2,663 research outputs found
Trade and Wages: A Deeper Investigation
A new presentation of the specific factors model shows how labor fares under international trade by considering how the price elasticity of the nominal wage rate responds to the terms of trade as well as factor endowments. Gains to labor are decomposed into measurable terms of trade effects and production bias effects. If trade is caused by differences in technology, trade can harm the interests of labor when the elasticities of substitution are sufficiently small. If trade is caused by differences in labor endowments, trade raises real wages in the labor abundant country, even if exports are capital intensive.trade, real wages, beta function, specific factors
Relative Survival and Contribution of Saugers Stocked in the Peoria Pool of the Illinois River, 1990–1995
Numbers of sauger Stizostedion canadense declined in the Peoria Pool of the Illinois River from the 1970s to the 1990s. Stocking was evaluated as a means of supplementing natural reproduction in the pool. Marked fry were stocked in 1991–1994 (20–176/ha), and marked fingerlings were stocked in 1990–1995 (,1–20/ha). In 1990, fingerlings with a mean total length of 44 mm were stocked in June, and 92-mm fingerlings were stocked in September and October. Relative survival was 4.9:1 in favor of the 44-mm fingerlings. During 1991–1994, relative survival averaged 440:1 for stocked fingerlings (39–61 mm) versus fry. From 1990 to 1995, contribution of stocked saugers to the year-classes averaged 33.9% at age 0. Because of the immigration of wild saugers into Peoria Pool and emigration of stocked and wild fish to other pools, contributions of stocked saugers to individual year-classes decreased each year subsequent to stocking. Mean contribution of stocked saugers at harvestable ages (age 2 and older) was 9.1%. Total contribution of all stocked saugers after 6 years to all year-classes was 22.8%
The Relationship Between Arachidonic Acid Release and Catecholamine Secretion from Cultured Bovine Adrenal Chromaffin Cells
Increased arachidonic acid release occurred during activation of catecholamine secretion from cul- tured bovine adrenal medullary chromaffin cells. The nicotinic agonist l,l-dimethyl-4-phenylpiperazinium (DMPP) caused an increased release of prcincubated [ 3 H]arachidonic acid over a time course which corre- sponded to the stimulation of catecholamine secretion. Like catecholamine secretion, the DMPP-induced [ 3 H]arachidonic acid release was calcium-dependent and was blocked by the nicotinic antagonist mecamylamine. Depolarization by elevated K + , which induced catechol amine secretion, also stimulated arachidonic acid release. Because arachidonic acid release from cells probably re- sults from phospholipase A 2 activity, our findings indicate that phospholipase A 2 may be activated in chromaffin cells during secretion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66068/1/j.1471-4159.1984.tb06690.x.pd
Arachidonic Acid Release and Catecholamine Secretion from Digitonin-Treated Chromaffin Cells: Effects of Micromolar Calcium, Phorbol Ester, and Protein Alkylating Agents
The relationship between catecholamine secretion and arachidonic acid release from digitonin-treated chromaffin cells was investigated. Digitonin renders permeable the plasma membranes of bovine adrenal chromaffin cells to Ca 2+ , ATP, and proteins. Digitonin-treated cells undergo exocytosis of catecholamine in response to micromolar Ca 2+ in the medium. The addition of micromolar Ca 2+ to digitonin-treated chromaffin cells that had been prelabeled with [ 3 H]arachidonic acid caused a marked increase in the release of [ 3 H]arachidonic acid. The time course of [ 3 H]arachidonic acid release paralleled catecholamine secretion. Although [ 3 H]arachidonic acid release and exocytosis were both activated by free Ca 2+ in the micromolar range, the activation of [ 3 H]arachidonic acid release occurred at Ca 2+ concentrations slightly lower than those required to activate exocytosis. Pretreatment of the chromaffin cells with N -ethylmaleimide (NEM) or p -bromophenacyl bromide (BPB) resulted in dose-dependent inhibition of 10 Μ M Ca 2+ -stimulated [ 3 H]arachidonic acid release and exocytosis. The IC 50 of NEM for both [ 3 H]arachidonic acid release and exocytosis was 40 Μ M. The IC 50 of BPB for both events was 25 Μ M. High concentrations (5–20 m M ) of Mg 2+ caused inhibition of catecholamine secretion without altering [ 3 H]arachidonic acid release. A phorbol ester that activates protein kinase C, 12- O -tetradecanoylphorbol-13-acetate (TPA), caused enhancement of both [ 3 H]arachidonic acid release and exocytosis. The findings demonstrate that [ 3 H]arachidonic acid release is stimulated during catecholamine secretion from digitonin-treated chromaffin cells and they are consistent with a role for phospholipase A 2 in exocytosis from chromaffin cells. Furthermore the data suggest that protein kinase C can modulate both arachidonic acid release and exocytosis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65534/1/j.1471-4159.1985.tb07140.x.pd
Predicting the Focus of Cryogenicaly-Cooled Optical Systems
Results of an experimental study to ascertain how well the focal -plane location of cryogenically -cooled optical systems can be predicted are reported. These results indicate that if the required low- temperature thermal expansion and index -of- refraction data are available, the focal shift caused by cooling to cryogenic temperatures can be accurately predicted by simply computing the shift in the paraxial focus. In this study, the differences between the measured focal shifts and the computed shift in the paraxial focus were less than the diffraction -limited depth -of -focus tolerance. The results of this study also indicate that for off - the -shelf optical systems ray- tracing analysis may not adequately predict the absolute location of the focal plane. Thus, the following method of predicting the focal -plane location of a cryogenically- cooled optical system is suggested: first measure the focal -plane location with the optics at room temperature, and then add the computed paraxial focal shift to the measured location
Frequency of Natural Hybridization between Saugers and Walleyes in the Peoria Pool of the Illinois River, as Determined by Morphological and Electrophoretic Criteria
External morphological characteristics and protein electrophoresis at two diagnostic loci were used to determine the proportion of 704 Stizostedion samples collected from the Peoria Pool of the Illinois River during March 1995 that were saugers S. canadense, walleyes S. vitreum, or their hybrids. Morphological analyses indicated that 616 (87.5%) fish were saugers, 58 (8.2%) were walleyes, and 30 (4.3%) were hybrids; electrophoretic analyses indicated that 625 (88.8%) fish were saugers, 50 (7.1%) were walleyes, and 29 (4.1%) were hybrids. Clear discrepancies between the morphological and electrophoretic analyses affected at least 43 (6.1%) fish. Only 2% of saugers were hybrids, but at least 14% of walleyes possessed sauger alleles. Polymorphism at the PGM-1* locus in Peoria Pool saugers was also identified. We recommend electrophoretic screening for hybrids if saugers or walleyes are collected for use as broodstock from waters where they co-occur
Efficacy of tofacitinib monotherapy in methotrexate-naive patients with early or established rheumatoid arthritis.
IntroductionTofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). Tofacitinib monotherapy was previously shown to inhibit structural damage, reduce clinical signs and symptoms of RA, and improve physical functioning over 24 months in methotrexate (MTX)-naive adult patients with RA. In this post hoc analysis, we compared efficacy and safety of tofacitinib in patients with early (disease duration <1 year) versus established (≥1 year) RA.MethodsMTX-naive patients ≥18 years with active RA received tofacitinib monotherapy (5 or 10 mg two times a day, or MTX monotherapy, in a 24-month Phase 3 trial.ResultsOf 956 patients (tofacitinib 5 mg two times a day, n=373; tofacitinib 10 mg two times a day, n=397; MTX, n=186), 54% had early RA. Baseline disease activity and functional disability were similar in both groups; radiographic damage was greater in patients with established RA. At month 24, clinical response rates were significantly greater in patients with early versus established RA in the tofacitinib 5 mg two times a day group. Both tofacitinib doses had greater effects on clinical, functional and radiographic improvements at 1 and 2 years compared with MTX, independent of disease duration. No new safety signals were observed.ConclusionsTreatment response was generally similar in early and established RA; significantly greater improvements were observed at month 24 with tofacitinib 5 mg two times a day in early versus established RA. Tofacitinib 5 and 10 mg two times a day demonstrated greater efficacy versus MTX irrespective of disease duration. No difference in safety profiles was observed between patients with early or established RA.Trial registration numberNCT01039688; Results
The effectiveness of coated urea prills and copper treated urea prills as nitrogen sources for rumen microorganisms
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