Effect of Substitution of Ca on Thermal Expansion of Cordierite (Mg2Al4Si5O18)

The effect of substitution of calcium on the anisotropic axial thermal expansion of cordierite was investigated by using a high-temperature X-ray diffraction technique. The compositions were prepared by the sol–gel route. In the Mg2-xCax-Al4Si5O18 system, single-phase cordierite can be prepared for x up to 0.5. Thermal expansion anisotropy (αa–αc) of cordierites reduces progressively by the substitution of increasing amounts of Ca for Mg.

Letter: To Molly Wesley from John Wesley, March 30, 1751

Digitized from a letter in the Drew University Methodist Collection. 1 Item (4 p.); 20.5 x 33 cm.

The martyrs of Golbanti : or missionary heroism illustrated in the lives of Rev. John and Mrs. Houghton, of East Africa / by Robert Brewin.

http://www.archive.org/details/martyrsofgolbant00brewiala

Ca(2+) signals coordinate zygotic polarization and cell cycle progression in the brown alga Fucus serratus

Zygotes of the fucoid brown algae provide excellent models for addressing fundamental questions about zygotic symmetry breaking. Although the acquisition of polarity is tightly coordinated with the timing and orientation of the first asymmetric division-with zygotes having to pass through a G1/S-phase checkpoint before the polarization axis can be fixed -the mechanisms behind the interdependence of polarization and cell cycle progression remain unclear. In this study, we combine in vivo Ca(2+) imaging, single cell monitoring of S-phase progression and multivariate analysis of high-throughput intracellular Ca(2+) buffer loading to demonstrate that Ca(2+) signals coordinate polarization and cell cycle progression in the Fucus serratus zygote. Consistent with earlier studies on this organism, and in contrast to animal models, we observe no fast Ca(2+) wave following fertilization. Rather, we show distinct slow localized Ca(2+) elevations associated with both fertilization and S-phase progression, and we show that both S-phase and zygotic polarization are dependent on pre-S-phase Ca(2+) increases. Surprisingly, this Ca(2+) requirement cannot be explained by co-dependence on a single G1/ S-phase checkpoint, as S phase and zygotic polarization are differentially sensitive to pre-S-phase Ca(2+) elevations and can be uncoupled. Furthermore, subsequent cell cycle progression through M phase is independent of localized actin polymerization and zygotic polarization. This absence of a morphogenesis checkpoint, together with the observed Ca(2+)dependences of S phase and polarization, show that the regulation of zygotic division in the brown algae differs from that in other eukaryotic model systems, such as yeast and Drosophila.

Pharmacological profiling of store-operated Ca(2+) entry in retinal arteriolar smooth muscle

Objective: Pharmacological profiling of store-operated Ca(2+) entry (SOCE) and molecular profiling of ORAI and TRPC expression in arterioles. 
Methods: Fura-2 based microfluorimetry was used to assess CPA-induced SOCE in rat retinal arteriolar myocytes. Arteriolar ORAI and TRP transcript expression were screened using RT-PCR. 
Results: SKF96365 and LOE908 blocked SOCE (IC(50) s of 1.2µM and 1.4µM, respectively). Gd(3+) and La(3+) potently inhibited SOCE (IC(50) s of 21nM and 42nM, respectively), but Ni(2+) showed lower potency (IC(50) = 11.6µM). 2-aminoethyldiphenyl borate (2APB) inhibited SOCE (IC(50) = 3.7µM) but enhanced basal influx (>100µM). Verapamil and nifedipine had no effect at concentrations that inhibit L-type Ca(2+) channels, but diltiazem inhibited SOCE by approximately 40% (=0.1µM). RT-PCR demonstrated transcript expression for ORAI 1, 2 and 3, and TRPC1, 3, 4 and 7. Transcripts for TRPV1 and 2, which are activated by 2APB, were also expressed. 
Conclusion: The pharmacological profile of SOCE in retinal arteriolar smooth muscle appears unique when compared to other vascular tissues. This suggests that the molecular mechanisms underlying SOCE can differ, even in closely related tissues. Taken together, the pharmacological and molecular data are most consistent with involvement of TRPC1 in SOCE, although involvement of ORAI or other TRPC channels cannot be excluded. © 2012 John Wiley & Sons Ltd.

Compte rendu: Johann Wolfgang Unger (2013), The Discursive Construction of the Scots Language : Education, Politics and Everyday Life, Amsterdam, John Benjamins, coll. « Discourse Approaches to Politics, Society and Culture, 51 », 178 p. [ISBN : 978-9-027-20642-8]

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Letters to the Honourable John H. Dunn, 1837-1838

The recipient of the letters is John Henry Dunn who was born on St. Helena (a British territory island of volcanic origin located in the South Atlantic Ocean) in 1792 to John Charles Dunn and Elizabeth Bazette. He was married to Charlotte Roberts on May 4th, 1820 and they had 6 sons and 2 daughters. He came to Canada in 1820 in which year he became the Receiver General for Canada. He held this position until 1841.Charlotte died in 1835. In 1822 he was named to the Province’s Legislative Council. He was president of the Welland Canal Company from 1825-1833. In 1836 he was named to the executive council of Upper Canada but resigned 3 weeks later with fellow counselors when lieutenant governor Sir Francis Bond refused the advice of the council. Dunn was made the Receiver General for the newly formed Province of Canada in 1841, and was elected to represent Toronto in the legislative assembly that year. He married his second wife on March 9th, 1842. Her name was Sophie-Louise Juchereau Duchsnay. They had a son and a daughter. In 1843 he resigned, and was not re-elected in 1844. He returned to England with his family and died in London on April 21, 1854. Dunn was a supporter of the Welland Canal, St. Lawrence Canals and other public improvements. Between the passage of the Canada Trade Act and the Act of the Union he had tried to insure that projects received funding despite financial constraints. He claimed that he has saved Upper Canada from bankruptcy. His son, Alexander Roberts Dunn received the Victoria Cross for his role in the Charge of the Light Brigade at Balaclava. Dunn Street in Niagara Falls is named after John Henry Dunn. The town and township of Dunnville were also named for him. Sources: http://biographi.ca/009004-119.01-e.php?id_nbr=3889 http://www.niagarafrontier.com/cityfalls.html

Niagara Falls Seminary [school for young Ladies] advertisement, ca. 1840

One broadside advertising the Niagara Falls Seminary [school for young Ladies], run by Mrs. Shotter of Drummondville, ca. 1840. The advertisement contains information about fees and courses, including a complete English education, music, French, drawing and flower painting, and dancing. The bottom of the page contains a list of references for Mrs. Shotter, including Ex-Consul Buchanan, Colonel Delatre, Rev. W. Leeming, Rector of Chippawa (all of Drummondville); Dr. Mewburn (Stamford); Rev. T.B. Fuller, Rector of Thorold; John Stayner, Esq., P.M. Queenston; William Gamble, Esq., Milton, near Toronto; and Hon. John Hamilton, Kingston.

Niagara Falls Seminary [school for young Ladies] advertisement, ca. 1840

One broadside advertising the Niagara Falls Seminary [school for young Ladies], run by Mrs. Shotter of Drummondville, ca. 1840. The advertisement contains information about fees and courses, including a complete English education, music, French, drawing and flower painting, and dancing. The bottom of the page contains a list of references for Mrs. Shotter, including Ex-Consul Buchanan, Colonel Delatre, Rev. W. Leeming, Rector of Chippawa (all of Drummondville); Dr. Mewburn (Stamford); Rev. T.B. Fuller, Rector of Thorold; John Stayner, Esq., P.M. Queenston; William Gamble, Esq., Milton, near Toronto; and Hon. John Hamilton, Kingston.

John Forester : observateur d’épisodes dramatiques de la planification urbain

Commentaires sur le livre de John Forester, "Dealing With Differences: Dramas of Mediating Public Disputes", Oxford, Oxford University Press, 2009.

Análisis de la actuación de la Autoridad Ejecutiva Temporal de las Naciones Unidas – (UNTEA) en la protección de los derechos políticos de los grupos vulnerables. Estudio de caso: Adhesión de Papúa Occidental a Indonesia (1962-1969)

Estudio de caso en el análisis de la situación afrontada por la población de Papúa Occidental durante el periodo de 1962-1969, época en la que la nueva República de Indonesia y Holanda se disputaban la soberanía sobre el territorio papuano. Dicha disputa tuvo lugar durante la época de Guerra Fría, lo que llevó a que Estados Unidos junto con sus aliados en la región y la Unión Soviética intervinieran en él. Finalmente, Estados Unidos teniendo en cuenta sus intereses favoreció a la República de Indonesia y obligó a Holanda firmar el Acuerdo de Nueva York, en el que se establecía que sería la Autoridad Ejecutiva Temporal de las Naciones Unidas quien administrara y preparara el territorio para un futuro Acto de Libre Elección. En cualquiera que fuese el panorama, las Naciones Unidas no cumplieron con lo establecido en el Acuerdo lo que llevó a que fueran condescendientes con todas las peticiones indonesias sin tener en cuenta los deseos y los derechos de la población papuana, violándose su derecho de auto-determinación de los pueblos.

Gap junction-mediated spontaneous Ca(2+) waves in differentiated cholinergic SN56 cells

Neuronal gap junctions are receiving increasing attention as a physiological means of intercellular communication, yet our understanding of them is poorly developed when compared to synaptic communication. Using microfluorimetry, we demonstrate that differentiation of SN56 cells (hybridoma cells derived from murine septal neurones) leads to the spontaneous generation of Ca(2+) waves. These waves were unaffected by tetrodotoxin (1microM), but blocked by removal of extracellular Ca(2+), or addition of non-specific Ca(2+) channel inhibitors (Cd(2+) (0.1mM) or Ni(2+) (1mM)). Combined application of antagonists of NMDA receptors (AP5; 100microM), AMPA/kainate receptors (NBQX; 20microM), nicotinic AChR receptors (hexamethonium; 100microM) or inotropic purinoceptors (brilliant blue; 100nM) was also without effect. However, Ca(2+) waves were fully prevented by carbenoxolone (200microM), halothane (3mM) or niflumic acid (100microM), three structurally diverse inhibitors of gap junctions, and mRNA for connexin 36 was detected by PCR. Whole-cell patch-clamp recordings revealed spontaneous inward currents in voltage-clamped cells which we inhibited by Cd(2+), Ni(2+) or niflumic acid. Our data suggest that differentiated SN56 cells generated spontaneous Ca(2+) waves which are propagated by intercellular gap junctions. We propose that this system can be exploited conveniently for the development of neuronal gap junction modulators.

Distribution of calcium (Ca) and magnesium (Mg) in the leaves of Brassica rapa under varying exogenous Ca and Mg supply

Background and Aims Leafy vegetable Brassica crops are an important source of dietary calcium (Ca) and magnesium (Mg) and represent potential targets for increasing leaf Ca and Mg concentrations through agronomy or breeding. Although the internal distribution of Ca and Mg within leaves affects the accumulation of these elements, such data are not available for Brassica. The aim of this study was to characterize the internal distribution of Ca and Mg in the leaves of a vegetable Brassica and to determine the effects of altered exogenous Ca and Mg supply on this distribution. Methods Brassica rapa ssp. trilocularis ‘R-o-18’ was grown at four different Ca:Mg treatments for 21 d in a controlled environment. Concentrations of Ca and Mg were determined in fully expanded leaves using inductively coupled plasma-mass spectrometry (ICP-MS). Internal distributions of Ca and Mg were determined in transverse leaf sections at the base and apex of leaves using energy-dispersive X-ray spectroscopy (EDS) with cryo-scanning electron microscopy (cryo-SEM). Key Results Leaf Ca and Mg concentrations were greatest in palisade and spongy mesophyll cells, respectively, although this was dependent on exogenous supply. Calcium accumulation in palisade mesophyll cells was enhanced slightly under high Mg supply; in contrast, Mg accumulation in spongy mesophyll cells was not affected by Ca supply. Conclusions The results are consistent with Arabidopsis thaliana and other Brassicaceae, providing phenotypic evidence that conserved mechanisms regulate leaf Ca and Mg distribution at a cellular scale. The future study of Arabidopsis gene orthologues in mutants of this reference B. rapa genotype will improve our understanding of Ca and Mg homeostasis in plants and may provide a model-to-crop translation pathway for targeted breeding.