bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adhesion of Streptococcus sanguinis to glass surfaces measured by isothermal microcalorimetry (IMC)
Authors: Hauser‐Gerspach Irmgard , de Freitas Patricia Scandiucci , Dan Daniels A.U. , Meyer Jürg 
Published: August 2007

AbstractBacterial adhesion is the first step in the development of the oral biofilm, called dental plaque. Plaque is the cause of caries, periodontal diseases, and periimplantitis. Investigations of dental plaque, including bacterial adhesion, employ various in vivo and invitro models using microscopic methods. Microcalorimetry offers another direct approach. The model organism Streptococcus sanguinis is one of the first colonizers adhering to the saliva‐coated human tooth surfaces or dental materials within minutes after tooth cleaning. TAM III™ thermostats, equipped with microcalorimeters, were used for isothermal microcalorimetric (IMC) measurements of heat production as a function of time, expressed by power–time (p–t) curves. Continuous measurements of heat production of growing S. sanguinis cells showed their overall metabolic activity and were highly reproducible. For the adhesion experiments the bacteria were allowed to adhere to different amounts of glass beads. Growing S. sanguinis cells produced a characteristic p–t curve with a maximum of 500 μW at 4.5 h when reaching 109 cells ml−1. The same number of stationary S. sanguinis cells, suspended in PBS produced only ∼30 μW at 0.5 h due to adhesion. But the amount of heat increased with available glass surface area, indicating that a portion of the heat of adhesion was measured. Similar results were obtained with stationary S. sanguinis cells suspended in human saliva. This study shows that microcalorimetric evaluation of initial bacterial adhesion is indeed possible and may become a rapid, reproducible screening method to study adhesion of different bacteria to different dental materials or to modified surfaces. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Finite element analysis of subsurface damage of ceramic prostheses in simulated intraoral dental resurfacing
Authors: Song Xiao‐Fei , Yin Ling , Han Yi‐Gang , Li Jia 
Published: August 2007

AbstractFinite element analysis (FEA) was used to investigate the stress fields and the degrees of subsurface damage of ceramic prostheses in simulated intraoral dental resurfacing operations using clinical diamond burs. A two‐dimensional finite element model was established with the dental operational parameters and the material properties as input variables. This model enabled to predict the stress fields and to evaluate the depths of subsurface damage in ceramic prostheses as functions of the dental resurfacing operational conditions. The results indicate that the tensile, shear, compressive, and equivalent von Mises stresses were all centered under the diamond bur–specimen contact zone. The maximum values of these stresses were concentrated at the diamond grit exit point, decreasing with an increase in depth of cut. The predicted depths of subsurface damage increased with an increase in both the depth of cut and the maximum chip thickness, in the range of 30–140 μm. Also, the depths of subsurface damage were experimentally measured using scanning electron microscopy (SEM). The FEA predictions were found to be in agreement with the SEM experimental observations. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Human iliac crest cancellous bone elastic modulus and hardness differ with bone formation rate per bone surface but not by existence of prevalent vertebral fracture
Authors: Wang Xiang , Sudhaker Rao D. , Ajdelsztajn Leonardo , Ciarelli Traci E. , Lavernia Enrique J. , Fyhrie David P. 
Published: August 2007

AbstractThe goals of this study were to measure tissue‐level elastic moduli and hardness of human cancellous bone using nanoindentation, and determine the relationship between nanoindentation results and previously measured bone histomorphometric variables and bone mineralization. Forty iliac crest biopsies were used in this study, which were collected from Caucasian females with vertebral fracture or from a normal healthy female Caucasian population. They were also categorized into two groups according to high or low bone formation rate per bone surface (BFR/BS). Thirty‐two sites were randomly selected on each specimen for nanoindentation with a Berkovich diamond indenter. Two sets of elastic moduli and hardness were calculated using the continuous stiffness measurement method and the Oliver–Pharr method, respectively. Relationships between nanoindentation results and donor age, bone mineralization, and histomorphometric variables were examined. No difference in elastic moduli or hardness was observed between the normal and fracture groups. Significantly lower elastic moduli were observed in the high BFR/BS group. The elastic moduli and hardness measurements were not significantly correlated with the bone mineralization measured independently in a previous study. Linear correlation between elastic modulus and hardness calculated using the Oliver–Pharr method was not different between the normal and fracture groups or between the high and low BFR/BS groups. Nanoindentation hardness was a very good predictor of bone tissue elastic modulus for both normal and osteoporotic bone tissues. Osteoporosis may not change the relationship between bone tissue elastic modulus, bone hardness, and bone mineralization. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
A bFGF/TCP‐composite inhibits bone formation in a sheep model
Authors: Maus Uwe , Andereya Stefan , Ohnsorge Jörg A. K. , Gravius Sascha , Siebert Christian H. , Niedhart Christopher 
Published: August 2007

AbstractBasic fibroblast growth factor is a well known osteostimulative protein. The effects of basic fibroblast growth factor are dose‐dependent and, when used with a carrier, influenced by the release kinetics. Aim of our study was to determine the effects of a composite of basic fibroblast growth factor and a newly developed, in situ setting tricalcium phosphate (TCP) cement. A trepanation defect in the distal femoral epiphysis of Merino‐Mix sheep with a diameter of 9.4 mm and 10 mm depth was filled with the in situ setting TCP cement combined with 0 or 200 μg of bFGF/cm3 TCP, autologous bone graft or left empty. The sheep were euthanized after 3 months. The defect and the periimplant area were examined by microradiography, histology, and histomorphometry. The data was analyzed with the help of the Wilcoxon and Kruskal–Wallis tests. Defects filled with TCP with or without bFGF showed a close bone‐cement contact. The histomorphometric analysis revealed that the addition of bFGF inhibited the ingrowth of bone significantly, while the resorption of the cement was not influenced. In conclusion, the clinical application of this bFGF/TCP‐composite does not seem promising. The reason for the inhibition of new bone formation will be discussed, but requires further investigation. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Efficacy of ciprofloxacin implants in treating experimental osteomyelitis
Authors: Alvarez H. , Castro C. , Moujir L. , Perera A. , Delgado A. , Soriano I. , Évora C. , Sánchez E. 
Published: August 2007

AbstractCiprofloxacin (CFX) implants containing poly(D,L‐lactide) and calcium phosphates (tricalcium phosphate and hydroxyapatite) was evaluated in 50 rabbits in an experimental osteomyelitis model. Their femoral cavity was inoculated with Staphylococcus aureus. After 2 weeks, the infected focus was cleaned out and the delivery system implanted. The infection and subsequent response to treatment were evaluated by microbiological analysis, biochemical and hematological markers, body weight, temperature, clinical signs, X‐rays, and histology. Infected bone cultures, treated with CFX implants, showed reduced bacterial growth against controls. All CFX was released within 6 weeks. All animals recovered within 4 weeks. Even 12 weeks after implantation, no recurrence of infection was observed. Serum C‐reactive protein, platelet, and leukocyte levels increased in all animals before treatment, and 4 weeks after it were maintained or rose in control animals, while decreased to normal levels in treated ones. Body weight was characterized by pretreatment losses, then gains during recuperation, or further loss in untreated animals; with no significant intraindividual differences in body temperature. Body weight, leucocytes, platelets, and C‐reactive protein turned out to be highly useful markers for monitoring this kind of infection and its treatment. CFX implants demonstrated to be an effective therapy for S. aureus bone infection. Their efficacy was also reflected in decreasing severity of clinical signs, nonprogress of radiological signs indicative of infection, and good integration into bone structure. Histological examination revealed repair, with new bone formation extending into implants. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Molecular phylogeny of the three paedomorphic mediterranean gobies (Perciformes: Gobiidae)
Authors: Giovannotti Massimo , Cerioni Paola Nisi , La Mesa Mario , Caputo Vincenzo 
Published: August 2007

AbstractPelagic gobies are considered of particular zoological interest because the acquisition of a pelagic lifestyle is achieved through the persistence of larval anatomical features. The Mediterranean Sea is inhabited by three goby species (Aphia minuta, Crystallogobius linearis and Pseudaphya ferreri) characterized by paedomorphic traits. Owing to the shared larval morphological features, these species have generally been considered as a monophyletic group. This study aimed at establishing the phylogenetic relationships of these paedomorphic species within the family Gobiidae to ascertain whether the pelagic lifestyle achieved through paedomorphosis is due to an event that took place in a common ancestor or not. For this purpose, we amplified by polymerase chain reaction and sequenced the mitochondrial 12S rDNA (complete sequence) and 16S rDNA (partial sequence) of 15 Mediterranean gobies. The phylogenetic analysis strongly supported the polyphyletic origin of the three paedomorphic gobies, indicating that the heterochronic change leading to the retention of larval features seems to have occurred independently in the ancestors of these species. Thus, the sharing of morphological traits can be considered homoplasious and the classification of these species in the same taxonomic group is rejected on the basis of molecular data. J. Exp. Zool. (Mol. Dev. Evol.) 308B:722–729, 2007. © 2007 Wiley‐Liss, Inc.
Vertex disjoint equivalent subgraphs of order 3
Authors: Nakamigawa Tomoki 
Published: August 2007

AbstractLet k be a fixed integer at least 3. It is proved that every graph of order (2k − 1 − 1/k)n + O(1) contains n vertex disjoint induced subgraphs of order k such
that these subgraphs are equivalent to each other and they are equivalent to one of four graphs: a clique, an independent set, a star, or the complement of a star. In particular, by substituting 3 for k, it is proved that every graph of order 14n/3 + O(1) contains n vertex disjoint induced subgraphs of order 3 such that they are equivalent to each other. © 2007 Wiley Periodicals, Inc. J Graph Theory 56: 159–166, 2007
Examination of hospital referral practices for CT pulmonary angiography
Authors: Kiley Cristin A. , Lowry Kristie J. , Mysliwiec Vincent 
Published: August 2007

AbstractGuidelines for the evaluation of venous thromboembolism (VTE) include a history and physical examination in conjunction with computed tomographic pulmonary angiography (CTPA), Doppler ultrasonography, and D‐dimer measurements. We performed a retrospective analysis to evaluate the diagnostic yield of CTPA at our facility. Patients between the ages of 18 and100 with a CTPA completed through the emergency department and/or any inpatient service over a 6‐month period were reviewed and a retrospective Simplified Wells Score was calculated. Three hundred and three patients underwent CTPA for acute VTE. A Simplified Wells Score was calculated for 279 subjects, with a mean score of 1.6 ± 1.6. Twenty CTPA procedures demonstrated VTE, a positive rate of 7.2%, which was lower than expected. This result likely reflects lack of adherence to a clinical algorithm for assessment of VTE and an overly cautious approach to symptom evaluation. Journal of Hospital Medicine 2007;2:253–257. © 2007 Society of Hospital Medicine.
The impact of climate variability on soybean yields in Argentina. Multivariate regression
Authors: Penalba Olga C. , Bettolli M. Laura , Vargas Walter M. 
Published: August 2007

AbstractClimate variability is examined and discussed in this work, emphasizing its influence over the fluctuation of soybean yield in the Pampas (central‐eastern Argentina). Monthly data of rainfall, maximum and minimum temperatures, thermal range and seasonal rainfall were analysed jointly with the soybean yield in the period 1973‐2000. Low‐frequency variability was significant only in the minimum temperature during November in almost all the stations. This situation is favourable to the crop since during this month, seed germination, a growth stage sensitive to low temperatures, takes place. In the crop's core production region, 72% of the series of soybean yield presented a positive trend. Except in years with extreme rainfall situations, interannual variability of the soybean yield is in phase with the seasonal rainfall interannual variability. During these years, losses in the soybean crop occurred, with yield negative anomalies greater than one standard deviation. Soybean yield showed spatial coherence at the local scale, except in the crop's core zone. The association between each climate variable and yield did not show a defined regional pattern. Summer high temperature and rainfall excesses during the period of maturity and harvest have the greatest negative impact on the crop, whilst higher minimum temperatures during the growing season favour high yields. The joint effect of climate variables over yield was studied with multivariate statistical models, assuming that the effect of other factors (such as soil, technology, pests) is contained in the residuals. The regression models represent the estimates of the yield satisfactorily (high percentage of explained variance) and can be used to assess expected anomalies of mean soybean yield for a particular year. However, the predictor variables of the yield depend on the region. Copyright © 2007 Royal Meteorological Society
A high‐resolution radar experiment on the island of Jersey
Authors: Rico‐Ramirez M. A. , Cluckie I. D. , Shepherd G. , Pallot A. 
Published: August 2007

AbstractA very high‐resolution X‐band vertically pointing weather radar was deployed in the island of Jersey, UK, from February to May 2004, to study the variation of the vertical reflectivity of precipitation (VPR) in this region. Intercomparison studies were carried out with a C‐band scanning weather radar operated by Jersey Met. Department. C‐band radar rainfall estimations and raingauge measurements were well correlated at very short ranges (<10 km), but there are clear difficulties in the estimation of precipitation due to ground clutter, and anomalous propagation echoes as well as the variation of VPR. Average VPRs were obtained from the X‐band radar that helped reduce the bright band enhancement in C‐band scanning weather radar measurements. This paper presents the overall results obtained during this radar experiment. The experiment was one of a series designed to understand the VPR and design removal algorithms for bright band contamination of quantitative radar measurements of precipitation. Copyright © 2007 Royal Meteorological Society
The influence of an upper‐level frontal zone on the Mack Lake Wildfire environment
Authors: Zimet Tarisa , Martin Jonathan E. , Potter Brian E. 
Published: August 2007

AbstractMeteorological assessment of wildland fire danger has traditionally involved the identification of several synoptic weather types empirically determined to influence wildfire spread. Specifically, in the Great Lakes Region, high wildfire danger is often witnessed in association with northwesterly synoptic‐scale flow aloft. Such synoptic‐scale flow is regularly associated with the development of upper‐level frontal zones also known as upper‐level jet/front systems, which are often characterised by intrusions of stratospheric air into the troposphere. The notion that upper‐frontal development can play an important role in promoting wildfire spread is advanced through interrogation of the output from a fine‐scale numerical simulation of a documented explosive wildfire case; the Mack Lake Fire of May 1980.The Mack Lake case was characterised by a developing upper‐level front embedded within a shortwave trough in the vicinity of the fire location. The upper‐level front originated in northwesterly flow in central Canada as an upper‐tropospheric ridge amplified over western North America. A thermally indirect circulation at the jet exit region both contributed to the intensification of the front and was associated with a maximum in quasi‐geostrophic descent at mid‐levels upstream of the fire region. The subsidence ushered dry air from the middle and upper‐troposphere downward along sloping isentropes adiabatically warming and drying it along the way. A well‐developed dry air intrusion associated with the operation of these processes extended to nearly the 750 hPa level far downstream from the actual upper‐frontal zone supplying the fire environment with dry air that originated in the upper‐troposphere/lower stratosphere. The organised subsidence was also responsible for downward advection of high momentum air from within the frontal zone into the fire environment, further influencing the wildfire spread. We conclude that upper‐frontal processes, characteristic of northwesterly synoptic‐scale flow, are likely a contributing factor to the prevalence of wildfire spread under such synoptic‐scale conditions. Copyright © 2007 Royal Meteorological Society
Modelling the impact of high‐rise buildings in urban areas on precipitation initiation
Authors: Carraça M. G. D. , Collier C. G. 
Published: August 2007

AbstractThe impact of urban areas upon precipitation distribution has been studied for many years. However, the relative importance of the distribution and type of surface morphology and urban heating remains unclear.A simple model of the surface sensible heat flux is used to explore the impact of urban heterogeneity. Sensitivity experiments are carried out to test the validity of the model, and experiments with a schematic urban morphology are used to investigate the impact of different types of building arrays. It is found that high‐rise buildings over relatively small areas may have just as much impact as somewhat lower buildings covering a much larger area. The urban area produces considerable spatial variation in surface sensible heat flux. Data from a C‐band radar located to the north of Greater Manchester provides evidence that convective cells may be initiated by the sensible heat flux input generated by the high‐rise buildings in the city centre when the atmospheric boundary layer is unstable. Copyright © 2007 Royal Meteorological Society
Assessment of some spatial climatic layers through GIS and statistical analysis techniques in Samsun Turkey
Authors: Guler Mustafa , Cemek Bilal , Gunal Hikmet 
Published: August 2007

AbstractAn empirical methodology in modelling and mapping air temperatures (monthly minimum, mean and maximum), monthly relative humidities and cumulative precipitation using geographical information system (GIS) techniques was proposed. Linear regression analyses were developed between weather data and some of the geographical and climatical variables (altitude, monthly mean temperature and relative humidity) of the study area. Data were obtained from 11 different meteorological stations located in the study area, and elaborated from a 250 m resolution digital elevation model (DEM). Analyses of digital layers of each independent variable with basic GIS techniques were used, and the most suitable models obtained from regression analysis were used to create final maps. The coefficients of determination for monthly mean and minimum temperatures were 0.68 and 0.98, respectively. In the case of monthly relative humidity, r2 ranged between 0.80 and 0.98, while in the case of monthly cumulative precipitation, it ranged from 0.82 to 0.98, respectively. Maximum monthly temperature, particularly for the summer months had a low relationship with elevation, therefore determination coefficient ranged from 0.46 to 0.81. When spatial information is available, the proposed method could be used as an alternative to classical interpolation techniques. Copyright © 2007 Royal Meteorological Society
Forecasting of thunderstorms in the pre‐monsoon season at Delhi
Authors: Ravi N , Mohanty U C , Madan O P , Paliwal R K 
Published: August 2007

AbstractAccurate prediction of thunderstorms during the pre‐monsoon season (April–June) in India is essential for human activities such as construction, aviation and agriculture. Two objective forecasting methods are developed using data from May and June for 1985–89. The developed methods are tested with independent data sets of the recent years, namely May and June for the years 1994 and 1995. The first method is based on a graphical technique. Fifteen different types of stability index are used in combinations of different pairs. It is found that Showalter index versus Totals total index and Jefferson's modified index versus George index can cluster cases of occurrence of thunderstorms mixed with a few cases of non‐occurrence along a zone. The zones are demarcated and further sub‐zones are created for clarity. The probability of occurrence/non‐occurrence of thunderstorms in each sub‐zone is then calculated. The second approach uses a multiple regression method to predict the occurrence/nonoccurrence of thunderstorms. A total of 274 potential predictors are subjected to stepwise screening and nine significant predictors are selected to formulate a multiple regression equation that gives the forecast in probabilistic terms. Out of the two methods tested, it is found that the multiple regression method gives consistently better results with developmental as well as independent data sets; it is a potential method for operational use. Copyright © 1999 Royal Meteorological Society
Spatial interpolation of GPS integrated water vapour measurements made in the Swiss Alps
Authors: Morland June , Mätzler Christian 
Published: August 2007

AbstractThe 31 stations in the Swiss GPS network are located at altitudes between 330 and 3584 m and have provided hourly Integrated Water Vapour (IWV) measurements since November 2000. A correction based on an exponential relationship is proposed for the decrease in IWV with altitude. The scale height depends on the ratio of IWV measured at Jungfraujoch (3584 m) to that measured at Payerne (498 m). An additional coefficient, dependent on the east‐west and north‐south spatial differences in the IWV, improves the fit to the data. The IWV at heights between 750 and 3500 m was estimated from GPS measurements at Payerne and compared with the Payerne radiosounding. The altitude correction introduced an additional bias of 0.2 to 0.4 mm between GPS and radiosonde. The IWV was normalized to 500 m and the increases and decreases due to the passage of a series of frontal systems between 11 and 14 January 2004 were mapped. A four‐year climatology of IWV normalized to 500 m showed that the Alpine stations are more moist in spring, summer and autumn than the stations in the Swiss plains to the north of the Alps. This was attributed to more moist Mediterranean air being blocked by the Alps. Copyright © 2007 Royal Meteorological Society