981 resultados para 4000
Resumo:
Island races of passerine birds display repeated evolution towards larger body size compared with their continental ancestors. The Capricorn silvereye (Zosterops lateralis chlorocephalus) has become up to six phenotypic standard deviations bigger in several morphological measures since colonization of an island approximately 4000 years ago. We estimated the genetic variance-covariance (G) matrix using full-sib and 'animal model' analyses, and selection gradients, for six morphological traits under field conditions in three consecutive cohorts of nestlings. Significant levels of genetic variance were found for all traits. Significant directional selection was detected for wing and tail lengths in one year and quadratic selection on culmen depth in another year. Although selection gradients on many traits were negative, the predicted evolutionary response to selection of these traits for all cohorts was uniformly positive. These results indicate that the G matrix and predicted evolutionary responses are consistent with those of a population evolving in the manner observed in the island passerine trend, that is, towards larger body size.
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The scarcity of large parcels of land in well-serviced areas is one motivator for redeveloping industrial or commercial property that is abandoned or underused and often environmentally contaminated – so-called brownfield land. Poor industrial waste disposal practices caused by industrial activities including gas works, factories, railway land and waste tips have contributed to many instances of contaminated land identified as brownfield sites. It is estimated there are between 10,000 and 160,000 brownfield sites in Australia, with Queensland accounting for around 4000 of these.
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The health of an individual is determined by the interaction of genetic and individual factors with wider social and environmental elements. Public health approaches to improving the health of disadvantaged populations will be most effective if they optimise influences at each of these levels, particularly in the early part of the life course. In order to better ascertain the relative contribution of these multi-level determinants there is a need for robust studies, longitudinal and prospective in nature, that examine individual, familial, social and environmental exposures. This paper describes the study background and methods, as it has been implemented in an Australian birth cohort study, Environments for Healthy Living (EFHL): The Griffith Study of Population Health. EFHL is a prospective, multi-level, multi-year longitudinal birth cohort study, designed to collect information from before birth through to adulthood across a spectrum of eco-epidemiological factors, including genetic material from cord-blood samples at birth, individual and familial factors, to spatial data on the living environment. EFHL commenced the pilot phase of recruitment in 2006 and open recruitment in 2007, with a target sample size of 4000 mother/infant dyads. Detailed information on each participant is obtained at birth, 12-months, 3-years, 5-years and subsequent three to five yearly intervals. The findings of this research will provide detailed evidence on the relative contribution of multi-level determinants of health, which can be used to inform social policy and intervention strategies that will facilitate healthy behaviours and choices across sub-populations.
Confirmation of the assignment of vibrations of goethite: An ATR and IES study of goethite structure
Resumo:
Transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM/EDS) and X-ray diffraction (XRD) were used to characterize the morphology of synthetic goethite. The behavior of the hydroxyl/water molecular units of goethite and its thermally treated products were characterized using Fourier transform-infrared emission spectroscopy (FT-IES) and attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy. The results showed that all the expected vibrational bands between 4000 and 650 cm−1 including the resolved bands (3800–2200 cm−1) were confirmed. A band attributed to a new type of hydroxyl unit was found at 3708 cm−1 and assigned to the FeO–H stretching vibration without hydrogen bonding. This hydroxyl unit was retained up to the thermal treatment temperature of 500 °C. On the whole, seven kinds of hydroxyl units, involving three surface hydroxyls, a bulk hydroxyl, a FeO–H without hydrogen bonding, a nonstoichiometric hydroxyl and a reversed hydroxyl were observed, and three kinds of adsorbed water were found in/on goethite.
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“Epidemics” of a benign disease causing polyarthralgia and rash were first described in Australia in 1927.63 Following the recovery of the causative agent and the advent of serologic tests able to diagnose Ross River virus infection, epidemic polyarthritis has been recognized as endemic in Australia and has occurred as epidemics in numerous Pacific nations. Approximately 4000 cases of epidemic polyarthritis are reported in Australia each year, with a peak of 7800 cases in 1996. Some confusion has been generated recently by use of the term Ross River fever to describe clinical Ross River virus infections because fever does not develop in more than half of those with clinical disease.59 Additional confusion has been generated by efforts to describe any polyarthritis caused by an Australian arbovirus as epidemic polyarthritis. The term epidemic polyarthritis should be used to describe only clinical disease caused by Ross River virus.
Resumo:
This study was a step forward in modeling, simulation and microcontroller implementation of a high performance control algorithm for the motor of a blood pump. The rotor angle is sensed using three Hall effect sensors and an algorithm is developed to obtain better angular resolution from the three signals for better discrete-time updates of the controller. The performance of the system was evaluated in terms of actual and reference speeds, stator currents and power consumption over a range of reference speeds up to 4000 revolutions per minute. The use of fewer low cost Hall effect sensors compared to expensive high resolution sensors could reduce the cost of blood pumps for total artificial hearts.
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The structures of the compounds from the reaction of the drug dapsone [4-(4-aminophenylsulfonyl)aniline] with 3,5-dinitrosalicylic acid, the salt hydrate [4-(4-aminohenylsulfonyl)anilinium 2-carboxy-4,6-dinitrophenolate monohydrate] (1) and the 1:1 adduct with 5-nitroisophthalic acid [4-(4-aminophenylsulfonyl)aniline 5-nitrobenzene-1,3-dicarboxylic acid] (2) have been determined. Crystals of 1 are triclinic, space group P-1, with unit cell dimensions a = 8.2043(3), b = 11.4000(6), c = 11.8261(6)Å, α = 110.891(5), β = 91.927(3), γ = 98.590(4)deg. and Z = 4. Compound 2 is orthorhombic, space group Pbcn, with unit cell dimensions a = 20.2662(6), b = 12.7161(4), c = 15.9423(5)Å and Z = 8. In 1, intermolecular analinium N-H…O and water O-H…O and O-H…N hydrogen-bonding interactions with sulfone, carboxyl, phenolate and nitro O-atom and aniline N-atom acceptors give a two-dimensional layered structure. With 2, the intermolecular interactions involve both aniline N-H…O and carboxylic acid O-H…O and O-H…N hydrogen bonds to sulfone, carboxyl, nitro and aniline acceptors, giving a three-dimensional network structure. In both structures π--π aromatic ring associations are present.
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ROBERT EVAPORATORS in Australian sugar factories are traditionally constructed with 44.45 mm outside diameter stainless steel tubes of ~2 m length for all stages of evaporation. There are a few vessels with longer tubes (up to 2.8 m) and smaller and larger diameters (38.1 and 50.8 mm). Queensland University of Technology is undertaking a study to investigate the heat transfer performance of tubes of different lengths and diameters for the whole range of process conditions typically encountered in the evaporator set. Incorporation of these results into practical evaporator designs requires an understanding of the cost implications for constructing evaporator vessels with calandrias having tubes of different dimensions. Cost savings are expected for tubes of smaller diameter and longer length in terms of material, labour and installation costs in the factory. However these savings must be considered in terms of the heat transfer area requirements for the evaporation duty, which will likely be a function of the tube dimensions. In this paper a capital cost model is described which provides a relative cost of constructing and installing Robert evaporators of the same heating surface area but with different tube dimensions. Evaporators of 2000, 3000, 4000 and 5000 m2 are investigated. This model will be used in conjunction with the heat transfer efficiency data (when available) to determine the optimum tube dimensions for a new evaporator at a specified evaporation duty. Consideration is also given to other factors such as juice residence time (and implications for sucrose degradation and control) and droplet de-entrainment in evaporators of different tube dimensions.
Resumo:
The ability to control the properties of single-wall nanotubes (SWNTs) produced in the arc discharge is important for many practical applications. Our experiments suggest that the length of SWNTs significantly increases (up to 4000 nm), along with the purity of the carbon deposit, when the magnetic field is applied to arc discharge. Scanning electron microscopy and transmission electron microscopy analyses have demonstrated that the carbon deposit produced in the magnetic-field-enhanced arc mainly consists of the isolated and bunched SWNTs. A model of a carbon nanotube interaction and growth in the thermal plasma was developed, which considers several important effects such as anode ablation that supplies the carbon plasma in an anodic arc discharge technique, and the momentum, charge, and energy transfer processes between nanotube and plasma. It is shown that the nanotube charge with respect to the plasma as well as nanotube length depend on plasma density and electric field in the interelectrode gap. For instance, nanotube charge changes from negative to positive value with an electron density decrease. The numerical simulations based on the Monte Carlo technique were performed, which explain an increase in the nanotubes produced in the magnetic-field-enhanced arc discharge. © 2008 American Institute of Physics.
Resumo:
A defect-selective photothermal imaging system for the diagnostics of optical coatings is demonstrated. The instrument has been optimized for pump and probe parameters, detector performance, and signal processing algorithm. The imager is capable of mapping purely optical or thermal defects efficiently in coatings of low damage threshold and low absorbance. Detailed mapping of minor inhomogeneities at low pump power has been achieved through the simultaneous action of a low-noise fiber optic photothermal beam defection sensor and a common-mode-rejection demodulation (CMRD) technique. The linearity and sensitivity of the sensor have been examined theoretically and experimentally, and the signal to noise ratio improvement factor is found to be about 110 compared to a conventional bicell photodiode. The scanner is so designed that mapping of static or shock sensitive samples is possible. In the case of a sample with absolute absorptance of 3.8 x 10(-4), a change in absorptance of about 0.005 x 10(-4) has been detected without ambiguity, ensuring a contrast parameter of 760. This is about 1085% improvement over the conventional approach containing a bicell photodiode, at the same pump power. The merits of the system have been demonstrated by mapping two intentionally created damage sites in a MgF2 coating on fused silica at different excitation powers. Amplitude and phase maps were recorded for thermally thin and thick cases, and the results are compared to demonstrate a case which, in conventional imaging, would lead to a deceptive conclusion regarding the type and location of the damage. Also, a residual damage profile created by long term irradiation with high pump power density has been depicted.
Resumo:
Deriving an estimate of optimal fishing effort or even an approximate estimate is very valuable for managing fisheries with multiple target species. The most challenging task associated with this is allocating effort to individual species when only the total effort is recorded. Spatial information on the distribution of each species within a fishery can be used to justify the allocations, but often such information is not available. To determine the long-term overall effort required to achieve maximum sustainable yield (MSY) and maximum economic yield (MEY), we consider three methods for allocating effort: (i) optimal allocation, which optimally allocates effort among target species; (ii) fixed proportions, which chooses proportions based on past catch data; and (iii) economic allocation, which splits effort based on the expected catch value of each species. Determining the overall fishing effort required to achieve these management objectives is a maximizing problem subject to constraints due to economic and social considerations. We illustrated the approaches using a case study of the Moreton Bay Prawn Trawl Fishery in Queensland (Australia). The results were consistent across the three methods. Importantly, our analysis demonstrated the optimal total effort was very sensitive to daily fishing costs-the effort ranged from 9500-11 500 to 6000-7000, 4000 and 2500 boat-days, using daily cost estimates of $0, $500, $750, and $950, respectively. The zero daily cost corresponds to the MSY, while a daily cost of $750 most closely represents the actual present fishing cost. Given the recent debate on which costs should be factored into the analyses for deriving MEY, our findings highlight the importance of including an appropriate cost function for practical management advice. The approaches developed here could be applied to other multispecies fisheries where only aggregated fishing effort data are recorded, as the literature on this type of modelling is sparse.
Resumo:
The purpose of this research was to analyse the phonological system of the Limi dialect of Humla Bhotia. Humla Bhotia is a Tibeto-Burman language that is spoken by approximately 4000 5000 people in the far northwestern Humla province of the Kingdom of Nepal. The language has not previously been the subject of analysis. The data base for this thesis was collected on two different dialects of Humla Bhotia in Kathmandu, the capital of Nepal, from February to May 2000. I had three language informants who speak Humla Bhotia as their mother tongue. One of the informants speaks the Upper Humla dialect and the other two informants speak the Limi dialect. In this thesis I have concentrated on the phonology of the dialect of Limi but occasionally I also make reference to the Upper Humla dialect. The Limi data base consists of 600 words elicited in isolation, sentences where words have been checked for consonantal and pitch variation, and five texts comprising 117 sentences. Firstly, I have studied the geographical location, population and dialects of Humla Bhotia. Five dialects were identified: Limi, Upper Humla, La Yakba, Nyinba and Humli Khyampa. Information on the dialect areas is based on the accounts of seven mother tongue speakers of the language and on Nancy Levine s (1988) anthropological research of the ethnic group Nyinba. Secondly, I have analysed the phonological system of Limi from the viewpoint of American stucturalism much along the lines followed by Pike 1966 [1947] ja 1967 [1948]. In defining the prosodic elements I have also used acoustic analysis. In the Limi dialect there are 7 vowel phonemes. No vowel clusters occur within the same syllable. In this preliminary analysis 29 contrastive plosives, 8 affricates and 5 6 fricatives were found. The data also revealed 4 nasal phonemes, two rhotic phonemes, one lateral phoneme and two central approximants. Further research is however called for to check the phonemic status of these segments. Four contrastive prosodic elements were encountered: nasalisation, length, phonation type and pitch movement. There are two contrastive types of phonation: tense and lax. Many words were found with a third type of phonation, modal phonation. How modal phonation relates to the prosodic system is unclear at this stage and is therefore left for further research to determine. There are two contrastive pitch movement tonemes: a rising toneme and falling toneme. The falling toneme occurs in free variation with a level pitch contour. Rising appears to be linked with lax phonation and falling with tense phonation.
Resumo:
The research is related to the Finnish Jabal Harun Project (FJHP), which is part of the research unit directed by Professor Jaakko Frösén. The project consists of two interrelated parts: the excavation of a Byzantine monastery/pilgrimage centre on Jabal Harun, and a multiperiod archaeological survey of the surrounding landscape. It is generally held that the Near Eastern landscape has been modified by millennia of human habitation and activity. Past climatic changes and human activities could be expected to have significantly changed also the landscape of the Jabal Harun area. Therefore it was considered that a study of erosion in the Jabal Harun area could shed light on the environmental and human history of the area. It was hoped that it would be possible to connect the results of the sedimentological studies either to wider climatic changes in the Near East, or to archaeologically observable periods of human activity and land use. As evidence of some archaeological periods is completely missing from the Jabal Harun area, it was also of interest whether catastrophic erosion or unfavourable environmental change, caused either by natural forces or by human agency, could explain the gaps in the archaeological record. Changes in climate and/or land-use were expected to be reflected in the sedimentary record. The field research, carried out as part of the FJHP survey fieldwork, included the mapping of wadi terraces and cleaning of sediment profiles which were recorded and sampled for laboratory analyses of facies and lithology. To obtain a chronology for the sedimentation and erosion phases also OSL (optically stimulated luminescence) dating samples were collected. The results were compared to the record of the Near Eastern palaeoclimate, and to data from geoarchaeological studies in central and southern Jordan. The picture of the environmental development was then compared to the human history in the area, based on archaeological evidence from the FJHP survey and the published archaeological research in the Petra region, and the question of the relationship between human activity and environmental change was critically discussed. Using the palaeoclimatic data and the results from geoarchaeological studies it was possible to outline the environmental development in the Jabal Harun area from the Pleistocene to the present.It is appears that there was a phase of accumulation of sediment before the Middle Palaeolithic period, possibly related to tectonic movement. This phase was later followed by erosion, tentatively suggested to have taken place during the Upper Palaeolithic. A period of wadi aggradation probably occurred during the Late Glacial and continued until the end of the Pleistocene, followed by significant channel degradation, attributed to increased rainfall during the Early Holocene. It seems that during the later Holocene channel incision has been dominant in the Jabal Harûn area although there have been also small-scale channel aggradation phases, two of which were OSL-dated to around 4000-3000 BP and 2400-2000 BP. As there is no evidence of tectonic movements in the Jabal Harun area after the early Pleistocene, it is suggested that climate change and human activity have been the major causes of environmental change in the area. At a brief glance it seems that many of the changes in the settlement and land use in the Jabal Harun area can be explained by climatic and environmental conditions. However, the responses of human societies to environmental change are dependent on many factors. Therefore an evaluation of the significance of environmental, cultural, socio-economic and political factors is needed to decide whether certain phenomena are environmentally induced. Comparison with the wider Petra region is also needed to judge whether the phenomena are characteristic of the Jabal Harun area only, or can they be connected to social, political and economic development over a wider area.
Resumo:
Infrared spectra are recorded for S-methyl dithiocarbazate and its N-deuterated compound in two molecular conformations in the solid state and in solution between 4000 and 30 cm−1. The assignments have been supported from a complete normal coordinate analysis; the conformation sensitive bands of the –CSNHNH2 grouping are discussed. The assignments are compared with those of related molecules to check the internal consistency and to obtain the pattern of the characteristic bands of thiocarbazoyl (–CSNHNH2) group. The magnitudes of the C–N and S–CH3 torsional barriers are estimated from the force constants.
Resumo:
A continuing education program PROFICIENCE is described, which is the collaborative effort of 14 Professional Institutions in Bangalore and the Indian Institute of Science, to give full-term rigorous courses of topical interest. The novel aspect is that the professional institutions are coming together to evolve the academic needs that are met by the Indian Institute of Science. More than 4000 participants have benefited since its inception in August 1980.