In vitro study of the effect of wound dressings on planktonic and biofilms from diabetic foot isolates

The management of wound bioburden has previously been evaluated using various antimicrobial wound dressings on bacterial pathogens isolated from various wounds. In this present study, the antimicrobial effect of silver-impregnated dressings (Acticoat and Silvercel) and honey-impregnated dressing (Medihoney™ Apinate) on both planktonic bacteria and quasi-biofilms by Staphylococcus aureus and Proteus mirabilis were assessed using a 6-well plate and standard agar technique. In the 6-well plate assay, a bacterial suspension of 108 colony forming unit (CFU)/mL was inoculated on each dressing in excess Luria-Bertani broth and incubated at 35 – 37°C for 30 and 60 minutes and 24 hours. After each incubation time, bacteria were recovered in sodium thioglycolate solution (STS) and the CFU/mL determined on LB agar. Dressings were cut into circular shapes (2cm diameter and placed on Mueller Hinton agar plates pre-inoculated with bacterial suspensions to determine their zones of inhibition (ZOI) after 24 hours incubation. None of the dressings was effective to significantly inhibit bacterial growth or biofilm formation at all the times tested. Acticoat and Medihoney™ Apinate produced ZOIs between 1.5 – 15 mm against both Staphylococcus aureus and Proteus mirabilis. It is possible that, dressings augmented with antibiotics can significantly reduce quasi-biofilms on standard agar.

The in vitro assessment of the synergistic effects of antibiotics and wound dressings on biofilms from diabetic foot pathogens

The impact of biofilm in the effective control of wound microbiome is an ongoing dilemma which has seen the use of different treatment strategies. The effects of wound dressings and antibiotics on both planktonic bacteria and biofilms have been separately evaluated in previous studies. In this current study, the combined antimicrobial effects of some selected wound dressings (silver-impregnated: Acticoat and Silvercel; and honey-impregnated: Medihoney™ Apinate) and antibiotics (ceftazdime and levofloxacin) on Klebsiella pneumoniae and Proteus mirabilis in their quasi-biofilm state were assessed using zone of inhibition (ZOI) test. Before the addition of the wound dressings, bacterial suspension of 108 colony forming units per mL and different concentrations of ceftazidime and levofloxacin (256, 512, 1024 and 5120µg/mL) of a final volume of 1mL were inoculated on Mueller Hinton agar and allowed to dry. Wound dressings cut into circular shapes (2cm diameter) were aseptically placed on the agar plates and incubated at 35 – 37°C for 24 hours. ZOIs associated with Acticoat, Silvercel and Medihoney™ Apinate dressings were compared with that of Atrauman (non-medicated control) dressing. All three dressings showed significant (p < 0.05) biofilm-inhibiting activity against both bacteria at antibiotic concentrations of 1024 and 5120µg/mL with ZOI between 17.5 and 35mm.

A exportação do mel português: um estudo exploratório sobre as motivações, barreiras e estratégias

Dissertação de Mestrado apresentado ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Empreendedorismo e Internacionalização, sob orientação de Professor Doutor António Correia de Barros

Despacho económico de unidades com funções de custo não convexas usando enxames

Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica Ramo de Energia

On the applicability of mathematics : philosophical and historical perspectives

The present thesis is a contribution to the debate on the applicability of mathematics; it examines the interplay between mathematics and the world, using historical case studies. The first part of the thesis consists of four small case studies. In chapter 1, I criticize "ante rem structuralism", proposed by Stewart Shapiro, by showing that his so-called "finite cardinal structures" are in conflict with mathematical practice. In chapter 2, I discuss Leonhard Euler's solution to the Königsberg bridges problem. I propose interpreting Euler's solution both as an explanation within mathematics and as a scientific explanation. I put the insights from the historical case to work against recent philosophical accounts of the Königsberg case. In chapter 3, I analyze the predator-prey model, proposed by Lotka and Volterra. I extract some interesting philosophical lessons from Volterra's original account of the model, such as: Volterra's remarks on mathematical methodology; the relation between mathematics and idealization in the construction of the model; some relevant details in the derivation of the Third Law, and; notions of intervention that are motivated by one of Volterra's main mathematical tools, phase spaces. In chapter 4, I discuss scientific and mathematical attempts to explain the structure of the bee's honeycomb. In the first part, I discuss a candidate explanation, based on the mathematical Honeycomb Conjecture, presented in Lyon and Colyvan (2008). I argue that this explanation is not scientifically adequate. In the second part, I discuss other mathematical, physical and biological studies that could contribute to an explanation of the bee's honeycomb. The upshot is that most of the relevant mathematics is not yet sufficiently understood, and there is also an ongoing debate as to the biological details of the construction of the bee's honeycomb. The second part of the thesis is a bigger case study from physics: the genesis of GR. Chapter 5 is a short introduction to the history, physics and mathematics that is relevant to the genesis of general relativity (GR). Chapter 6 discusses the historical question as to what Marcel Grossmann contributed to the genesis of GR. I will examine the so-called "Entwurf" paper, an important joint publication by Einstein and Grossmann, containing the first tensorial formulation of GR. By comparing Grossmann's part with the mathematical theories he used, we can gain a better understanding of what is involved in the first steps of assimilating a mathematical theory to a physical question. In chapter 7, I introduce, and discuss, a recent account of the applicability of mathematics to the world, the Inferential Conception (IC), proposed by Bueno and Colyvan (2011). I give a short exposition of the IC, offer some critical remarks on the account, discuss potential philosophical objections, and I propose some extensions of the IC. In chapter 8, I put the Inferential Conception (IC) to work in the historical case study: the genesis of GR. I analyze three historical episodes, using the conceptual apparatus provided by the IC. In episode one, I investigate how the starting point of the application process, the "assumed structure", is chosen. Then I analyze two small application cycles that led to revisions of the initial assumed structure. In episode two, I examine how the application of "new" mathematics - the application of the Absolute Differential Calculus (ADC) to gravitational theory - meshes with the IC. In episode three, I take a closer look at two of Einstein's failed attempts to find a suitable differential operator for the field equations, and apply the conceptual tools provided by the IC so as to better understand why he erroneously rejected both the Ricci tensor and the November tensor in the Zurich Notebook.

Cooperation among selfish individuals in insect societies

Kin selection is the key to understanding the evolution of cooperation in insect societies. However, kin selection also predicts potential kin conflict, and understanding how these conflicts are resolved is a major goal of current research on social insects

E-Cigarettes: A Review of New Trends in Cannabis Use.

The emergence of electronic cigarettes (e-cigs) has given cannabis smokers a new method of inhaling cannabinoids. E-cigs differ from traditional marijuana cigarettes in several respects. First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette. Recreational cannabis users can discretely "vape" deodorized cannabis extracts with minimal annoyance to the people around them and less chance of detection. There are nevertheless several drawbacks worth mentioning: although manufacturing commercial (or homemade) cannabinoid-enriched electronic liquids (e-liquids) requires lengthy, complex processing, some are readily on the Internet despite their lack of quality control, expiry date, and conditions of preservation and, above all, any toxicological and clinical assessment. Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear. More simply ground cannabis flowering heads or concentrated, oily THC extracts (such as butane honey oil or BHO) can be vaped in specially designed, pen-sized marijuana vaporizers. Analysis of a commercial e-liquid rich in cannabidiol showed that it contained a smaller dose of active ingredient than advertised; testing our laboratory-made, purified BHO, however, confirmed that it could be vaped in an e-cig to deliver a psychoactive dose of THC. The health consequences specific to vaping these cannabis preparations remain largely unknown and speculative due to the absence of comprehensive, robust scientific studies. The most significant health concerns involve the vaping of cannabinoids by children and teenagers. E-cigs could provide an alternative gateway to cannabis use for young people. Furthermore, vaping cannabinoids could lead to environmental and passive contamination.

The bees of Niagara: a test of the intermediate disturbance hypothesis /

This study examined the bee fauna of the Carolinian Zone in Ontario, Canada. In 2003, 15687 individuals from 152 species of bees were collected. Tliere were many rare species but few abundant species. There were three distinct bee seasons. The Niagara bee assemblage was less diverse compared to other Carolinian Zone assemblages and types of landscapes. This study also examined how anthropogenic disturbance affects the diversity of bee assemblages. The intermediate disturbance hypothesis (IDH) was tested by selecting field sites subject to low, intermediate, and high disturbance. Intermediate disturbance had the highest species richness (SR=1 15) and most bees (N=556I), followed by low disturbance (SR= 100, N=2975), then high disturbance (SR=72, N=1364), supporting the IDH. Increased species richness in areas of intermediate disturbance was due to higher abundance, possibly because more blooming flowers were found there. Bees were larger in high disturbance areas but smaller in areas of high and intermediate disturbance.

The nesting biology of Ceratina (Hymenoptera: Apidae) in the Niagara Region : new species, nest site selection and parasitism

One of the most common bee genera in the Niagara Region, the genus Ceratina (Hymenoptera: Apidae) is composed of four species, C. dupla, C. calcarata, the very rare C. strenua, and a previously unknown species provisionally named C. near dupla. The primary goal of this thesis was to investigate how these closely related species coexist with one another in the Niagara ~ee community. The first necessary step was to describe and compare the nesting biologies and life histories of the three most common species, C. dupla, C. calcarata and the new C. near dupla, which was conducted in 2008 via nest collections and pan trapping. Ceratina dupla and C. calcarata were common, each comprising 49% of the population, while C. near dupla was rare, comprising only 2% of the population. Ceratina dupla and C. near dupla both nested more commonly in teasel (Dipsacus sp.) in the sun, occasionally in raspberry (Rubus sp.) in the shade, and never in shady sumac (Rhus sp.), while C. calcarata nested most commonly in raspberry and sumac (shaded) and occasionally in teasel (sunny). Ceratina near dupla differed from both C. dupla and C. calcarata in that it appeared to be partially bivoltine, with some females founding nests very early and then again very late in the season. To examine the interactions and possible competition for nests that may be taking place between C. dupla and C. calcarata, a nest choice experiment was conducted in 2009. This experiment allowed both species to choose among twigs from all three substrates in the sun and in the shade. I then compared the results from 2008 (where bees chose from what was available), to where they nested when given all options (2009 experiment). Both C. dupla and C. calcarata had the same preferences for microhabitat and nest substrate in 2009, that being raspberry and sumac twigs in the sun. As that microhabitat and nest substrate combination is extremely rare in nature, both species must make a choice. In nature Ceratina dupla nests more often in the preferred microhabitat (sun), while C. calcarata nests in the preferred substrate (raspberry). Nesting in the shade also leads to smaller clutch sizes, higher parasitism and lower numbers of live brood in C. calcarata, suggesting that C. dupla may be outcompeting C. calcarata for the sunny nesting sites. The development and host preferences of Ceratina parasitoids were also examined. Ceratina species in Niagara were parasitized by no less than eight species of arthropod. Six of these were wasps from the superfamily Chalcidoidea (Hymenoptera), one was a wasp from the family Ichneumonidae (Hymenoptera) and one was a physogastric mite from the family Pyemotidae (Acari). Parasites shared a wide range of developmental strategies, from ichneumonid larvae that needed to consume multiple Ceratina immatures to complete development, to the species from the Eulophidae (Baryscapus) and Encyrtidae (Coelopencyrtus), in which multiple individuals completed development inside a single Ceratina host. Biological data on parasitoids is scarce in the scientific literature, and this Chapter documents these interactions for future research.

Pica 13: Newsletter of the Mackenzie Heritage Printery Museum, 2001

The Mackenzie Heritage Printery Museum in Queenston, Ontario, is Canada’s largest working printing museum. The museum is housed in the 19th century home of William Lyon Mackenzie, a journalist and politician who published the Colonial Advocate and was instrumental in the Rebellion of 1837. The museum contains a Louis Roy Press, the oldest in Canada and one of the few original wooden presses remaining in the world.

The True and Wonderful Story of Paul Gasford

"The following true and remarkable story is taken from the Christian advocate, a respectable paper published by the Methodist Connexion, in the city of New-York."--Preface, t.p. verso. The Christian advocate was first published in 1826. See ULS. Caption title: Paul Gasford. In printed wrapper. "Advice from a bee."--poem, p. [16]. "English classics, for sale by M. Day, 374 Pearl-st."--p. [4] of wrapper.

Letter - E.C. Schmon to Arthur A. Schmon, 31 May 1918

The letter reads: " Darling Artie, I have just been reading the war news and Oh! how terribly discouraging it is. This mornings paper says the allies have yieldes on a forty-mile front, that Soissons had been taken by the Germans and Rheims is in grave peril and may fall at any moment. And think - only the third day of the new drive, too. I know that everything will end all right, but it surely has an awful affect on you, to read these reports. Of course no one knows, but it is the opinion of people in military circles here, that the war will last two years more at least; and in all probability five or six. Cheerful prospects. Yes? So you see, Artie dear, that you must come home on a leave, the very first opportunity you have. Understand? I am going down to Red Cross now, to do a little work. Tonight Mrs. Mizger, Doris and the two Braun girls are coming down. They want to see the rest of the pretty things that are in our sacred chest, and I just love to them, too. There are days when I have them out three or four times and I picture each thing in our little nest - after the war is over - - (Joy!!) Au revoir, honey-bunch boy. All the love, hugs and kisses that you desire. Always your, Wifie. P.S. And still no mail. Boo! Hoo! L."

A Teacher’s Formative Assessment Perceptions and Practices in Oral Intermediate English Courses at the Université de Montréal

Au cours des dernières années, les pratiques de l’évaluation comme aide à l’apprentissage (c’est-à-dire l’auto-évaluation, l’évaluation par les pairs, la rétroaction) dans la salle de classe ont été de plus en plus considérées comme des éléments essentiels (Black & Wiliam, 1998; Harlen & Winter, 2004; van de Watering & van der Rijt, 2006). Cependant, dans le domaine de l’apprentissage d’une langue seconde la recherche sur ce sujet est plutôt limitée. En nous fondant sur les études de Colby-Kelly et Turner (2007) et de Lyster et Ranta (1997), nous avons mené une recherche exploratoire visant à combler ce besoin. L’objectif général était de comprendre comment l’évaluation formative se réalise dans deux cours d’anglais intermédiaire à l’Université de Montréal, et de comparer comment ces pratiques sont perçues et vécues par la professeure et ses étudiants. Trois questions de recherche étaient posées: 1. Quelle est la nature de l’évaluation formative dans une salle de classe d’anglais langue seconde? 2. Est-ce que les pratiques de la professeure reflètent ce qu’elle pense de l’évaluation formative? 3. Quels sont les correspondances et différences entre les croyances de la professeure et les perceptions de ses étudiants quant aux bénéfices de l’évaluation formative pour l’apprentissage de l’anglais langue seconde? La collecte de données comprend des observations en classe, des entrevues auprès de la professeure et des questionnaires pour les étudiants. Pour répondre à notre première question de recherche, nous avons analysé la rétroaction donnée par la professeure pendant une production orale réalisée par ses étudiants à partir de la typologie de feedback et de uptake de l’étude de Lyster et Ranta (1997). En ce qui a trait à la deuxième question de recherche, nous avons fait des entrevues avec la professeure en vue d’expliciter ses perceptions relativement à l’évaluation formative. À la fin du trimestre, nous avons comparé ses réponses avec sa pratique à partir des enregistrements vidéo produits en classe. Finalement, pour répondre à notre dernière question de recherche nous avons comparé les réponses données par la professeure aux entrevues avec les réponses des étudiants à un questionnaire adapté à partir de celui de Colby-Kelly et Turner. Finalement, nous présentons et discutons les résultats les plus significatifs obtenus dans cette étude qualitative Nous concluons cette thèse en proposant de avenues pour des recherches futures.

Comparison of Microwave and Electrical Properties Selected Conducting Polymers

Microwave properties of conductive polymers is crucial because of their wide areas of applications such as coating in reflector antennas, coating in electronic equipments, firequenry selective .surfaces, EMI materials, satellite communication links, microchip antennas, and medical applications. This work involves a comparative study of dielectric properties of selected conducting polymers such as polyaniline. poly(3,4-eth),lenedio.syt2iophene), polvthiophene, polvpvrrole. and pohparaphenylene diazomethine (PPDA) in microwave and DC,fields. The inicrowave properties such as dielectric constant, dielectric loss. absorption coefficient, heating coefficient, skin depth, and conductivity in the microwave frequency (S hand), and DC fields were compared. PEDOT and polccuiiline were found to exhibit excellent properties in DC field and microwave frequencies, which make thein potential materials in many of the alorenientioned applications

Preparation of Low-Protein Natural Rubber Latex: Effect of Polyethylene Glycol

Low-protein content natural rubber latex was produced by using a nonionic surfactant-polyethylene glycol (PEG). Extractable protein content of natural rubber latex was found to decrease with PEG treatment and reduction increased with increase in the molecular weight of PEG. The low-protein latex samples were characterized by tensile testing, Fourier transform infrared and thermogravimetric analysis. The results have shown 35% reduction in the extractable protein content, without any compromise on the mechanical properties of the latex; however, thermal stability of low-protein latex was found to be reduced marginally with PEG treatment.