(Table 2) Contents of chlorophyll a, organic carbon, nitrogen, and phosphorus and their molar ratios in dried matter of Ahnfeltia tobuchiensis agar containing seaweed from the Izmena Bay, Kunashir Island (South Kurils)

A complex study of influence of various environmental factors on rates of oxygen (M_O2 ), ammonium (M_NH4), and phosphate (M_PO4) metabolism in Ahnfeltia tobuchiensis has been carried out in situ in the Izmena Bay of the Kunashir Island. The following environmental factors have been included into the investigation: photosynthetically active radiation (PAR); ammonium (NH4); phosphate (PO4); and contents of carbon (C), nitrogen (N), phosphorus (P), and chlorophyll a (Chl) in tissue. Population of agar-containing seaweed A. tobuchiensis forms a layer with thickness up to 0.5 m, which occupies about 23.3 km**2; biomass is equal to 125000 tons. Quantitative assessment of organic matter production and nutrient consumption during oxygen metabolism has been carried out for the whole population. It has been shown that daily oxygen metabolism depends on PAR intensity, concentrations of PO4 and NH4 in seawater, and contents of N and P in tissues (r**2=0.78, p<0.001). Average daily NH4 consumption is 0.21 µmol/g of dry weight/hour and depends on NH4 and O2 concentrations in seawater and on ? and Chl a contents in algal tissues (r**2=0.64, p<0.001). Average daily PO4 consumption is 0.01 µmol/g of dry weight/hour and depends on NH4 concentrations in seawater and on P contents in algal tissues (r**2=0.40, p<0.001).

AVALIAÇÃO POR MEIO DE MODELOS DE GESSO DAS ALTERAÇÕES DENTOESQUELÉTICAS, PROMOVIDAS PELA EXPANSÃO RÁPIDA DA MAXILA ASSISTIDA CIRURGICAMENTE (ERMAC)

Este estudo avaliou as alterações produzidas nos arcos dentais superiores de pacientes submetidos à Expansão Rápida da Maxila Assistida Cirurgicamente (ERMAC). A amostra utilizada foi composta de 50 modelos de gesso superiores de 18 pacientes, sendo seis do sexo masculino e 12 do sexo feminino, com média de idade de 23,3 anos. Para cada paciente foram preparados três modelos de gesso obtidos em diferentes fases: Inicial, antes do procedimento operatório (T1); três meses pós-expansão (travamento do expansor) e momento da remoção do aparelho expansor tipo Hyrax e colocação da placa removível de acrílico para contenção (T2); seis meses pós-expansão e momento de remoção da placa de acrílico (T3). O dispositivo expansor utilizado foi o disjuntor tipo Hyrax. O procedimento cirúrgico adotado foi a osteotomia lateral da maxila sem o envolvimento da lâmina pterigóide, osteotomia da espinha nasal à linha média dental (incisivos centrais superiores), separação da sutura palatina mediana por meio de cinzel e separação do septo nasal. O início da ativação ocorreu no terceiro dia pós-operatório, sendo ¼ de volta pela manhã e ¼ à noite, sendo que as ativações seguiram critérios clínicos para o controle da expansão. As medidas foram realizadas por meio da máquina de medição tridimensional (SAC), baseando-se nas alterações nos três planos (vertical, sagital e transversal) que ocorreram nos modelos de gesso. Concluiu-se que: 1. Houve um aumento estatisticamente significante nas distâncias transversais em todos os grupos de dentes (de incisivos centrais até segundos molares) de T1 para T2, demonstrando a efetividade do tratamento. De T2 para T3 não houve diferença estatisticamente significante para nenhuma variável, indicando, assim, estabilidade após seis meses do término da ERMAC; 2. Houve um aumento estatisticamente significante nas inclinações dos primeiros e segundos molares dos lados direito e esquerdo e dos segundos pré-molares apenas do lado esquerdo, sugerindo um comportamento assimétrico dos dentes avaliados; 3. Houve um aumento na largura palatina nos intervalos analisados, com diferenças estatisticamente significantes entre T1 x T2 e T1 x T3; 4. Não foram observadas diferenças estatisticamente significantes na profundidade palatina nos intervalos analisados.(AU)

AVALIAÇÃO POR MEIO DE MODELOS DE GESSO DAS ALTERAÇÕES DENTOESQUELÉTICAS, PROMOVIDAS PELA EXPANSÃO RÁPIDA DA MAXILA ASSISTIDA CIRURGICAMENTE (ERMAC)

Este estudo avaliou as alterações produzidas nos arcos dentais superiores de pacientes submetidos à Expansão Rápida da Maxila Assistida Cirurgicamente (ERMAC). A amostra utilizada foi composta de 50 modelos de gesso superiores de 18 pacientes, sendo seis do sexo masculino e 12 do sexo feminino, com média de idade de 23,3 anos. Para cada paciente foram preparados três modelos de gesso obtidos em diferentes fases: Inicial, antes do procedimento operatório (T1); três meses pós-expansão (travamento do expansor) e momento da remoção do aparelho expansor tipo Hyrax e colocação da placa removível de acrílico para contenção (T2); seis meses pós-expansão e momento de remoção da placa de acrílico (T3). O dispositivo expansor utilizado foi o disjuntor tipo Hyrax. O procedimento cirúrgico adotado foi a osteotomia lateral da maxila sem o envolvimento da lâmina pterigóide, osteotomia da espinha nasal à linha média dental (incisivos centrais superiores), separação da sutura palatina mediana por meio de cinzel e separação do septo nasal. O início da ativação ocorreu no terceiro dia pós-operatório, sendo ¼ de volta pela manhã e ¼ à noite, sendo que as ativações seguiram critérios clínicos para o controle da expansão. As medidas foram realizadas por meio da máquina de medição tridimensional (SAC), baseando-se nas alterações nos três planos (vertical, sagital e transversal) que ocorreram nos modelos de gesso. Concluiu-se que: 1. Houve um aumento estatisticamente significante nas distâncias transversais em todos os grupos de dentes (de incisivos centrais até segundos molares) de T1 para T2, demonstrando a efetividade do tratamento. De T2 para T3 não houve diferença estatisticamente significante para nenhuma variável, indicando, assim, estabilidade após seis meses do término da ERMAC; 2. Houve um aumento estatisticamente significante nas inclinações dos primeiros e segundos molares dos lados direito e esquerdo e dos segundos pré-molares apenas do lado esquerdo, sugerindo um comportamento assimétrico dos dentes avaliados; 3. Houve um aumento na largura palatina nos intervalos analisados, com diferenças estatisticamente significantes entre T1 x T2 e T1 x T3; 4. Não foram observadas diferenças estatisticamente significantes na profundidade palatina nos intervalos analisados.(AU)

Drift distances, times and primary grain sources of the Arctic Ocean, Exp302 (ACEX)

Knowledge of the long-term history of the perennial ice is an important issue that has eluded study because the Cenozoic core material needed has been unavailable until the recent Arctic Coring Expedition (ACEX). Detrital Fe oxide mineral grains analyzed by microprobe from the last 14 Ma (164 m) of the ACEX composite core on the Lomonosov Ridge were matched to circum-Arctic sources with the same mineral and 12-element composition. These precise source determinations and estimates of drift rates were used to determine that these sand grains could not be rafted to the ACEX core site in less than a year. Thus the perennial ice cover has existed since 14 Ma except for the unlikely rapid return to seasonal ice between the average sampling interval of about 0.17 Ma. Both North America and Russia contributed significant Fe grains to the ACEX core during the last 14 Ma.

AVALIAÇÃO POR MEIO DE MODELOS DE GESSO DAS ALTERAÇÕES DENTOESQUELÉTICAS, PROMOVIDAS PELA EXPANSÃO RÁPIDA DA MAXILA ASSISTIDA CIRURGICAMENTE (ERMAC)

Este estudo avaliou as alterações produzidas nos arcos dentais superiores de pacientes submetidos à Expansão Rápida da Maxila Assistida Cirurgicamente (ERMAC). A amostra utilizada foi composta de 50 modelos de gesso superiores de 18 pacientes, sendo seis do sexo masculino e 12 do sexo feminino, com média de idade de 23,3 anos. Para cada paciente foram preparados três modelos de gesso obtidos em diferentes fases: Inicial, antes do procedimento operatório (T1); três meses pós-expansão (travamento do expansor) e momento da remoção do aparelho expansor tipo Hyrax e colocação da placa removível de acrílico para contenção (T2); seis meses pós-expansão e momento de remoção da placa de acrílico (T3). O dispositivo expansor utilizado foi o disjuntor tipo Hyrax. O procedimento cirúrgico adotado foi a osteotomia lateral da maxila sem o envolvimento da lâmina pterigóide, osteotomia da espinha nasal à linha média dental (incisivos centrais superiores), separação da sutura palatina mediana por meio de cinzel e separação do septo nasal. O início da ativação ocorreu no terceiro dia pós-operatório, sendo ¼ de volta pela manhã e ¼ à noite, sendo que as ativações seguiram critérios clínicos para o controle da expansão. As medidas foram realizadas por meio da máquina de medição tridimensional (SAC), baseando-se nas alterações nos três planos (vertical, sagital e transversal) que ocorreram nos modelos de gesso. Concluiu-se que: 1. Houve um aumento estatisticamente significante nas distâncias transversais em todos os grupos de dentes (de incisivos centrais até segundos molares) de T1 para T2, demonstrando a efetividade do tratamento. De T2 para T3 não houve diferença estatisticamente significante para nenhuma variável, indicando, assim, estabilidade após seis meses do término da ERMAC; 2. Houve um aumento estatisticamente significante nas inclinações dos primeiros e segundos molares dos lados direito e esquerdo e dos segundos pré-molares apenas do lado esquerdo, sugerindo um comportamento assimétrico dos dentes avaliados; 3. Houve um aumento na largura palatina nos intervalos analisados, com diferenças estatisticamente significantes entre T1 x T2 e T1 x T3; 4. Não foram observadas diferenças estatisticamente significantes na profundidade palatina nos intervalos analisados.(AU)

Evaluation of molar weight and deacetylation degree of chitosan during chitin deacetylation reaction: Used to produce biofilm

Chitosan is a polysaccharide derived from chitin, mainly of crustacean shells and shrimp wastes. The utilization of chitosan is related to the molar weight and deacetylation degree of the biopolymer. The aim of this work is to study the chitin deacetylation reaction, by the viscosity average molar weight and deacetylation degree of chitosan as a function of reaction time. Deacetylation was carried out in concentrated alkaline solution, 421 g L−1, at 130◦C and the reaction occurred during 4 h. Chitosan paste obtained after 20, 90 and 240 min was used to produce biofilms, which were characterized according water vapor permeability and mechanical properties (tensile strength and percentage tensile elongation at break). During the reaction time deacetylation degree reached 93%, and a 50% reduction in the viscosity average molar weight value in relation to the value of the first 20 min of reaction was found Both reactions presented a kinetic behavior of the pseudo-first order. Biofilm produced from the paste of chitosan with high deacetylation degree showed higher water vapor permeability (WVP), tensile strength (TS) and elongation (E) when compared to films with a low deacetylation.

Supplementation of cattle fed tropical grasses with microalgae increases microbial protein production and average daily gain

A series of 3 experiments were conducted to evaluate the use of microalgae as supplements for ruminants consuming low-CP tropical grasses. In Exp. 1, the chemical composition and in vitro protein degradability of 9 algae species and 4 protein supplements were determined. In Exp. 2, rumen function and microbial protein (MCP) production were determined in Bos indicus steers fed speargrass hay alone or supplemented with Spirulina platensis, Chlorella pyrenoidosa, Dunaliella salina, or cottonseed meal (CSM). In Exp. 3, DMI and ADG were determined in B. indicus steers fed speargrass hay alone or supplemented with increasing amounts of NPN (urea combined with ammonia sulfate), CSM, or S. platensis. In Exp. 1, the CP content of S. platensis and C. pyrenoidosa (675 and 580 g/kg DM) was highest among the algae species and higher than the other protein supplements evaluated, and Schizochytrium sp. had the highest crude lipid (CL) content (198 g/kg DM). In Exp. 2, S. platensis supplementation increased speargrass hay intake, the efficiency of MCP production, the fractional outflow rate of digesta from the rumen, the concentration of NH3N, and the molar proportion of branched-chain fatty acids in the rumen fluid of steers above all other treatments. Dunaliella salina acceptance by steers was low and this resulted in no significant difference to unsupplemented steers for all parameters measured for this algae supplement. In Exp. 3, ADG linearly increased with increasing supplementary N intake from both S. platensis and NPN, with no difference between the 2 supplements. In contrast, ADG quadratically increased with increasing supplementary N intake from CSM. It was concluded that S. platensis and C. pyrenoidosa may potentially be used as protein sources for cattle grazing low-CP pastures.

Infrared and infrared emission spectroscopy of gallium oxide α-GaO(OH) nanostructures

Infrared spectroscopy has been used to study nano to micro sized gallium oxyhydroxide α-GaO(OH), prepared using a low temperature hydrothermal route. Rod-like α-GaO(OH) crystals with average length of ~2.5 μm and width of 1.5 μm were prepared when the initial molar ratio of Ga to OH was 1:3. β-Ga2O3 nano and micro-rods were prepared through the calcination of α-GaO(OH) The initial morphology of α-GaO(OH) is retained in the β-Ga2O3 nanorods. The combination of infrared and infrared emission spectroscopy complimented with dynamic thermal analysis were used to characterise the α-GaO(OH) nanotubes and the formation of β-Ga2O3 nanorods. Bands at around 2903 and 2836 cm-1 are assigned to the -OH stretching vibration of α-GaO(OH) nanorods. Infrared bands at around 952 and 1026 cm-1 are assigned to the Ga-OH deformation modes of α-GaO(OH). A significant number of bands are observed in the 620 to 725 cm-1 region and are assigned to GaO stretching vibrations.

The Influence of Farm Management on NSW Rural Property Income and Total Average Annual Returns

The importance of agriculture in many countries has tended to reduce as their economies move from a resource base to a manufacturing industry base. Although the level of agricultural production in first world countries has increased over the past two decades, this increase has generally been at a less significant rate compared to other sectors of the economies. Despite this increase in secondary and high technology industries, developed countries have continued to encourage and support their agricultural industries. This support has been through both tariffs and price support. Following pressure from developing economies, particularly through the World Trade Organisation (WTO), GATT Uruguay round and the Cairns Group developed countries are now in various stages of winding back or de-coupling agricultural support within their economies. A major concern of farmers in protected agricultural markets is the impact of a free market trade in agricultural commodities on farm incomes, profitability and land values. This paper will analyse both the capital and income performance of the NSW rural land market over the period 1990-1999. This analysis will be based on several rural land use classifications and will compare the total return from rural properties based on the farm income generated by both the average farmer and those farmers considered to be in the top 20% of the various land use areas. The analysis will provide a comprehensive overview of rural production in a free trade economy.

Can students with low vision maintain sustained reading rates?

Purpose: Students with low vision may be disadvantaged when compared with their normally sighted peers, as they frequently work at very short working distances and need to use low vision devices. The aim of this study was to examine the sustained reading rates of students with low vision and compare them with their peers with normal vision. The effects of visual acuity, acuity reserve and age on reading rate were also examined. Method: Fifty-six students (10 to 16 years of age), 26 with low vision and 30 with normal vision were required to read text continuously for 30 minutes. Their position in the text was recorded at two-minute intervals. Distance and near visual acuity, working distance, cause of low vision, reading rates and reading habits were recorded. Results: A total of 80.7 per cent of the students with low vision maintained a constant reading rate during the 30 minutes of reading, although they read at approximately half the rate (104 wpm) compared with their normally sighted peers (195 wpm). Only four of the low vision subjects could not complete the reading task. Reading rates increased significantly with acuity reserve and distance and near visual acuity but there was no significant relationship between age and sustained reading rate. Conclusions: The majority of students with low vision were able to maintain appropriate reading rates to cope in integrated educational settings. Surprisingly only relatively few subjects (16 per cent) used their prescribed low vision devices even though the average accommodative demand was 9 D and generally, they revealed a greater dislike of reading compared to students with normal vision.

Peak-to-average power ratio of IEEE 802.11a PHY layer signals

In this chapter we propose clipping with amplitude and phase corrections to reduce the peak-to-average power ratio (PAR) of orthogonal frequency division multiplexed (OFDM) signals in high-speed wireless local area networks defined in IEEE 802.11a physical layer. The proposed techniques can be implemented with a small modification at the transmitter and the receiver remains standard compliant. PAR reduction as much as 4dB can be achieved by selecting a suitable clipping ratio and a correction factor depending on the constellation used. Out of band noise (OBN) is also reduced.

Interleaved PC-OFDM to reduce peak-to-average power ratio

Parallel combinatory orthogonal frequency division multiplexing (PC-OFDM yields lower maximum peak-to-average power ratio (PAR), high bandwidth efficiency and lower bit error rate (BER) on Gaussian channels compared to OFDM systems. However, PC-OFDM does not improve the statistics of PAR significantly. In this chapter, the use of a set of fixed permutations to improve the statistics of the PAR of a PC-OFDM signal is presented. For this technique, interleavers are used to produce K-1 permuted sequences from the same information sequence. The sequence with the lowest PAR, among K sequences is chosen for the transmission. The PAR of a PC-OFDM signal can be further reduced by 3-4 dB by this technique. Mathematical expressions for the complementary cumulative density function (CCDF)of PAR of PC-OFDM signal and interleaved PC-OFDM signal are also presented.

Typical accuracy and quality control of a process for creating CT-Based virtual bone models

A pragmatic method for assessing the accuracy and precision of a given processing pipeline required for converting computed tomography (CT) image data of bones into representative three dimensional (3D) models of bone shapes is proposed. The method is based on coprocessing a control object with known geometry which enables the assessment of the quality of resulting 3D models. At three stages of the conversion process, distance measurements were obtained and statistically evaluated. For this study, 31 CT datasets were processed. The final 3D model of the control object contained an average deviation from reference values of −1.07±0.52 mm standard deviation (SD) for edge distances and −0.647±0.43 mm SD for parallel side distances of the control object. Coprocessing a reference object enables the assessment of the accuracy and precision of a given processing pipeline for creating CTbased 3D bone models and is suitable for detecting most systematic or human errors when processing a CT-scan. Typical errors have about the same size as the scan resolution.

Microscopic modelling of freeway operations

Freeways are divided roadways designed to facilitate the uninterrupted movement of motor vehicles. However, many freeways now experience demand flows in excess of capacity, leading to recurrent congestion. The Highway Capacity Manual (TRB, 1994) uses empirical macroscopic relationships between speed, flow and density to quantify freeway operations and performance. Capacity may be predicted as the maximum uncongested flow achievable. Although they are effective tools for design and analysis, macroscopic models lack an understanding of the nature of processes taking place in the system. Szwed and Smith (1972, 1974) and Makigami and Matsuo (1990) have shown that microscopic modelling is also applicable to freeway operations. Such models facilitate an understanding of the processes whilst providing for the assessment of performance, through measures of capacity and delay. However, these models are limited to only a few circumstances. The aim of this study was to produce more comprehensive and practical microscopic models. These models were required to accurately portray the mechanisms of freeway operations at the specific locations under consideration. The models needed to be able to be calibrated using data acquired at these locations. The output of the models needed to be able to be validated with data acquired at these sites. Therefore, the outputs should be truly descriptive of the performance of the facility. A theoretical basis needed to underlie the form of these models, rather than empiricism, which is the case for the macroscopic models currently used. And the models needed to be adaptable to variable operating conditions, so that they may be applied, where possible, to other similar systems and facilities. It was not possible to produce a stand-alone model which is applicable to all facilities and locations, in this single study, however the scene has been set for the application of the models to a much broader range of operating conditions. Opportunities for further development of the models were identified, and procedures provided for the calibration and validation of the models to a wide range of conditions. The models developed, do however, have limitations in their applicability. Only uncongested operations were studied and represented. Driver behaviour in Brisbane was applied to the models. Different mechanisms are likely in other locations due to variability in road rules and driving cultures. Not all manoeuvres evident were modelled. Some unusual manoeuvres were considered unwarranted to model. However the models developed contain the principal processes of freeway operations, merging and lane changing. Gap acceptance theory was applied to these critical operations to assess freeway performance. Gap acceptance theory was found to be applicable to merging, however the major stream, the kerb lane traffic, exercises only a limited priority over the minor stream, the on-ramp traffic. Theory was established to account for this activity. Kerb lane drivers were also found to change to the median lane where possible, to assist coincident mergers. The net limited priority model accounts for this by predicting a reduced major stream flow rate, which excludes lane changers. Cowan's M3 model as calibrated for both streams. On-ramp and total upstream flow are required as input. Relationships between proportion of headways greater than 1 s and flow differed for on-ramps where traffic leaves signalised intersections and unsignalised intersections. Constant departure onramp metering was also modelled. Minimum follow-on times of 1 to 1.2 s were calibrated. Critical gaps were shown to lie between the minimum follow-on time, and the sum of the minimum follow-on time and the 1 s minimum headway. Limited priority capacity and other boundary relationships were established by Troutbeck (1995). The minimum average minor stream delay and corresponding proportion of drivers delayed were quantified theoretically in this study. A simulation model was constructed to predict intermediate minor and major stream delays across all minor and major stream flows. Pseudo-empirical relationships were established to predict average delays. Major stream average delays are limited to 0.5 s, insignificant compared with minor stream delay, which reach infinity at capacity. Minor stream delays were shown to be less when unsignalised intersections are located upstream of on-ramps than signalised intersections, and less still when ramp metering is installed. Smaller delays correspond to improved merge area performance. A more tangible performance measure, the distribution of distances required to merge, was established by including design speeds. This distribution can be measured to validate the model. Merging probabilities can be predicted for given taper lengths, a most useful performance measure. This model was also shown to be applicable to lane changing. Tolerable limits to merging probabilities require calibration. From these, practical capacities can be estimated. Further calibration is required of traffic inputs, critical gap and minimum follow-on time, for both merging and lane changing. A general relationship to predict proportion of drivers delayed requires development. These models can then be used to complement existing macroscopic models to assess performance, and provide further insight into the nature of operations.