A Method for the Deposition of Transparent Conducting Thin-Films of Tin Oxide

A modified method has been developed for the deposition of transparent semiconducting thin films of tin oxide, involving the chemical vapour phase oxidation of tin iodide. These films show sheet resistances greater than 100 Ω/□ and an average optical transmission in the visible range exceeding 80%. The method avoids uncontrolled contamination, resulting in better reproducibility of the films. The films showed direct and indirect transitions and the possibility of an indirect forbidden transition. X-ray diffraction studies reveal that the films are polycrystalline. The low mobility values of the films have been attributed to the grain boundary scattering effect.

Heat-Transfer During Polymer Combustion

The nature of surface and subsurface reactions in polymer combustion is poorly underst0od.l During the burning of thermoplastic polymers a melt layer is observed on the surface, and below the melt layer there is thermal wave penetration. But the exact thickness of the melt layer and the thickness of the thermal wave penetration have not been precisely measured, although a qualitative idea has been given.

EPR observation of phase transitions in calcium cadmium acetate hexahydrate: Using Mn2+ and Cu2+ ions as probe

Results of temperature dependence of EPR spectra of Mn2+ and Cu2+ ions doped calcium cadmium acetate hexahydrate (CaCd(CH3COO)4•6H2O) have been reported. The investigation has been carried out in the temperature range between room temperature ( 300 K) and liquid nitrogen temperature. A I-order phase transition at 146 ± 0.5 K has been confirmed. In addition a new II-order phase transition at 128 ± 1 K has been detected for the first time. There is evidence of large amplitude hindered rotations of CH3 groups which become frozen at 128 K. The incorporation of Cu2+ and Mn2+ probes at Ca2+ and Cd2+ sites respectively provide evidence that the phase transitions are caused by the molecular rearrangements of the common coordinating acetate groups between Ca2+ and Cd2+ sites. In contradiction to the previous reports of a change of symmetry from tetragonal to orthorhombic below 140 K, the symmetry of the host is concluded to remain tetragonal in all the three observed phases between room temperature and liquid nitrogen temperature.

Språkbad - ett effektivt sätt att lära sig språk? : Föräldrars och elevers tankar kring språkbad i Helsingfors

Tutkimuksen tarkoituksena oli selvittää helsinkiläisten perusopetuksen yläluokkien kielikylpy-oppilaiden ja heidän vanhempiensa käsityksiä ruotsinkielisestä kielikylvystä. Tarkoituksena oli tutkia syitä kielikylpymenetelmän tai vastaavasti perinteisen opetuksen valitsemiseksi sekä oppilaiden ja heidän vanhempiensa käsityksiä kielikylpyoppilaiden koulumenetyksestä ja kielitaidosta. Tarkoituksena oli myös selvittää, mikä asema kielikylvyllä on oppilaiden elämässä koulukontekstin ulkopuolella sekä miten oppilaat ja heidän vanhempansa suhtautuvat kielikylpyyn kokonaisuutena. Tutkimuksen perusjoukkoon kuuluivat kaikki lukuvuonna 2002−2003 Helsingin perusopetuksen yläluokkien ruotsinkielisessä kielikylvyssä olevat oppilaat sekä heidän vanhempansa. Otokseen saatiin 128 oppilasta ja 94 vanhempaa. Näiden lisäksi tutkimukseen osallistui 40 vanhempaa, joiden lapset osallistuivat yksikieliseen suomenkieliseen perusopetukseen. Tutkimusjoukon oppilaista osa on ollut alaluokilla varhaisessa täydellisessä kielikylvyssä ja osa varhaisessa osittaisessa kielikylvyssä. Tutkimus edustaa survey-tutkimusta, jossa aineistonhankintamenetelmänä on käytetty sekä lomakekyselyä että haastattelua. Teemahaastatteluun valittiin 10 oppilasta tutkimuksen perusjoukosta. Tutkimusaineisto kerättiin kevään 2003 aikana. Aineistosta laskettiin frekvenssejä, keskilukuja ja korrelaatioita sekä käytettiin ristiintaulukointeja. Keskiarvojen merkitsevyystestaukset suoritettiin yksisuuntaisilla varianssianalyyseillä F- ja t-testein. Tutkimuksen teoriaosuudessa käsitellään kielitaidon ja kaksikielisyyden käsitteitä sekä esitellään erilaisia pedagogisia menetelmiä, joilla pyritään kehittämään kielitaitoa. Teoriaosuudessa pohditaan myös asenteiden ja motivaation merkitystä kielen omaksumisessa. Tutkimustulokset osoittavat, että perusopetuksen yläluokkien kielikylpyoppilailla ja heidän vanhemmillaan on varsin yhdensuuntaisia käsityksiä kielikylvystä. Kielikylpyyn ollaan varsin tyytyväisiä kokonaisuutena, mutta kehitettävää ja parannettavaa on. Opiskelu kielikylpyluokalla miellettiin positiivisena, mutta ruotsinkielisen opetuksen määrään toivottiin muutosta. Vanhemmat arvostivat kielikylpyä erityisesti siinä käytettävien opetusmenetelmien ja saavutettavien tulosten perusteella. Sekä vanhemmat että oppilaat kokevat ruotsin kielen oppimisen erittäin tarpeelliseksi ja hyödylliseksi peilaten vastauksissaan tulevaisuuden opiskelu- ja työelämän tarpeita. Oppilaiden ruotsin kielen taidot arvioitiin erittäin korkeiksi. Kielikylpykielen asema oppilaiden elämässä koulun ulkopuolella oli erittäin vähäinen. Ruotsin kielen käyttötilanteet rajoittuivat matkoihin ja erilaisiin opastustilanteisiin. Omaehtoista kielen käyttöä ei juuri ilmennyt hyvästä kielitaidosta huolimatta. Oppilaiden käsityksissä ei ollut havaittavissa eroja eri sukupuolten välillä. Joissain tapauksissa luokka-asteella, mutta erityisesti oppilaan koululla ja kielikylpymuodolla oli vaikutusta tutkittuihin käsityksiin.

Characterisation of chicken Campylobacter jejuni isolates using resolution optimised single nucleotide polymorphisms and binary gene markers

The principal objective of this study was to determine if Campylobacter jejuni genotyping methods based upon resolution optimised sets of single nucleotide polymorphisms (SNPs) and binary genetic markers were capable of identifying epidemiologically linked clusters of chicken-derived isolates. Eighty-eight C. jejuni isolates of known flaA RFLP type were included in the study. They encompassed three groups of ten isolates that were obtained at the same time and place and possessed the same flaA type. These were regarded as being epidemiologically linked. Twenty-six unlinked C. jejuni flaA type I isolates were included to test the ability of SNP and binary typing to resolve isolates that were not resolved by flaA RFLP. The remaining isolates were of different flaA types. All isolates were typed by real-time PCR interrogation of the resolution optimised sets of SNPs and binary markers. According to each typing method, the three epidemiologically linked clusters were three different clones that were well resolved from the other isolates. The 26 unlinked C. jejuni flaA type I isolates were resolved into 14 SNP-binary types, indicating that flaA typing can be unreliable for revealing epidemiological linkage. Comparison of the data with data from a fully typed set of isolates associated with human infection revealed that abundant lineages in the chicken isolates that were also found in the human isolates belonged to clonal complex (CC) -21 and CC-353, with the usually rare C-353 member ST-524 being especially abundant in the chicken collection. The chicken isolates selected to be diverse according to flaA were also diverse according to SNP and binary typing. It was observed that CC-48 was absent in the chicken isolates, despite being very common in Australian human infection isolates, indicating that this may be a major cause of human disease that is not chicken associated.

Comparison of nitrogen fertilization methods and rates for subsurface drip irrigated corn in the semi-arid Great Plains

In semi-arid areas such as western Nebraska, interest in subsurface drip irrigation (SDI) for corn is increasing due to restricted irrigation allocations. However, crop response quantification to nitrogen (N) applications with SDI and the environmental benefits of multiple in-season (IS) SDI N applications instead of a single early-season (ES) surface application are lacking. The study was conducted in 2004, 2005, and 2006 at the University of Nebraska-Lincoln West Central Research and Extension Center in North Platte, Nebraska, comparing two N application methods (IS and ES) and three N rates (128, 186, and 278 kg N ha(-1)) using a randomized complete block design with four replications. No grain yield or biomass response was observed in 2004. In 2005 and 2006, corn grain yield and biomass production increased with increasing N rates, and the IS treatment increased grain yield, total N uptake, and gross return after N application costs (GRN) compared to the ES treatment. Chlorophyll meter readings taken at the R3 corn growth stage in 2006 showed that less N was supplied to the plant with ES compared to the IS treatment. At the end of the study, soil NO3-N masses in the 0.9 to 1.8 m depth were greater under the IS treatment compared to the ES treatment. Results suggested that greater losses of NO3-N below the root zone under the ES treatment may have had a negative effect on corn production. Under SDI systems, fertigating a recommended N rate at various corn growth stages can increase yields, GRN, and reduce NO3-N leaching in soils compared to concentrated early-season applications.

Perennial grassland dynamics on fertile plains: Is coexistence mediated by disturbance?

The response of grasslands to disturbance varies with the nature of the disturbance and the productivity of the landscape. In highly productive grasslands, competitive exclusion often results in decreased species richness and grazing may allow more species to coexist. Once widespread, grasslands dominated by Dichanthium sericeum (Queensland bluegrass) and Astrebla spp. (Mitchell grass) occur on fertile plains but have been reduced in extent by cultivation. We tested the effects of exclusion of livestock grazing on these grasslands by comparing the floristic composition of sites in a nature reserve with an adjacent stock reserve. In addition, sites that had been cultivated within the nature reserve were compared with those where grazing but no cultivation had occurred. To partition the effects of temporal variation from spatial variation we sampled sites in three different years (1998, 2002 and 2004). Some 194 taxa were recorded at the nature reserve and surrounding stock routes. Sampling time, the occurrence of past cultivation and livestock grazing all influenced species composition. Species richness varied greatly between sampling periods relating to highly variable rainfall and water availability on heavy clay soils. Native species richness was significantly lower at previously cultivated sites (13-22 years after cultivation), but was not significantly influenced by grazing exclusion. After 8 years it appears that reintroducing disturbance in the form of livestock grazing is not necessary to maintain plant species richness in the reserve. The highly variable climate (e.g. droughts) probably plays an important role in the coexistence of species by negating competitive exclusion and allowing interstitial species to persist.

Multiple-quantum artifacts in single-quantum two-dimensional correlated NMR spectra of strongly coupled spins

Artifacts in the form of cross peaks have been observed along two- and three-quantum diagonals in single-quantum two-dimensional correlated (COSY) spectra of several peptides and oligonucleotides. These have been identified as due to the presence of a non-equilibrium state of kind I (a state describable by populations which differ from equilibrium) of strongly coupled spins carried over from one experiment to the next in the COSY algorithm.

Field isolates of Tomato spotted wilt virus overcoming resistance in capsicum in Australia

In 2002 at Virginia, South Australia, capsicum cultivars having the Tsw resistance gene against Tomato spotted wilt virus (TSWV) developed symptoms typical of TSWV infection and several glasshouse-grown crops were almost 100% infected. Samples reacted with TSWV antibodies in ELISA. Virus isolates from infected plants induced severe systemic symptoms, rather than a hypersensitive reaction, when inoculated onto capsicum cultivars and Capsicum chinense genotypes ( PI 152225 and PI 159236) that carry the Tsw resistance gene. Isolates virulent towards the Tsw gene had molecular and biological properties very similar to standard TSWV isolates, including a hypersensitive reaction in Sw-5 (TSWV-resistant) tomato genotypes. Tsw-virulent isolates were found during surveys at Virginia in 2002 and 2004 in both TSWV-resistant and susceptible cultivars of capsicum and tomato.

Management of mould mite Tyrophagus putrescentiae (Schrank) (Acarina: Acaridae): A case study in stored animal feed

An integrated pest management (IPM) strategy was developed to manage infestations of mould mite Tyrophagus putrescentiae (Schrank) in stored animal feed, due to the increasing importance of these mites as pests of feed processing and storage facilities in Australia. This strategy involved several aspects such as limiting the moisture content of the processed feed to 12%, admixing vegetable oil to some feed (2% w/w), strict hygiene practice in and around the processing and storage facility, and rejection of infested grain at the receiving point. Additionally, seven contact insecticides and the fumigant phosphine were evaluated for their effectiveness against the mould mite to assess their potential integration into the IPM strategy. Among them, pyrethrin synergised with piperonyl butoxide, the insect growth regulator s-methoprene and a newly developed bacterium-based material spinosad controlled the mites. Moreover, the fumigant phosphine at 1 mg/litre over a six days exposure period also controlled these mites. So far, the IPM strategy, without any involvement of insecticides or fumigant has resulted in a complete eradication of the mite population in this particular case of stored animal feed.

Incidence and pathogenicity of Phytophthora palmivora and Pythium vexans associated with durian decline in far northern Queensland

In recent years, dieback of durian has become a major problem in mature orchards in the northern Queensland wet tropics region. A survey of 13 durian orchards was conducted during the dry season (July-September 2001) and following wet season (February-April 2002), with roots and soil from the root zone of affected trees being sampled. Phytophthora palmivora was recovered from the roots of affected trees on 12 of the 13 farms in the dry season, and all farms in the wet season. Pythium vexans was recovered from all 13 farms in both seasons. P. palmivora and P. vexans were recovered from diseased roots of 3-month-old durian seedlings cv. Monthong artificially inoculated with these organisms.

Three new species of Tilletia on native grasses from northern Australia

Three new species of Tilletia are reported from grasses in northern Australia, namely T. pseudoraphidis on Pseudoraphis spinescens, T. sehimicola on Sehima nervosum and T. majuscula on Yakirra majuscula.

Copper binding by Pseudomonas aeruginosa

A copper-binding complex formed in the exopolysaccharide fraction of Image was isolated and characterized using a variety of techniques. By comparison with model Cu(II) complexes of uronic acids, it is shown that the Image forms a square-planer, cupric complex similar to cupric glucuronates.