Spin-crossover, mesomorphic and thermoelectrical properties of cobalt(II) complexes with alkylated N3-Schiff bases

Three new cobalt(ii) complexes, [Co(L12)2](BF4)2 (1), [Co(L14)2](BF4)2·H2O (2) and [Co(L16)2](BF4)2·H2O (3), where L12-16 are N3-Schiff bases appended with linear C12-16 carbon chains at the nitrogen atoms, were obtained in good yields by facile one-pot reactions. The single crystal X-ray structure of complex 1 shows a tetragonally compressed CoN6 coordination geometry. The melting temperatures of 1-3 were lower than 373 K, while their decomposition temperatures were above 473 K. All complexes have high-spin Co(ii) centres at 300 K and exhibit a columnar mesophase above 383 K. Complexes 1 and 3 showed normal thermal spin-crossover behaviour with weak hysteresis loops at about 320 K. Hence, these complexes showed uncoupled phase transitions (class iiia). The values for the Seebeck coefficient (Se) of the cobalt redox couples formed from 1 and 2 were 1.89 ± 0.02 mV K-1 and 1.92 ± 0.08 mV K-1, respectively, identifying them as potential thermoelectrochemical materials

Antimicrobial activity of Warbugia ugandensis against gramnegative multi‐drug resistant bacteria

The rise in antibiotic resistance has resulted in decreasing numbers of effective antimicrobial agents available to treat infections caused by multi‐drug resistant (MDR) bacteria. This has necessitated a search for new antimicrobial agents. Herbal remedies may offer alternative treatment options especially because they elicit little or no transferable resistance if used in optimal concentrations. This study evaluated the antimicrobial properties of W. ugandensis against eight multi drug resistant (MDR) Gram‐negative bacterial isolates. The herbal extracts were obtained using methanol as an organic solvent and water as an inorganic solvent. Determination of the Minimum Inhibitory Concentrations (MICs) and the sub‐lethal concentrations of the effective extracts was done using broth inoculation method followed by colony count. The test isolates were habituated in sub‐lethal extract concentrations (SLC) for 72 h to investigate effect on their sensitivity to conventional antibiotics. Methanol extracts from the root and stem‐bark of W. ugandensis were active against the test strains and their inhibitory effect was significantly different (p<0.05) from that of other extracts. We determined that the extracts had an inhibitory rather than a lytic (cidal) mode of action. The extracts from this plant had an effective MIC of 42 μg/ml and exhibited an inhibitory mode of action and did not elicit resistance to conventional antibiotics. Methanol extracts from the root and bark of this plant may provide potential sources for further development of alternative antimicrobial agents for the treatment of MDR infections.Key words: multi‐drug resistant (MDR) bacteria, minimum inhibitory concentrations (MICs), sub‐lethal concentration (SLC

Recording Loss: film as method and the spirit of Orford Ness

This is the author accepted manscript. The final version is available from Routledge via the DOI in this record.This paper explores the use of film as a method to explore themes of change and loss which emerged during recording of archaeological features at Orford Ness, UK. Owned by the National Trust, Orford Ness is an exposed shingle spit off the Suffolk coast recognised for its natural and cultural heritage. The research discussed in this paper engaged with a community archaeology project which has been recording features on the shingle spit as they are altered and erased by erosion and other coastal processes. The authors experimented with film as a method to investigate the work being undertaken by practitioners and volunteers in this dynamic landscape. We conclude that, within interdisciplinary heritage research, experimenting with film as a method facilitates the representation of embodied practices and exposes processes of meaning-making. We frame our discussion about the active production of meaning through an analysis of the way that film engaged with qualities articulated in the National Trust’s Spirit of Place statement for the site.Arts and Humanities Research Counci

Evaluation of an Antigen-Antibody “Combination” Enzyme Linked Immunosorbent Assay for Diagnosis of Hepatitis C Virus Infections

Background: Development of “combination” assays detecting in parallel, within a single test, Hepatitis C Virus (HCV) antigens and antibodies, not only reduces the window period in HCV-infection but also costs. Reduction of costs is important for developing countries where money and personal resources are limited.Methods: We compared the Monolisa® HCV Antigen-Antibody Ultra (Bio-Rad Laboratories Limited, Marnes La Coquette, France) with the AXSYM HCV version 3.0 (Abbot Diagnostics, Germany)-the latter assay detecting only antibodies to HCV. Seventy three HCV-PCR positive and negative samples were tested.Results: Although the two assays showed comparable results, two samples from a bone marrow transplant (BMT) patient of viral loads 7.8 x 105 and 8.9 x 106 IU/mL could not be detected by the Monolisa® HCV Antigen-Antibody Ultra assay. Failure to detect the two samples with viral loads considered above threshold of detection for antigen proteins suggested a lack of sensitivity by this assay to discover viral capsid protein in patient samples. Genotyping of these samples revealed genotype 1b, a HCV-subtype which is widespread and should thus be easily detected.Conclusion: We conclude that although this assay depicts high sensitivity and specificity in detecting antibodies to HCV, it seems not to add further benefit in our study population to detect HCV infections by enhanced sensitivity due the potential contingency to trace viral capsid antigens.Keywords: Ag-Ab Combination assay, Hepatitis C Virus, ELISA, Monolisa HCV Ag-Ab Ultr

Laboratory surveillance of cholera in Nyanza province during the outbreak from April to July 2007

Cholera continues to be an important cause of morbidity and mortality in many areas of the world, and there is currently a high frequency of new outbreaks in Africa. Following a confirmed cholera outbreak in Siaya, Kisumu, Bondo and Nyando districts, Nyanza province in western Kenya between April and July 2007, a laboratory surveillance study was conducted at the New Nyanza Provincial General Hospital’s Microbiology Laboratory. The study aimed at isolating and identifying the strain of Vibrio cholerae, Identifying the mean age of the patients and monitoring the susceptibility patterns to major antibiotics. It further aimed at determining effectiveness of empiric management of cholera. A total of 219 samples were processed out of which a total of 85 samples (39%) were found positive for Vibrio cholerae 01 sero‐type Inaba. The mean age recorded was 19 years (1 ≤ 80). The modal ages recorded were 8, 20 and 25. 55% (47) of the recorded cases were females while 45% (38) were males. Generally, V.Cholerae 01 sero‐type Inaba showed antibiotic resistance to trimethoprim‐sulfamethoxazole, nalidixic acid, sulfasoxazole, streptomycin and furazolidone. Tetracycline a commonly used antibiotic for empiric management was 100% effective on all isolates and remains the drug of choice. Samples obtained for case‐control study did not yield any cholera isolate. No prior exposure to any antibiotic was recorded among all the subjects. The study confirmed the effectiveness of empirical therapy on cholera and further identified the need of proper hygiene, water treatment, proper waste management and proper eating habits as means of controlling morbidity and mortality of cholera.Key words: Cholera, morbidity, mortality, empiric management, antibiotic resistanc

DAYA ANTIBAKTERIAL EKSTRAK UMBI WORTEL (Daucus carrota) TERHADAP Escherichia coli SECARA IN VITRO

Tujuan penelitian ini untuk mengetahui daya antibakterial ekstrak umbi wortel dan besarnya konsentrasi ekstrak umbi wortel sebagai antibakterial terhadap Escherichia coli

The vocal apparatus: An understudied tool to reconstruct the evolutionary history of echolocation in bats?

Laryngeal echolocation in bats could have evolved following two scenarios: a single origin from a common ancestor or an independent acquisition inside the two clades Yinpterochiroptera and Yangochiroptera. Later, some members of Yinpterochiroptera possibly lost their ability to echolocate. In bats, the larynx produces vocalizations for communication and, in most species, for echolocation. Here, we describe how comparative chiropteran laryngeal morphology is a novel area of research that could improve the understanding of echolocation and may help resolve the evolutionary history of bats. This review provides morphological descriptions and comparisons of the bat larynx and bioacoustics interpretations. We discuss the importance of understanding: (1) laryngeal sound production so it may be linked with the evolution of the chiropteran auditory system; and (2) the evolution of laryngeal morphology to understand the ecological and behavioural aspects of bat biology. We find that a strong phylogenetic signal is potentially the main source explaining macroevolutionary variation in laryngeal form among bats. We predict that the three parameters of sound production in echolocation (frequency, intensity, and rate of calls) are independently modulated by different laryngeal components, but this hypothesis remains understudied in terms of species diversity

Left High and Dry: Deglaciation of Dogger Bank, North Sea, Recorded in Proglacial Lake Evolution

Reconstructions of palaeo-ice sheet retreat in response to climate warming using offshore archives can provide vital analogs for future ice-sheet behavior. At the Last Glacial Maximum, Dogger Bank, in the southern North Sea, was covered by the Eurasian Ice Sheet. However, the maximum extent and behavior of the ice sheet in the North Sea basin is poorly constrained. We reveal ice-marginal dynamics and maximum ice extent at Dogger Bank through sedimentological and stratigraphic investigation of glacial and proglacial lake sediments. We use a large, integrated subsurface dataset of shallow seismic reflection and geotechnical data collected during windfarm site investigation. For the first time, an ice stream is identified at Dogger Bank, based on preserved subglacial bedforms, eskers and meltwater channels. During ice-sheet advance, a terminal thrust-block moraine complex formed, whose crest runs approximately north-northeast to south-southwest. Subsequent ice stream shutdown caused stagnation of ice, and rapid retreat of the ice-sheet margin. The moraine complex, and outwash head from an adjacent ice-sheet lobe to the west, dammed a large (approximately 750 km2) proglacial lake. Subsequent sedimentation infilled the lake with 30 m of glacial outwash sediments. A lobate subaqueous fan formed at the ice-sheet margin, which thins toward the southeast with iceberg scours and ice-rafted debris at the base, and is onlapped by lake sediments calibrated to core as alternating clay and silt laminae, interpreted to be varves. The lake became isolated from the retreating ice-sheet margin, and ice-sheet retreat slowed. Sediment-laden meltwater was supplied to the ice-distal proglacial lake for c. 1500–2000 years. Subsequent ice-sheet retreat off Dogger Bank was more rapid due to the negative subglacial slope. The stepped retreat of rapid downwasting, slow retreat, and a final rapid phase off Dogger Bank occurred after the LGM at around 27 ka and before formation of a ribbon lake, dated previously to 23 ka and approximately 60 m lower in elevation, formed to the north of Dogger Bank. The complicated stratigraphic architecture revealed through these data improves forecasting of ground conditions for turbine footings at Dogger Bank, an important step in the provision of clean, sustainable energy

PENGARUH IRADIASI SINAK·X TERHADAP LEKOSIT MENCIT

Pengaruh iradiasi sinar-X terhadap lekosit mencit. Salah satu sindrom biologi akibat radiasi adalah sindrom hemopoetik