Electrophilic Addition of Phenylisocyanate at gamma-CH of Thio-beta-diketonates of Some Transition Metals

The quasi-aromatic property of metal chelates of thio-beta-diketones has been studied by reacting them with phenylisocyanate, where addition takes place at the gamma-CH in a stepwise manner. Mono-thiodiketonates of Ni(II), Pd(II), cu(II) and Co(III) and the dithio-acetylacetonate of Ni(II) react with phenylisocyanate to produce mono-, di- and triphenylamido [with cobalt (III) only] substituted derivatives. In the case of tris (ethylthioacetoacetato) cobalt (III), it is found that the reaction with phenylisocyanate gives two isomers, a chocolate coloured isomer in which the phenylamido carbonyl is not coordinated while the green coloured isomer has bonding through phenylemido carbonyl oxygen. The reactions of the thiodiketonates have been compared with those of beta-diketonates and beta-ketoiminates. The reaction products have been characterised by elemental analyses, magnetic moments, and electronic, IR and 1H NMR spectral studies.

Catalyst-free plasma enhanced growth of graphene from sustainable sources

Details of a fast and sustainable bottom-up process to grow large area high quality graphene films without the aid of any catalyst are reported in this paper. We used Melaleuca alternifolia, a volatile natural extract from tea tree plant as the precursor. The as-fabricated graphene films yielded a stable contact angle of 135°, indicating their potential application in very high hydrophobic coatings. The electronic devices formed by sandwiching pentacene between graphene and aluminum films demonstrated memristive behavior, and hence, these graphene films could find use in nonvolatile memory devices also.

Recruitment sources of brown trout identified by otolith trace element signatures.

This study examined whether element: Ca ratios within the otoliths of juvenile brown trout could provide accurate trace element signatures for specific natal tributaries, and attempted to match these to trace element natal signatures found within the otoliths of adult trout caught in the main stem rivers of the same catchment. The trace element signatures of juvenile trout otoliths were analysed from a sample of eight tributaries representing the main sub-catchments of the Motueka River catchment, New Zealand. Trace element signatures were determined using laser ablation inductively coupled plasma mass spectrometry, and differentiated using linear discriminant function analysis with an overall cross-validated classification success of 96.8%. Temporal stability in element: Ca ratios was investigated by repeat collections of juvenile fish over two years. Natal signatures from 11 of 23 adult trout sampled from the catchment main stems were matched to one of the eight tributary signatures showing recruitment sources to be spread relatively evenly throughout the catchment. This study demonstrates the potential of using otolith trace element analysis to determine the natal origins of freshwater fish within a catchment.

Diploid and tetraploid progenitors of wheat are valuable sources of resistance to the root lesion nematode Pratylenchus thornei

The root lesion nematode Pratylenchus thornei is widely distributed in Australian wheat (Triticum aestivum) producing regions and can reduce yield by more than 50%, costing the industry AU$50 M/year. Genetic resistance is the most effective form of management but no commercial cultivars are resistant (R) and the best parental lines are only moderately R. The wild relatives of wheat have evolved in P. thornei-infested soil for millennia and may have superior levels of resistance that can be transferred to commercial wheats. To evaluate this hypothesis, a collection of 251 accessions of wheat and related species was tested for resistance to P. thornei under controlled conditions in glasshouse pot experiments over two consecutive years. Diploid accessions were more R than tetraploid accessions which proved more R than hexaploid accessions. Of the diploid accessions, 11 (52%) Aegilops speltoides (S-[B]-genome), 10 (43%) Triticum monococcum (A (m) -genome) and 5 (24%) Triticum urartu (A (u) -genome) accessions were R. One tetraploid accession (Triticum dicoccoides) was R. This establishes for the first time that P. thornei resistance is located on the A-genome and confirms resistance on the B-genome. Since previous research has shown that the moderate levels of P. thornei resistance in hexaploid wheat are dose-dependent, additive and located on the B and D-genomes, it would seem efficient to target A-genome resistance for introduction to hexaploid lines through direct crossing, using durum wheat as a bridging species and/or through the development of amphiploids. This would allow resistances from each genome to be combined to generate a higher level of resistance than is currently available in hexaploid wheat.

Heterotrophic Bacteria Associated with Cyanobacteria in Recreational and Drinking Water

Cyanobacterial mass occurrences, also known as water blooms, have been associated with adverse health effects of both humans and animals. They can also be a burden to drinking water treatment facilities. Risk assessments of the blooms have generally focused on the cyanobacteria themselves and their toxins. However, heterotrophic bacteria thriving among cyanobacteria may also be responsible for many of the adverse health effects, but their role as the etiological agents of these health problems is poorly known. In addition, studies on the water purification efficiency of operating water treatment plants during cyanobacterial mass occurrences in their water sources are rare. In the present study, over 600 heterotrophic bacterial strains were isolated from natural freshwater, brackish water or from treated drinking water. The sampling sites were selected as having frequent cyanobacterial occurrences in the water bodies or in the water sources of the drinking water treatment plants. In addition, samples were taken from sites where cyanobacterial water blooms were surmised to have caused human health problems. The isolated strains represented bacteria from 57 different genera of the Gamma-, Alpha- or Betaproteobacteria, Actinobacteria, Flavobacteria, Sphingobacteria, Bacilli and Deinococci classes, based on their partial 16S rRNA sequences. Several isolates had no close relatives among previously isolated bacteria or cloned 16S rRNA genes of uncultivated bacteria. The results show that water blooms are associated with a diverse community of cultivable heterotrophic bacteria. Chosen subsets of the isolated strains were analysed for features such as their virulence gene content and possible effect on cyanobacterial growth. Of the putatively pathogenic haemolytic strains isolated in the study, the majority represented the genus Aeromonas. Therefore, the Aeromonas spp. strains isolated from water samples associated with adverse health effects were screened for the virulence gene types encoding for enterotoxins (ast, alt and act/aerA/hlyA), flagellin subunits (flaA/flaB), lipase (lip/pla/lipH3/alp-1) and elastase (ahyB) by PCR. The majority (90%) of the Aeromonas strains included one or more of the six screened Aeromonas virulence gene types. The most common gene type was act, which was present in 77% of the strains. The fla, ahyB and lip genes were present in 30 37% of the strains. The prevalence of the virulence genes implies that the Aeromonas may be a factor in some of the cyanobacterial associated health problems. Of the 183 isolated bacterial strains that were studied for possible effects on cyanobacterial growth, the majority (60%) either enhanced or inhibited growth of cyanobacteria. In most cases, they enhanced the growth, which implies mutualistic interactions. The results indicate that the heterotrophic bacteria have a role in the rise and fall of the cyanobacterial water blooms. The genetic and phenotypic characteristics and the ability to degrade cyanobacterial hepatotoxins of 13 previously isolated Betaproteobacteria strains, were also studied. The strains originated from Finnish lakes with frequent cyanobacterial occurrence. Tested strains degraded microcystins -LR and -YR and nodularin. The strains could not be assigned to any described bacterial genus or species based on their genetic or phenotypic features. On the basis of their characteristics a new genus and species Paucibacter toxinivorans was proposed for them. The water purification efficiency of the drinking water treatment processes during cyanobacterial water bloom in water source was assessed at an operating surface water treatment plant. Large phytoplankton, cyanobacterial hepatotoxins, endotoxins and cultivable heterotrophic bacteria were efficiently reduced to low concentrations, often below the detection limits. In contrast, small planktonic cells, including also possible bacterial cells, regularly passed though the water treatment. The passing cells may contribute to biofilm formation within the water distribution system, and therefore lower the obtained drinking water quality. The bacterial strains of this study offer a rich source of isolated strains for examining interactions between cyanobacteria and the heterotrophic bacteria associated with them. The degraders of cyanobacterial hepatotoxins could perhaps be utilized to assist the removal of the hepatotoxins during water treatment, whereas inhibitors of cyanobacterial growth might be useful in controlling cyanobacterial water blooms. The putative pathogenicity of the strains suggests that the health risk assessment of the cyanobacterial blooms should also cover the heterotrophic bacteria.

L-rhamnose-1-dehydrogenase gene and L-rhamnose catabolism in the yeast Pichia stipitis

The purpose of this work was to identify some of the genes of the catabolic route of L-rhamnose in the yeast Pichia stipitis. There are at least two distinctly different pathways for L-rhamnose catabolism. The one described in bacteria has phosphorylated intermediates and the enzymes and the genes of this route have been described. The pathway described in yeast does not have phosphorylated intermediates. The intermediates and the enzymes of this pathway are known but none of the genes have been identified. The work was started by purifying the L-rhamnose dehydrogenase, which oxidates L-rhamnose to rhamnonic acid-gamma-lactone. NAD is used as a cofactor in this reaction. A DEAE ion exchange column was used for purification. The active fraction was further purified using a non-denaturing PAGE and the active protein identified by zymogram staining. In the last step the protein was separated in a SDS-PAGE, the protein band trypsinated and analysed by MALDI-TOF MS. This resulted in the identification of the corresponding gene, RHA1, which was then, after a codon change, expressed in Saccharomyces cerevisiae. Also C- or N-terminal histidine tags were added but as the activity of the enzyme was lost or strongly reduced these were not used. The kinetic properties of the protein were analysed in the cell extract. Substrate specifity was tested with different sugars; L-rhamnose, L-lyxose and L-mannose were oxidated by the enzyme. Vmax values were 180 nkat/mg, 160 nkat/mg and 72 nkat/mg, respectively. The highest affinity was towards L-rhamnose, the Km value being 0.9 mM. Lower affinities were obtained with L-lyxose, Km 4.3 mM, and L-mannose Km 25 mM. Northern analysis was done to study the transcription of RHA1 with different carbon sources. Transcription was observed only on L-rhamnose suggesting that RHA1 expression is L-rhamnose induced. A RHA1 deletion cassette for P. stipitis was constructed but the cassette had integrated randomly and not targeted to delete the RHA1 gene. Enzyme assays for L-lactaldehyde dehydrogenase were done similarly to L-rhamnose dehydrogenase assays. NAD is used as a cofactor also in this reaction where L-lactaldehyde is oxidised to L-lactate. The observed enzyme activities were very low and the activity was lost during the purification procedures.

Sources and seasonal dynamics of Alternaria inoculum associated with leaf blotch and fruit spot of apples

Alternaria leaf blotch and fruit spot caused by Alternaria spp. cause annual losses to the Australian apple industry. Control options are limited, mainly due to a lack of understanding of the disease cycle. Therefore, this study aimed to determine potential sources of Alternaria spp. inoculum in the orchard and examine their relative contribution throughout the production season. Leaf residue from the orchard floor, canopy leaves, twigs and buds were collected monthly from three apple orchards for two years and examined for the number of spores on their surface. In addition, the effects of climatic factors on spore production dynamics in each plant part were examined. Although all four plant parts tested contributed to the Alternaria inoculum in the orchard, significant higher numbers of spores were obtained from leaf residue than the other plant parts supporting the hypothesis that overwintering of Alternaria spp. occurred mainly in leaf residue and minimally on twigs and buds. The most significant period of spore production on leaf residue occurred from dormancy until bloom and on canopy leaves and twigs during the fruit growth stage. Temperature was the single most significant factor influencing the amount of Alternaria inoculum and rainfall and relative humidity showed strong associations with temperature influencing the spore production dynamics in Australian orchards. The practical implications of this study include the eradication of leaf residue from the orchard floor and sanitation of the canopy after harvest to remove residual spores from the trees.

Potential Animal and Environmental Sources of Q Fever Infection for Humans in Queensland

Q fever is a vaccine-preventable disease; despite this, high annual notification numbers are still recorded in Australia. We have previously shown seroprevalence in Queensland metropolitan regions is approaching that of rural areas. This study investigated the presence of nucleic acid from Coxiella burnetii, the agent responsible for Q fever, in a number of animal and environmental samples collected throughout Queensland, to identify potential sources of human infection. Samples were collected from 129 geographical locations and included urine, faeces and whole blood from 22 different animal species; 45 ticks were removed from two species, canines and possums; 151 soil samples; 72 atmospheric dust samples collected from two locations and 50 dust swabs collected from domestic vacuum cleaners. PCR testing was performed targeting the IS1111 and COM1 genes for the specific detection of C.burnetii DNA. There were 85 detections from 1318 animal samples, giving a detection rate for each sample type ranging from 2.1 to 6.8%. Equine samples produced a detection rate of 11.9%, whilst feline and canine samples showed detection rates of 7.8% and 5.2%, respectively. Native animals had varying detection rates: pooled urines from flying foxes had 7.8%, whilst koalas had 5.1%, and 6.7% of ticks screened were positive. The soil and dust samples showed the presence of C.burnetii DNA ranging from 2.0 to 6.9%, respectively. These data show that specimens from a variety of animal species and the general environment provide a number of potential sources for C.burnetii infections of humans living in Queensland. These previously unrecognized sources may account for the high seroprevalence rates seen in putative low-risk communities, including Q fever patients with no direct animal contact and those subjects living in a low-risk urban environment.

Activated carbon + HFC 134a based two stage thermal compression adsorption refrigeration using low grade thermal energy sources

A thermodynamic analysis is presented for the two stage thermal compression process for an adsorption refrigeration cycle with HFC-134a as the working fluid and activated carbon as the adsorbent. Three specimens of varying achievable packing densities were evaluated. The influence of evaporating, condensing/adsorption and desorption temperatures was assessed through three performance indicators, namely,the uptake efficiency, the coefficient of performance and the exergetic efficiency. Conditions under which a two stage thermal compression process performs better than the single stage unit are identified. It is concluded that two stage thermal compression will be a viable proposition when the heat source temperature is low or when adsorption characteristics are weak or when adequate packing densities are difficult to realize. (C) 2008 Elsevier Ltd. All rights reserved.

Sources of vase life variation in cut roses: A review

n determining vase life (VL), it is often not considered that the measured VL in a particular experiment may greatly depend on both the preharvest and evaluation environmental conditions. This makes the comparison between studies difficult and may lead to erroneous interpretation of results. In this review, we critically discuss the effect of the growth environment on the VL of cut roses. This effect is mainly related to changes in stomatal responsiveness, regulating water loss, whereas cut flower carbohydrate status appears less critical. When comparing cultivars, postharvest water loss and VL often show no correlation, indicating that components such as variation in the tissue resistance to cavitate and/or collapse at low water potential play an important role in the incidence of water stress symptoms. The effect of the growth environment on these components remains unknown. Botrytis cinerea sporulation and infection, as well as cut rose susceptibility to the pathogen are also affected by the growth environment, with the latter being largely unexplored. A huge variability in the choices made with respect to the experimental setup (harvest/conditioning methods, test room conditions and VL terminating symptoms) is reported. We highlight that these decisions, though frequently overlooked, influence the outcome of the study. Specifications for each of these factors are proposed as necessary to achieve a common VL protocol. Documentation of both preharvest conditions and a number of postharvest factors, including the test room conditions, is recommended not only for assisting comparisons between studies, but also to identify factors with major effects on VL.

TlBr raw material purification, crystal growth, annealing, detector fabrication and characterisation for gamma-ray detector applications

The research reported in this thesis dealt with single crystals of thallium bromide grown for gamma-ray detector applications. The crystals were used to fabricate room temperature gamma-ray detectors. Routinely produced TlBr detectors often are poor quality. Therefore, this study concentrated on developing the manufacturing processes for TlBr detectors and methods of characterisation that can be used for optimisation of TlBr purity and crystal quality. The processes under concern were TlBr raw material purification, crystal growth, annealing and detector fabrication. The study focused on single crystals of TlBr grown from material purified by a hydrothermal recrystallisation method. In addition, hydrothermal conditions for synthesis, recrystallisation, crystal growth and annealing of TlBr crystals were examined. The final manufacturing process presented in this thesis deals with TlBr material purified by the Bridgman method. Then, material is hydrothermally recrystallised in pure water. A travelling molten zone (TMZ) method is used for additional purification of the recrystallised product and then for the final crystal growth. Subsequent processing is similar to that described in the literature. In this thesis, literature on improving quality of TlBr material/crystal and detector performance is reviewed. Aging aspects as well as the influence of different factors (temperature, time, electrode material and so on) on detector stability are considered and examined. The results of the process development are summarised and discussed. This thesis shows the considerable improvement in the charge carrier properties of a detector due to additional purification by hydrothermal recrystallisation. As an example, a thick (4 mm) TlBr detector produced by the process was fabricated and found to operate successfully in gamma-ray detection, confirming the validity of the proposed purification and technological steps. However, for the complete improvement of detector performance, further developments in crystal growth are required. The detector manufacturing process was optimized by characterisation of material and crystals using methods such as X-ray diffraction (XRD), polarisation microscopy, high-resolution inductively coupled plasma mass (HR-ICPM), Fourier transform infrared (FTIR), ultraviolet and visual (UV-Vis) spectroscopy, field emission scanning electron microscope (FESEM) and energy-dispersive X-ray spectroscopy (EDS), current-voltage (I-V) and capacity voltage (CV) characterisation, and photoconductivity, as well direct detector examination.

Sources and concentrations of volatile organic compounds

Volatile organic compounds (VOCs) have a great influence on tropospheric chemistry; they affect ozone formation and they or their reaction products are able to take part in secondary organic aerosol formation; some of the VOCs are themselves toxic. Knowing the concentrations and sources of different reactive volatile organic compounds is essential for the development of ozone control strategies and for studies of secondary organic aerosol formation. The objective of this work was to study volatile organic compounds in urban air, develop and validate determination methods for them, characterize their concentrations and estimate the contributions of different VOC sources. Of the different compound groups detected in the urban air of Helsinki, alkanes were found to have the highest concentrations, but when the concentrations were scaled against the reactivity with hydroxyl radicals (OH), aromatic hydrocarbons and alkenes were found to have the greatest effect on local chemistry. Comparisons with rural sites showed that concentrations at Utö and Hyytiälä were generally lower than those in Helsinki, especially for the alkenes and aromatic hydrocarbons, but concentrations of halogenated hydrocarbons at Utö and carbonyls at Hyytiälä were at the same level as in Helsinki. Most halogenated hydrocarbons do not have any significant sources in Helsinki, and carbonyls are formed in the atmosphere in the reactions of other VOCs, and are therefore also produced in other than urban areas. At Hyytiälä carbonyls were found to have an important role in the local chemistry. The contribution of carbonyls as an OH sink was higher than that of the monoterpenes and aromatic hydrocarbons. Based on the emission profile and concentration measurements, the contributions of different sources were estimated at urban (Helsinki) and residential (Järvenpää) sites using a chemical mass balance (CMB) receptor model. It was shown that it is possible to apply CMB in the case of a large number of different compounds with different properties. According to the CMB analysis, the major sources for these VOCs in Helsinki were traffic and distant sources. At the residential site in Järvenpää, the contribution due to traffic was minor, while distant sources, liquid gasoline and wood combustion made higher contributions. It was also shown that wood combustion can be an important source at some locations of VOCs usually considered as traffic-related compounds (e.g., benzene).

Markers for seedling and adult plant crown rot resistance in four partially resistant bread wheat sources

Key message: QTLidentified for seedling and adult plant crown rot resistance in four partially resistant hexaploid wheat sources. PCR-based markers identified for use in marker-assisted selection. Abstract: Crown rot, caused by Fusarium pseudograminearum, is an important disease of wheat in many wheat-growing regions globally. Complete resistance to infection by F. pseudograminearum has not been observed in a wheat host, but germplasm with partial resistance to this pathogen has been identified. The partially resistant wheat hexaploid germplasm sources 2-49, Sunco, IRN497 and CPI133817 were investigated in both seedling and adult plant field trials to identify markers associated with the resistance which could be used in marker-assisted selection programs. Thirteen different quantitative trait loci (QTL) conditioning crown rot resistance were identified in the four different sources. Some QTL were only observed in seedling trials whereas others appeared to be adult plant specific. For example while the QTL on chromosomes 1AS, 1BS, and 4BS contributed by 2-49 and on 2BS contributed by Sunco were detected in both seedling and field trials, the QTL on 1DL present in 2-49 and the QTL on 3BL in IRN497 were only detected in seedling trials. Genetic correlations between field trials of the same population were strong, as were correlations between seedling trials of the same population. Low to moderate correlations were observed between seedling and field trials. Flanking markers, most of which are less than 10 cM apart, have now been identified for each of the regions associated with crown rot resistance.

Personal health records as sources of productivity evidence

Capturing data from various data repositories and integrating them for productivity improvements is common in modern business organisations. With the well-accepted concept of achieving positive gains through investment in employee health and wellness, organisations have started to capture both employee health and non-health data as Employer Sponsored electronic Personal Health Records (ESPHRs). However, non-health related data in ESPHRs has hardly been taken into consideration with outcomes such as employee productivity potentially being suited for further validation and stimulation of ESPHR usage. Here we analyse selected employee demographic information (age, gender, marital status, and job grade) and health-related outcomes (absenteeism and presenteeism) of employees for evidence-based decision making. Our study considered demographic and health-related outcomes of 700 employees. Surprisingly, the analysis shows that employees with high sick leave rates are also high performers. A factor analysis shows 92% of the variance in the data can be explained by three factors, with the job grade capable of explaining 62% of the variance. Work responsibilities may drive employees to maintain high work performance despite signs of sickness, so ESPHRs should focus attention on high performers. This finding suggests new ways of extracting value from ESPHRs to support organisational health and wellness management to help assure sustainability in organisational productivity.