bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integration, validation and point spacing optimisation of digital elevation models
Authors: Buckley Simon J. , Mitchell Harvey L. 
Published: December 2004

AbstractIn recent years, collection and processing techniques for creating digital elevation models (DEMs; defined here as being surfaces composed of regular or irregular point data, without distinction) have advanced rapidly, allowing terrain to be represented with greater detail and accuracy. Accordingly, the amount of terrain data in existence proliferates as the resolution of sensors improves and acquisition costs lower. It is therefore becoming common for several models to cover any given area as higher accuracy or revised surveys are performed. Such coinciding data‐sets allow improvement to the terrain depiction by integration techniques which merge and validate the individual DEMs. However, amalgamation of all available points is impractical, as errors and differences between the DEMs degrade the accuracy of the merged model, and the data volume may result in heavy oversampling. Consequently, this paper develops a DEM integration method by detailing the error budgets of individual and fused terrain models, then describing the merging procedure. Initially, comparison of the input surfaces is performed to isolate differences. Next, objects on the terrain surface are optionally removed before a surface matching algorithm is employed to detect and overcome systematic effects. Finally, the models are intelligently merged and the point distribution optimised to achieve an efficient surface representation. The methodology was used to integrate a dense airborne laser scanning DEM with sparser photogrammetric data encompassing a larger area. Surface matching proved to be vital, recovering a previously unidentifiable bias between the input DEMs, improving the accuracy of the fused surface.
Optimising the accuracy of a low‐cost photogrammetric motion study system
Authors: Chong Albert K. 
Published: December 2004

AbstractGenerally, a low‐cost image‐based motion study system consists of a set of two or more video imaging cameras and a set of object space control targets. The control targets are required to provide for the computation of exterior parameters of the video frames of objects in motion. Subsequently, the computed exterior orientation parameters are used to compute the position of the motion targets. In general, the accuracy of the motion data is dependent largely on the accuracy of the 3D coordinates of the control targets, the computed camera and lens parameters and the frame rate of the camera. Obviously, it is difficult to improve the frame rate of a low‐cost camera; however, the other factors may be optimised analytically. Optimising the accuracy of the control targets is a straightforward process and is discussed briefly in the paper. Optimising the computed camera and lens parameters was the main focus of the research. Consequently, the paper provides the detail of the developed optimising technique. The results show that an optimal principal distance and other lens parameters can be determined by analysing the error of a set of highly accurate object distances. The evaluation shows that the accuracy of the video motion study system can be improved by as much as six times or a reduction of scaling error from 1·06 to 1·01.
Right‐Angle Rooftop Polygon Extraction in Regularised Urban Areas: Cutting the Corners
Authors: Croitoru A. , Doytsher Y. 
Published: December 2004

AbstractRapid urban development is achieved in some areas by the application of industrialized construction techniques. This approach creates extensive ‘‘regularised’’ urban areas, which are governed by a small set of building models. This paper describes a scheme for building rooftop extraction from aerial and high resolution satellite imagery that makes use of the characteristics of regularised urban areas. As the scheme is based on a bottom‐up approach, emphasis is put on reducing the number of low‐level features that should be considered during the polygon rooftop extraction. This is achieved with a set of geometric rules, which are defined based on the geometry of the building model. Experiments with real‐world imagery show that this basis provides efficient filtering of the right‐angle corners, thus improving the overall extraction performance.
Three‐Dimensional city model visualisation for real‐time guided museum tours
Authors: Lerma José L. , Vidal Jesús , Portalés Cristina 
Published: December 2004

AbstractNowadays, there is a trend to show different kinds of cartographic data (and related information) not only in 2D but also in 3D. Additionally, all the data must be easily accessible through the Internet, interactively, and preferably in real time. All these requirements make the management and visualisation of huge volumes of geographical information complicated, mainly in urban areas. This paper deals with these issues and prepares the reader to overcome them. Furthermore, a methodology is proposed for visualising large 3D city models when photogrammetric data and existing geographical information systems are available. Finally, a real‐time interactive animation is introduced, which provides guided museum tours with the aid of the 3D city model of Valencia.
Potentiation by Angiotensin II of Spontaneous Excitatory Postsynaptic Currents in Rat Supraoptic Magnocellular Neurones
Authors: Ozaki Y. , Soya A. , Nakamura J. , Matsumoto T. , Ueta Y. 
Published: December 2004

AbstractThe physiological actions of angiotensin II in the supraoptic (SON) and paraventricular nuclei have been widely demonstrated, including the modulation of firing rate and release of arginine vasopressin and oxytocin. Here, we investigated whether angiotensin II modulates synaptic inputs into the SON. To do this, we measured spontaneous excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs) from rat SON neurones in thin slice preparations using the whole‐cell patch‐clamp technique. Angiotensin II reversibly increased the frequency of spontaneous EPSCs in a dose‐related manner without affecting the amplitude, indicating that angiotensin II potentiated EPSCs via a presynaptic mechanism. Angiotensin II‐induced potentiation of EPSCs was unaffected in the presence of tetrodotoxin. On the other hand, angiotensin II did not cause significant effects on IPSCs. The potentiation of EPSCs by angiotensin II was potently suppressed by previous exposure to the angiotensin type 1 (AT1) receptor antagonist, losartan. Our results suggest that angiotensin II potentiates the excitatory synaptic inputs into SON neurones, via the AT1 receptors.
Circulating Ghrelin Levels and Central Ghrelin Receptor Expression are Elevated in Response to Food Deprivation in a Seasonal Mammal (Phodopus sungorus)
Authors: Tups A. , Helwig M. , Khorooshi R. M. H. , Archer Z. A. , Klingenspor M. , Mercer J. G. 
Published: December 2004

AbstractGhrelin is an endogenous ligand for the growth hormone secretagogue receptor (GHSR). However, the functional interaction of ligand and receptor is not very well understood. We demonstrate that GHSR mRNA is up‐regulated after food deprivation (48 h) in the hypothalamic arcuate nucleus and ventromedial nucleus of the seasonal Siberian hamster, Phodopus sungorus. This increase is accompanied by a two‐fold elevation of circulating ghrelin concentration. Chronic changes in feeding state imposed by food restriction over a period of 12 weeks during long day‐length induced increased GHSR gene expression, whereas food restriction for 6 weeks had no effect. Phodopus sungorus reveals remarkable seasonal changes in body weight, fat mass and circulating leptin levels. Ghrelin is generally regarded as having opposing effects on appetite and body weight with respect to those exhibited by leptin. However, our study revealed that seasonal adaptations were not accompanied by changes in either GHSR gene expression or circulating ghrelin concentration. Therefore, we suggest that ghrelin only plays a minor role in modulating long‐term seasonal body weight cycles. Our findings imply that ghrelin predominantly acts as a short‐term regulator of feeding.
Estimation of Parameters for a Mathematical Model of Growth Hormone Secretion
Authors: Brown D. , Stephens E. A. , Smith R. G. , Li G. , Leng G. 
Published: December 2004

AbstractHere, we describe partial calibration of a parsimonious mathematical model of growth hormone (GH) secretion. From first principles, we derived a model of the effects on GH secretion from pituitary somatotrophs of stimulation by GH‐releasing factor (GRF) or GH secretagogue, and of inhibition by somatostatin. We obtained a concise model by collapsing the many processes of the signal transduction cascade into a single step broadly reflecting the initial binding of GRF to its receptors. In the model, GH secretion is proportional to the rate of binding of GRF to activatable receptors. Desensitization occurs because of reduction of free receptors/available effector units, and resensitization occurs as those lost are replaced. This replacement is speeded up in the presence of somatostatin, which also inhibits GH secretion by reducing the constant of proportionality between the rate of GH secretion and the rate of GRF binding. We derived simple mathematical equations for the rate of GH secretion and cumulative secretion. Using these, we tested the model against data obtained from experiments performedin vitro, and made it quantitative using rigorous statistical approaches to optimize parameter estimates. The behaviour of the calibrated model matches experimental observations closely.
Role of chloroplast trienoic fatty acids in plant disease defense responses
Authors: Yaeno Takashi , Matsuda Osamu , Iba Koh 
Published: December 2004

SummaryTrienoic fatty acids (TAs) are the major polyunsaturated fatty acid species in the membrane lipids in plant cells. TAs are crucial for the adaptation to abiotic stresses, especially low‐ or high‐temperature stress. We show that TAs in chloroplast membrane lipids are involved in defense responses against avirulent bacterial pathogens. Avirulent pathogen invasion of plants induces a transient production of reactive oxygen intermediates (ROI), programmed cell death and subsequent disease resistance. The Arabidopsis fad7fad8 mutation, which prevents the synthesis of TAs in chloroplast lipids, caused the reduction in ROI accumulation in leaves inoculated with Pseudomonas syringae pv. tomato DC3000 (avrRpm1). Linolenic acid, the most abundant TA, activated the NADPH oxidase that is responsible for ROI generation. TAs were transferred from chloroplast lipids to extrachloroplast lipids coincident with ROI accumulation after inoculation with Pst DC3000 (avrRpm1). Furthermore, the fad7fad8 mutant exhibited reduced cell death and was compromised in its resistance to several avirulent P. syringae strains. These results suggest that TAs derived from chloroplast lipids play an important role in the regulation of plant defense responses.
A novel reporter for intrachromosomal homoeologous recombination in Arabidopsis thaliana
Authors: Li Liangliang , Santerre‐Ayotte Samuel , Boivin Eric Benoît , Jean Martine , Belzile François 
Published: December 2004

SummaryA reporter system using engineered introns as recombination substrates in the uidA (GUS) gene has been developed and characterized in Arabidopsis thaliana. The non‐coding nature of the recombination substrate has allowed us to monitor recombination events between duplicated copies of the intron that are either identical (homologous recombination) or harbour sequence polymorphisms (homoeologous recombination). The effects of substrate length and divergence on the frequency of recombination events were examined. A positive correlation between substrate length and somatic recombination frequency was found as the frequency of recombination increased 183‐fold when the recombination substrate was lengthened from 153 to 589 bp. The existence of 11 polymorphisms in a 589‐bp recombination substrate (1.9% sequence divergence) led to an almost 10‐fold reduction in the frequency of recombination. This result demonstrates that relatively modest levels of sequence divergence can substantially reduce the frequency of recombination in plants. A molecular analysis of recombination products revealed that the recombination junctions are more frequent in the central segment of the recombination substrate.
Efficacy of pre‐treatment with lufenuron for the prevention ofMicrosporum canisinfection in a feline direct topical challenge model
Authors: MORIELLO KAREN A. , DEBOER DOUGLAS J. , SCHENKER RUDOLF , BLUM JENIFER L. , VOLK LYNN M. 
Published: December 2004

Abstract Oral lufenuron is reportedly an effective treatment for some cats with dermatophytosis. The purpose of this study was to determine if lufenuron, when used as a pre‐treatment prior to challenge exposure, would be protective against the development of infection after the direct topical application of fungal macrocondia (Microsporum canisspores). Three groups (n = 6/group) of juvenile cats were treated with either monthly oral lufenuron (30 or 133 mg/kg) or placebo. After 2 months of treatment, kittens were challenged using 105Microsporum canisspores applied to the skin under occlusion. Cats were examined weekly and the following data collected: Wood's lamp examination; scoring for scale/crust, erythema and induration; lesion size; and the development of satellite lesions. Fungal cultures were performed bi‐weekly. All cats became infected; the infections progressed, and then regressed, in a similar fashion in all groups. There were no consistent statistically significant differences in weekly infection scores between treated and untreated cats throughout the study. Treated cats did not recover faster than untreated cats. We conclude that oral lufenuron at the dosing schedule and conditions used in this study did not prevent dermatophytosis or alter the course of infection by direct topical challenge.
A prospective study of the clinical findings, treatment and histopathology of 44 cases of pyotraumatic dermatitis
Authors: HOLM BIRGIT R. , REST JOAN R. , SEEWALD WOLFGANG 
Published: December 2004

Abstract  Pyotraumatic dermatitis (hot spot) is a common clinical syndrome in dogs but there are few prospective scientific studies related to it. The aim of this study was to investigate correlations among clinical pyotraumatic dermatitis, histopathology of the lesions and possible predisposing causes. The relationship of these with breed, age, sex and location of lesion was assessed statistically. A clinical diagnosis of acute pyotraumatic dermatitis was made in 44 privately owned dogs. Males exceeded females (P = 0.0348) and lesions were more common in dogs aged 4 years or less (P < 0.0001). Lesions were most often seen on the cheek, neck and lateral thigh with a significant correlation between breed and site of lesion (P < 0.0001). In 31 cases a possible underlying cause was found or suspected. In contrast to previous studies, no otitis externa was recorded and the study was conducted in an area without endemic fleas. Fourteen breeds were represented of which Rottweiler, German shepherd dog and golden retriever were most common. There was no significant seasonal incidence and no correlation among site of lesion and cause, time of year, age or sex. Histopathologically, the dogs could be separated into four patterns by the presence or absence of eosinophils and/or folliculitis. Eosinophils have not previously been recorded in pyotraumatic dermatitis but were seen in 29 cases. Acute folliculitis was seen in 20 cases. However, no correlation was seen among age, sex, breed, underlying cause or site of lesion and histopathology. Twenty‐seven cases were cultured for bacteria of which 25 grew Staphylococcus intermedius and two were negative.
Pemphigus foliaceus in the horse: a retrospective study of 20 cases
Authors: VANDENABEELE SOPHIE I. J. , WHITE STEPHEN D. , AFFOLTER VERENA K. , KASS PHILIP H. , IHRKE PETER J. 
Published: December 2004

Abstract  Twenty horses with pemphigus foliaceus were seen over a period of 15 years in a veterinary medical teaching hospital. Breeds seen were seven quarterhorses, five thoroughbreds, three cross‐bred horses, two Arabians and one of each of the following: standardbred, Tennessee walker and warmblood. There was no breed, age or sex predisposition. Nine were mares, ten were geldings and one was a stallion. Ages ranged from 2.5 months to 25 years, with a mean of 8.6 years. Sixteen (80%) of the pemphigus foliaceus horses first exhibited signs between September and February. There was a statistically significant more common occurrence of pemphigus foliaceus during those months. Signs in the four other horses were first noted in March, May or June. Three of those horses were < 13 months of age. Oedema (14/20) and crusts (13/20) were the most common lesions. Pain was present in 9/20 horses, pruritus in 7/20 and pyrexia in 7/20. Follow‐up was available for 13 horses. Five of these horses were euthanased. In three horses the reason for euthanasia was laminitis secondary to treatment. Four horses remained lesion‐free after medication was discontinued. Two horses required maintenance medication and are doing well at the time of writing.
The Vibration Signal and Juvenile Hormone Titers in Worker Honeybees, Apis mellifera
Authors: Schneider Stanley S. , Lewis Lee A. , Huang Zachary Y. 
Published: December 2004

AbstractWe examined the association between the vibration signal and juvenile hormone (JH) titers of honeybees by comparing vibrated recipients and non‐vibrated control workers that had been matched for age, colony of origin, and time of collection. Recipients collected at the moment they received vibration signals (0‐min bees) did not have higher JH titers compared with controls, which suggests that a worker's initial JH level did not influence its likelihood of receiving signals. In contrast, JH titers in workers collected 15–30 min after receiving vibration signals were slightly, but significantly higher than those of controls monitored for the same amount of time. These trends were consistent among colonies, despite the fact that we collected different age ranges of workers and observed pronounced variation in JH titers within and between the 0‐ and 15–30‐min groups of bees. Thus, over a broad age range of workers the vibration signal may contribute to elevated JH levels, and this effect does not occur because recipients have higher titers at the moment they receive signals. Because JH affects response thresholds in honeybees, increased titers elicited by the vibration signal may allow the signal to influence the performance of a variety of tasks in different worker age groups.
Behavioural and Genetic Data Suggest that Bechstein's Bats Predominantly Mate Outside the Breeding Habitat
Authors: Kerth Gerald , Morf Lea 
Published: December 2004

AbstractInvestigating mating systems of species with a cryptic lifestyle often requires a combination of behavioural and genetic data. We used such a combined approach to investigate the mating system of the communal breeding Bechstein's bat (Myotis bechsteinii). Although females of this species are philopatric, gene flow among colonies is high. Gene flow occurs if dispersing males mate within the colony to which they moved. Males could gain local matings by defending resources or females in their breeding habitat. Alternatively, mating may take place at swarming sites, apart from the breeding habitat of the females, where males and females of several colonies meet. Whether or not males defend resources or females in the breeding habitat is of importance for understanding the mating system. Detailed observations of individual foraging and roosting behaviour over 4 yr suggest that males do not defend resources or females to gain matings. Moreover, paternity assignment based on microsatellite data of four complete juvenile cohorts showed that local males fathered less than 25% of the juveniles born in the colony where they settled. Even more striking, none of the males that had immigrated into our study area reproduced with the local females.
Changes in selected serum parameters of broiler chicken fed supplemental chromium
Authors: Króliczewska B. , Zawadzki W. , Dobrzanski Z. , Kaczmarek‐Oliwa A. 
Published: December 2004

SummaryThe present study was conducted to evaluate the effect of chromium (Cr) from Cr yeast on the growth performance and total cholesterol, high‐density lipoprotein (HDL) and low‐density lipoprotein (LDL) cholesterol, triglycerides, glucose, total protein and Cr concentration in the serum of broiler chicken. The birds were fed a control diet or a control diet supplemented with Cr at a level of 300, 500 μg/kg Cr. The supplementation of 500 μg/kg Cr increased body weight, weight gain and feed efficiency (p < 0.05). In addition, supplementation with Cr decreased the serum total cholesterol, LDL cholesterol (p < 0.05), triglycerides (p < 0.05) and glucose (p < 0.05) concentrations whereas serum HDL cholesterol increased. Serum total protein and serum Cr concentration slightly but not significantly increased in both Cr groups. The study suggest that Cr supplementation particularly at 500 μg/kg Cr from Cr yeast can influence on carbohydrate and lipid metabolism of broiler chicken and can be used as additives in animal diet but it still needs more investigations.
Rumen odd and branched chain fatty acids in relation to in vitro rumen volatile fatty acid productions and dietary characteristics of incubated substrates
Authors: Vlaeminck B. , Fievez V. , Van Laar H. , Demeyer D. 
Published: December 2004

SummaryA first aim of this batch in vitro experiment (21 h) was to use changes in odd and branched chain fatty acid (OBCFA) patterns to suggest shifts in microbial populations, associated with four types of incubated whole dairy cow diets. Principal component analysis suggested higher dietary starch increased the proportion of C15:0 and C17:0, whereas increased neutral detergent fibre content was positively related to anteiso C15:0 concentrations, which is in agreement with the importance of these fatty acids in respectively amylolytic and cellulolytic bacteria. A second aim of the experiment was to relate rumen volatile fatty acid proportions to OBCFA by principal component regression and to compare these relations with predictions based on diet proximate composition. The R2 values achieved for the regressions between acetate, propionate and butyrate, and OBCFA were 79.6%, 86.6% and 84.9% respectively. Moreover, in the current study, predictions of the rumen fermentation pattern showed higher R2 (p < 0.01) when based on OBCFA compared with proximate feed composition. If relations persist in vivo, there could be scope for milk OBCFA to predict the supply of specific rumen nutrients.