Determination and persistence of methiocarb in artichokes

A simple and rapid method for the determination of methiocarb in artichokes by high-performance liquid chromatography with UV detection is described. No derivatization is needed and the limit of determination (0.01 ppm) is analogous to that of fluorometric detection. The results of trials carried out with granular and liquid formulations of this active ingredient are also reported. Immediately after treatment with the liquid formulation methiocarb residues averaged 1.47 ppm, while after treatment with the granular formulation residues were considered fortuitous. The decay rate of methiocarb residues in artichokes shows that the decrease and eventual disappearance of this active ingredient can chiefly be ascribed to the dilution effect due to head growth.

Anatomic and radiograph study of the persistence of Foramen of Huschke

Aim: the aim of this study is to assess and locate the Foramen of Huschke. Study design: anatomical. Material and Method: using contrast material like gutta-percha and barium sulfate, through extraoral radiographs, such as panoramic, submental vertex and corrected saggital linear Temporal Mandibular Joint tomograms in four skulls where we clinically checked the existence of foramen of Huschke. Results: The results proved that the foramen of Huschke can be observed in skulls submitted to contrast using radiographic techniques.

Persistence of epoxy-based sealer residues in dentin treated with different chemical removal protocols

The presence of residual endodontic sealer in the pulp chamber may cause discoloration of the dental crown and interfere with the adhesion of restorative materials. The aim of this study was to compare the efficacy of different solvents in removing residues of an epoxy resin-based sealer (AH Plus) from the dentin walls of the pulp chamber, by scanning electron microscopy (SEM). Forty-four bovine incisor dental crown fragments were treated with 17% EDTA and 2.5% NaOCl. Specimens received a coating of AH Plus and were left undisturbed for 5 min. Then, specimens were divided in four groups (n = 10) and cleaned with one of the following solutions: isopropyl alcohol, 95% ethanol, acetone solution, or amyl acetate solution. Negative controls (n = 2) did not receive AH Plus, while in positive controls (n = 2) the sealer was not removed. AH Plus removal was evaluated by SEM, and a score system was applied. Data were analyzed by Kruskal-Wallis and Dunn tests. None of the solutions tested was able to completely remove AH Plus from the dentin of the pulp chamber. Amyl acetate performed better than 95% ethanol and isopropyl alcohol (p < 0.05), but not better than acetone (p > 0.05) in removing the sealer from dentin. No significant differences were observed between acetone, 95% ethanol, and isopropyl alcohol (p > 0.05). It was concluded that amyl acetate and acetone may be good options for cleaning the pulp chamber after obturation with AH Plus. SCANNING 35:17-21, 2013. © 2012 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Antimicrobial resistance and persistence of Staphylococcus epidermidis clones in a Brazilian university hospital

Oxacillin is an alternative for the treatment of Staphylococcus spp. infections; however, resistance to this drug has become a major problem over recent decades. The main objective of this study was to epidemiologically characterize coagulase-negative staphylococci (CoNS) strains recovered from blood of patients hospitalized in a Brazilian teaching hospital. Oxacillin resistance was analyzed in 160 strains isolated from blood culture samples by phenotypic methods, detection of the mecA gene, and determination of intermediate sensitivity to vancomycin on brain heart infusion agar supplemented with 4 and 6 μg/mL vancomycin. In addition, characterization of the epidemiological profile by staphylococcal cassette chromosome mec (SCC. mec) typing and clonal analysis by pulsed-field gel electrophoresis (PFGE) were performed. The mecA gene was detected in 72.5% of the isolates. Methicillin-resistant CoNS isolates exhibited the highest minimum inhibitory concentrations and multiresistance when compared to methicillin-susceptible CoNS strains. Typing classified 32.8% of the isolates as SCC. mec I and 50% as SCC. mec III. PFGE typing of the SCC. mec III Staphylococcus epidermidis isolates identified 6 clones disseminated in different wards that persisted from 2002 to 2009. The high oxacillin resistance rates found in this study and clonal dissemination in different wards highlight the importance of good practices in nosocomial infection control and of the rational use of antibiotic therapy in order to prevent the dissemination of these clones. © 2013 Elsevier Inc.

Persistence of experimental Rocio virus infection in the golden hamster (Mesocricetus auratus)

ABSTRACT: Rocio virus (ROCV) is an encephalitic flavivirus endemic to Brazil. Experimental flavivirus infections have previously demonstrated a persistent infection and, in this study, we investigated the persistence of ROCV infection in golden hamsters (Mesocricetus auratus). The hamsters were infected intraperitoneally with 9.8 LD50/0.02 mL of ROCV and later anaesthetised and sacrificed at various time points over a 120-day period to collect of blood, urine and organ samples. The viral titres were quantified by real-time-polymerase chain reaction (qRT-PCR). The specimens were used to infect Vero cells and ROCV antigens in the cells were detected by immunefluorescence assay. The levels of antibodies were determined by the haemagglutination inhibition technique. A histopathological examination was performed on the tissues by staining with haematoxylin-eosin and detecting viral antigens by immunohistochemistry (IHC). ROCV induced a strong immune response and was pathogenic in hamsters through neuroinvasion. ROCV was recovered from Vero cells exposed to samples from the viscera, brain, blood, serum and urine and was detected by qRT-PCR in the brain, liver and blood for three months after infection. ROCV induced histopathological changes and the expression of viral antigens, which were detected by IHC in the liver, kidney, lung and brain up to four months after infection. These findings show that ROCV is pathogenic to golden hamsters and has the capacity to cause persistent infection in animals after intraperitoneal infection.

Feedbacks between vegetation and disturbance processes promote long-term persistence of forest-grassland mosaics in south Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The South Omaha Community Scholarship Program: A Qualitative Study of Persistence of Hispanic Students at Bellevue University

The purpose of this case study was to determine the impact of the South Omaha Community Scholarship Program on the persistence of the Hispanic students who participated. Previous research on Hispanic student persistence has focused on the reasons why students do not persist and more recent research has been conducted on programs and retention efforts, colleges and universities are implementing on their campuses. This study researched a specific program, The South Omaha Community Scholarship Program, designed to provide financial, academic and other needed resources to help Hispanic students persist to graduation. The researcher believes this study was important because it provided an overview of how the South Omaha Community Scholarship Program is affecting students both on campus and in their community. Eight interviews were conducted, with eligible students, in person. Students eligible for the study were current students or recent graduates of the South Omaha Community Scholarship Program and had attained at least junior or senior status as of the fall of 2009, as defined by Bellevue University. Research questions were based on the four components of the program and the affect the program had on the student’s life, outside of Bellevue University. The four components of the program were: financial aid, academic advising, the scholarship aid, and the Professional Enrichment Program. The results of the study were broken into five components with an additional section that provided other themes that were derived from the interviews. The five components were: (a) financial aid counseling, (b) academic advising, (c) scholarship aid, (d) Professional Enrichment Program, and (e) the South Omaha Community Scholarship Program beyond Bellevue University. Other themes that were derived from the interviews were: class format, deciding on a college, higher education class, campus resources, and a sense of community on-campus. The research found that the scholarship, provided by the South Omaha Community Scholarship Program, was the primary motivating factor for students to attend Bellevue University and persist in college. The interviewed students also commented on how the scholarship had given them the opportunity to attend college, even though that opportunity had seemed out of reach. The interviewed students also commented on their academic advising experience, campus resources, and feeling a sense of community on-campus as other campus related areas that were affected by the South Omaha Community Scholarship Program. Finally, students provided examples of how the South Omaha Community Scholarship Program impacted their connection to their South Omaha community through volunteer and employment opportunities. Adviser: Richard Hoover

Persistence of Inflammatory Response to Intense Exercise in Diabetic Rats

In this study we evaluated the onset and resolution of inflammation in control and streptozotocin-induced diabetic rats subjected to a single session of intense exercise. The following measurements were carried out prior to, immediately after, and 2 and 24 hours after exercise: plasma levels of proinflammatory cytokines (TNF-alpha, IL-1 beta, IL-6, CINC-2 alpha/beta, MIP-3 alpha, and IL-6), immunoglobulins (IgA and IgM), acute phase proteins (CRP and C3), and creatine kinase (CK) activity. We also examined the occurrence of macrophage death by measurements of macrophages necrosis (loss of membrane integrity) and DNA fragmentation. An increase was observed in the concentration of IL-1 beta (3.3-fold) and TNF-alpha (2.0-fold) and in the proportion of necrotic macrophages (4.5-fold) in diabetic rats 24 hours after exercise, while the control group showed basal measurements. Twenty-four hours after the exercise, serum CK activity was elevated in diabetic rats but not in control animals. We concluded that lesion and inflammations resulting from intense exercise were greater and lasted longer in diabetic animals than in nondiabetic control rats.

The persistence of musical memories: A descriptive study of earworms

We describe some characteristics of persistent musical and verbal retrieval episodes, commonly known as "earworms." In Study 1, participants first filled out a survey summarizing their earworm experiences retrospectively. This was followed by a diary study to document each experience as it happened. Study 2 was an extension of the diary study with a larger sample and a focus on triggering events. Consistent with popular belief, these persistent musical memories were common across people and occurred frequently for most respondents, and were often linked to recent exposure to preferred music. Contrary to popular belief, the large majority of such experiences were not unpleasant. Verbal earworms were uncommon. These memory experiences provide an interesting example of extended memory retrieval for music in a naturalistic situation.

Development of the Heat and Energy Concept Inventory: Preliminary Results on the Prevalence and Persistence of Engineering Students' Misconceptions

BACKGROUND Students frequently hold a number of misconceptions related to temperature, heat and energy. There is not currently a concept inventory with sufficiently high internal reliability to assess these concept areas for research purposes. Consequently, there is little data on the prevalence of these misconceptions amongst undergraduate engineering students. PURPOSE (HYPOTHESIS) This work presents the Heat and Energy Concept Inventory (HECI) to assess prevalent misconceptions related to: (1) Temperature vs. Energy, (2) Temperature vs. Perceptions of Hot and Cold, (3) Factors that affect the Rate vs. Amount of Heat Transfer and (4) Thermal Radiation. The HECI is also used to document the prevalence of misconceptions amongst undergraduate engineering students. DESIGN/METHOD Item analysis, guided by classical test theory, was used to refine individual questions on the HECI. The HECI was used in a one group, pre-test-post-test design to assess the prevalence and persistence of targeted misconceptions amongst a population of undergraduate engineering students at diverse institutions. RESULTS Internal consistency reliability was assessed using Kuder-Richardson Formula 20; values were 0.85 for the entire instrument and ranged from 0.59 to 0.76 for the four subcategories of the HECI. Student performance on the HECI went from 49.2% to 54.5% after instruction. Gains on each of the individual subscales of the HECI, while generally statistically significant, were similarly modest. CONCLUSIONS The HECI provides sufficiently high estimates of internal consistency reliability to be used as a research tool to assess students' understanding of the targeted concepts. Use of the instrument demonstrates that student misconceptions are both prevalent and resistant to change through standard instruction.

The Persistence of Shattered Dreams: a Comparative Study of the Audacity of the American Dream

In my thesis, I use historical and literary analysis to study how the concept of the American Dream was popularized during the Great Depression and how cultural understanding of the term has changed following the 2008 Recession. By comparing popular media, literature, and political documents within a historical framework from the 1930s and after 2008 through the present day, I analyze how the term ¿American Dream¿ has persisted as an element of the United States¿ national ethos. I explore why the language of the American Dream does not appear to carry the same resonance in American society as in the 1930s, even though the post-2008 economic environment is somewhat comparable to conditions created by the Great Depression and associated reform measures. This comparative historical approach in scholarly studies of the American Dream is unique because the two periods have not previously been discussed in relation to one another in order to show transformations in cultural understanding of the Dream. The American Dream, both embodying a dual identity as an aspiration to aspire to and also as a delusional fantasy which can lead to cynicism, is a highly complex idea in lived experience. The concept¿s ambiguous nature allows for individuals to interpret it differently, allowing for the term to remain resilient throughout different periods in United States history. While the meaning of the term has been subject to change, it is grounded upon an idealistic concept of American individualism and hope that through one¿s merit, one will be able to achieve one¿s vision of success. Through interdisciplinary analysis, I show that the American Dream will alter to suit the needs of contemporary society and the term¿s power will continue to endure in society despite evidence of rising cynicism since 2008.