PENGARUH LIKUIDITAS, KUALITAS AKTIVA, SENSITIVITAS, EFISIENSI DAN SOLVABILITAS TERHADAP RETURN ON ASSETS (ROA) PADA BANK PEMBANGUNAN DAERAH

Bank is business entities that raise funds from the public in deposits form and distribute to the public in credit form and or other forms in order to improve the living standart of the general public. The main function of banks as an intermediatery between surplus and deficit fund. Beside that, bank should have a minimum capital 8 percent to anticipate lossing and in this research capital of bank should be rise but in fact it is not. The objective of this research is to know the influence of financial performance that consist of LDR, IPR, APB, NPL, IRR, BOPO, FBIR and FACR to ROA on regional development banks. This research uses multiple regression analysis with purposive sampling method. The results show that APB has significant influence whereas the others variable have unsignificant influence. The independent variable that has dominant influence is APB because it’s partial determination coefficient value is higher than another independent variable with value 9,42 percent and residual influenced by the others independent variables

Use of a capacitive affinity biosensor for sensitive and selective detection and quantification of DNA—A model study

AbstractA capacitive DNA-sensor model system was used to monitor the capture of complementary single-stranded DNAs. The sensor chip consisted of a gold electrode, which was carefully insulated with a polytyramine layer and covalently tagged with 25-mer oligo-C. As low as 10−11 moles per liter of target oligo-G could be detected by injecting 250μL of sample. Elevated temperature was used to reduce non-specific hybridization. Less than 10% of non-target 25-mer oligo-T interacted nonspecifically with the oligo-C probes when hybridization process was performed at 50°C. Studying the relationship of length of the analyte to the signal strength, the output from the capacitive DNA-sensor increased to almost the double; from 50 to 88-nFcm−2, when a 25-mer oligo-G was used instead of a 15-mer. By sandwich hybridization at room temperature, it was possible to further increase the signal, from 78-nFcm−2 for the target 50-mer oligo-G alone, to 114-nFcm−2

Characterisation and Antimicrobial Potential of Actinobacteria Isolated from Momela Soda Lakes, Tanzania

Extreme environments such as soda lakes are potential sources of microbes with biotechnological applications in different sectors. This study aimed at isolation, characterization and investigation of antibacterial potential of actinobacteria from Momela Soda Lakes, at Arusha National Park in Tanzania. One hundred and twenty (120) isolates were recovered from soil and water samples using the dilution plate technique. The isolates were morphologically and biochemically characterized, and further, screened for antimicrobial activity by disc diffusion method as well as the micro dilution technique. Cytotoxic effects were determined using the brine shrimp lethality test. Results showed that, all 120 isolates were Gram-positive rod-coccus shaped. Forty-four out of them showed antibacterial activity against Staphylococcus aureus and Escherichia coli. The Streptomyces (101TI) and Dietzia (56BI) strains exhibited exceptionally higher antibacterial activity compared to the rest with inhibition zones of 16.25 and 21.00 mm, respectively. These two strains were toxic against brine shrimp-larvae. Microbacterium (5LI), Hoyosella (113BI), Streptomyces (62BI), Dietzia (117SI), Hoyosella (37SI) and Microbacterium (3BI) strains had low antibacterial and cytotoxic activities. This study therefore revealed that Momela Soda Lakes harbour actinobacteria with antimicrobial potential. Keywords: Actinobacteria; antimicrobial activity; extremophiles; Momela soda lake

Anti-termite Activities of Extracts from Euphorbia tithymaloides and Euphorbia tithymaloide variegatus

The objective of this work was to investigate the anti-termite properties of solvent extracts of two Euphorbia plant species, Euphorbia tithymaloides and Euphorbia tithymaloides “variegatus”. Termiticidal activity of stem barks and leaf extracts were analysed by using anti-termite activity tests. All crude extracts obtained by petroleum ether and ethyl acetate exhibited 100% repellency activities at a concentration of 36 mg mL-1. Average repellency time decreased as the concentration of crude extracts were increased. Contact bioassay tests revealed that crude extracts from stem barks are more potent than extracts from leaves; and non-polar solvents gave crude extracts which are more effective that those extracted by polar solvents. Crude extracts obtained by petroleum ether from stem barks of both E. tithymaloides and E. tithymaloides “variegatus” plants species gave dissimilar peaks in GC-MS chromatograms, except two peaks, which correspond to the compounds: 1-heptadecene and n-hexadecanoic acid. Crude extract from E. tithymaloides gave a prominent peak corresponding to the compound tetracontane as the principal constituent (73.7%) of the extract. Since this peak is absent in crude extracts from E. tithymaloides “variegatus” stem barks, its presence in crude extracts from E. tithymaloides stem barks can be attributed to its high termite lethality assay results. In general, from the results obtained from this work, it could be concluded that the Euphorbia species are potential sources of botanical pesticides against termites

Development of an Ultrasensitive Capacitive DNA-sensor: A promising tool towards microbial diagnostics

Fast and sensitive detection of pathogenic microbial cells is a highly important task in medical diagnostics, environmental analysis and evaluation of food safety. Accordingly, the idea of microorganism identification by the recognition of specific DNA sequence using electrochemical technique is one of the leading researches in the development of diagnostic devices. In other words, it should only be a matter of time before a small portable electrochemical device is available at the care centre for quick diagnoses of a patient’s infectious disease. However, bottlenecks for such diagnostic systems include selectivity, sensitivity, automation, sample pre-treatment and the architecture of miniaturization. In this thesis, a novel, highly sensitive and automated flow-based DNA-sensor technique for the detection of specific bacterial DNA sequences is introduced. The technique consists of a solid gold electrode that is functionalised using a simple and cheap chemistry to capture desired single stranded DNA in a complex matrix. The technology platform is based on the change in electrical property (capacitance) upon hybridization of the desired ssDNA to a capture probe. The physical and electrochemical properties of the modified electrode surface were studied using atomic force microscopy and cyclic voltammetry in reference to the innovative capacitive DNA-sensor assay. The DNA-sensor was optimized using homo-oligonucleotides with different number of bases (15- to 50 bases in probe length). The signal amplitude was found to increase with increase in oligonucleotide length, from 15- to 25-mer. However, there was no significant difference in signal readout between 25- and 50-mer. When using sandwich hybridization the signal readout for 50-mer oligonucleotides was increased by 46 %, from 78 to 114 -nF cm-2. In addition, stability and selectivity of the DNA-sensor were investigated at elevated temperatures by applying different types of homo-oligonucleotides on the same capture probe; the sensor proved to be exceedingly stable in wide range of temperatures, from 23 to 50 oC, with selectivity (> 95 %). To demonstrate the capability of the developed capacitive DNA-sensor in a real application, a specific capture probe designed to recognise 16S rDNA of Escherichia coli and other members in the family Enterobacteriacea was used. This, to explicitly detect certain patches of E. coli 16S rDNA from a laboratory culture. The study showed that unamplified E. coli 16S rDNA could be sensitively detected at very low concentration corresponds to 10 E. coli cells per millilitre with only 15 min hybridization time. The sensor also showed a good selectivity over Lactobacillus reuteri 16S rDNA (Lactobacillaceae) from a laboratory culture. Furthermore, a new approach for pre-treatment of the bacterial DNA-sample prior to flow-based DNA-sensor analysis is demonstrated. The novel pre-treatment method utilizes a commercial single stranded DNA binding protein to efficiently stabilize the heat generated single-stranded DNA. Subsequent addition of formamide in the mixture resulted in denaturation of the protein, and hence, hybridization of the heat-generated target ssDNA to capture probe takes place. Another promising application showed for the developed DNA-sensor is the identification of Methicillin-resistant Staphylococcus aureus based on detection of the mecA gene. The study showed that the sensor adequately could detect and recover 95 % of 0.01 nM mecA gene from spiked human saliva, with a detection limit of 0.6 pM. In conclusion, the work presented in this thesis demonstrates the development of a sensitive and effective biosensor for bacterial detection based on specific DNA sequence analysis. Compared to the commercially existing techniques for bacterial detection, the developed capacitive DNA-sensor proved to be non-complex, fast and efficient. This thesis work lays the groundwork for the development of a hand-held, field-adopted DNA-sensor for on-site microbial diagnostics, useful in e.g. remote areas

Evaluation of Polytyramine Film and 6-Mercaptohexanol Self-Assembled Monolayers as the Immobilization Layers for a Capacitive DNA Sensor Chip: A Comparison

The performance of a biosensor is associated with the properties of an immobilization layer on a sensor chip. In this study, gold sensor chips were modified with two different immobilization layers, polytyramine film and 6-mercaptohexanol self-assembled monolayer. The physical, electrochemical and analytical properties of polytyramine film and mercaptohexanol self-assembled monolayer modified gold sensor chips were studied and compared. The study was conducted using atomic force microscopy, cyclic voltammetry and a capacitive DNA-sensor system (CapSenze™ Biosystem). The results obtained by atomic force microscopy and cyclic voltammetry indicate that polytyramine film on the sensor chip surface possesses better insulating properties and provides more spaces for the immobilization of the capture probe than a mercaptohexanol self-assembled monolayer. A capacitive DNA sensor hosting a polytyramine single-stranded DNA-modified sensor chip displayed higher sensitivity and larger signal amplitude than that of a mercaptohexanol single-stranded DNA-modified sensor chip. The linearity responses for polytyramine single-stranded DNA- and mercaptohexanol single-stranded DNA-modified sensor chips were obtained at log concentration ranges, equivalent to 10−12 to 10−8 M and 10−10 to 10−8 M, with detection limits of 4.0 × 10−13 M and 7.0 × 10−11 M of target complementary single-stranded DNA, respectively. Mercaptohexanol single-stranded DNA- and polytyramine single-stranded DNA-modified sensor chips exhibited a notable selectivity at an elevated hybridization temperature of 50 °C, albeit the signal amplitudes due to the hybridization of the target complementary single-stranded DNA were reduced by almost 20% and less than 5%, respectively

Evaluation of polytyramine film and 6-mercaptohexanol self-assembled monolayers as the immobilization layers for a capacitive dna sensor chip : A comparison

The performance of a biosensor is associated with the properties of an immobilization layer on a sensor chip. In this study, gold sensor chips were modified with two different immobilization layers, polytyramine film and 6-mercaptohexanol self-assembled monolayer. The physical, electrochemical and analytical properties of polytyramine film and mercaptohexanol self-assembled monolayer modified gold sensor chips were studied and compared. The study was conducted using atomic force microscopy, cyclic voltammetry and a capacitive DNA-sensor system (CapSenze™ Biosystem). The results obtained by atomic force microscopy and cyclic voltammetry indicate that polytyramine film on the sensor chip surface possesses better insulating properties and provides more spaces for the immobilization of the capture probe than a mercaptohexanol self-assembled monolayer. A capacitive DNA sensor hosting a polytyramine single-stranded DNA-modified sensor chip displayed higher sensitivity and larger signal amplitude than that of a mercaptohexanol singlestranded DNA-modified sensor chip. The linearity responses for polytyramine single-stranded DNAand mercaptohexanol single-stranded DNA-modified sensor chips were obtained at log concentration ranges, equivalent to 10−12 to 10−8 M and 10−10 to 10−8 M, with detection limits of 4.0 × 10−13 M and 7.0 × 10−11 M of target complementary single-stranded DNA, respectively. Mercaptohexanol single-stranded DNA-and polytyramine single-stranded DNA-modified sensor chips exhibited a notable selectivity at an elevated hybridization temperature of 50◦C, albeit the signal amplitudes due to the hybridization of the target complementary single-stranded DNA were reduced by almost 20% and less than 5%, respectively

Rapid detection of mecA gene of methicillin-resistant Staphylococcus aureus by a novel, label-free real-time capacitive biosensor

This work presents a rapid, selective and sensitive automated sequential injection flow system with a capacitive biosensor for detection of the mecA gene (the model chosen for this study), which emerges from methicillin-resistant Staphylococcus aureus. A DNA-based 25-mer capture probe was immobilized on the surface of a gold electrode which was integrated in the capacitive sensor system. A constant current pulse was applied and the resulting capacitance was measured. Injection of the target DNA sample to the sensor surface induced hybridization to occur between the target and the complementary sequence, which resulted in a shift in the measured capacitance (ΔC). The ΔC was directly proportional to the concentrations of the applied target probe with linearity ranging from 10−12 to 10−7 M. The biosensor had a detection limit of 6.0 × 10−13 M and a recovery of 95 % of the mecA gene when spiked in human saliva. The biosensor showed a promising selectivity. It could clearly discriminate single-base, two-base and twelve-base mismatch probes with a decrease in the signal strength by 13 %, 26 %, and 89 %, respectively relative to the signal strength of the complementary target probe. There was no significant signal observed for the non-complementary probe. The biosensor-chip could be re-used for more than 12 cycles with residual capacity of 94.5 ± 4.3 % and a RSD of 4.6 % by regenerating the biosensor-chip with a solution of 50 mM NaOH

Enzymatic oil extraction and positional analysis of omega-3 fatty acids in Nile perch and salmon heads

The use of commercial proteases, bromelain and Protex 30L for oil extraction/recovery of polyunsaturated fatty acids (PUFA) from Nile perch and salmon heads was evaluated. Four phases were obtained after hydrolysis, oily phase, emulsion, aqueous phase and sludge. An increase in water content during the hydrolysis resulted in a decrease in oil yield. Maximum oil yield was obtained when hydrolysis was performed with Protex 30L at 55 C, without pH adjustment or water addition. An oil yield of 11.2% and 15.7% of wet weight was obtained from Nile perch and salmon heads, respectively, compared to 13.8% and 17.6%, respectively obtained using solvent extraction. Fatty acid distribution analysis showed 50% of palmitic acid was in sn-2 position in Nile perch triglycerides (TAG), while only 16% of this fatty acid was in sn-2 position in salmon oil TAG. (C) 2010 Elsevier Ltd. All rights reserved

Phylogenetic diversity of Actinobacteria from Momela soda lakes, Arusha National Park, Tanzania

The Momela soda lakes consist of seven small, hypersaline, alkaline lakes, situated in the East African rift valley at Arusha National Park, Tanzania. The lakes are fed by separate underground water sources with slightly varying mineral contents resulting in colour variation and supporting different kinds of prokaryotic and eukaryotic species. In this study, the diversity of Actinobacteria in surface water and sediments of five Lakes were investigated using culture-dependent and culture-independent molecular techniques. A total of 34 out of 112, and 13 out of 85, representatives of Actinobacteria isolates and clones, respectively, were selected for gene sequencing using the CD-HIT program. Analysis of their 16S rRNA gene sequences displayed the presence of species affiliated to 15 different genera, namely Mycobacterium, Rhodococcus, Microbacterium, Isoptericola, Dietzia, Leucobacter, Jonesia, Nesterenkonia, Micrococcus, Streptomyces, Hoyosella, Norcadiopsis, Cellulomonas, Bogoriella, and Agromyces. The results showed 5 and 12 putative new Actinobacteria isolates and clones, respectively. This is the first report of isolation of bacteria from the genus Mycobacterium from a soda lake globally, as well as the genera Hoyosella, Isoptericola, Jonesia, Micrococcus, Leucobacter and Agromyces from a soda lake in East Africa. Because Actinobacteria are known as a source of biotechnologically important compounds, the species revealed set a platform to search for novel bioactive compounds