Hydrogen sulphide as inhibitor and substrates for the cytochrome c-cytochrome c oxidase system /

It has previously been recognized that the major biochemical toxicity induced by sulphide is due to an inhibition of cytochrome ~ oxidase. Inhibition of this enzyme occurs at 30°C and pH 7.4 with a Ki of approximately 0.2 ~M, and a kon of 104 M-1 s-l, under catalytic conditions. However, the equimo1ar mixture of sulphide and the enzyme shows identical catalytic behaviour to that of the native enzyme. This cannot readily be attributed to rapid dissociation of sulphide, as both spectroscopic and plot analysis indicate the koff value is low. The addition of stoichiometric sulphide to the resting oxidized enzyme gives rise to the appearance of a low-spin ferric-type spectrum not identical with that seen on the addition of excess sulphide to the enzyme aerobically. Sulphide added to the enzyme anaerobically gives rise to another low-spin, probably largely ferric, form which upon admission of oxygen is then converted into a 607 nm species closely resembling Compound C. The 607 nm form is probably the precursor of oxyferricytochrome aa3. The addition of successive a1iquots of Na2S solution to the enzyme induces initial uptake of approximately 3 moles of oxygen per mole of the enzyme. Thus, it is concluded that: 1. the initial product of sulphide-cytochrome c oxidase interaction is not an inhibited form of the enzyme, but the low-spin (oxyferri) ~3+~+ species; 2. a subsequent step in which sulphide reduces cytochrome ~ occurs; 3. the final inhibitory step, in which a further molecule of sulphide binds to the cytochrome ~ iron centre in the cytochrome ~2+~+ species, gives the cytochrome a2+~+-H2S form which is a half-reduced fully inhibited species;4. a 607 run form of the enzyme is produced which may be converted into a catalytically active low-spin (oxyferri) state; and therefore 5. liganded sulphide may be able to reduce the cytochrome 33 -Cu centre without securing the prior reduction of the cytochrome a_ haem group or the Cud centre associated with it.

Crystal growth, characterization and point contact spectroscopy on CuxTiSe₂

Various s e t s of single c rys t a l s and poly c rys t a l s of Cux TiSe2 were grown. X- r ay diffraction and ene rgy dispersive spe c t ros copy r e sul t s verified tha t the c rys t a l s were the cor r e c t compos i t ion and c rys t a l s t ruc tur e . Re s i s t ivi ty me a sur ement s and magne t i c sus c ept ibi l i ty me a sur ement s de t e rmined the supe r conduc t ing t r ans i t ion t empe r a tur e s for the c rys t a l s . The c rys t a l s in each growth had various supe r conduc t ing t r ans i t ion t empe r a tur e s . Also, the me a sur ement s indi c a t ed tha t the c rys t a l s were inhomogeneous. Point cont a c t spe c t ros copy expe r iment s were employed on various single c rys t a l s . Inspe c t ion of the da t a indi c a t ed tha t the ma t e r i a l ha s a single ene rgy gap . A progr am was bui l t ut i l i z ing the Levenbe rg-Ma rqua rdt me thod and theory on point cont a c t spe c t ros copy to de t e rmine the supe r conduc t ing ene rgy gap. Plot s of the supe r conduc t ing ene rgy gap a t various t empe r a tur e s were in di s agr e ement wi th wha t was expe c t ed for a convent iona l supe r conduc tor .

The new blockbuster film sequel : changing cultural and economic conditions within the film industry

Film sequels are a pervasive part of film consumption practices and have become an important part of the decision making process for Hollywood studios and producers. This thesis indicates that sequels are not homogenous groups of films, as they are often considered, but offer a variety of story construction and utilize a variety of production methods. Three types of blockbuster sequel sets are identified and discussed in this thesis. The Traditional Blockbuster Sequel Set, as exemplified by Back to the Future (1985, 1989, 1990) films, is the most conventional type of sequel set and capitalizes on the winning formula of the first film in the franchise. The MultiMedia Sequel Set, such as The Matrix (1999,2003) trilogy, allows the user/viewer to experience and consume the story as well as the world of the film through many different media. The Lord a/ the Rings (2001, 2002, 2003) set of films is an illustration of The Saga Sequel Set where plot lines are continuous over the entire franchise thus allowing the viewer to see the entire set as a unified work. The thesis also demonstrates how the blockbuster sequel sets, such as the Pirates a/ the Caribbean (2003, 2006, 2007) franchise, restructure the production process of the Hollywood film industry.

Welland Canal Survey of Lands Job Northrup 1828

Survey map and description of Job Northrup's land created by The Welland Canal Company. Included is a written description of the land along with a drawing of the land. Noteable features include; 12 mile creek, dry dock. The land was used by the Welland Canal Company for canal and hydraulic purposes. The total amount of land surveyed is 10 acres, 3 roads and 20 perches. The deed for the land is dated January 23rd 1828. Surveyor notes are seen in pencil on the map.The surveyor's notes on the map itself are as follows: "the plot in red lines, containing 2 roads and 10 perches, was laid off by Geo. Keefer on Aug. 2nd, 1834 as an additional quantity of land required by the Company for Lock house and other purposes". "The dry dock quantity is 1.2-32" "1 1/2 acres of the above survey for Dry Dock company. Survey July 18th 1833 by Geo. Keefer."

The Bond Girl phenomenon: defining the female protagonists of the James Bond films

Please consult the paper edition of this thesis to read. It is available on the 5th Floor of the Library at Call Number: Z 9999 C65 F86 2005

Discourses of Masculinity and Femininity in The Hunger Games: "Scarred," "Bloody," and "Stunning"

This article explores how characters in The Hunger Games trilogy are portrayed relative to Connell's gendered discourses of hegemonic masculinity, marginal masculinity, and emphasized femininity. We briefly review the plot of The Hunger Games trilogy and then discuss the ways in which three of the characters are represented with respect to societal gendered discourses, heteronormativity, and the use of violence. We argue that the ways in which these aspects are portrayed relate to the main characters' performance of discourses of hegemonic masculinity (Gale), marginalized masculinity (Peeta), and a complex amalgamation of the two that also draws somewhat on emphasized femininity (Katniss). Finally, we conclude that, while the trilogy could be read as taking a feminist stance with a strong female protagonist, it nonetheless also constrains Katniss in heteronormative ways.

Electron Transfer Involving the Phylloquinone (A1) Cofactor of Photosystem I Examined with Time Resolved Absorbance and Electron Paramagnetic Resonance Spectroscopy

The dependence of the electron transfer (ET) rate on the Photosystem I (PSI) cofactor phylloquinone (A1) is studied by time-resolved absorbance and electron paramagnetic resonance (EPR) spectroscopy. Two active branches (A and B) of electron transfer converge to the FX cofactor from the A1A and A1B quinone. The work described in Chapter 5 investigates the single hydrogen bond from the amino acid residue PsaA-L722 backbone nitrogen to A1A for its effect on the electron transfer rate to FX. Room temperature transient EPR measurements show an increase in the rate for the A1A- to FX for the PsaA-L722T mutant and an increased hyperfine coupling to the 2-methyl group of A1A when compared to wild type. The Arrhenius plot of the A1A- to FX ET in the PsaA-L722T mutant suggests that the increased rate is probably the result of a slight change in the electronic coupling between A1A- and FX. The reasons for the non-Arrhenius behavior are discussed. The work discussed in Chapter 6 investigates the directionality of ET at low temperature by blocking ET to the iron-sulfur clusters FX, FA and FB in the menB deletion mutant strain of Synechocyctis sp. PCC 6803, which is unable to synthesize phylloquinone, by incorporating the high midpoint potential (49 mV vs SHE) 2,3-dichloro-1,4-naphthoquinone (Cl2NQ) into the A1A and A1B binding sites. Various EPR spectroscopic techniques were implemented to differentiate between the spectral features created from A and B- branch electron transfer. The implications of this result for the directionality of electron transfer in PS I are discussed. The work discussed in Chapter 7 was done to study the dependence of the heterogeneous ET at low temperature on A1 midpoint potential. The menB PSI mutant contains plastiquinone-9 in the A1 binding site. The solution midpoint potential of the quinone measures 100 mV more positive then wild-type phylloquinone. The irreversible ET to the terminal acceptors FA and FB at low temperature is not controlled by the forward step from A1 to FX as expected due to the thermodynamic differences of the A1 cofactor in the two active branches A and B. Alternatives for the ET heterogeneity are discussed.

The electromyographic threshold in boys and men

Abstract Background Children have been shown to have higher lactate (LaTh) and ventilatory (VeTh) thresholds than adults, which might be explained by lower levels of type-II motor-unit (MU) recruitment. However, the electromyographic threshold (EMGTh), regarded as indicating the onset of accelerated type-II MU recruitment, has been investigated only in adults. Purpose To compare the relative exercise intensity at which the EMGTh occurs in boys versus men. Methods Participants were 21 men (23.4 ± 4.1 years) and 23 boys (11.1 ± 1.1 years), with similar habitual physical activity and peak oxygen consumption (VO2pk) (49.7 ± 5.5 vs. 50.1 ± 7.4 ml kg−1 min−1, respectively). Ramped cycle ergometry was conducted to volitional exhaustion with surface EMG recorded from the right and left vastus lateralis muscles throughout the test (~10 min). The composite right–left EMG root mean square (EMGRMS) was then calculated per pedal revolution. The EMGTh was then determined as the exercise intensity at the point of least residual sum of squares for any two regression line divisions of the EMGRMS plot. Results EMGTh was detected in 20/21 of the men (95.2 %) and only in 18/23 of the boys (78.3 %). The boys’ EMGTh was significantly higher than the men’s (86.4 ± 9.6 vs. 79.7 ± 10.0 % of peak power output at exhaustion; p < 0.05). The pattern was similar when EMGTh was expressed as percentage of VO2pk. Conclusions The boys’ higher EMGTh suggests delayed and hence lesser utilization of type-II MUs in progressive exercise, compared with men. The boys–men EMGTh differences were of similar magnitude as those shown for LaTh and VeTh, further suggesting a common underlying factor.

Indenture between Captain Thomas Bushby and Sarah Bushby and Edward Clarke Campbell

Indenture of bargain and sale between Captain Thomas Bushby of the Island of Jersey and his wife Sarah Bushby to Edward Clarke Campbell of the town of Niagara regarding 100 acres in Sherbrooke Forest in the District of Niagara, also Lots 6 and 7 in the town plot of Sherbrooke. This document was registered in the Township of Sherbrooke on December 28, 1849 - instrument no. 503, March 17, 1849.

Indenture between Thomas Murtagh and Samuel Zimmerman

Indenture of mortgage in fee between Thomas Murtagh of the Town of Elgin and Samuel Zimmerman of NIagara Falls regarding Lot no. 15 in Block N in the Town Plot of Elgin - instrument no. 3164[9?], September 24, 1855.

Indenture between St. Catharines Victoria Lawn Cemetery and Mrs. H.K. Woodruff

Indenture between St. Catharines Victoria Lawn Cemetery and Mrs. H.K. Woodruff for a perpetual care fund and $67.20 into a general care and improvement fund in respect to the southerly portion of Lot no.9 in section P of the St. Catharines Victoria Lawn Cemetery. The deed no. is 859. This is the S.D. Woodruff plot, Nov. 4, 1932.

Indenture (vellum) between the Honourable William Dickson of Niagara and Robert Dickson of Niagara

Indenture (vellum) between the Honourable William Dickson of Niagara and Robert Dickson of Niagara for the mill tract and town plot in Dumfries, Ontario, Jan. 16, 1841.

Indenture between the Honourable William Dickson and of Niagara and Commander Thomas Bushby, then Lieutenant in the Royal Navy

Indenture between the Honourable William Dickson and of Niagara and Commander Thomas Bushby, then Lieutenant in the Royal Navy for land in the village plot of Sherbrooke – instrument no. 230. This was recorded on Sept. 15, 1843 in Book A, folio 281-282. April 15, 1843.

Construcción y prueba de un viscosimetro de esfera descendenta con registro osciloscopio

Tesis (Maestría en Ciencias con Especialidad en Físico-Química) UANL

Meditaciones sobre la pasión Sma. de N. Sr. Jesucristo

UANL