Mechanistic studies of the photocatalytic oxidation of microcystin-LR: An investigation of byproducts of the decomposition process

Microcystins (cyclic heptapeptides) are produced by a number of freshwater cyanobacteria and cause concern in potable water supplies due to their acute and chronic toxicity. The present study reports the structural characterization of the degradation products of the photocatalytic oxidation of microcystin-LR, so aiding the mechanistic understanding of this process. TiO₂ photocatalysis is a promising technology for removal of these toxins from drinking water. However, before it can be adopted in any practical application it is necessary to have a sufficient knowledge of degradation byproducts and their potential toxicity. Liquid chromatography-mass spectrometry analysis demonstrated that the major destruction pathway of microcystin appears to be initiated via three mechanisms: UV irradiation, hydroxyl radical attack, and oxidation. UV irradiation caused geometrical isomerization of microcystin converting the (4E), (6E) of the Adda configuration to (4E), 6(Z) or 4(Z), 6(E). Hydroxyl radical attack on the conjugated diene structure of Adda moiety produced dihyroxylated products. Further oxidation cleaved the hydroxylated 4-5 and/or 6-7 bond of Adda to form aldehyde or ketone peptide residues, which then were oxidized into the corresponding carboxylic acids. Photocatalysis also hydrolyzed the peptide bond on the ring structure of microcystin to form linear structures although this appeared to be a minor pathway.

The structure of an unconventional HD-GYP protein from Bdellovibrio reveals the roles of conserved residues in this class of cyclic-di-GMP phosphodiesterases

UNLABELLED: Cyclic-di-GMP is a near-ubiquitous bacterial second messenger that is important in localized signal transmission during the control of various processes, including virulence and switching between planktonic and biofilm-based lifestyles. Cyclic-di-GMP is synthesized by GGDEF diguanylate cyclases and hydrolyzed by EAL or HD-GYP phosphodiesterases, with each functional domain often appended to distinct sensory modules. HD-GYP domain proteins have resisted structural analysis, but here we present the first structural representative of this family (1.28 Å), obtained using the unusual Bd1817 HD-GYP protein from the predatory bacterium Bdellovibrio bacteriovorus. Bd1817 lacks the active-site tyrosine present in most HD-GYP family members yet remains an excellent model of their features, sharing 48% sequence similarity with the archetype RpfG. The protein structure is highly modular and thus provides a basis for delineating domain boundaries in other stimulus-dependent homologues. Conserved residues in the HD-GYP family cluster around a binuclear metal center, which is observed complexed to a molecule of phosphate, providing information on the mode of hydroxide ion attack on substrate. The fold and active site of the HD-GYP domain are different from those of EAL proteins, and restricted access to the active-site cleft is indicative of a different mode of activity regulation. The region encompassing the GYP motif has a novel conformation and is surface exposed and available for complexation with binding partners, including GGDEF proteins.

IMPORTANCE: It is becoming apparent that many bacteria use the signaling molecule cyclic-di-GMP to regulate a variety of processes, most notably, transitions between motility and sessility. Importantly, this regulation is central to several traits implicated in chronic disease (adhesion, biofilm formation, and virulence gene expression). The mechanisms of cyclic-di-GMP synthesis via GGDEF enzymes and hydrolysis via EAL enzymes have been suggested by the analysis of several crystal structures, but no information has been available to date for the unrelated HD-GYP class of hydrolases. Here we present the multidomain structure of an unusual member of the HD-GYP family from the predatory bacterium Bdellovibrio bacteriovorus and detail the features that distinguish it from the wider structural family of general HD fold hydrolases. The structure reveals how a binuclear iron center is formed from several conserved residues and provides a basis for understanding HD-GYP family sequence requirements for c-di-GMP hydrolysis.

Pre-Processing Power Traces to Defeat Random Clocking Countermeasures

We describe a pre-processing correlation attack on an FPGA implementation of AES, protected with a random clocking countermeasure that exhibits complex variations in both the location and amplitude of the power consumption patterns of the AES rounds. It is demonstrated that the merged round patterns can be pre-processed to identify and extract the individual round amplitudes, enabling a successful power analysis attack. We show that the requirement of the random clocking countermeasure to provide a varying execution time between processing rounds can be exploited to select a sub-set of data where sufficient current decay has occurred, further improving the attack. In comparison with the countermeasure's estimated security of 3 million traces from an integration attack, we show that through application of our proposed techniques that the countermeasure can now be broken with as few as 13k traces.

Intentionality, morality, and the incest taboo in Madagascar

In a recent article (Astuti & Bloch, 2015), cognitive anthropologists Rita Astuti and Maurice Bloch claim that the Malagasy are ambivalent as to whether considerations of intentionality are relevant to moral judgments concerning incest and its presumed catastrophic consequences: when making moral judgments about those who commit incest, the Malagasy take into account whether the incest is intentional or not, but, when making moral judgments relating to incest’s catastrophic consequences, they do not take intentionality into account. Astuti & Bloch explain the irrelevance of intentionality in terms of incest entailing such a fundamental attack on the transcendental social order that the Malagasy become dumbfounded and leave aside considerations of intentionality. Finally, they claim that a similar dumbfound reaction is what is involved in the moral dumbfounding concerning incest that social psychologist Jonathan Haidt has found in the US. In this article, we argue that (i) Astuti & Bloch are unclear about many aspects of their claims (in particular, about the moral judgments at stake), (ii) they do not provide sufficient evidence that considerations of intentionality are deemed irrelevant to moral judgments relating to incest’s presumed catastrophic consequences (and hence for the claim that the Malagasy are ambivalent), (iii) their hypothesis that conceiving of incest as an attack on the transcendental social renders considerations of intentionality irrelevant lacks coherence, and (iv) the extension of their explanatory account to the moral dumfounding of American students in Haidt’s well-known scenario of intentional incest is unwarranted.

Selecting Robust Strategies in RTS Games via Concurrent Plan Augmentation

Thesis (Master's)--University of Washington, 2015

How to increase and attract more tourists into Kenya throught experiental marketing

This marketing plan project is a culmination of extensive strategies with the use of experiential marketing to address issues confronting the Kenyan tourism industry in order to have a sustainable tourism sector. Following the terrorist attack carried out by Islamist militants’ belonging to al-Shabaab terrorist organization on Nairobi’s Westgate shopping mall in September 2013, tourist forecast has gone down sharply with an average of 20% fall in tourists’ arrivals which is likely to have an impact on the tourism sector in Kenya. Even before the deadly attack on Westgate, the most lethal attack by Islamist terrorists in 15 years in Kenya, the government through the Kenya tourist board had announced that in 2013 tourist arrivals were down by 12%, at 495,978, according to an October 2013 report by Bloomberg. Tourism revenues were also down by 7.4%, over FY12/13 (July-June) to reach KES96.24bn, according to a September 2013 report on the local Capital FM website. Beyond 2013, much will depend on how quickly the Kenya tourist board can regain control of the situation. The Kenyan government believes that the Westgate mall attack was a 'one-off' incident, with a low probability of a similar event happening again over the short term period. Germany, United States, United Kingdom, Australia, Italy, France and Canada continue to be the key source market however; the Kenya tourist board can make continued growth stronger from new emerging markets in order to increase new arrivals into the country. The marketing plan outlines the objectives to be implemented and provides the implementation strategy, activity plans, monitoring and evaluation plans, financial requirements projections and proposes a new structure of experiential marketing. A number of regional forces are identified that will impact tourism into the country including global, social and economic forces, emerging trends in visitor motivations and behavior, emerging forces in experiential marketing. A major component of the strategy identifies target markets for Kenya to commensurate with the level of resources that will be available for marketing and promotion, in keeping with the forces and trends identified and the nature of the Kenya tourism environment. The agreed upon target market segments are: generic/mass travel, experiential travel, creative travel, adventure seeking travel, senior/extended/long stay travel, and business related travel. The strategy phases the development of the target markets over the years of the marketing strategies in order to yield the best opportunity for results. A core activity in developing a marketing strategy is determining the nature of experiences Kenya offers in tourism. The strategy’s experience development process will continue to develop within the context of the products identified which will be promoted regionally: culture/heritage, nature, community-based. Each county in the country has a significant number of attractions and experiences and the challenge of the country is to bring these together in a creative and innovative way in order to encourage tourists to visit more than one county in Kenya.

An investigation into the oxidation of organic sulphides, organic selenides and simple hydrocarbons by Mortierella isabellina NRRL 1757

The work presented in this thesis is divided into three separate sections 4!> Each' 'section is involved wi th a different problem, however all three are involved with a microbial oxidation of a substrate~ A series of 'aryl substituted phenyl a.nd be,nzyl methyl sulphides were oxidized to the corre~pondi~g sulphoxides by 'Mo:rtierellai's'a'b'e'llina NRR.L17'S7 @ For this enzymic Qxidation, based on 180 labeled experiments, the oxygen atom is derived fr'orn the atmosphere and not from water. By way of an u~.traviolet analysis, the rates of oxidation, in terms of sulphox~ de appearance, were obtained and correlated with the Hatnmett p s~grna constants for the phenyl methyl sulphide series. A value of -0.67 was obtained and, is interpreted in terms of a mechanism of oxidation that involves an electrophilic attack on the sulphide sulphur by an enzymic ironoxygen activated complex and the conversion of the resulti!lg sulphur cation to sulphoxide. A series of alkyl phenyl selen~des have been incubated with the fu~gi, Aspergillus niger ATCC9l42, Aspergillus fO'etidus NRRL 337, MIIJisabellina NF.RLl757 and'He'lminth'osparium sp'ecies NRRL 4671 @l These fu?gi have been reported to be capable of carrying out the efficient oxidation of sulphide to sulphoxide, but in no case was there any evidence to supp'ort the occurrence of a microbialox,idation. A more extensive inves·t~gation was carried out with'M,e 'i's'a'b'e'l'l'i'na, this fu~gus was capable of oxidizing the correspondi~g sulphides to sulphoxi.de·s·$ Usi:ng a 1abel.edsubstra.te, [Methyl-l4c]-methyl phenyl selenide, the fate of this compound was invest~gated followi!lg an i'ncubation wi th Me isabellina .. BeSUldes th. e l4C-ana1YS1Q S-,'. a quant"ltta"lve selen'lum ana1Y"S1S was carried out with phenyl methyl selenide. These techniques indicate that thesel'enium was capable of enteri!1g thefu!1gal cell ef'ficiently but that s'ome metabolic cleav~ge of the seleni'um-carbon bond' may take plac'e Ie The l3c NMR shifts were assigned to the synthesized alkyl phenyl sulphides and selenides@ The final section involved the incubation ofethylben~ zene and p-e:rtr.hyltoluene wi th'M ~ 'isab'e'llina NRRL 17574b Followi~ g this incubation an hydroxylated product was isolated from the medium. The lH NMR and mass spectral data identify the products as I-phenylethanol and p-methyl-l-phenylethanol. Employi!lg a ch'iral shift re~gent,tri~ (3-heptafluorobutyl-dcamphorato)'- europium III, the enantiomeric puri ty of these products was invest~gated. An optical rotation measurement of I-phenylethanol was in ~greement with the results obtained with the chiral shift re~gen,te 'M.isabe'l'lina is capable of carryi~g out an hydroxylation of ethylbenzene and p-ethyltoluene at the ~ position.

The Columbian Newspaper vol. IV no. 1105- June 12, 1813

The "Columbian" was established by Mr. Holt in 1808 as an "organ of the Clintonians" (Journalism in the United States, from 1690-1872 By Frederic Hudson) and a replacement to the "Citizen". It was a passionate Democratic paper that supported both Jefferson and Madison. Holt later sold the "Columbian" to Alden Spooner, who published the Long Island "Star". The Columbian ceased in 1821. This issue includes the following War of 1812 topics: Page 2: copies of letters from U.S. Gen. H. Dearborn describing the U.S. attack on Ft. George 27 May 1813; letter from Gen. H. Dearborn describing U.S. pursuit of British troops at Beaver Dams and the U.S. capture of Fort Erie; list of U.S. killed and wounded in Commodore Isaac Chauncey's squadron in attack on York 27 April, 1813; list of killed and wounded in Commodore Isaac Chauncey's squadron in attack on Ft. George 27 May 1813; abstract of the cartel for the exchange of prisoners of war between Great Britain and the United States; mention of troop movements through New York on their way to the battle front; list of persons killed or lost on the privateer Saratoga; Page 3: account of the loss of the U.S. war ships the Growler and Eagle to the British; news from Quebec and Kingston of troop movements; U.S. ship Syren unsuccessfully pursues British ship Herald; account of a U.S. cargo ship being captured by a British military ship; account of U.S. ship Siro capturing British ship Loyal Sam; report from Halifax of recent British troop and ship movements; list of recent troop enrollments in various states; report of British troop build up in Kingston;

Boston Patriot Vol. 8 No. 13- October 24, 1812

A semi-weekly paper that began in 1809 and ceased in 1816. Its succeeding title was the Boston Patriot and Morning Advertiser. Publishers included: Everett and Munroe, 1809-Mar. 7, 1810; Isaac Munroe, Mar. 10, 1810-May 1, 1811; Munroe and French, May 4, 1811-1813; D.C. Ballard, 1814-1816. Editor: David Everett, Mar. 10, 1810-Oct. 23, 1811. Topics of interest include: Page 1: announcement of war against Great Britain and the reasons for the war; Page 2: announcement of nomination of war supporter Francis Carr for Congress; Statement of the Senate of Massachusetts in support of the war; 3 accounts of the American attack on Queenston; Page 3: report of the movement of war ships in and out of the port of Boston; news of naval movements by American and British ships; Page 4: advertisement of American and British muskets and swords for sale;

The New York Weekly Museum Newspaper, Vol. II, No.25- October 23, 1813

A weekly paper that was published from 1805 to 1814. War related news includes: Page 99 - Weekly Retrospect: American report on British naval movements near Louisiana; General William Harrison reports on: a victory at Moravian Town (Moraviantown) on October 5; Ottawas, Chippewas, Wyandots Miamies and Delaware First Nations (Indians) leaving the British side; Tecumseh remaining with the British; American army and navy attempt for a reduction of Mackinac and St. Joseph's; Colonel Chapin attacking a British picket guard near Fort George on October 6; Report that the British have abandoned the Fort George area for Kingston and is being pursued by General McClure; Forces in Sackett's Harbour ready for an attach on Canada; General Provost believed to have left Kingston for Montreal with 1000 men; Report from Burlington (Lake Champlain) of an attack on St. Armands against Colonel Clark on October 15; Report of the American's taking of the Packet Morgiana by the Schooner Saratoga under Captain Adderton by Newport; Announcement by the New York City Common Council for a celebration of Perry and Harrison's victories on the evening of October 23. The rest of the newspaper contains literary works (poems and translations), marriages, deaths and other anecdotes. The motto on the front page states: "Visiting Every Flower with Labour Meet, and Gathering all its Treasures, Sweet by Sweet."

The New York Weekly Museum Newspaper, Vol. II, No.26- October 30, 1813

A weekly paper that was published from 1805 to 1814. War related news includes: Page 103 - Weekly Retrospect: Reports on the Napoleanic Wars in Europe; Possible French and English troop movements from Europe to America and Canada; Mention of British vessels captured by American privateers Scourge, Rattlesnake and Lion; Report on New York celebration of Commodore Perry and General Harrison's victories on Lake Erie and in Canada respectively; Creek Indians attack on a supply convoy near Savannah, the provisions were recovered by General Floyd; General Harrison's account on Moravian Town (Moraviantown) and Munsey; Movements of General Wilkinson's army. Page 104 - an editorial about the madness of the times and its reflection on humanity. The rest of the newspaper contains literary works (poems and translations), marriages, deaths and other anecdotes. The motto on the front page states: "Visiting Every Flower with Labour Meet, and Gathering all its Treasures, Sweet by Sweet."

Correspondence between Mr. Monroe and Mr. Canning and between Mr. Madison and Mr. Rose

Full Title: Report of the Committee to whom was Referred the Correspondence between Mr. Monroe and Mr. Canning, and between Mr. Madison and Mr. Rose, relative to the attack on the Chesapeake : and also a communication from the President of the United States of the 30 March last, with a letter from Mr. Erskine to the Secretary of State, and a letter from M. Champagny to Gen. Armstrong Printed by R. C. Weightman

Letter written by John Bentley, Sept. 26, 1813.

Transcript [original spelling and grammar retained]: Sacketts Harbour 26th Sept. 1813. Dear wife. From this you are informed that I am in health at this Date. When I last wrote to you I some expected to go upon and expedition but to us unknown we sat out and went up the Lake 3 Days Landed at Oswego The British Fleet appeared off, and we returned and saw our fleet upon our return, I think that our Regt. going was only a maneuver to get the Fleet out that our Fleet might come a threat[?] of them We expect to embark immediately into Canada as preparations are making to convey us over to them we are anxious to commence an action with them. Troops are daily coming in to the Harbour to take the Stand in our absence, we shall not be here 3 days before we try their[?] Powder. they are daily defecting[?] to us from Canada very fearful of the consequence of our Resisting[?] of them…our Fleet is now out and has been for 6 or 7 days. The Lake Erie fleet has done great things. I hope ours will be as successful. I think that our Generals are waiting to hear from them as every thing is ready[?] of to embark various opinions reflecting were we shall attack them some say at Kingston others at Montreal and others at Prescot—Mr. William Butler and D[?]…are well and in Spirits, Sergt Daniel White is very hearty for him, M. Samuel C[?] is well and in good health Benjm Thompson is well Charles Bryant is well [?] is well Eben[?] Smith is very much plagued with the Rheumatik Disease[?] he……… his limbs very often for being Crippled[?] he is at the Hospital I often visit it to see the sick Jacob Barnes is at the Hospital but recovering fast been very sick. Luther Gregory is at the Hospital and on the recovery, Sergt. L[?] & Smith are well, Henry ………[?] is well, very healthy have not more die here than 3…[?]to the best of my knowledge. I will make a few remarks upon the place it abounds in Lime Rock more than Thomaston and not every person to my knowledge burn it, and in the whole Town not but one Pump that supplies the Towns People and Soldiers and a ………[?] of such a Lake of water the Lake water is good for drinking but the water near the Shore is exposed to all kind of filth being thrown into it. The officers with whom I have been with have used me kindly and I get quietly by them. The Lieut. Downer who recruits at Thomaston tell me he has thots[?] of Leaving the army if so I must say I am greatly sorry as he was my ……[?] friend although he Left us and went in a northern Company it is a Company……………[?]worthy an officer as he proves to be, I cannot get any higher than a Sergeant or Quarter Master Sergeant which I may have without any friends at Thomaston assisting me. I am a Sergeant and Sergeant Daniel White is expecting[?] to be a Quarter Master Sergeant, and a number of his friends from Thomaston have went to their Major for him in the 9th Regt Major….[?] and he expects to obtain a Commission as I ……[?] expect to be promoted and it died away he will have the Laugh upon me, I wish that My Friend Dawes would[?] put the question to Col. Foot? to write to our Col. E.W. Ripley if he has …[?]in the …[?]taken by him and others of my …[?] friends[?]. I expect to come home this winter without fail. I remain your Loving Husband till Death. John Bentley for Betsey Bentley Thomaston P.S. The next Letter will be ……[?]to Mr. Dawes[?] and shall write as soon as our Fleet arrives or if we are ordered off tomorrow shall write before I leave this Place. I have understood that many letters have been ……[?]to me. I have received only 2 from Mary, one from Mr. Dawes, one from William Thompson and have answered them please to write……[?]to S. Harbour.

Additional Return for Ordnance Stores for the Use of Capt. Thos. Biddle’s Compy Corps of Artillery, June 24, 1814

Jacob Hindman (1789-1827) was an American military officer who was a captain of the Second U.S. Artillery during the War of 1812. He commanded troops at the battles at Fort George and Stony Creek in 1813, and in June of that year became the major of the Second Artillery. He remained in this position until May of 1814 when the regiment was merged with the Corps of Artillery. During the Niagara campaign in 1814, Hindman’s company commanders included Nathan Towson, Thomas Biddle, John Ritchie, and Alexander Williams. During the British attack on Fort Erie in August 1814, Hindman led an assault for which he later received a brevet promotion to lieutenant colonel for “gallant conduct in the defense of Fort Erie”. In 1815, he received an additional brevet for “meritorious services”. He is generally regarded as one of the most successful artillerists of the War of 1812. James Hall (1793-1868) served with the U.S. military as a second lieutenant in the Second Artillery during the War of 1812. He fought in the Battle of Lundy’s Lane and was General Brown’s messenger during the attack on Fort Erie. He left the military in 1818 and became a newspaper editor and author. His experiences during the War of 1812 provided material for two stories, The Bearer of Despatches and Empty Pockets. Much of his work sought to popularize the West and promote western authors.

Sketches of the Battle Fields of Ontario from the War of 1812, July 15, 1876.

Accompanying caption from the Canadian Illustrated News, July 15, 1876: “We publish today a page of sketches consisting of the following battle fields in Ontario :--Lundy’s Lane where, without doubt, the hardest fought battle of 1812-15 took place, and in which more troops were engaged than in any other engagement of that war : the battle field of Stony Creek where the Canadians and Indians made a night attack on the Americans and achieved a victory over a greatly superior force and obliged the Americans to retreat back to the shelter of Old Fort George which was the scene of many engagements during the war. Beaver Dam battle field is just in the suburbs of the thriving village of Thorold, and the monument covers the remains of several soldiers whose bodies were unearthed during the building of the new Welland Canal at that place.”