No description available.

Objective: The purpose of this study is to determine the relationship between cone beam CT (CBCT) voxel size and tooth root fracture detection. Materials and Methods: Vertical and horizontal root fractures were induced in a total of 30 teeth, and 15 teeth were left intact. Teeth were imaged with projection digital radiography and the Kodak 9000 3D CBCT system with a native voxel size of 76 μm. The CBCT voxels were then downsampled to 100 μm, 200 μm and 300 μm. Five blinded observers evaluated both sets of images with a 1 week washout interval between each set of observations. Results: CBCT outperformed the projection images for fracture detection for all voxel sizes except 300 μm (p<0.05). No significant differences were found between the different voxel sizes (p>0.05). Conclusion: Although voxel size does not impact the interpretation of root fractures, in vitro, CBCT outperformed projection imaging for voxel sizes less than 300 μm.

Since Ferrero SpA established a manufacturing plant in Brantford, Ontario, there has been considerable interest in developing a hazelnut industry locally. One of the issues that needs to be overcome is to supply large numbers of suitable plants rapidly. They can be micropropagated, and then grown in the nursery. Usually, it takes two years to grow suitably sized plants in the nursery. This thesis investigated methods to grow suitably sized plants in one year and evaluated the nursery systems from financial aspect. Hazelnut seedlings were planted in ellepots and plastic pots, and then subjected to three treatments: grown in a retractable roof greenhouse, treated with root pruning technology or grown in outdoor environment. Also, two transplant timings were tested: the fall of 2011 and the spring of 2012. The results showed that pot type did not influence the growth of hazelnut seedlings. The retractable roof greenhouse increased growth and the root pruning technology changed the seedlings root structure but not their growth. Transplant timing did not affect the seedlings growth in the first year in the field. The retractable roof greenhouse has the potential to produce two crops of seedlings in one growing season compared to one crop in the outdoor nursery. The estimated cost per seedling under retractable roof greenhouse was $9.31, which was $1.95 cheaper than outdoor. / Ontario Centres of Excellence and Ontario Ministry of Agriculture, Food and Rural Affairs

No description available.

No description available.

<p>The objective of this study was to assess coronal discoloration due to four commonly used endodontic sealers with gutta-percha, using spectrophotometric analysis. Extracted human teeth were obturated with the experimental sealers and GP. The sealers that were tested included AH Plus, EndoRez, and Kerr Pulp Canal Sealer. The teeth were maintained in a moist environment at 37 C. Immediate pretreatment readings of the crowns of the extracted teeth with a spectrometer were used as baseline data. Subsequent readings were taken every two weeks for two months. Results were analysed using Wilcoxson Signed Rank sum test and Kruskal Wallis test.</p>

<p> <p>&nbsp / </p> </p> <p><font face="Times New Roman" size="3">The aim of this study was to compare the sealing ability of AH Plus sealer to the canal wall in the presence and absence of the smear layer.</font></p>

Background: Multiple sclerosis (MS) is a chronic, neurological disease characterized by targeted destruction on central nervous system (CNS) myelin. The autoimmune theory is the most widely accepted explanation of disease pathology. Circulating Th-1 cells become activated by exposure to CNS-specific antigens such as myelin basic protein. The activated Th-1 cells secrete inflammatory cytokines, which are pivotal for inflammatory responses. We hypothesize that enhanced production of inflammatory cytokines triggers cellular events within the dorsal root ganglia (DRG) and/or spinal cord, facilitating the development of neuropathic pain (NPP) in MS. NPP, the second worst disease-induced symptom suffered by patients with MS, is normally regulated by DRG and/or spinal cord. Objective: To determine gene and protein expression levels of tumor necrosis factor-alpha (TNF ) within DRG and/or spinal cord in an animal model of MS. Methods: Experimental autoimmune encephalomyelitis (EAE) was induced in adolescent female Lewis rats. Animals were sacrificed every 3 days post-disease induction. DRG and spinal cords were harvested for protein and gene expression analysis. Results: We show significant increases in TNF expression in the DRG and of EAE animals at peak disease stage, as assessed by clinical symptoms. Conclusion: Antigen-induced production of inflammatory cytokines such as TNF within the DRG identifies a potential noel mechanism for MS-induced NPP.

Objective: The purpose of this study is to determine the relationship between cone beam CT (CBCT) voxel size and tooth root fracture detection. Materials and Methods: Vertical and horizontal root fractures were induced in a total of 30 teeth, and 15 teeth were left intact. Teeth were imaged with projection digital radiography and the Kodak 9000 3D CBCT system with a native voxel size of 76 &mu;m. The CBCT voxels were then downsampled to 100 &mu;m, 200 &mu;m and 300 &mu;m. Five blinded observers evaluated both sets of images with a 1 week washout interval between each set of observations. Results: CBCT outperformed the projection images for fracture detection for all voxel sizes except 300 &mu;m (p&lt;0.05). No significant differences were found between the different voxel sizes (p&gt;0.05). Conclusion: Although voxel size does not impact the interpretation of root fractures, in vitro, CBCT outperformed projection imaging for voxel sizes less than 300 &mu;m.

Xylem is an inherent feature of all vascular plants and functions in water transport and mechanical support. In order to efficiently transport water, xylem cells are reinforced by secondary walls before they undergo programmed cell death and their cell contents are removed by autolysis to create a hollow tube. During their differentiation, xylem cells express various hydrolytic enzymes, such as proteases, nucleases and lipases, but only in a few examples has their role in xylem cell death been characterized. This thesis focuses on the regulatory aspects of xylem cell death and the autolytic cell clearance in vessel elements and fibers of hybrid aspen (Populus tremula L. x tremuloides Michx.) and in vessel elements of Arabidopsis thaliana. Using comparative transcriptomic analysis, candidate genes for fiber-specific cell death processes were identified. Further, a hypothesis is presented on the regulation of thermospermine levels in the vasculature by a negative feedback-loop involving auxin and the class III Homeodomain-Leucine Zipper (HD-ZIP III) transcription factor HOMEOBOX8 (PtHB8). The role of the Arabidopsis METACASPASE9 (AtMC9) in xylem cell death was characterized using molecular tools, such as reporter lines and fluorescent fusion proteins, and electron microscopy (TEM). This showed that cell death initiation is not controlled by AtMC9. Instead, evidence is presented for the involvement of AtMC9 in the post mortem autolysis of vessel elements that follows tonoplast rupture and leads to the formation of the hollow conduit. Cell death-associated genes were further observed to be expressed during the emergence of lateral roots in Arabidopsis thaliana. This led to the discovery that cells overlying a lateral root primordium undergo cell death, which was demonstrated by detection of DNA degradation and TEM analysis. It is concluded that cell death facilitates emergence of lateral roots through the overlying tissues in a concerted manner with cell wall remodelling. Together, these findings show that although individual hydrolytic enzymes may be dispensable for plant growth and development, their common regulators are the tool for understanding their function and importance. / Xylem är en karakteristisk vävnad i alla kärlväxter som leder vatten och mineraler samt har mekanisk stödfunktion. För att effektivt kunna transportera vatten förstärks xylemceller med sekundära cellväggar innan de dör genom programmerad celldöd. Deras cellinnehåll bryts ner genom autolys för att skapa ett ihåligt rör. Xylemceller uttrycker under sin differentiering olika hydrolytiska enzymer, såsom proteaser, lipaser och nukleaser, men bara för ett fåtal av dessa har funktionen under xylemcelldöd kartlagts. Denna avhandling fokuserar på reglering av xylemcelldöden och den autolytiska nedbrytningen av cellen, i såväl kärlelement och fibrer av hybridasp (Populus tremula L. x tremuloides Michx.) som i kärlelement av backtrav (Arabidopsis thaliana). Med hjälp av jämförande transkriptomanalys identifierades kandidatgener för fiber-specifika celldödsprocesser i hybridasp. Vidare utvecklades en hypotes om reglering av termosperminnivåer i vaskulaturen genom en negativ feedback-loop, som omfattar auxin reglering och klass III homeodomän-leucinzipper (HD-ZIP III) transkriptionsfaktorn HOMEOBOX8 (PtHB8). Funktionen av Arabidopsis METACASPASE9 (AtMC9) under xylemcelldöd karakteriserades med molekylära verktyg, såsom reporterlinjer och fluorescerande fusionsproteiner och elektronmikroskopi (TEM). Dessa analyser visade att celldödens initiering inte styrs av AtMC9. Istället presenteras bevis för en roll av AtMC9 i autolysen av kärlelement som sker post mortem efter att vakuolen har gått sönder och som slutför bildandet av det tomma kärlet. Genuttryck som associeras med celldöd observerades också under utvecklingen av laterala rötter i Arabidopsis thaliana. Detta ledde till upptäckten att celler som ligger ovanför ett lateralrotprimordium dör en programmerad celldöd och visar tecken på DNA-nedbrytning och autolys i TEM-analyser. Slutsatsen av denna studie är att celldöd i samspel med cellväggsmodifiering underlättar utväxten av laterala rötter genom de överliggande cellagren. Sammantaget tyder dessa upptäckter på att även om enstaka hydrolyserande enzymer inte är nödvändiga för växternas tillväxt och utveckling, så kan deras gemensamma reglering nyttjas för att förstå deras funktion och betydelse.