bluuebunny/crossref_metadata_2025 huggingface dataset:
Degree-day models in New South Wales: climatic variation in the accuracy of different algorithms and geographical bias correction procedures
Authors: Watson DM , Beattie GAC
Published: March 2005

Geographical variation in the accuracy of different indirect degree-day (IDD) models may result in significant error in the estimation of developmental events in organisms whose development is temperature dependent. This study compared IDDs based on the rectangle, triangle and sine wave models to direct degree-day (DDD) estimates at 20 sites in New South Wales. The value of geographical bias correction procedures for improving the accuracy of IDDs were also examined. Temperatures were recorded at hourly or shorter intervals over periods from 6 months to 4 years depending on the site. IDDs and DDDs were calculated using 7 lower developmental thresholds between 10 and 13�C. Geographical bias correction procedures were applied at 2 resolutions: local (using data from single sites, and regional (pooling data from sites having similar climatic features). Correction equations were obtained by regressing daily IDDs on daily DDDs. Independent data were used to assess the performance of these equations at improving IDDs. Models did not perform equally well throughout the state. The triangle model performed best at sites in the east and south of the state, however, it was often inaccurate. The sine wave and rectangle models performed best at sites in the west. Discriminant analysis identified average annual rainfall, average daily January relative humidity and average daily July cloud cover as the most efficient subset of climatic variables needed to correctly classify all but 1 site on the basis of model performance. Model performance was thus dependent on atmospheric moisture indices. Local bias correction greatly improved the accuracy of IDDs at sites with humid climates but were superfluous at semi-arid sites. Within most climatically defined regions there were significant differences in the correction equations used at different sites. At some sites there were also differences between years. However, the impact of within-site variability of corrected IDDs from year to year on accumulated estimates was reduced to within acceptable limits (i.e. errors <7 days) by increasing the amount of data used to generate the equations. Regional bias correction equations gave improved IDDs but the improvement achieved was not as good as that with local correction. Model selection as a source of error in IDDs, the consequences of selecting a model for its accuracy at estimating degree-days or its precision at predicting developmental events, and the benefits and limitations of geographical bias correction are discussed.
Barley grass seed and shearing effects on summer lamb growth and pelt quality
Authors: Holst PJ , Hall DG , Stanley DF
Published: March 2005

The effects of mature barley grass (Hordeum spp.) pasture on lamb growth rates, carcass180 crossbred lambs finished on summer pastures. The effect of shearing at weaning, using 2 types of combs (traditional or cover) was compared with a 'no shearing' treatment.Exposure to barley grass pasture over November and December produced growth rates of 82 � 5 g/day for lambs slaughtered in January compared with growth rates of 141 � 5 g/day on lucerne pasture over the same period. On the barley grass pasture, shearing gave an immediate and sustained advantage (P<0.05) in growth rate but no difference between cover or traditional comb. Carcass weights were 21.4 � 0.3 and 19.0 � 0.4 kg for lambs grazing lucerne pasture and barley grass pasture, respectively. Shearing reduced pelt damage from barley grass seed to the extent that 85% of unshorn pelts had >5 scars per pelt compared with 13% in pelts from shorn lambs. Type of shearing comb did not influence the result. The results suggest that maturing barley grass pastures must be avoided if adequate growth rates are to be achieved in weaner lambs.
Phosphorus requirements of winter-planted lettuce (Lactuca sativa L.) on a Karrakatta sand and the residual value of phosphate as determined by soil test
Authors: McPharlin IR , Jeffery RC , Pitman DH
Published: March 2005

The phosphorus (P) requirements of crisphead lettuce (Lactuca sativa L. cv. Oxley) was measured over 2 consecutive winter plantings using superphosphate that was freshly applied and applied 9 months before planting, at 0-600 kg/ha on a newly cleared Karrakatta sand of low natural P fertility. There was a significant (P<0.001) head yield response to level of applied P in both years. Phosphorus uptake by whole plants and plant shoots was related to level of applied P in Mitscherlich relationships (R2 = 0.88). Phosphorus recovery efficiency (fertiliser P uptake by shoots/P applied, both in kg/ha) by shoots decreased from 0.16 at 50 to 0.04 at 600 kg applied P/ha. Phosphorus recovery efficiency by whole plants (shoots plus roots) decreased from 0.18 at 50 to 0.05 at 600 kg P/ha. The level of freshly applied P required for either 95 or 99% of maximum relative yield over the 2 years (maximum yield, 86 t/ha) was 276 and 427 kg P/ha (Mitscherlich relationship, R2 = 0.95), respectively at <10 �g/g soil test P (newly cleared sites). The marketable yield was 82 and 95% of total yield at 276 and 427 kg P/ha respectively. Bicarbonate-soluble P extracted from the top 15 cm of soil was determined on residual P sites over 2 years where P was applied at 0-600 kg/ha. These soil test levels were related to head yield in a Mitscherlich relationship (R2 = 0.88). The critical soil test P values required for either 95 or 99% of maximum relative yield, over the 2 years, were 80 and 115 �g/g, respectively. Phosphorus in the wrapper leaf at early heading required for 95 or 99% of maximum yield was 0.59 � 0.03 and 0.61 � 0.03% (spline regression, R2 = 0.80), respectively. Soil and plant testing could be used to assist in reducing fertiliser costs, improving utilisation of freshly- and previously-applied fertiliser P by lettuce and reducing P losses to water systems on the Swan Coastal Plain in Western Australia.
Comparison of no-tillage and conventional tillage in the development of sustainable farming systems in the semi-arid tropics
Authors: Thiagalingam K , Dalgliesh NP , Gould NS , McCown RL , Cogle AL , Chapman AL
Published: March 2005

The results of 5 short-term (4-8 years) experiments and farm demonstrations in which no-tillage technology was compared with conventional or reduced tillage in the semi-arid tropics of the Northern Territory and Far North Queensland, during the mid 1980s to mid 1990s, are reviewed. In the Douglas-Daly and Katherine districts of the Northern Territory, dryland crops of maize, sorghum, soybean and mungbean sown using no-tillage with adequate vegetative mulch on the soil surface have produced yields comparable with, or higher than (especially in drier years), those obtained under conventional tillage. The importance of a surface mulch in ameliorating soil temperature, moisture and fertility, and in reducing soil movement and loss in crop production in the semi-arid tropics was confirmed. Management of mulch (pasture, crop residues and weeds) will be crucial in the application of no-tillage technology to the development of mixed dryland crop and livestock enterprises in the semi-arid tropics.
Weed control in tropical ley farming systems: a review
Authors: Martin CC
Published: March 2005

The first sustained effort to develop a ley farming system (a pasture legume rotated with a grain crop) for the Australian semi-arid tropics began in the late 1970s at Katherine, Northern Territory, where various strategies were identified and implemented. It was soon discovered that a main constraint to success was the invasion of the legume ley by grass weeds. This occurred despite the replacement of Townsville stylo (Stylosanthes humilis), which provided the base for the early work, with more competitive legumes such as Verano (Stylosanthes hamata) and Centurion centro (Centrosema pascuorum). Early weed control work focused on the use of chemicals, but later competition and population dynamics were studied in S. humilis pastures. The ley farming system comprised a number of essential elements, each of which offered opportunities for weed control First, a legume ley was rotated with grain crops. Past work concentrated on legume leys, but nitrogen (N)-fertilised grass leys may be successful if the N was economically supplied. Grasses can effectively suppress weeds. Rotation of herbicides is possible. Sicklepod (Senna obtusifolia) can be controlled with atrazine in the sorghum phase, and emergent Sida spp. can be controlled in the pasture phase using a herbicide roller. Second, cattle graze the legume ley and crop residues in the dry season. Cattle can be used to suppress grass weeds in the wet season. The major use of the legume ley, however, was to provide high quality food in the dry season when there was little other available food. Future research should investigate the economics of balancing the need for grass weed control with food provision in the dry season. Third, crops sown directly into a ley killed with a knockdown herbicide. Although the need for improved soil surface management was recognised early, development of reduced tillage was delayed until the availability of glyphosate. Initial work concentrated on improving plant establishment under mulch. Recent work has shown that mulches can effectively control weeds in crops without the use of herbicides; best weed control occurred when glyphosate was applied as a single application at sowing. Fourth, ley regenerated as an intercrop in the grain crop. There is no doubt that the presence of an intercrop reduces the yield of the grain crop. Future research should investigate the economics and risks associated with intercrop-induced changes in yield and herbicide use patterns. The extreme climate and sandy soils pose problems for herbicide use. There is marked seasonal variation in effectiveness of pre-emergence herbicides, ranging from zero to marked crop phytotoxicity. The effectiveness of knockdown herbicides is reduced by stressed target plants and rain soon after spraying. Mulch dynamics, grazing, competition and interference, and herbicide interactions with target plants and the environment, were identified as key features requiring attention in a ley farming system to achieve practical weed management.
Conservation tillage and ley farming in the semi-arid tropics of northern Australia - some economic aspects
Authors: Kirby GWM , Hristova VJ , Murti S
Published: March 2005

This paper examines some aspects of the economics of conservation tillage and ley farming in the semi-arid tropics of northern Australia. The distribution, 1 value and major trends in the enterprises comprising the agricultural sector of the semi-arid tropics are discussed in an industry context. The likely economic benefits for the farmer from the adoption of conservation tillage and ley farming come from mulch retention and increased yields. These benefits vary with the frequency of grain cropping, the legume species used and the commodity price relativities. The benefits are likely to be larger in drier growing seasons. Data on other factors, such as soil type and seasons, were inadequate for economic analysis. Some ley farming systems are more profitable than single enterprises in the short term. In the long term, the best choice for sustainable farming systems in the semi-arid tropics appears to be a legume pasture system or a legume pasture-crop system. Results to date from ley farming studies show that experimental designs need to be modified to incorporate higher cropping frequencies and more comprehensive joint product measures in order to allow a more critical economic assessment. Additional benefits to society from the adoption of conservation tillage and ley farming are likely to come from minimising adverse on-farm and off-farm effects of agricultural activities. There are strong arguments for continuing support for research and development in ley farming technology and a joint sharing of the costs between farmers and the community generally.
Evidence for the presence of Mn(III) intermediates in the bacterial oxidation of Mn(II)
Authors: Webb Samuel M. , Dick Gregory J. , Bargar John R. , Tebo Bradley M.
Published: March 2005

Bacterial oxidation of Mn(II) to Mn(IV) is believed to drive the oxidative segment of the global biogeochemical Mn cycle and regulates the concentration of dissolved Mn(II) in the oceanic water column, where it is a critical nutrient for planktonic primary productivity. Mn(II) oxidizing activity is expressed by numerous phylogenetically diverse bacteria and fungi, suggesting that it plays a fundamental and ubiquitous role in the environment. This important redox system is believed to be driven by an enzyme or enzyme complex involving a multicopper oxidase, although the biochemical mechanism has never been conclusively demonstrated. Here, we show that Mn(II) oxidation by spores of the marine
Bacillus
sp. strain SG-1 is a result of two sequential one-step electron transfer processes, both requiring the putative multicopper oxidase, MnxG, in which Mn(III) is a transient intermediate. A kinetic model of the oxidation pathway is presented, which shows that the Mn(II) to Mn(III) step is the rate-limiting step. Thus, oxidation of Mn(II) appears to involve a unique multicopper oxidase system capable of the overall two-electron oxidation of its substrate. This enzyme system may serve as a source for environmental Mn(III), a strong oxidant and competitor for siderophore-bound Fe(III) in nutrient-limited environments. That metabolically dormant spores catalyze an important biogeochemical process intimately linked to the C, N, Fe, and S cycles requires us to rethink the role of spores in the environment.
Quantitative prediction of perceptual decisions during near-threshold fear detection
Authors: Pessoa Luiz , Padmala Srikanth
Published: March 2005

A fundamental goal of cognitive neuroscience is to explain how mental decisions originate from basic neural mechanisms. The goal of the present study was to investigate the neural correlates of perceptual decisions in the context of emotional perception. To probe this question, we investigated how fluctuations in functional MRI (fMRI) signals were correlated with behavioral choice during a near-threshold fear detection task. fMRI signals predicted behavioral choice independently of stimulus properties and task accuracy in a network of brain regions linked to emotional processing: posterior cingulate cortex, medial prefrontal cortex, right inferior frontal gyrus, and left insula. We quantified the link between fMRI signals and behavioral choice in a whole-brain analysis by determining choice probabilities by means of signal-detection theory methods. Our results demonstrate that voxel-wise fMRI signals can reliably predict behavioral choice in a quantitative fashion (choice probabilities ranged from 0.63 to 0.78) at levels comparable to neuronal data. We suggest that the conscious decision that a fearful face has been seen is represented across a network of interconnected brain regions that prepare the organism to appropriately handle emotionally challenging stimuli and that regulate the associated emotional response.
Clues to CD2-associated Protein Involvement in Cytokinesis
Authors: Monzo Pascale , Gauthier Nils C. , Keslair Frédérique , Loubat Agnès , Field Christine M. , Le Marchand-Brustel Yannick , Cormont Mireille
Published: March 2005

Cytokinesis requires membrane trafficking coupled to actin remodeling and involves a number of trafficking molecules. CD2-associated protein (CD2AP) has been implicated in dynamic actin remodeling and membrane trafficking that occurs during endocytosis leading to the degradative pathway. In this study, we present several arguments for its implication in cytokinesis. First, endogenous CD2AP was found concentrated in the narrow region of the midzone microtubules during anaphase and in the midbody during late telophase. Moreover, we found that CD2AP is a membrane- and not a microtubule-associated protein. Second, the overexpression of the first two Src homology 3 domains of CD2AP, which are responsible for this localization, led to a significant increase in the rate of cell multinucleation. Third, the CD2AP small interfering RNA interfered with the cell separation, indicating that CD2AP is required for HeLa cells cytokinesis. Fourth, using the yeast two-hybrid system, we found that CD2AP interacted with anillin, a specific cleavage furrow component, and the two proteins colocalized at the midbody. Both CD2AP and anillin were found phosphorylated early in mitosis and also CD2AP phosphorylation was coupled to its delocalization from membrane to cytosol. All these observations led us to propose CD2AP as a new player in cytokinesis.
Mto2p, a Novel Fission Yeast Protein Required for Cytoplasmic Microtubule Organization and Anchoring of the Cytokinetic Actin Ring
Authors: Venkatram Srinivas , Jennings Jennifer L. , Link Andrew , Gould Kathleen L.
Published: March 2005

Microtubules regulate diverse cellular processes, including chromosome segregation, nuclear positioning, and cytokinesis. In many organisms, microtubule nucleation requires γ-tubulin and associated proteins present at specific microtubule organizing centers (MTOCs). In fission yeast, interphase cytoplasmic microtubules originate from poorly characterized interphase MTOCs and spindle pole body (SPB), and during late anaphase from the equatorial MTOC (EMTOC). It has been previously shown that Mto1p (Mbo1p/Mod20p) function is important for the organization/nucleation of all cytoplasmic microtubules. Here, we show that Mto2p, a novel protein, interacts with Mto1p and is important for establishing a normal interphase cytoplasmic microtubule array. In addition, mto2Δ cells fail to establish a stable EMTOC and localize γ-tubulin complex members to this medial structure. As predicted from these functions, Mto2p localizes to microtubules, the SPB, and the EMTOC in an Mto1p-dependent manner. mto2Δ cells fail to anchor the cytokinetic actin ring in the medial region of the cell and under conditions that mildly perturb actin structures, these rings unravel in mto2Δ cells. Our results suggest that the Mto2p and the EMTOC are critical for anchoring the cytokinetic actin ring to the medial region of the cell and for proper coordination of mitosis with cytokinesis.
Galectin-3 Is a Downstream Regulator of Matrix Metalloproteinase-9 Function during Endochondral Bone Formation
Authors: Ortega Nathalie , Behonick Danielle J. , Colnot Céline , Cooper Douglas N.W. , Werb Zena
Published: March 2005

Endochondral bone formation is characterized by the progressive replacement of a cartilage anlagen by bone at the growth plate with a tight balance between the rates of chondrocyte proliferation, differentiation, and cell death. Deficiency of matrix metalloproteinase-9 (MMP-9) leads to an accumulation of late hypertrophic chondrocytes. We found that galectin-3, an in vitro substrate of MMP-9, accumulates in the late hypertrophic chondrocytes and their surrounding extracellular matrix in the expanded hypertrophic cartilage zone. Treatment of wild-type embryonic metatarsals in culture with full-length galectin-3, but not galectin-3 cleaved by MMP-9, mimicked the embryonic phenotype of Mmp-9 null mice, with an increased hypertrophic zone and decreased osteoclast recruitment. These results indicate that extracellular galectin-3 could be an endogenous substrate of MMP-9 that acts downstream to regulate hypertrophic chondrocyte death and osteoclast recruitment during endochondral bone formation. Thus, the disruption of growth plate homeostasis in Mmp-9 null mice links galectin-3 and MMP-9 in the regulation of the clearance of late chondrocytes through regulation of their terminal differentiation.
Sex structure and potential female fecundity in a Epinephelus guttatus spawning aggregation: applying ultrasonic imaging
Authors: Whiteman E. A. , Jennings C. A. , Nemeth R. S.
Published: March 2005

Ultrasonic imaging was used to determine the spawning population structure and develop a fecundity estimation model for a red hind Epinephelus guttatus spawning aggregation within the Red Hind Bank Marine Conservation District, St Thomas, U.S.V.I. The spawning population showed considerable within‐month and between‐month variation in population size‐ and sex‐structure. In the spawning season studied, males appeared to arrive at the aggregation site first in December although females represented a large proportion of the catch early in the aggregation periods in January and February. Spawning occurred in January and February, and size frequency distributions suggested that an influx of small females occurred during the second spawning month. An overall sex ratio of 2·9 : 1 (female : male) was recorded for the whole reproductive season. The sex ratio, however, differed between months and days within months. More females per male were recorded in January than in February when the sex ratio was male biased. Fecundity estimates for this species predicted very high potential fecundities (2·4 × 105−2·4 × 106 oocytes). The ultrasound model also illustrated a rapid increase in potential female fecundity with total length. Ultrasonic imaging may prove a valuable tool in population assessment for many species and locations in which invasive fishing methods are clearly undesirable.
Temporal changes in the relationship between condition indices and proximate composition of juvenile Coregonus artedi
Authors: Pangle K. L. , Sutton T. M.
Published: March 2005

The Fulton‐condition factor (K) and per cent whole‐body water content were examined to determine whether these indices can estimate the proximate composition of juvenile lake herring Coregonus artedi exposed to a simulated Lake Superior winter over a 225 day laboratory experiment. The K was positively correlated to whole‐body crude lipid, crude protein, and gross energy content and negatively correlated to whole‐body water content for each sampling period of the experiment (days 75, 150 and 225). In contrast, there was only a weak positive correlation between K and whole‐body ash content. While per cent water content was negatively correlated with crude lipid, crude protein and gross energy content for each of the three sampling periods, the correlation between this predictor and ash content was only weakly negative. The indices can be used to accurately estimate temporal changes in proximate composition of juvenile lake herring during winter periods.
Aggregation of a Distributed Source in Morphogen Gradient Formation
Authors: Lander A. D. , Nie Q. , Vargas B. , Wan F. Y. M.
Published: March 2005

In the development of a biological entity, ligands (such as Decapentaplegic (Dpp) along the anterior–posterior axis of the Drosophila wing imaginal disc) are synthesized at a localized source and transported away from the source for binding with cell surface receptors to form concentration gradients of ligand–receptor complexes for cell signaling. Generally speaking, activities such as diffusion and reversible binding with degradable receptors also take place in the region of ligand production. The effects of such morphogen activities in the region of localized distributed ligand source on the ligand–receptor concentration gradient in the entire biological entity have been modeled and analyzed as System F in [1]. In this paper, we deduce from System F, a related end source model (System A) in which the effects of the distributed ligand source is replaced by an idealized point stimulus at the border between the (posterior) chamber and the ligand production region that simulates the average effects of the ligand activities in the production zone. This aggregated end source model is shown to adequately reproduce the significant implications of System F and to contain the corresponding ad hoc point source model, System R of [2], as a special case. Because of its simpler mathematical structure and the absence of any limitation on the ligand synthesis rate for the existence of steady‐state gradients, System A type models are expected to be used widely. An example of such application is the recent study of the inhibiting effects of the formation of nonsignaling ligand–nonreceptor complexes [3].
Leopard food habits in the Lopé National Park, Gabon, Central Africa
Authors: Henschel P. , Abernethy K. A. , White L. J. T.
Published: March 2005

To determine leopard Panthera pardus (Linnaeus) food habits in the Lopé National Park in Gabon, Central Africa, 196 leopard scats were collected and analysed. Prey items were determined using undigested matter isolated from the scats, and a reference collection of hairs and bones from potential prey species. A minimum of 30 different prey species were identified, 27 of which were mammalian. Leopards preyed mainly on ungulates, which made up 59% of the biomass consumed. Diurnal primates (18%) and large rodents (17%) were also heavily preyed upon. The mean prey weight estimated from scats was 29.2 kg. The most important single prey species was found to be red river hog Potamochoerus porcus (Linnaeus), making up 20% of the biomass consumed, followed by forest buffalo Syncerus caffer nanus (Boddaert) and cane rat Thryonomys swinderianus (Temminck), each comprising 13% of biomass consumed.
Spatial patterns in species–area relationships and species distribution in a West African forest–savanna mosaic
Authors: Hovestadt Thomas , Poethke H. Joachim , Linsenmair K. Eduard
Published: March 2005

Aim To investigate the relationship between the slopezof the species–area relationship (SAR) and the intensity of spatial patterns in species number and dissimilarity for woody plants with different modes of seed dispersal. According to island theory we expect, for any given archipelago, steeper slopes and more pronounced spatial patterns for groups of less dispersive species.

Location Ivory Coast, West Africa.

Methods In a West African forest–savanna mosaic we collected presence–absence data for woody plant species in 49 forest islands. The parameters of the SARs were fitted by nonlinear regressions and then compared for plant species aggregated according to their mode of seed dispersal. We used the Mantel test to calculate the intensity of spatial patterns in species number, i.e. residual deviation from SAR, and species dissimilarity.

Results Thez‐value for bird‐dispersed species was lower (0.11) than that for wind‐dispersed species (0.27), with mammal‐dispersed species taking an intermediate value (0.16). This result suggests that, as a group, bird‐dispersed species are better colonizers. The spatial pattern in species number as well as species similarity was more pronounced for bird‐ compared with wind‐dispersed species.

Main conclusions The standard interpretation of the theory of island biogeography claims that shallow slopes in the SAR imply low isolation of islands, i.e. good dispersal abilities of species. The results of our study appear to contradict this statement. The contradiction can eventually be resolved by a more detailed account of the colonization process, i.e. by distinguishing between dispersal and consecutive establishment of populations.
The inselberg flora of Atlantic Central Africa. I. Determinants of species assemblages
Authors: Parmentier Ingrid , Stévart Tariq , Hardy Olivier J.
Published: March 2005

Aims  To identify the relative contributions of environmental determinism, dispersal limitation and historical factors in the spatial structure of the floristic data of inselbergs at the local and regional scales, and to test if the extent of species spatial aggregation is related to dispersal abilities.

Location  Rain forest inselbergs of Equatorial Guinea, northern Gabon and southern Cameroon (western central Africa).

Methods  We use phytosociological relevés and herbarium collections obtained from 27 inselbergs using a stratified sampling scheme considering six plant formations. Data analysis focused on Rubiaceae, Orchidaceae, Melastomataceae, Poaceae, Commelinaceae, Acanthaceae, Begoniaceae and Pteridophytes. Data were investigated using ordination methods (detrended correspondence analysis, DCA; canonical correspondence analysis, CCA), Sørensen's coefficient of similarity and spatial autocorrelation statistics. Comparisons were made at the local and regional scales using ordinations of life‐form spectra and ordinations of species data.

Results  At the local scale, the forest‐inselberg ecotone is the main gradient structuring the floristic data. At the regional scale, this is still the main gradient in the ordination of life‐form spectra, but other factors become predominant in analyses of species assemblages. CCA identified three environmental variables explaining a significant part of the variation in floristic data. Spatial autocorrelation analyses showed that both the flora and the environmental factors are spatially autocorrelated: the similarity of species compositions within plant formations decreasing approximately linearly with the logarithm of the spatial distance. The extent of species distribution was correlated with their a priori dispersal abilities as assessed by their diaspore types.

Main conclusions  At a local scale, species composition is best explained by a continuous cline of edaphic conditions along the forest‐inselberg ecotone, generating a wide array of ecological niches. At a regional scale, these ecological niches are occupied by different species depending on the available local species pool. These subregional species pools probably result from varying environmental conditions, dispersal limitation and the history of past vegetation changes due to climatic fluctuations.
Vaccine coverage with hepatitis B and other vaccines in the Colombian Amazon: do health worker knowledge and perception influence coverage?
Authors: de la Hoz Fernando , Perez Ligia , Wheeler Jeremy G. , de Neira Marlen , Hall Andrew J.
Published: March 2005

Objectives  We conducted a vaccination coverage survey in the Colombian Amazon, an area highly endemic for hepatitis B (HB), where HB vaccine was introduced in 1992. The aim was to measure vaccine coverage and factors influencing it, especially those related to health services.

Methods  A total of 3573 children younger than 11 years were randomly selected from four populations. Vaccination status was ascertained through the vaccination card and a questionnaire on socio‐demographic factors was applied to children's caretakers. Health workers (HW) in charge of vaccination in rural and urban areas were interviewed regarding knowledge and practices in vaccination. Individual and HW characteristics were related to individual vaccination using logistic regression.

Results  Overall cumulated vaccination coverage was high for polio (96%, 95% CI: 94–98), measles (94%, 95% CI: 92.8–95.2), BCG (91%, 95% CI: 90–93), DPT (90%, 95% CI: 88–92) and HB (88%, 95% CI: 86–90). However, <50% of children completed the primary course of vaccination in the first year of life. Individual factors improving the likelihood of being either fully or HB vaccinated were: age > 1 year, living in Leticia, being affiliated to the social security, and living in a house with a roof made of tiles rather than palm tree leaf. Among the variables related to HWs, poor knowledge of vaccine contraindications predicted a lower chance of being fully or HB vaccinated in the population served by them, even after controlling for individual variables.

Conclusions  The HB control program in Colombia has achieved good coverage in one of the most endemic areas of the country. However, barriers to vaccination arise from inequities in the distribution of health insurance and inadequate HW knowledge.
Calibration of 6q subtelomere deletions to define genotype/phenotype correlations
Authors: Eash D , Waggoner D , Chung J , Stevenson D , Martin CL
Published: March 2005

Testing for subtelomere abnormalities in patients with idiopathic mental retardation has become a useful diagnostic tool. However, limited data exist regarding genotype/phenotype correlations for specific subtelomere imbalances. We have ascertained five patients with 6q subtelomere deletions either as a result of an isolated deletion or as a result of an unbalanced translocation, and developed a molecular ruler assay utilizing BAC or PAC clones and determined the size of the deleted regions to range from <0.5 to 8 Mb. To establish genotype/phenotype correlations for distal 6q, we compared the clinical features of these patients to previously reported cases of 6q subtelomere and cytogenetically visible deletions and found that they shared multiple abnormalities, suggesting that the causative genes may lie in the region of the smallest 6q subtelomeric deletion, approximately 400 kb from the telomere. However, multiple unique features were present only in patients with cytogenetically visible 6q deletions, indicative that genes involved in the development of these features may lie more proximally on 6q. These initial studies demonstrate the ability to develop genotype/phenotype correlations for subtelomere rearrangements, which will aid in the diagnosis and prognosis of these patients and may help narrow the search for relevant developmental genes.
Evidence for, and a spectrum of, neurological involvement in carriers of the fragile X pre‐mutation: FXTAS and beyond
Authors: Loesch DZ , Churchyard A , Brotchie P , Marot M , Tassone F
Published: March 2005

A neurodegenerative disorder, fragile X‐associated tremor/ataxia syndrome (FXTAS), occurs in some older men carrying a small CGG repeat expansion (pre‐mutation) in the FMR1 gene. We surveyed a sample of older pre‐mutation males to estimate the prevalence and spectrum of neurological involvement. Twelve pre‐mutation males aged 50–82 years and 11 age‐matched normal controls ascertained in an unbiased manner were included in a neurological assessment that also used standard scales for tremor (Clinical Rating Scale for Tremor), ataxia (International Cooperative Ataxia Rating Scale, ICARS) and parkinsonian signs (Unified Parkinson's Disease Rating Scale). Axial FLAIR images of the brain, and neuropsychological and molecular tests were also conducted in pre‐mutation carriers. The neurological disorder meeting all the criteria for diagnosis of ‘definite’ to ‘possible’ FXTAS occurred in five of 12 pre‐mutation carriers (41.7%), and this prevalence was significantly higher compared with normal controls (0%). The ataxia (ICARS) score and the sum of all three tremor/ataxia scores were significantly higher in pre‐mutation carriers than in controls, and mRNA was elevated in all but one carrier, but did not correlate with the degree of neurological involvement. In conclusion, the findings provide further evidence that the pre‐mutation allele of FMR1 is a significant cause of late‐onset neurodegeneration, presenting with a broad spectrum of clinical manifestations.
Reproductive decision making before and after predictive testing for Huntington's disease: an Australian perspective
Authors: Richards FH , Rea G
Published: March 2005

A retrospective study examined both pre‐ and post‐result reproductive decision making for 281 people at risk for Huntington's disease aged 18–45 years who had undergone predictive testing in one centre in Australia between 1990 and 2002. Forty‐eight per cent of subjects had one or more pre‐result pregnancies, and of these, three had prenatal linkage testing. One high‐risk (50%) pregnancy was terminated. Four couples chose an alternative reproductive option. Following testing, data were available for 231 subjects, and no significant difference was found between mutation carriers and non‐carriers in the occurrence of post‐result pregnancies. This contrasts with the finding of a recent European study, although the outcome of the present study may have been influenced by loss of follow‐up data for 50 subjects. Five carriers (17%) had a total of six prenatal tests. Four showed a carrier result and these pregnancies were terminated. Two carriers utilized an alternative reproductive option (donor insemination and pre‐implantation genetic diagnosis). The results of this study confirm previous findings of a low uptake of prenatal testing and alternative reproductive options by people at risk for Huntington's disease undergoing predictive testing.
Zygomycosis involving lungs, heart and brain, superimposed on pulmonary edema
Authors: Tomita Tatsuo , Ho Hoy , Allen Mariano , Diaz Jesus
Published: March 2005

Zygomycosis is an uncommon but frequently fatal infection and occurs mostly in immunosuppressed hosts, whereas approximately 50% of zygomycosis occurs in diabetic patients. The current patient initially presented with persistent pulmonary edema secondary to renal failure. This was the last of four admissions within 1 year for this 68‐year‐old woman, for whom the chief complaints were shortness of breath and chest pain. Her past medical history included insulin‐requiring type 2 diabetes and hypertension for 10 years, and chronic heart and renal failure. She was previously admitted to the hospital for what appeared to be pulmonary edema secondary to renal failure. In the last admission the patient developed pulmonary hemorrhage and metabolic acidosis. Transbronchial biopsy was performed, showing irregular fungal hyphae in the blood vessels, morphologically consistent with zygomycosis. Central nervous system computed tomography also revealed a large infarct in the cerebral hemisphere. The patient died on the seventh hospital day. At autopsy three organs were extensively involved by zygomycosis: (i) lungs were diffusely hemorrhagic with acute infarcts; (ii) pericardium had fibrotic inflammation; and (iii) the left cerebral hemisphere, cerebellum and pons had large hemorrhagic infarct by zygomycosis infection. Corticosteroid medication and hemodialysis triggered increasing hyperglycemia, metabolic acidosis and iron overload, which contributed to zygomycosis infection that subsequently spread to the heart and brain as a rare consequence.
Prevalence of asthma, eczema and allergic rhinitis: Two surveys, 6 years apart, in Kota Bharu, Malaysia
Authors: QUAH B. S. , WAN‐PAUZI I. , ARIFFIN N. , MAZIDAH A. R.
Published: March 2005

Objective:  This study was undertaken to determine the prevalence of asthma, eczema, and allergic rhinitis in school children in Kota Bharu, Malaysia, and in so doing to determine the differences in symptom prevalence rates of asthma, and atopic diseases in Kota Bharu school children between 1995 and 2001.

Methodology:  In two studies (1995 and 2001), year one primary school (PS) pupils (6–7 years old) and secondary school (SS) year two pupils (13–14 years old) were randomly selected from the district of Kota Bharu, Kelantan, Malaysia. In 1995, 3939 PS children and 3116 SS children participated, and in 2001 3157 PS children and 3004 SS children participated. The Phase I International Study of Asthma and Allergies in Childhood prevalence written questionnaire and video questionnaire (only shown to SS children) were used in both studies.

Results:  The written questionnaire showed no significant changes in the prevalence (1995, 2001) of ever wheeze (8.3%, 6.9%P = 0.06), current wheeze (5.4%, 4.3%P = 0.08), exercise‐induced wheeze (EIW; 3.9%, 3.7%P = 0.63), and rhinoconjunctivitis (4.6%, 5%P = 0.42) among PS children. The prevalence of flexural itchy rash increased from 14% to 17.6% (P = 0.004) and night cough decreased from 20.4% to 17.5% (P = 0.005). There were also no significant changes in these symptoms among SS children (1995, 2001): ever wheeze (10.7%, 12%P = 0.37), current wheeze (6.8%, 5.7%P = 0.20), EIW (9.9%, 11.6%P = 0.28), night cough (21.6%, 24%P = 0.39), rhinoconjunctivitis (11%, 15%P = 0.11), and flexural itchy rash (12%, 13%P = 0.11). The video questionnaire showed no significant changes in the prevalence of symptoms in the previous 12 months (1995 vs 2001) for wheeze at rest (3.8%, 2.8%P = 0.12), EIW (6.9%, 8.8%P = 0.32), waking with wheeze (1.7%, 1.7%P = 1.0), and severe wheeze (2.1%, 3%P = 0.12). Night cough in the previous 12 months increased significantly from 5.1% to 8.3% (P = 0.007).

Conclusion:  Although asthma and atopic disorders are common in this country, the results revealed no major changes in the prevalence rates of these diseases over a period of 6 years.
Nasal wash as an alternative to bronchoalveolar lavage in detecting early pulmonary inflammation in children with cystic fibrosis
Authors: PITREZ P. M. C. , BRENNAN S. , TURNER S. , SLY P. D.
Published: March 2005

Objective:  The aim of this study was to determine whether nasal inflammation reflects pulmonary inflammation in young children with cystic fibrosis (CF), as assessed by inflammatory markers in nasal wash (NW) and bronchoalveolar lavage (BAL), respectively.

Methods:  CF patients younger than 6 years of age who were to undergo bronchoscopy for routine BAL from May 2000 to October 2001 were recruited for this study. NW was collected immediately after the patient was sedated for bronchoscopy. Total cell counts (TCC), differential cell counts and interleukin (IL)‐8 levels (enzyme‐linked immunosorbent assay) were assessed in NW and BAL.

Results:  In total, 19 children with CF (mean age, 1.9 years; SD, 1.7 years) were included in the study. There was a significant relationship between IL‐8 and the percentages of neutrophils in NW (r 2 = 0.76; P < 0.001) and in BAL fluid (r 2 = 0.62; P = 0.006). Similarly, IL‐8 concentrations in the NW correlated with those in the BAL (r 2 = 0.48; P = 0.036) and neutrophil percentages in NW correlated significantly with those in BAL (r 2 = 0.7; P = 0.004).

Conclusion:  When measured under ‘ideal’ conditions, nasal IL‐8 reflects lower airway levels and may reflect the inflammatory stimulus that results in neutrophilic inflammation. These data encourage further assessment of nasal wash under clinically appropriate conditions to determine its utility for assessing inflammation in young children with CF.
Clinical presentation of metabolic alkalosis in an adult patient with cystic fibrosis
Authors: SWEETSER Lisel J. , DOUGLAS James A. , RIHA Renata L. , BELL Scott C.
Published: March 2005

Abstract:  In subtropical and tropical climates, dehydration is common in cystic fibrosis patients with respiratory exacerbations. This may lead to a clinical presentation of metabolic alkalosis with associated hyponatraemia and hypochloraemia. An adult cystic fibrosis patient who presented with a severe respiratory exacerbation accompanied by metabolic alkalosis is presented and the effects of volume correction are reported.
Fluticasone given once versus twice a day: Meta‐analysis
Authors: MASOLI Matthew , WEATHERALL Mark , BEASLEY Richard
Published: March 2005

Objective:  The aim of this study was to examine the efficacy of fluticasone administered once daily compared to twice daily in asthma.

Methodology:  A meta‐analysis was performed of randomized double‐blind trials of at least 4 weeks duration that compared fluticasone administered once versus twice a day and presented data on at least one clinical outcome measure.

Results:  Six studies of 1517 children and adults with asthma met the inclusion criteria. Studies were predominantly in subjects with moderate asthma, treated with doses of fluticasone ranging from 200 to 500 µg per day. Twice‐daily dosing was associated with significantly greater efficacy compared with once‐daily dosing, for all outcome measures except night wakenings. The mean (95% CI) differences between twice and once‐daily administration for FEV1 and peak expiratory flow were 0.11 L (0.07–0.16) and 12.9 L/min (8.6–17.1), respectively. Twice‐daily fluticasone was associated with significantly fewer withdrawals due to asthma than once‐daily fluticasone, with an odds ratio of 0.44 (0.30–0.67).

Conclusion:  The findings suggest that twice‐daily administration of fluticasone will provide greater therapeutic benefit than a once‐daily morning regimen.
Metabolic activity in skeletal muscles of patients with non‐hypoxaemic chronic obstructive pulmonary disease studied by 31P‐magnetic resonance spectroscopy
Authors: HAMAOKA Tomoko , TATSUMI Koichiro , SAITO Yoshiichito , ARAI Yasuhiro , HORIE Yoshimasa , MASUYAMA Shigeru , TANABE Nobuhiro , TAKIGUCHI Yuichi , IKEHIRA Hiroo , OBATA Takayuki , SASAKI Yasuhito , TANADA Syuzi , KURIYAMA Takayuki
Published: March 2005

Objective:  An alteration of high energy phosphate metabolism in muscles may contribute to exercise intolerance. The objective of this study was to clarify the changes in high energy phosphate metabolites in muscles during exercise in patients with non‐hypoxaemic chronic obstructive pulmonary disease (COPD), which influences the impairment of muscle metabolism.

Methodology:  Calf muscle energy metabolism was studied in eight stable non‐hypoxaemic COPD patients and eight control subjects, using 31P‐magnetic resonance spectroscopy (MRS). MRS spectra were acquired at rest, during exercise at two levels of intensity, and during recovery. The control subjects exercised under both normoxic and hypoxic conditions. The intensity of exercise was standardized by the maximal isometric voluntary contraction (MVC) of the calf muscle and the cross‐sectional area (CSA) of calf muscle.

Results:  MVC and CSA were lower in COPD patients. No significant differences in intracellular pH, inorganic phosphate/phosphocreatine ratio or percentage recovery in inorganic phosphate/phosphocreatine ratio were observed between the two groups in muscles at rest, during exercise or during recovery.

Conclusions:  Muscle metabolites, during exercise standardized by muscle CSA and MVC, did not differ between non‐hypoxaemic COPD patients and control subjects. MVC, CSA or both, are assumed to be closely related to muscle metabolism, as no difference in high energy phosphate metabolites was observed for COPD patients compared to control subjects when the load was standardized for MVC and CSA. This suggests that high energy metabolites are consumed to a similar extent in the same muscle volume in non‐hypoxaemic COPD patients and control subjects.
Cutting and Pasting Irregularly Shaped Patches for Texture Synthesis
Authors: Dong Feng , Lin Hai , Clapworthy Gordon
Published: March 2005

This paper proposes a patch‐based texture synthesis approach that cuts and stitches irregularly shaped texture patches to generate new texture images with minimized visual discontinuity. It works well on a wide range of textures. A semiautomatic algorithm is developed to obtain the irregularly shaped patches. To synthesize strictly structured textures, a regular pasting method is proposed to identify the texture structures and subsequently position the irregularly shaped patches according to the identified structures. The results and comparisons with related work are given.
A Bidirectional Deposition Model of Wax Crayons
Authors: Rudolf Dave , Mould David , Neufeld Eric
Published: March 2005

We present a physically inspired model of wax crayons, which synthesizes drawings from collections of user‐specified strokes. Paper is represented by a height‐field texture, and a crayon is modeled with a 2D mask that evolves as it interacts with the paper. The amount of wax deposition is computed based on the crayon contact profile, contact force and friction. Previously deposited wax is smeared by crayon action, based on wax softness and contact information. Deposited wax can also be carved from the paper by the crayon and redeposited at another location. The distributed wax is rendered using a simplified Kubelka–Monk model, which approximates light transmission and scattering effects.