used V beta 3 TCR genes coexpressed with TCR V alpha 2 transcripts, which were also used by V beta 8.2-positive T cells. Furthermore, V beta 10-positive T cells reactive to MBP-(44-67) were encephalitogenic when injected immediately after positive selection. After induction of EAE by sorted V beta 8.2- or V beta 10-positive T-cell lines, immunocytochemical analysis of the spinal cord tissue showed a predominance of the injected TCR or of nontypable alpha/beta T cells after injection of the depleted line. Our results demonstrate heterogeneity of TCR beta-chain usage even for a single autoantigen in an inbred strain. Moreover, V beta 8.2-positive T cells are not essential for the induction and progression of adoptive-transfer EAE.
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Leather hardcover notebook containing a handwritten copy of John Winthrop's course of experimental and philosophical lectures presented between March 10, 1746 and June 16, 1746. The first one-hundred pages of the volume are divided into twenty chapters which were presented in thirty-three lectures. The chapters contain text and diagrams on mechanical powers, the lever, the pulley, the axis in peritrochio, the inclined plane, the wedge, the screw, compound engines, the laws of motion, gravity, attraction of cohesion, the power of repulsion, magnetism, fluids, electricity, opticks, and astronomy. There is a five-page addenda to the course summary added in 1747, and a sixty-page text titled "The Method of Astronomical calculations" containing thirteen problems related to calculating distances with a list of astronomical characters, and followed with charts related to the eclipse of Jupiter's satellites.
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This hardcover volume contains manuscript copies of Charles Morton's "A System of Ethicks," "Pneumatics. Or a treatise of the Rev'd Mr. Charles Morton about ye Nature of Spirit," "Appendix of the Souls of Brutes," "Some Theological Questions Answd," and a one-page list "Texts of Scripture to prove if ye head of Christ &c." copied by Harvard student Ebenezer Williams in February 1707/8.
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The small hardcover notebook contains a manuscript copy of Charles Morton's Natural Philosophy copied by student Ebenezer Parkman (Harvard Class of 1721) in 1720, as well as notes on Hebrew grammar. The flyleaf has a faded note, "[This copy] was probably made by Parkman H.U. 1721 afterward minister of Westboro." The title page of the volume includes the handwritten title "Phylosophia Natvralis: Naturall Philosophy, By the Reverd Mr. Charles Morton Pastor of a Church in Charles Town, Beegan [sic] to recite it December 11, 1720 Willm Brattle's Book 1720 ended January 30 Anno Domini 1720 [January 30, 1720/1721]." The final page of the transcription is signed and dated "June 18, 1720 Parkman." The last pages of the volume consist of notes on Hebrew Grammar titled "Instruction in Hebrew."
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With the huge growth in enrolment in higher education, the key question facing young people today is not so much “what to study” as “whether to study”. Taking a methodologically innovative approach, this paper measures the net present value of university education and compares returns from studying a range of different subjects. We use data from 5 European countries (France, Italy, Hungary, Poland and Slovenia) and include (opportunity) costs in the computation. Results suggest that enrolling in science, technology, engineering and mathematics (STEM) courses is often not the best investment for students, especially female students. In choosing what to study, therefore, students are taking decisions that are consistent with their own private returns. This suggests that policymakers should consider changing the incentives offered if they wish to change students’ behaviour.
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At head of title: Dept. of libraries, loans, and course of study.
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Head-piece; initial.
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"B-133220."
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Cover title: Introductory address delivered before the Young Men's Association of Albany on the evening of December 4, 1838, by William B. Sprague.