3,053 research outputs found

    Physico-chemical characterization and cytotoxicity studies of seed extracts of Khaya senegalensis (Desr.) A. Juss.

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    The seeds of Khaya senegalensis were extracted using petroleum ether and methanol with the aim of determining the physico-chemical properties of the seed oil and the cytotoxicity of the two extracts. Therefractive index of the oil was found to be 1.458, while the relative density was 0.953. The iodine and saponification values were 88.40 and 195.58, respectively. The peroxide and acid values were 4.6 and2.69, respectively. Brine shrimp lethality bioassay of petroleum ether and methanol extracts of the seeds showed that the extracts were moderately cytotoxic at high concentration. The LC50 values usingProbit analysis method for petroleum ether and methanol extracts were 827.39 and 51.79 ìg/ml, respectively. Therefore, the seed oil of K. senegalensis was found to be non-drying oil and the extractsfrom the seeds may contain bioactive compounds of potential therapeutic and prophylactic significance

    Cytotoxicity and antimicrobial studies of 1,6,8- trihydroxy-3-methyl-anthraquinone (emodin) isolated from the leaves of Cassia nigricans Vahl

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    Emodin was isolated from the ethyl acetate extract of the leaves of Cassia nigricans Vahl. The structure of the emodin was established by chemical spectroscopy. The LC50 (lower – upper limits) of the emodinwas 42.77 (11.80 – 72.94) ìg/ml. Emodin was found to be highly cytotoxic. It showed significant antimicrobial activity on some common pathogens. The isolation of this active principle emodin, from the leaves of Cassia nigricans for the first time and the antimicrobial activity of the compound are reported in the present study. The isolation of the active principle justifies the use of the leaves of C. nigricans in herbal medicine for the treatment of skin diseases and gastro-intestinal disorders

    The use of microsatellite polymorphism in genetic mapping of the ostrich (Struthio camelus)

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    The aim of this study was to determine microsatellite polymorphism in ostriches and using it in creation the genetic map of the ostrich. The polymorphism analysis covered 30 microsatellite markers characteristic of ostrich, for the CAU (China Agricultural University) group. The material consisted of 150 ostriches (Struthio camelus). The 30 microsatellite loci was examined and a total of 343 alleles was identified. The number of alleles at a single locus ranged from 5 at locus CAU78 to 34 at locus CAU85. The values for the observed heterozygosity Ho ranged from 0.467 (locus CAU78) to 0.993 (locus CAU16), whereas for the expected heterozygosity He - from 0.510 (locus CAU78) to 0.953 (locus CAU85). Analyzing the individual loci, the highest PIC value, more than 0.7 was observed for: loci CAU85 (0.932), CAU64 (0.861) and CAU32, 75 (0.852), respectively. It should be noted, that the microsatellite markers used in our study were very polymorphic as evidenced by the large number of detected alleles and high rates of heterozygosity, PIC and PE as well. The analysed microsatellite markers may be used in genetic linkage mapping of ostrich, the construction of a comparative genetic map with other ratites, such as emu and rhea, and population genetics studies or phylogenetic studies of these birds

    Assessing the competitiveness of Matera and the Basilicata Region (Italy) ahead of the 2019 European Capital of Culture

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    Cities/regions are increasingly using events to aid social/economic development. The European Capital of Culture promotes urban management and economic production using culture to drive social legacies, job creation and civic repositioning. This paper aims to understand how Matera and Basilicata’s residents perceive destination competitiveness ahead of the 2019 European Capital of Culture. This paper adapts the Integrated Model of Destination Competitiveness and suggests a new determinant to understand resident perceptions. This paper contributes a new determinant to consider in competitiveness research: social conditions to improve local wellbeing. Two hundred respondents identify strengths/weaknesses of each competitiveness determinant. The results presented in this study display sample mean values and standard deviations for each indicator, as well as Wilcoxon test statistic (z). Competitive indicators are those showing means above 4.0. Descriptive and inferential analyses using SPSS 17 show strengths/weaknesses comparing Matera (city) and Basilicata (region) with similarities and differences outlined to consider both urban and regional perspectives and differences. For the data analysis, Wilcoxon paired signed rank test displays differences in the competitiveness factors between Matera and Basilicata. Wilcoxon (a nonparametric alternative to paired sample t-test) was performed since the data distribution was left skewed and Kolmogorov–Smirnov statistic indicates violation of normality assumption. Results show the majority of inherited, created and supporting resources are competitive, as well as image and social conditions; however, management and organisation needs improvement. It is essential that European Capital of Culture hosts have long-term competitive strategies in place to strengthen urban and regional capacity when delivering diverse cultural programmes, at present, and into the future. This study offers insight before the 2019 European Capital of Culture to inform planners and policymakers ahead of the event and offers consideration and discussion of social impacts and the need to gain such insight in competitiveness research going forward

    Antimony and bismuth oxide cluster ions

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    The formation of charged antimony and bismuth oxide clusters in a pulsed arc cluster ion source (PACIS) has been studied with time-of-Ñight mass spectrometric techniques. We compare series of antimony and bismuth oxide cluster anions with their known cationic counterparts. The anionic series and (M 2 O 3 ) n MO 2h ave been predicted proceeding from the known cationic series and n Ob y adding O2~and have been experimentally established. All these series contain the metal atoms (M \ Sb or Bi) in the formal oxidation state ]3. However, only in the case of antimony, oxygen rich oxide clusters appear, that can be explained with a gradual transition in the oxidation number from ]3 to ]5 of single antimony atoms in the cluster. To estimate the inÑuence of the special oxide formation conditions comparative investigations with the PACIS and a laser vaporisation cluster source have been carried out for bismuth oxide cations. The similar oxide cluster distributions at comparable oxygen availability display clearly that the special thermodynamical stability of the discussed magic clusters is the signiÐcant driving force for their formation

    Recent results from systematic parameterizations of Ginsparg-Wilson fermions

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    The Fixed Point Dirac Operator and Chirally Improved Fermions both use large numbers of gauge paths and the full Dirac structure to approximate a solution of the Ginsparg-Wilson equation. After a brief review of the two approaches we present recent results for quenched QCD with pion masses down to 210 MeV. We discuss the limits and advantages of approximate parameterizations and outline future perspectives.Comment: Lattice2002(plenary). References and Fig. 5 updated. Final version submitted to the proceeding

    Improving the teaching skills of residents as tutors/facilitators and addressing the shortage of faculty facilitators for PBL modules

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    BACKGROUND: Residents play an important role in teaching of medical undergraduate students. Despite their importance in teaching undergraduates they are not involved in any formal training in teaching and leadership skills. We aimed to compare the teaching skills of residents with faculty in facilitating small group Problem Based Learning (PBL) sessions. METHODS: This quasi experimental descriptive comparative research involved 5 postgraduate year 4 residents and five senior faculty members. The study was conducted with all phase III (Final year) students rotating in Gastroenterology. The residents and faculty members received brief training of one month in facilitation and core principles of adult education. Different aspects of teaching skills of residents and faculty were evaluated by students on a questionnaire (graded on Likert Scale from 1 to 10) assessing i) Knowledge Base-content Learning (KBL), ii) PBL, iii) Student Centered Learning (SCL) and iv) Group Skills (GS). RESULTS: There were 33 PBL teaching sessions in which 120 evaluation forms were filled; out of these 53% forms were filled for residents and 47% for faculty group. The faculty showed a statistically greater rating in KBL (faculty 8.37 Vs resident 7.94; p-value 0.02), GS (faculty 8.06 vs. residents 7.68; p-value 0.04). Differences in faculty and resident scores in the PBL and SCL were not significant. The overall score of faculty facilitators, however, was statistically significant for resident facilitators. (p = .05). CONCLUSION: 1) Residents are an effective supplement to faculty members for PBL; 2) Additional facilitators for PBL sessions can be identified in an institution by involvement of residents in teacher training workshop
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