606 research outputs found

    Cyanobacteria from the Baltic Sea and Finnish lakes as an energy source and modulators of bioenergetic pathways

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    Cyanobacteria are a diverse group of oxygenic photosynthetic bacteria that inhabit in a wide range of environments. They are versatile and multifaceted organisms with great possibilities for different biotechnological applications. For example, cyanobacteria produce molecular hydrogen (H2), which is one of the most important alternatives for clean and sustainable energy. Apart from being beneficial, cyanobacteria also possess harmful characteristics and may become a source of threat to human health and other living organisms, as they are able to form surface blooms that are producing a variety of toxic or bioactive compounds. The University of Helsinki Culture Collection (UHCC) maintains around 1,000 cyanobacterial strains representing a large number of genera and species isolated from the Baltic Sea and Finnish lakes. The culture collection covers different life forms such as unicellular and filamentous, N2-fixing and non-N2-fixing strains, and planktonic and benthic cyanobacteria. In this thesis, the UHCC has been screened to identify potential strains for sustainable biohydrogen production and also for strains that produce compounds modifying the bioenergetic pathways of other cyanobacteria or terrestrial plants. Among the 400 cyanobacterial strains screened so far, ten were identified as high H2-producing strains. The enzyme systems involved in H2 metabolism of cyanobacteria were analyzed using the Southern hybridization approach. This revealed the presence of the enzyme nitrogenase in all strains tested, while none of them are likely to have contained alternative nitrogenases. All the strains tested, except for two Calothrix strains, XSPORK 36C and XSPORK 11A, were suggested to contain both uptake and bidirectional hydrogenases. Moreover, 55 methanol extracts of various cyanobacterial strains were screened to identify potent bioactive compounds affecting the photosynthetic apparatus of the model cyanobacterium, Synechocystis PCC 6803. The extract from Nostoc XPORK 14A was the only one that modified the photosynthetic machinery and dark respiration. The compound responsible for this effect was identified, purified, and named M22. M22 demonstrated a dual-action mechanism: production of reactive oxygen species (ROS) under illumination and an unknown mechanism that also prevailed in the dark. During summer, the Baltic Sea is occupied by toxic blooms of Nodularia spumigena (hereafter referred to as N. spumigena), which produces a hepatotoxin called nodularin. Long-term exposure of the terrestrial plant spinach to nodularin was studied. Such treatment resulted in inhibition of growth and chlorosis of the leaves. Moreover, the activity and amount of mitochondrial electron transfer complexes increased in the leaves exposed to nodularin-containing extract, indicating upregulation of respiratory reactions, whereas no marked changes were detected in the structure or function of the photosynthetic machinery. Nodularin-exposed plants suffered from oxidative stress, evidenced by oxidative modifications of various proteins. Plants initiated strategies to combat the stress by increasing the levels of alpha-tocopherol, mitochondrial alternative oxidase (AOX), and mitochondrial ascorbate peroxidase (mAPX).Siirretty Doriast

    Biochemical and molecular characterization of two low-phytate pea lines

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    Phytate is the major storage form of phosphorus in crop seeds, but is not well digested by humans and non-ruminant animals. In addition, phytate chelates several essential micronutrients which are also excreted contributing to phosphorus pollution in the environment. This research was aimed at the biochemical and molecular characterization of two low phytate pea mutant lines, 1-150-81 and 1-2347-144 developed at the Crop Development Centre, University of Saskatchewan in collaboration with Dr. Victor Raboy, USDA, Idaho. Low phytic acid (lpa) crops are low in phytic acid and high in inorganic phosphorus (Pi). In Study I, two lpa pea genotypes, 1-150-81, 1-2347-144, and their progenitor CDC Bronco were evaluated in field trials for two years. The lpa genotypes did not significantly differ from CDC Bronco in all agronomic traits assessed except for lower seed weight and grain yield. The concentration of IP6 at 14 DAF was not significantly different among CDC Bronco, 1-150-81 and 1-2347-144. However, the concentrations of IP6 among CDC Bronco, 1-150-81 and 1-2347-144 started to differ significantly from 21 DAF onwards. The lpa genotypes 1-150-81 and 1-2347-144 showed 65% and 60% reduction in IP6, respectively, when compared to their progenitor CDC Bronco at 49 DAF. The Pi concentrations between the lpa genotypes were similar and significantly higher than CDC Bronco from 21 DAF to 49 DAF. At 49 DAF, 1-150-81 and 1-2347-144 were 72 and 84% higher in Pi, respectively, than CDC Bronco. The total P concentration was similar in lpa genotypes and CDC Bronco throughout the seed development. This study elucidated the rate and accumulation of phosphorus compounds in lpa genotypes. In Study II, aiming at understanding the genetic basis of the lpa mutation in pea lines 1-150-81 and 1-2347-144, a 1530 bp open reading frame of myo-inositol phosphate synthase gene (MIPS) was amplified from CDC Bronco and the lpa genotypes. Sequencing results showed no difference in coding sequence in MIPS between CDC Bronco and lpa genotypes. Transcript levels of both MIPS and myo-inositol tetrakisphosphate1-kinase (ITPK1) were relatively lower at 49 DAF than at 14 DAF for CDC Bronco and lpa lines. There was no difference in expression level of both MIPS and ITPK1 between CDC Bronco and the lpa genotypes at 49 DAF. The data demonstrated that mutation in MIPS was not responsible for lpa trait in pea. Study III was aimed at developing a single nucleotide polymorphism (SNP) based genetic linkage map and mapping genomic regions associated with phytic acid-phosphorus (PA-P) concentration using PR-15 recombinant inbred lines (RILs) derived from a cross between a low phytate (lpa) pea genotype, 1-2347-144 and normal phytate pea cultivar CDC Meadow. A total of 163 RILs were genotyped using 1536 SNP markers in an Illumina GoldenGate array. Three hundred and sixty seven polymorphic SNP markers, ordered into 7 linkage groups (LGs), generated a linkage map with a total length of 437.2 cM. The phytic acid locus was mapped on to LG5. A quantitative trait locus (QTL) for iron bioavailability was mapped on to the same location in LG5 as phytic acid concentration. Potential benefits arising out of this research include improved bioavailability of phosphorus, iron and zinc in foods and feeds, less phosphorus excretion and environmental pollution and a saving in feed costs

    The translation profession in Malaysia: the translator’s status and self-perception

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    This paper aims to discuss the current status of translators practising in Malaysia and their perceptions towards the profession. The study was motivated by the dearth of literature on the status of the translator’s profession in Malaysia. Past studies have shown that translation is not considered a full-fledged profession in many other countries. Translators also do not perceive their own job as belonging to a profession due to a number of reasons. This study which adopts hermeneutic phenomenology as its method of inquiry is mostly qualitative in nature with an inclusion of some basic quantitative measures. The findings of this study has revealed that though Malaysian translators regard themselves as professionals in society, clients and the public unfortunately do not share the same views. The translators also cited unfair competition from amateur translators and unprofessional practices in their profession due to a lack of code of ethics, as challenges which seriously undermine the status of their professions. The findings of this study markedly highlight the concerted effort that is needed to set up a professional body to represent the translators in Malaysia

    Knowledge and awareness on administration of local anesthesia and its various complications faced by undergraduate and postgraduate dental students - a cross sectional study

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    Local anaesthetics are an inseparable part of dental practice. Local anesthesia helps in relieving pain of the patient and also makes the comfortable during the dental procedure.also makes it painless as possible. Although they are effective in controlling pain, without proper knowledge of the safe dose and methods of administration inevitable complications arise. This study was done to assess knowledge and awareness of dental students on administration of local anesthesia and its various complications. An online survey was conducted with the help of Google forms was distributed to 103 undergraduate students pursuing dentistry. The questionnaire consisted of 15 questions that were based on dosage, administration and complication of local anesthesia. After obtaining the responses, data was tabulated in excel sheet and was subjected to statistical analysis. Results show that 40.8% agree that 4.4 mg/kg is the maximum dosage of 2% lidocaine with adrenaline, 45.6% students agree the importance of aspiration. 24.3% students know the complication of transient amaurosis to be blindness. 34% students know that ocular complications arise due to local anesthetic administration. No statistically significant difference noticed with the responses based on gender and educational status (p-value > 0.05). The overall knowledge and awareness about local anesthesia and its complications were only moderate among the undergraduate and postgraduate dental students. Postgraduates showed a better knowledge when compared to undergraduates

    Analysis and Modeling of Statistical Properties of FMDFB Subband Coefficients

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    Fast Multiscale Directional Filter Bank (FMDFB) is an image representation scheme used in several image processing applications. The statistical nature of the FMDFB subbands is analyzed, and a mathematical model of FMDFB coefficients is proposed. Experimental results are justified by goodness-of-fit tests

    The construction and validation of solution-focused group work (SFGW) for Malaysian adolescents

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    Solution-focused Group Work (SFGW) approach is proven to be effective in resolving adolescents’ life struggles and assist them to lead a successful adolescence hood.  Common practices of developing the intervention module and assessing the module are presented in this study.  The data was collected by two stages: (i) validation process by 4 counseling module development experts; and (ii) a total of 30 samples aged 14-15 years old was piloted to obtain the reliability score of SFGW.  The collected data were subjected to descriptive test.  The result yielded that SFGW have good validity and high reliability with Cronbach’s alpha of .87 and .94 respectively.   Hence, it is concluded that SFGW is a valid and reliable module for adolescents who increases their self-efficacy, achievement motivation and goal-setting behaviors

    Grey Relational Analysis-Based Optimisation of Input Parameters of Incremental Forming Process Applied to the AA6061 Alloy

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    Incremental forming is mainly based on the deformation occurring locally on sheet metal. A hemispherical head tool deforms the sheet metal progressively, and its path is controlled by means of a CNC machine. Even though the process is a time-consuming one, the cost reduction connected with punches and dies makes this process attractive for rapid prototyping. In single point incremental forming, the quality of formability mainly depends on the forming parameters and the tool path generated. In this study, cone-shaped components were formed from AA6061 alloy sheets with a thickness of 1.15 mm. Factors, such as feed rate, spindle speed, and step depth are considered as input parameters to determine the output response in terms of surface roughness and wall thickness. Taguchi’s technique was used for conducting the experiments with the smallest number of repetitions to evaluate the output. Grey relational analysis was introduced to determine the optimal forming parameters with respect to the output response. The experiments conducted with the optimised parameters show a minimal deviation of 0.15% in the grade value compared to the predicted grade which is acceptable

    Factors influencing readiness of cashless system in Malaysia

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    The government of Malaysia has intended to transform Malaysia into a digital era by 2020, as stated in the Financial Blueprint 2011. Growth in electronic payments and mobile banking are significantly increasing, but private researchers have mentioned that Malaysia is not ready to meet this goal by 2020 due to a lack of security and data privacy. The objective of this paper is to determine the factors influencing readiness level of Malaysia in adopting digital payments and going cashless. Key variables like usage, awareness, trend analysis and descriptive comparison between cash and cashless economy are being used as core parameters in this study. Regression analysis was conducted to generate the outcomes. The results indicated that Malaysia was 20% cashless in 2018. Hence, the country is still far from meeting its aim of wanting to be operating in full cashless mode by 2020. It has been deduced that Malaysia may potentially need an estimated amount of 10 years or more to be able to operate fully in cashless mode and completely utilise digital payments as routine paying methods. Furthermore, sufficient strategic moves and action plans to boost digital payments and awareness in assisting transformation towards digitalisation are required in Malaysia. Also, involvement from all parties, including profitable and non-profitable organisations from every economic sector will assist towards realising this digital transformation

    Effect Of Essential Oils And Organic Acids On Selected Food-Borne Pathogens And Physicochemical Properties Of Shrimps

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    Udang (Penaeus monodon), dikategorikan sebagai makanan yang mudah rosak dan jangka hayat bawah penyimpanan sejuk pada 4°C adalah terhad. Bahan pengawet yang sedia ada (natrium metabisulfida) berpotensi membawa risiko ke atas kesihatan manusia. Oleh itu, pengawet alternatif dari sumber semula jadi diperlukan. Tujuan kajian ini adalah untuk mengkaji keberkesanan minyak pati (kayu manis, bawang putih, limau) dan asid organik (asid laktik, asid tartarik dan natrium diasetat) untuk merencat patogen bawaan makanan, meningkatkan kualiti mikrob dan fisikokimia. Udang harimau segar dicelup dalam rawatan yang mengandungi minyak pati atau/dan asid organik selama 30 minit, dikeluarkan dan disimpan pada 4°C selama 10 hari. Shrimps (Penaeus monodon) are and have a limited s shelf-life under refrigerated storage. Existing preservatives (sodium metabisulfite) have potential risk on human health. There is a need for a safer alternative with reduced health effects to extend the shelf life and maintain the quality of shrimp. The aim of this study was to assess effects of selected essential oils and organic acids (singly and mixture) on microbial safety, quality and shelf-life of fresh shrimps. Initially, shrimps (Penaeus monodon) were dipped in essential oil (cinnamon, garlic and lime) or organic acid (tartaric acid lactic acid and sodium diacetate) (singly and mixture) for 30 mins and stored at 4 ºC to determine the most effective essential oil or mixture of essential oil and organic acid that can reduce total plate counts (TPC) and improve shelf-life of the shrimps stored at 4 ºC
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