Dominant Feature (dominant + feature)

Distribution by Scientific Domains


Selected Abstracts


TWO TAXATION AGENDAS: THE GALLOP GOVERNMENT'S FIRST TERM

ECONOMIC PAPERS: A JOURNAL OF APPLIED ECONOMICS AND POLICY, Issue 1 2005
Michael McLure
This essay reviews state taxation policy in Western Australia over the Gallop Government's first term of office. Two tax agendas emerged, one concerning reform of the State's tax system and the other concerning measures to increase the tax yield in response to mid-term fiscal stress from unanticipated growth in expenditure. It is suggested that the lack of integration of these two agendas represented a lost policy opportunity, as integration would have provided the potential to implement a much more ambitious tax reform program than that realised by the Government. The lack of integration is partly attributed to the unrealistically low forward estimates of public expenditure outlined in the Government's first budget, as this served to mask the need for additional taxation revenue (and the consequent desirability of an integrated whole-of-term taxation policy) at the very time that reform measures were being actively contemplated. As a consequence, the dominant feature of the Government's first-term tax policy was not reform, but the introduction of large mid-term revenue-raising measures, especially increases in the State's highly inefficient conveyance duty. [source]


Low-frequency passive seismic experiments in Abu Dhabi, United Arab Emirates: implications for hydrocarbon detection

GEOPHYSICAL PROSPECTING, Issue 5 2010
Mohammed Y. Ali
ABSTRACT Low-frequency passive seismic experiments utilizing arrays of 3-component broadband seismometers were conducted over two sites in the emirate of Abu Dhabi in the United Arab Emirates. The experiments were conducted in the vicinity of a producing oilfield and around a dry exploration well to better understand the characteristics and origins of microtremor signals (1,6 Hz), which had been reported as occurring exclusively above several hydrocarbon reservoirs in the region. The results of the experiments revealed that a strong correlation exists between the recorded ambient noise and observed meteorological and anthropogenic noises. In the frequency range of 0.15,0.4 Hz, the dominant feature is a double-frequency microseism peak generated by the non-linear interactions of storm induced surface waves in the Arabian Sea. We observed that the double-frequency microseism displays a high variability in spectral amplitude, with the strongest amplitude occurring when Cyclone Gonu was battering the eastern coast of Oman; this noise was present at both sites and so is not a hydrocarbon indicator. Moreover, this study found that very strong microtremor signals in the frequency range of 2,3 Hz were present in all of the locations surveyed, both within and outside of the reservoir boundary and surrounding the dry exploration well. This microtremor signal has no clear correlation with the microseism signals but significant variations in the characteristics of the signals were observed between daytime and nighttime recording periods that clearly correlate with human activity. High-resolution frequency-wavenumber (f - k) spectral analyses were performed on the recorded data to determine apparent velocities and azimuths of the wavefronts for the microseism and microtremor events. The f - k analyses confirmed that the double-frequency microseism originates from wave activity in the Arabian Sea, while the microtremor events have an azimuth pointing towards the nearest motorways, indicating that they are probably being excited by traffic noise. Results drawn from particle motion studies confirm these observations. The vertical-to-horizontal spectral ratios of the data acquired in both experiments show peaks around 2.5,3 Hz with no dependence on the presence or absence of subsurface hydrocarbons. Therefore, this method should not be used as a direct hydrocarbon indicator in these environments. Furthermore, the analyses provide no direct evidence to indicate that earthquakes are capable of stimulating the hydrocarbon reservoir in a way that could modify the spectral amplitude of the microtremor signal. [source]


Assessing the distortionary impact of state trading in China

AGRICULTURAL ECONOMICS, Issue 3-4 2010
Steve McCorriston
Trade policy; State trading enterprises; China Abstract State trading is a common feature in the management of imports and exports of agricultural products and it has been a long-standing feature of China's agricultural trade regime. While the use of state trading was modified by China's accession to the WTO, it remains a dominant feature for some commodities, even though there have been recent attempts to diminish its importance. In this article, we review the role that the state trading enterprise (STE), China National Cereals, Oils and Foodstuffs Import and Export Company (COFCO), continues to play in the importing and exporting of some agricultural commodities. We then review the economic theory that has been developed to measure the tariff equivalent of importing STEs. Finally, we apply that theory through a calibration exercise to measure the tariff equivalent of COFCO in China's import market for wheat. The distortionary impact of COFCO depends on the bias in government policy toward agriculture, the competitiveness of the domestic procurement market, and also the number of firms that are allocated licenses to import alongside COFCO. [source]


Mammographic features of breast cancer in young symptomatic women

JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2003
Sophia Zadelis
Summary The present study provides a descriptive analysis of the mammographic appearance of breast cancer in women aged 30,39 years presenting with symptoms, based on 65 cancers confirmed with histology. We correlate the findings with clinical presentation and histological findings. We describe, categorize and illustrate the different lesions seen on mammography. Our study shows that microcalcification, with or without associated masses, is a dominant feature of breast cancer visualized on mammography in women in this age group. [source]


Melting out of sea ice causes greater photosynthetic stress in algae than freezing in,

JOURNAL OF PHYCOLOGY, Issue 5 2007
Peter J. Ralph
Sea ice is the dominant feature of polar oceans and contains significant quantities of microalgae. When sea ice forms and melts, the microalgal cells within the ice matrix are exposed to altered salinity and irradiance conditions, and subsequently, their photosynthetic apparatuses become stressed. To simulate the effect of ice formation and melting, samples of sea-ice algae from Cape Hallett (Antarctica) were exposed to altered salinity conditions and incubated under different levels of irradiance. The physiological condition of their photosynthetic apparatuses was monitored using fast and slow fluorescence-induction kinetics. Sea-ice algae exhibited the least photosynthetic stress when maintained in 35, and 51, salinity, whereas 16, 21, and 65, treatments resulted in significant photosynthetic stress. The greatest photosynthetic impact appeared on PSII, resulting in substantial closure of PSII reaction centers when exposed to extreme salinity treatments. Salinity stress to sea-ice algae was light dependent, such that incubated samples only suffered photosynthetic damage when irradiance was applied. Analysis of fast-induction curves showed reductions in J, I, and P transients (or steps) associated with combined salinity and irradiance stress. This stress manifests itself in the limited capacity for the reduction of the primary electron receptor, QA, and the plastoquinone pool, which ultimately inhibited effective quantum yield of PSII and electron transport rate. These results suggest that sea-ice algae undergo greater photosynthetic stress during the process of melting into the hyposaline meltwater lens at the ice edge during summer than do microalgae cells during their incorporation into the ice matrix during the process of freezing. [source]


Current and historical patterns of drainage connectivity in eastern Australia inferred from population genetic structuring in a widespread freshwater fish Pseudomugil signifer (Pseudomugilidae)

MOLECULAR ECOLOGY, Issue 2 2004
B. B. M. Wong
Abstract Dispersal can play an important role in the genetic structuring of natural populations. In this regard, freshwater fishes often exhibit extensive population genetic subdivision and are ideal subjects for investigating current and historical patterns of connection and dissociation between drainages. We set out to generate a comprehensive molecular phylogeny for a widespread freshwater fish from eastern Australia, the Pacific blue-eye Pseudomugil signifer. Although movement via flood events may be important in the southern end of the species' range, genetic structuring revealed the importance of historical drainage connections and dissociations in mediating or disrupting dispersal. A dominant feature of our phylogeny is a split between northern and southern populations, which appears to be congruent with a biogeographical barrier recently implicated as important for the connectivity of freshwater organisms in eastern Australia. The extent of the split also has taxonomic implications consistent with suggestions that the Pacific blue-eye may represent more than a single species. [source]


Hydrogen bonding and ,,, interactions in 1-benzofuran-2,3-dicarboxylic acid and its 1:1 cocrystals with pyridine, phenazine and 1,4-phenylenediamine

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2009
Hatem M. Titi
The structure of 1-benzofuran-2,3-dicarboxylic acid (BFDC), C10H6O5, (I), exhibits an intramolecular hydrogen bond between one ,COOH group and the other, while the second carboxyl function is involved in intermolecular hydrogen bonding to neighbouring species. The latter results in the formation of flat one-dimensional hydrogen-bonded chains in the crystal structure, which are ,,, stacked along the normal to the plane of the molecular framework, forming a layered structure. 1:1 Cocrystallization of BFDC with pyridine, phenazine and 1,4-phenylenediamine is associated with H-atom transfer from BFDC to the base and charge-assisted hydrogen bonding between the BFDC, monoanion and the corresponding ammonium species, while preserving, in all cases, the intramolecular hydrogen bond between the carboxyl and carboxylate functions. The pyridinium 2-carboxylato-1-benzofuran-3-carboxylic acid, C5H6N+·C10H5O5,, (II), and phenazinium 3-carboxylato-1-benzofuran-2-carboxylic acid, C12H9N2+·C10H5O5,, (III), adducts form discrete hydrogen-bonded ion-pair entities. In the corresponding crystal structures, the two components are arranged in either segregated or mixed ,,, stacks, respectively. On the other hand, the structure of 4-aminoanilinium 2-carboxylato-1-benzofuran-3-carboxylic acid, C6H9N2+·C10H5O5,, (IV), exhibits an intermolecular hydrogen-bonding network with three-dimensional connectivity. Moreover, this fourth structure exhibits induction of supramolecular chirality by the extended hydrogen bonding, leading to a helical arrangement of the interacting moieties around 21 screw axes. The significance of this study is that it presents the first crystallographic characterization of pure BFDC, and manifestation of its cocrystallization with a variety of weakly basic amine molecules. It confirms the tendency of BFDC to preserve its intramolecular hydrogen bond and to prefer a monoanionic form in supramolecular association with other components. The aromaticity of the flat benzofuran residue plays an important role in directing either homo- or heteromolecular ,,, stacking in the first three structures, while the occurrence of a chiral architecture directed by multiple hydrogen bonding is the dominant feature in the fourth. [source]


Two enantiomerically pure cyclic arenesulfonamide hydrochloride salts

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2009
Lionel Kiefer
The crystal structures of N -[(1R)-1-(1-naphthyl)ethyl]-3,4-dihydro-2H -1,2-benzothiazin-4-aminium 1,1-dioxide chloride, C20H21N2O2S+·Cl,, (I), a six-membered cyclic sulfonamide, and (1R)- N -[(5,5-dioxo-6,7-dihydrodibenzo[d,f][1,2]thiazepin-7-yl)methyl]-1-(1-naphthyl)ethanaminium chloride, C26H25N2O2S+·Cl,, (II), a seven-membered cyclic sulfonamide, both representative of a novel family of agonists of the extracellular calcium sensing receptor (CaSR) of possible clinical importance, are reported. The known chirality of the naphthylethylamine precursor has enabled assignment of the absolute configuration of both compounds, which is crucial for the receptor recognition. The crystal structures, though different, reveal for these agonists a notable absence of intramolecular ,,, stacking between their respective aromatic groups. This suggests a common structural feature that allows CaSR agonists to be distinguished from antagonists, since in the latter, such interactions have been shown to be important. The connectivities between molecules in the crystal structures are also different, but both involve hydrogen bonding mediated by chloride ions as a common dominant feature. [source]


Childhood ocular rosacea: Considerations for diagnosis and treatment

AUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 4 2009
Esther Hong
ABSTRACT Rosacea in children is not as well described as it is in adults. Ocular signs may be a dominant feature and some children with what has previously been called periorificial dermatitis may in fact have rosacea. We report three cases of paediatric ocular rosacea responding to prolonged treatment with oral erythromycin. Our cases demonstrate the close association of periorificial dermatitis with childhood rosacea, and highlight the importance of eye signs in its diagnostic criteria. [source]


Review of singleton fetal and neonatal deaths associated with cranial trauma and cephalic delivery during a national intrapartum-related confidential enquiry

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 5 2005
Fidelma O'Mahony
Objective To review delivery details of intrapartum-related fetal and neonatal deaths with singleton cephalic presentation and birthweight of 2500 g or more in which traumatic cranial or cervical spine injury or substantial difficulty at delivery of the head was a dominant feature. Design Review of freestyle summary reports and standard questionnaire responses submitted to the national secretariat for the Confidential Enquiry into Stillbirths and Death in Infancy (CESDI) during the 1994/1995 intrapartum-related mortality enquiry following regional multidisciplinary panel review. Setting United Kingdom. Sample Of the 873 cases of intrapartum-related deaths reported in the 1994,1995 national enquiry, 709 weighed more than 2499 g. Reports from 181 (89 from 1994 and 92 from 1995) with a chance of meeting criteria for cranial or cervical trauma as significant contributors to death were examined in detail. Thirty-seven were judged to meet the criteria stated in the objectives (23 from 1994 and 14 from 1995) and form the basis for this review. Methods Electronic and hand search of CESDI records relating to intrapartum-related deaths. Main outcome measures Intrapartum events and features of care. Results There was evidence of fetal compromise present before birth in 33 of the 37 (89%) study group cases reviewed. One delivery was performed vaginally without instrumentation, and in one there was no attempt at vaginal delivery before caesarean section (CS) in the second stage of labour. Twenty-four cases (65%) were delivered vaginally and 11 (30%) by CS after failure to deliver vaginally with instruments. A single instrument was used in six cases of vaginal delivery (four ventouse and two Kjelland's forceps). At least two separate attempts with different instruments were made in 24 cases. Overall, the ventouse was used in 27 cases and forceps in 29 cases. In six cases, three separate attempts were made with at least two different instruments, all of which included use of ventouse. The grade of operator was recorded in 27 cases. Of these, a consultant obstetrician was present at only one delivery and no consultant was recorded to have made the first attempt to deliver a baby. In six cases, shoulder dystocia was also reported. Conclusions This study suggests a lower incidence of death from difficult cephalic delivery and cranial trauma than previously reported. The CESDI studies were believed to have achieved high levels of ascertainment for all intrapartum-related deaths from which the cases reported here were selected. Strictly applied entry criteria used in this study could have restricted the number of cases considered as could limited in vivo or postmortem investigations and lack of detailed autopsy. When cranial traumatic injury was observed, it was almost always associated with physical difficulty at delivery and the use of instruments. The use of ventouse as the primary or only instrument did not prevent this outcome. Some injuries occurred apparently without evidence of unreasonable force, but poorly judged persistence with attempts at vaginal delivery in the presence of failure to progress or signs of fetal compromise were the main contributory factor regardless of which instruments were used. [source]


SHARED AND UNIQUE FEATURES OF DIVERSIFICATION IN GREATER ANTILLEAN ANOLIS ECOMORPHS

EVOLUTION, Issue 2 2006
R. Brian Langerhans
Abstract Examples of convergent evolution suggest that natural selection can often produce predictable evolutionary outcomes. However, unique histories among species can lead to divergent evolution regardless of their shared selective pressures,and some contend that such historical contingencies produce the dominant features of evolution. A classic example of convergent evolution is the set of Anolis lizard ecomorphs of the Greater Antilles. On each of four islands, anole species partition the structural habitat into at least four categories, exhibiting similar morphologies within each category. We assessed the relative importance of shared selection due to habitat similarity, unique island histories, and unique effects of similar habitats on different islands in the generation of morphological variation in anole ecomorphs. We found that shared features of diversification across habitats were of greatest importance, but island effects on morphology (reflecting either island effects per se or phylogenetic relationships) and unique aspects of habitat diversification on different islands were also important. There were three distinct cases of island-specific habitat diversification, and only one was confounded by phylogenetic relatedness. The other two unique aspects were not related to shared ancestry but might reflect as-yet-unmeasured environmental differences between islands in habitat characteristics. Quantifying the relative importance of shared and unique responses to similar selective regimes provides a more complete understanding of phenotypic diversification, even in this much-studied system [source]


Maximum pixel spectrum: a new tool for detecting and recovering rare, unanticipated features from spectrum image data cubes

JOURNAL OF MICROSCOPY, Issue 2 2004
D. S. BRIGHT
Summary A new software tool, the maximum pixel spectrum, detects rare events within a spectrum image data cube, such as that generated with electron-excited energy-dispersive X-ray spectrometry in a scanning electron microscope. The maximum pixel spectrum is a member of a class of ,derived spectra' that are constructed from the spectrum image data cube. Similar to a conventional spectrum, a derived spectrum is a linear array of intensity vs. channel index that corresponds to photon energy. A derived spectrum has the principal characteristics of a real spectrum so that X-ray peaks can be recognized. A common example of a derived spectrum is the summation spectrum, which is a linear array in which the summation of all pixels within each energy plane gives the intensity value for that channel. The summation spectrum is sensitive to the dominant features of the data cube. The maximum pixel spectrum is constructed by selecting the maximum pixel value within each X-ray energy plane, ignoring the remaining pixels. Peaks corresponding to highly localized trace constituents or foreign contaminants, even those that are confined to one pixel of the image, can be seen at a glance when the maximum pixel spectrum is compared with the summation spectrum. [source]


Quasi-biennial oscillations in spectral aerosol optical depth

ATMOSPHERIC SCIENCE LETTERS, Issue 4 2009
S. Naseema Beegum
Abstract Analysis of long-term time series of monthly mean aerosol optical depths (AOD) at four tropical stations over Asia and Africa revealed the presence of significant annual oscillations (AO) and quasi-biennial oscillations (QBO). While the AOs were the dominant features, the QBOs in AOD (QBOAOD) were also quite strong and were well associated with the QBO in stratospheric zonal wind (QBOU). At the equatorial stations, QBOAOD were out of phase with QBOU, while they were in phase at the off-equatorial stations. However, QBO in both outgoing longwave radiation (OLR) and rainfall showed an out-of-phase relationship with QBOAOD at all stations. Copyright © 2009 Royal Meteorological Society [source]