bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of actinomycin D on developing hamster molar tooth germs in vitro
Authors: Lyaruu D. M. , van Duin M. A. , Bervoets T. J. M. , Wöltgens J. H. M. , Bronckers A. L. J. J.
Published: October 2007

The aim of this study was to evaluate the toxic effects of actinomycin D on the developing hamster tooth germ in organ culture. Hamster tooth germs during early secretory amelogenesis were exposed in vitro for 24 h to 10−9 M‐5 × 10−5 M actinomycin D. Actinomycin D dose‐dependently ( 10−7 M) decreased the tooth germ dry weight but mineralization was affected only by doses 10−5 M. However, the uptakes of TCA‐insoluble 32P and [3H]thymidine were significantly reduced dose‐dependently from 10−8 M actinomycin D, indicating that the drug inhibits the synthesis of phosphate‐containing macfomolecules as well as DNA synthesis. Histologically, 10−8 M actinomycin D was the lowest dose which was not toxic to any cell type in the developing tooth germ. At 10−7 M actinomycin D, the most sensitive cells were the proliferating preodontoblasts followed by pre‐ameloblasts; the mature secretory ameloblasts and odontoblasts appeared unaffected. Higher doses resulted in increased cytotoxicity to the secretory cells and, eventually, total degeneration of most cells. The data suggest that children treated for cancer during tooth development using anti‐chemotherapy cocktails containing actinomycin D (serum levels >10−7 M) may develop defects later on in the mature dentition as a direct consequence of the toxicity of the drug to the tooth organ.
Trends in dental health among Icelandic urban children
Authors: Bjarnasorr Sibilla , Finnbogason Stefán Y. , Köhler Birgitta , Holbrook W. Peter
Published: October 2007

Caries experience, oral hygiene and caries‐related salivary parameters were recorded in a 20% representative sample of 12‐year‐old schoolchildren in Reykjavik, Iceland in 1991. The majority of the children was re‐examined 3 years later in 1994. Trends in prevalence of caries and salivary bacteria were assessed by comparison with an analogous earlier longitudinal study (1984–87). Mean DPS values for 12‐year‐olds were 12.1 and 4.1, for 15‐year‐olds 23.3 and 11.3 in the earlier and later study, respectively. Reduction in DPS was 66% and 52% for the respective age groups. The decline was most pronounced in the group with low caries prevalence. Trends in caries experience were paralleled by salivary bacteria. The mean caries scores and frequency distributions of 15‐year‐olds in 1994 closely resembled those of 12‐year‐olds a decade earlier, suggesting a delay rather than a true fall in caries prevalence.
Pulp calcifications in traumatized primary incisors A morphological and inductive analysis study
Authors: Robertson Agneta , Lundgren Ted , Andreasen Jens O. , Dietz Wolfram , Hoyer Ingrid , Norén Jörgen G.
Published: October 2007

The purpose of this study was to investigate histopathological changes in primary teeth following trauma, and to look for possible correlations between the morphology of pulpal calcification and clinical findings. The material consisted of 123 primary teeth from 98 Danish children aged 9–108 months (mean age 33.5 ± 19.7 months) at the time of injury. The specimens were analyzed by means of light and scanning and transmission electron microscopy. Data from the clinical investigation and from predetermined ranked parameters from the histological analysis were processed in a computerized inductive analysis program. The results, describing patterns of co‐variation, are presented as a decision tree. The most common diagnosis was intrusion luxation (54%). In 41% of all teeth, the degree of obliteration was less than 1/4 of the pulpal lumen. In most cases (79%), no denticles were visible. When present, 80% of the denticles had a bone‐like appearance. Tissues occluding the pulpal lumen were either dentin‐like (49%). bone‐like (19%), or fibrotic (9%). It could be concluded that these varying responses could not be correlated with explicit clinical diagnoses. However, in certain combinations, histological parameters could be correlated to clinical findings.
Reported burning mouth symptoms among middle‐aged and elderly women
Authors: Hakeberg Magnus , Berggren Ulf , Hägglin Catarina , Ahlqwist Margareta
Published: October 2007

The aims of this investigation were to assess the prevalence of burning mouth symptoms (BM) in representative population of Swedish middle‐aged and elderly women (n= 1017) and its relation to general and oral health status. BM was reported by 4.6% (n= 47). and 85% of the BM subjects had experienced BM for more than 6 months. A stepwise multiple logistic regression with BM/non‐BM as dependent variable showed that 7 covariates were found to be predictive of BM. These variables were medication with antihypertensives, sedatives and female sex hormones. Moreover, headache, tinnitus, dry mouth, and reduced chewing ability were included in the final model.
Salivary IgA responses to bacteria in dental plaque as related to periodontal and HIV infection status
Authors: Myint Maung Maung , Steinsvoll Svein , Odden Kåre , Dobloug Jan , Schenck Karl
Published: October 2007

Levels of total IgA and specific IgA reactive withStreptococcus mutans, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescensandFusobacterium nucleatumwere measured by ELISA in parotid saliva from HIV+and HIV−persons with healthy gingiva (HG), chronic gingivitis, chronic marginal periodontitis (CMP), or neerotizing ulcerative periodontitis (NUP). When the HIV+ group was compared with the HIV−group regardless of periodontal status, total salivary IgA concentration was higher in HTV+patients, but no such difference was observed for total IgA output. HIV+CMP displayed higher total IgA concentration as compared with HIV−CMP. No significant differences in specific IgA outputs and ratios were detected between HTV+and HIV−subgroups with similar periodontal status. HIV−NUP displayed increased specific IgA output towardsS. mutansand increased specific IgA ratio values towardsS. mutans, P. gingivalisandP. nigrescensas compared with HIV+CMP, and increased specific IgA ratio values towardsS. mutansandP. nigrescensas compared with HIV+HG. No such differences were observed between the HIV−subgroups. In sum. salivary IgA responses to bacteria in dental plaque seem not to be related to chronic periodontal disease and HIV infection, but are possibly influenced by acute periodontal infection.
Comparative permeability of human vaginal and buccal mucosa to water
Authors: van der Bijl Pieter , Thompson Ivor O. C. , Squier Christopher A.
Published: October 2007

There is currently a resurgence of interest in the oral mucosa as a route for drug delivery. The relative scarcity of human oral mucosa for in vitro permeability studies, and the fact that vaginal mucosa is histologically similar and more abundant than the former, caused us to compare these 2 tissues with respect to their barrier properties to water. Specimens of fresh, clinically‐healthy human vaginal and buccal mucosa from non‐smokers were taken from excised tissue obtained during vaginal hysterectomies and various oral surgical procedures. Biopsies from each specimen were mounted in flow‐through diffusion cells and their permeability to tritiated water determined using a continuous flow‐through perfusion system. Specimens were examined histologically before and after permeability experiments and similarities between vaginal and buccal tissues verified. No statistically significant differences between mean steady state flux values (10–16 h) for vaginal and buccal mucosa. respectively, were found. Human vaginal mucosa is therefore as permeable as buccal mucosa to water, and these results warrant further investigation with other compounds to establish whether vaginal mucosa may be a useful model for buccal mucosa for drug permeability studies.
Research revisited: Gunnar Rølla's contribution to oral health
Authors: Bowen William H.
Published: October 2007

Gunnar Rølla's contributions to oral science cover an enormous range. They include research into the basic understanding of pellicle and plaque formation, to mechanisms for the prevention of oral diseases. Rølla has collaborated with over 100 persons from many different countries and thus his influence on dental research has been global.
Fluoride‐induced precipitates on enamel surface and subsurface areas visualised by electron microscopy and confocal laser scanning microscopy
Authors: Duschner H. , Götz H. , Øgaard B.
Published: October 2007

The present study examined the enamel surface after in vitro topical treatments with a neutral 2% NaF solution. For minimising the risk of artefacts, samples were inspected without pre‐treatment as fresh, naturally wet specimens by complementary techniques: variable pressure electron microscopy (VP‐SEM) and confocal laser scanning microscopy (CLSM). VP‐SEM provided information on the surface morphology, whereas CLSM allowed nondestructive visualisation of subsurface areas. Neutral NaF solutions induced globular precipitates on the enamel surfaces. If the globules formed may be described as “calcium fluoride like material”, the additional information of this experiment is that, after interaction with neutral solutions, they also contain considerable amounts of NaF. When the NaF solutions were soaked on pellets and then were brought into contact with the enamel surfaces, NaF crystallites of cubic shape are formed. Confocal optical tomographies of subsurface enamel after treatments with neutral NaF solutions revealed partly coroded enamel structures, whereas VP‐SEM showed intact surfaces. In between the coroded. areas, a fine granulate precipitate could be observed. This is evidence that fluoride induces the formation of sub‐surface precipitates only when applied during demineralisation. The precipitate could be readily removed by 24‐h contact with a KOH solution.
Fluoride in plaque fluid and saliva after NaF or MFP rinses
Authors: Ekstrand Jan
Published: October 2007

A micro‐analytic method, capable of measuring the fluoride concentration in 5 nl of plaque fluid, was used to follow changes in fluoride concentration in saliva and plaque fluid at 6 single tooth‐sites in 6 subjects for 180 min after a 0.048 M fluoride rinse as a NaF or MFP (sodium monoftuorophosphate) solution. The maximum fluoride concentrations in saliva after NaF was 13 × higher than with MFP. About 5% of the total amount of fluoride following the 20 ml NaF rinse was retained in the oral cavity. The corresponding figure following MFP was < 1%. The saliva/plaque fluid fluoride ratios for upper molars and lower incisors were significantly higher than for the upper incisors and lower molars. There was a tendency for a decline in the ratios with respect to time for all sites. To characterize the plaque fluid fluoride intra‐oral single‐site distribution and clearance, fluoride concentration versus time (AUC) was calculated from 10 to 60 min after a rinse. The NaF AUC followed the order: upper incisor, lower molar, upper molar and lower incisors reflecting a different exposure and clearance pattern due to the different access of the plaque to saliva. The MFP AUC values varied more, but were all significantly lower than the NaF AUC values. Analysis of plaque fluid fluoride curves at various sites revealed an exponential decline in most cases. With NaF, the baseline plaque fluid fluoride levels were not reached within 3 h. It is concluded that NaF solutions result in a significantly higher intra‐oral fluoride exposure than MFP solutions. The fluoride distribution and clearance of fluoride from different sites in the oral cavity are linked to salivary access to these sites. These site‐specific differences may have clinical consequences with regard to the dynamics of fluoride in the de‐ and remineralization processes.
Fractionation of salivary micelle‐like structures by gel chromatography
Authors: Rykke Morten , Young Alix , Devold Tove , Smistad Gro , Rölla Gunnar
Published: October 2007

Globular structures have been demonstrated in human parotid saliva by transmission electron microscopy and photon correlation spectroscopy. The aim of this study was to fractionate these salivary globular structures for analytical and preparative purposes using a gel‐filtration material capable of separating spherical particles up to 300‐400 nm in diameter. Freshly obtained parotid saliva was applied to a Sephacryl S‐1000 column. Peak fractions were collected and prepared for transmission electron microscopy (TEM) or for amino acid analysis. Bovine milk was included as the casein micelles by TEM appear to be similar to the salivary aggregates and their elution profiles are known. The salivary globular structures were eluted in one major peak. TEM of negatively stained samples from the peak fractions demonstrated globular protein aggregates consistent with the salivary structures in parotid saliva. Amino acid analysis showed characteristic amino acid profiles with unusual high levels of proline, 40‐45%. The casein micelles were eluted in one major peak and separated from the whey proteins. This study indicates that the salivary globular structures can be isolated by gel chromatography. The amino acid analysis indicates that proline‐rich proteins may be an important fraction of the salivary globular structures.
Incidence of human papillomavirus 6, 11, 16, 18 and 33 in normal oral mucosa of a Greek population
Authors: Lambropoulos A. F. , Dimitrakopoulos J. , Frangoulides E. , Katopodi R. , Kotsis A. , Karakasis D.
Published: October 2007

The polymerase chain reaction (PCR) was applied for the detection of human papillomavirus (HPV) infection in samples obtained from the clinically normal mucosa of the oral cavity of 169 asymptomatic subjects in northern Greece. Of the subjects, 9.5% were found to be infected with HPV. Typing of HPV by Southern blot hybridization revealed that 2.4%, 0%, 0%, 4.1%, 0.6% of the subjects were infected with HPV16, 18, 33, 6 and 11. respectively.
Craniofacial growth after a period of unilateral masticatory function in young rabbits
Authors: Poikela Aila , Kantomaa Tuomo , Pirttiniemi Pertti
Published: October 2007

Changes in craniofacial growth after a period of unilateral masticatory function were studied in rabbits. 10‐day‐old animals were divided into 3 groups. In Group I, mandibular and maxillary molars were ground down 2 X a week on the right side under general anesthesis until age 50 days, and were thereafter left to grow without grinding. In Group II, the right‐dide molars were ground left dide. The animals were thereafter left to grow. Group III consisted of unoperated control animals. All of the animals were fed whole pellets and water ad libitum, and were sacrificed at age 100 days. There were measurable differences in growth after periods of unilateral masticatory function. The mandibular ramus was higher, the condylar processus was larger sagittally, and angles between the anterior or posterior bordrs of the condylar process and inferior border of mandible were smaller in the treated than in the control animals, and there were differences between right and left dides of the same animal in themazilla and mandible. The inclination of the articular surface of the glenoid fossa was steeper anteriorly on both sides in the treated than in the controls. It was concluded that growth after a period of unilateral masticatory function in young rabbits does not rectify all of the asymmetric changes in the maxilla, mandible and glenoid fossa resulting from the asymmetric function.
Dentin bonding: effect of tubule orientation on hybrid‐layer formation
Authors: Schüpbach Peter , Krejci Ivo , Lutz Felix
Published: October 2007

Schüpbach P. Krejci I, Felix L: Dentin bonding: effect of tubule orientation on hybrid‐layer formation.

In an attempt to compare the morphology of the resin‐dentin interface in areas where the dentinal tubules run perpendicularly or at an angle to the cavity surface with that of areas where they run parallel to it, we studied a dentin adhesive system using transmission electron microscopy and fluorescence confocal laser scanning microscopy. The design of the study included the simulation of the normal hydrostatic pressure within the pulp and the dentinal tubules. Following acid etching of the dentinal surface with maleic acid/HEMA, the smear layer was removed, and a superficial zone was demineralized in such a way that the exposed collagenous dentin matrix retained its integrity. Confocal laser scanning microscopal investigations using primer labeled with rhodamine B showed that the penetration of the primer occurred not only vertically via surface porosities, but mainly laterally, via the dentinal tubules. The adhesive resin labeled with fluorescein completely infiltrated the demineralized layer, thereby forming a hybrid layer. The orientation of the dentinal tubules had a profound effect on the formation of the hybrid layer. In areas with perpendicular tubule orientation, the layer was 3.2 ± 0.8 μm thick, showing solid 27.2 ± 0.8 μm long resin tags in the dentinal tubules, and a network of tiny tags in their side‐branches. In areas with parallel tubule orientation, the layer was significantly thinner (1.3 ± 0.6 μm) and resin tags were absent.
Anatomy and ultrastructure of a Rhododendron root–fungus association
Authors: Peterson T. A. , Mueller W. C. , Englander L.
Published: October 2007

Light and electron microscopic investigations of the roots of Rhododendron and other ericaceous plants growing in the vicinity of Clavaria fruiting structures showed a fungal infection consistently associated with the epidermal and cortical cells of the "hair roots." Uninfected hair roots consisted of an epidermis and a one cell thick cortical layer surrounding the stele. Secondary growth in the stele and formation of a cork layer by division of the pericycle caused the cortex and epidermis to slough as the root matured. The structure of the infected hair roots was similar except for the presence of fungus in epidermal and cortical cells. As judged by the appearance of septa, at least two fungi were involved, one with dolipore septa that formed hyphal coils in the infected cells, and one with septa associated with Woronin bodies that occurred as single hyphal strands. Hyphae were found penetrating the cells from the exterior of the root and also passing from cell to cell. No correlation between fungal infection and the phenolic content of the cells could be made. Dissolution of both the fungal and host cytoplasm appeared to occur as the cells were sloughed. It appears that the fungus–root relationship is complex and is limited in duration to a short period of time during the development of the hair roots.
Electron microprobe analysis of the distribution of silicon in the leaves of Selaginella emmeliana
Authors: Dengler Nancy G. , Lin Eric Y-C.
Published: October 2007

Scanning electron microscopy and X-ray microanalysis of the ventral leaves of Selaginella emmeliana demonstrated high levels of silicon in the marginal sclereids and about one-half the abaxial epidermal cells. Although both of these cell types bear rows of knobs or warts on the outer tangential wall, the X-ray spectra indicate that silicon is distributed throughout the wall and that it is not concentrated in these projections. In S. emmeliana, stomata are confined to a band of low silicon cells overlying the midrib on the abaxial side of the leaf. A small proportion of these stomata also contain high levels of silicon and are characterized by a constricted stomatal aperture. A preliminary survey of three other species of Selaginella indicates that accumulation of silicon in the leaf epidermis is characteristic for each.
A spectrophotometric assay for asparaginase obtained from corn (Zea mays) endosperm tissue
Authors: Misra Santosh , Oaks Ann
Published: October 2007

Aspartate formed by the action of asparaginase (obtained from corn endosperm tissue) is converted to oxaloacetate (OAA) in the presence of α-ketoglutarate and a commercial glutamate-oxaloacetate transaminase (GOT). The OAA is then reduced to malate in the presence of a commercial malate dehydrogenase (MDH) and NADH + H+. The oxidation of NADH + H+ can be followed spectrophotometrically. Since the asparaginase activity is relatively low in plant tissue the asparaginase assay is prerun for a determined period of time before GOT and MDH are added to the system. The nanomoles of NADH oxidized in the above assay are quantitatively similar to the production of aspartate and NH4+ as assayed by traditional methods. Values for 1 h are in the order of 290 nmol∙mg protein−1 or 349 nmol∙endosperm−1.
Ultrastructure of haustorium development in Puccinia coronata avenae. I. Cytochemistry and electron probe X-ray analysis of the haustorial neck ring
Authors: Chong J. , Harder D. E.
Published: October 2007

The structure and composition of the haustorial neck ring in Puccinia coronata avenae was determined by histochemical methods and by electron-probe X-ray analysis (EDX). In mature haustoria, the neck ring structure was composed of two cylindrical bands. A broad band, nearer to the haustorial mother cell, was designated as the α (alpha) band and a narrower band, nearer to the haustorial body, the β (beta) band. The chemical composition of the two bands was different. The results of EDX analysis showed silicon as the major element present in the α band, and iron and phosphorus (possibly in the form of ferric pyrophosphate), the major elements of the β band. Digestion with protease or treatment with the organic solvents chloroform–methanol, ether–ethanol, or acetone failed to extract either band, indicating the presence of little, if any, protein or lipid materials.
Akinete ultrastructure of Nostoc species isolated from cycad coralloid roots
Authors: Caiola Maria Grilli , Vecchi Luisa De
Published: October 2007

Nostoc strains isolated from different cycad coralloid roots were grown in culture until sporulation to study the structure and ultrastructure of akinetes. These cells have cell walls enclosed by two different envelopes produced by the vegetative cells during akinete differentiation, and cytoplasm containing thylakoids, cyanophycin granules, polyhedral bodies, and polyglucoside and lipid bodies. Two main types of akinetes have been described differing in shape, size, envelope, and cytoplasmic features. They are considered as cells having a different grade of maturity and function. The factors which influence sporulation and the correlations between akinetes and heterocysts are discussed.
Accroissement de la résistance au froid (jusqu'à −30 °C) de plantules de Blé avec un milieu cryoprotecteur. Effets de ce traitement sur les ultrastructures de cellules parenchymateuses d'ébauches foliaires
Authors: Gazeau C. M.
Published: October 2007

Wheat seedlings treated with a frost-protecting medium containing a mixture of glycerol, dimethyl sulfoxyde, and saccharose, were subjected to cooling at the rate of 1 °C/min during a few hours. Seedlings treated in this way were resistant to temperatures of −30 °C. However on rewarming, the growth of leaves and coleoptiles was slightly slowed down compared with that of control seedlings.Seedling impregnation with the frost-protecting medium provoked few ultrastructural changes in the parenchyma cells of leaf primordia. Only lipidic, osmiophilic globules were relatively abundant, and these were scattered in the peripheral cytoplasm, along the plasmalemma. Cooling to −30 °C tended to make certain organelles migrate preferentially towards peripheral regions; the plasmalemma, osmiophilic globules, microtubules, and mitochondria came into contact with each other. In spite of the very cold temperature, some mitotic figures persisted with no evident signs of changes.On rewarming the seedlings, the various changes observed during cold treatments gradually diminished and disappeared. [Journal translation]
Étude comparative du métabolisme photosynthétique des feuilles et des gousses de soja Glycine max
Authors: Latché J. C. , Bailly-Fenech G. , Grima-Pettenati J. , Cavalié G.
Published: October 2007

Changes in photosynthetic carbon fixation processes were comparatively studied in soybean leaves and pods harvested at different growth stages. Newly fully expanded leaves exhibited both the highest 14CO2 assimilation rate and the maximum ribulose bisphosphate carboxylase levels. Amino acids biosynthesis was more important in young tissues and this result agreed with the evolution of nitrate reductase activities. The radiocarbon distribution in glycine and serine suggested that photorespiratory metabolism increases with leaf age; the activity of glycolate oxidase was found to be significantly lower in younger leaves than in mature ones. Net photosynthesis, chlorophyll content, and ribulose bisphosphate carboxylase activity were low in isolated pods compared to leaves. However, the study of photosynthate translocations within the pod revealed that the pod wall could contribute to the carbon nutrition of the seeds. Soluble compounds labelled after 14CO2 incorporation and glycolate oxidase activity measurement indicated that organic acids biosynthesis and photorespiratory metabolism are relatively higher in pods than in leaves.
Prolyl-4-hydroxylase activity in excised elongating and nonelongating regions of bean hypocotyl
Authors: Joyce Paul B. M. , Kimmins Warwick
Published: October 2007

Apical (elongating) and basal (nonelongating) segments of bean hypocotyls were labelled with [4-3H] proline and in vivo prolyl-4-hydroxylase activity, and peptidyl proline synthesis and hydroxylation were determined. Prolyl-4-hydroxylase activity was negligible in newly excised segments. However, if segments were aerated before labelling, hydroxylase activity, uptake, and incorporation of [4-3H]proline were all significantly increased. 3H loss was negligible in the presence of α, α′-dipyridyl or when sections were labelled with [2,3-3H]proline. In basal sections aerated for 24 h, prolyl-4-hydroxylase activity and the proportion of peptidyl proline hydroxylated were twice that observed in apical sections. The data indicated that peptidyl proline biosynthesis was similar in nonelongating and elongating segments. When apical sections were aerated in solutions of NaCl, mannitol, or benzimidazole, at concentrations inhibitory to elongation, there was an increased release of 3H from [4-3H]proline. However, a similar increase in 3H release occurred in the [2,3-3H]proline-labelled controls. The results suggest that neither increased prolyl-4-hydroxylase activity or peptidyl proline biosynthesis are an obligatory requirement for cessation of growth in excised bean hypocotyls.
Fine structure of the suberized cell walls in the boundary zone and necrophylactic periderm in wounded peach bark
Authors: Biggs A. R. , Stobbs L. W.
Published: October 2007

Bark on the scaffold limbs of 6-year-old peach (Prunus persica (L.) Batsch cv. Redhaven) trees was mechanically wounded and tissue samples for ultrastructural study were taken after 6, 8, 12, and 14 days. Examination with light and fluorescence microscopy revealed lignification of boundary zone cell walls after 6 days followed by suberization of the lignified cell walls after 8 days. Necrophylactic periderm was present by day 12 and, by day 14, three to five cells of the new phellem were observed. Examination of tissues with transmission electron microscopy revealed suberin lamellae on the inner wall of boundary zone cells. These cells contained senescing cytoplasm with fragments of undifferentiated dense material that formed a thin, discontinuous granular deposit inside the suberin layer. Suberin lamellae did not occlude plasmodesmata. Cells of the new phellem were radially compressed, heavily suberized, and lacked pits or plasmodesmata.
In vitro decay studies of selective delignification and simultaneous decay by the white rot fungi Ganoderma lucidum and G. tsugae
Authors: Adaskaveg James E. , Gilbertson Robert L.
Published: October 2007

The in vitro wood decay abilities of Ganoderma lucidum (W. Curt.: Fr.) Karst. and G. tsugae Murr. were studied using the following woods in agar block decay chambers: Vitis vinifera L., Quercus hypoleucoides A. Camus, Prosopis velutina Woot., Abies concolor (Gord. & Glend.) Lindl. ex. Hildebr., and Pseudotsuga menziesii (Mirb.) Franco. Grape wood lost the most weight while mesquite the least. Ganoderma lucidum isolates generally caused greater weight loss of all woods than did G. tsugae isolates. The range of the percent weight losses varied with the wood. Both Ganoderma species caused simultaneous decay in all woods. However, chemical analyses of the decayed blocks indicated that selective delignification by both species also occurred in grape and white fir blocks. Chemical analysis of the decayed oak blocks indicated the percentages of lignin and holocellulose were not statistically different from the controls. However, there was a trend towards delignification. The analyses of the Douglas-fir blocks indicated only simultaneous decay. Scanning electron microscopy demonstrated selective delignification and simultaneous decay of all woods tested. However, the extent of the delignification differed among the wood species. Delignification appeared mainly in areas of tracheids or fiber tracheids, while the rays were simultaneously decayed.
Genecological variation in recently established populations of Abutilon theophrasti (velvetleaf)
Authors: Warwick S. I. , Black L. D.
Published: October 2007

Life history and electrophoretic variation were examined in 39 populations of Abutilon theophrasti L., velvetleaf, collected from southern Ohio (39° N) to central Ontario (45° N). These collections represent a climatic gradient at the northern extreme of the distribution range of this weed species in North America. Plants from each of the 39 populations were grown from seed in a standard garden trial. A total of 51 growth, germination, and morphological characters were measured for each population. Significant among-population differences (p < 0.05) were found for 33 of the 51 characters. Many of these population differences were correlated with latitude and climate. These patterns of variation may well represent the first stages of differentiation in response to local environment. Of particular importance was the wide range of differences among populations in proportions of seeds exhibiting dormancy. Results from an electrophoretic survey of 16 enzyme systems provided evidence for very low levels of allozyme variation among the 39 populations of A. theophrasti. Only two enzymes were variable and only four multi-locus electrophoretic genotypes were evident among the 39 populations. Velvetleaf exhibited a number of genetic features characteristic of successful colonizers: high levels of fixed heterozygosity as a result of polyploidy, multilocus associations providing a reduced number of genotypes, and high levels of population differentiation in morphometric and life-history traits.
Morphogenesis in Punica granatum (pomegranate)
Authors: Jaidka Kanchan , Mehra P. N.
Published: October 2007

Explants of root, hypocotyl, cotyledon, stem, shoot tip, and leaf of seedlings obtained by in vitro germination of seeds, as well as embryos excised from seeds, were utilized for the induction of callus. Murashige and Skoog basal medium supplemented with naphthaleneacetic acid (4 ppm), kinetin (2 ppm), and coconut water (15%) was found to be optimal for induction and growth of callus from all explants. Growth rate experiments were performed with callus to study the effect of different growth regulators at various concentrations. The calluses were heterogeneous in nature and consisted predominately of diploid cells, although a few polyploid cells were also observed after two and four subcultures. Plantlets, isolated roots, leaves, and shoots were differentiated in various callus cultures. The root tips and shoot tips of such plantlets revealed only diploid constitution. Embryolike structures were formed in callus on transfer to media containing naphthaleneacetic acid and 6-benzylaminopurine. Embryoid development was traced to a single cell which was invariably isolated from the rest of the callus tissue. This initial divided to form a multicelled structure which later gave rise to a globular, ovoid, or heart-shaped embryoid, or one with irregular form. The embryoids germinated into complete plantlets with root and shoot. The embryoidal initials were mostly diploid but occasional aneuploids or polyploids were observed.
The ecology of Ramalina menziesii. V. Estimation of gross carbon gain and thallus hydration source from diurnal measurements and climatic data
Authors: Matthes-Sears U. , Nash III T. H.
Published: October 2007

All subsets regression analysis was used to determine the set of meteorological variables that best predicted daily gross carbon fixation of the lichen Ramalina menziesii Tayl. measured on 23 days at Hastings Reservation in central coastal California. The regression equation containing the two best predictor variables, the duration of diurnal atmospheric humidities equal to or above 90% and daily precipitation, was then used in conjunction with weather records to estimate daily, seasonal, and annual gross CO2 gain of R. menziesii at Hastings for the years 1981 – 1983. Calculated average annual gross CO2 fixation for these 3 years was 2756 mg CO2∙g dry weight−1. For 66% of this total gain, the most likely source of thallus hydration was rainfall. Dewfall was responsible for 15%, atmospheric water vapor uptake for 11%, and for the remaining 8% the source was uncertain. Three-fourths of the annual carbon fixation took place during the 6 months of the rainy season.
Ontogenèse des sacs embryonnaires non réduits chez Eragrostis curvula
Authors: Rabau T. , Longly B. , Louant B.-P.
Published: October 2007

The apomictic reproductive mode by diplospory is cytologically analysed in Eragrostis curvula (Schrad.) Nees, a tetraploid forage grass. The genesis of unreduced embryo sacs is followed; two kinds of sacs are then distinguished: (i) a monopolar one with a typical oogonial complex and a polar nucleus at the micropylar end; (ii) a bipolar one with an egg cell and two polar nuclei at the micropylar end, and some antipodial cells at the chalazal end. Monopolar sacs are 3 times more frequent than bipolar ones. Traces of sexuality are noted in E. curvula but with a low frequency. A chronology of female development is established according to stages of male development. This should make possible an early distinction and allow a useful comparison between diplospory and sexuality within the genus Eragrostis.
LID-DRIVEN CAVITY SIMULATION BY MESH-FREE METHOD
Authors: SHAMEKHI ABAZAR , SADEGHY KAYVAN
Published: October 2007

In this work mesh-free method is used for solving two dimensional lid-driven cavity flow in a wide range of Reynolds numbers. The algorithm of mesh-free characteristic based split has been employed for this purpose. The results obtained from mesh-free characteristic based split algorithm have been compared to those of the finite element. The effect of using different shape functions on accuracy and stability of solution has been discussed. The sensitivity of stability of solution to nodes irregularity has been investigated. The effects of number of Gaussian integration points on the accuracy have been discussed.
SINGULAR INTEGRAL EQUATION METHOD FOR A MOVING CRACK PROBLEM IN ANTIPLANE ELASTICITY OF FUNCTIONALLY GRADED MATERIALS
Authors: CHEN Y. Z. , LIN X. Y.
Published: October 2007

In this paper, elastic analysis for a Yoffe moving crack problem in antiplane elasticity of the functionally graded materials (FGMs) is presented. The crack is assumed to move with a constant velocity V. The traction applied on the crack face is arbitrary. The Fourier transform method is used to derive an elementary solution. Furthermore, using the obtained elementary solution a singular integral equation for the problem is obtained. After the singular integral equation is solved, the stress intensity factor (SIF) can be evaluated immediately. In the case of evaluating the SIFs at the leading crack tip and the trailing crack tip, the difference between the two cases is investigated. From the numerical solution of the SIFs, the influence caused by the velocity V and the FGM material property β1 are addressed. It is found that when the FGM material property β1 = 0, i.e. the homogeneous case, the SIFs at the crack tips do not depend on the moving velocity of the crack. Finally, numerical examples are given.
NATIVE AMERICAN ENTREPRENEURS AND STRATEGIC CHOICE
Authors: SWINNEY JANE , RUNYAN RODNEY
Published: October 2007

In a study of 149 entrepreneurs operating businesses in heavily Native American indigenous communities, no significant differences were found in three constructs of entrepreneurial business orientation and two constructs of small business orientation between Native American entrepreneurs and majority entrepreneurs. Community development officials can use the findings to lay the foundation for cultivating entrepreneurship among all community residents as no significant differences between indigenous and majority small business owners in their strategic choices of entrepreneurial and small business orientations was found. This information allows development officials to approach all potential entrepreneurs with a common method.
CIVIC CAPITALISM: ENTREPRENEURS, THEIR VENTURES AND COMMUNITIES
Authors: MONTI DANIEL J. , RYAN ANDREA D. , BRUSH CANDIDA , GANNON AMY
Published: October 2007

Entrepreneurs and everyday businessmen and women have long engaged in different kinds of civic-minded activities. This study explores ways that urban entrepreneurs and managers engage in civic activities while pursuing business growth. In this preliminary analysis of owners and managers who have participated in a technical assistance program geared for entrepreneurs who are ready to take their existing venture "to the next level", we identify a kind of entrepreneur whose business model incorporates a social mission. These are not "social entrepreneurs" who engage in business practices in order to push their social agenda. Nor are they mimicking businesses that follow a "corporate social responsibility" model because they were shamed into it or believe it will be good for their bottom line. These are people whose ventures must make a profit if their social mission is to be achieved. They run what we call a "civic enterprise". Their behavior reflects a kind of "civic-minded capitalism".
A MEMETIC ALGORITHM FOR PERFORMING MEMORY ASSIGNMENT IN DUAL-BANK DSPS
Authors: GRÉWAL G. , COROS S. , VENTRESCA M.
Published: October 2007

To increase memory bandwidth, many programmable Digital-Signal Processors (DSPs) employ two on-chip data memories. This architectural feature supports higher memory bandwidth by allowing multiple data memory accesses to occur in parallel. Exploiting dual memory banks, however, is a challenging problem for compilers. This, in part, is due to the instruction-level parallelism, small numbers of registers, and highly specialized register capabilities of most DSPs. In this paper, we present a new methodology based on a Memetic Algorithm (MA) for assigning data to dual-bank memories. Our approach is global, and integrates several important issues in memory assignment within a single model. Special effort is made to identify those data objects that could potentially benefit from an assignment to a specific memory, or perhaps duplication in both memories. Our computational results show that the MA is able to achieve a 54% reduction in the number of memory cycles and a reduction in the range of 7%–42% in the total number of cycles when tested with well-known DSP kernels and applications. Our computational results also show that, when compared with the Genetic Algorithm in Ref. 3, the memetic algorithm is able to find solutions that, on average, have 7%–20% less cost, with the biggest improvements being found for larger problem instances.
A NOVEL ALGORITHM FOR SOLVING THE STRING MATCHING PROBLEM
Authors: EL EMARY IBRAHIEM M. M. , JABER MOHAMMED S. M.
Published: October 2007

The string matching problem consists of finding one or more, generally all, exact occurrences of a pattern P in a text T. This paper presents a new algorithm for solving the string matching problem. Application of the proposed algorithm assists in improving the search process of a specific pattern in a certain unchangeable text through decreasing the number of character comparisons. Operation concept of such an algorithm depends on pattern reading to obtain the pattern length and the pattern first character and then a search is done in a table of two columns: the first column represents the word length in the text and the second one represents the start positions of each word classified by the same length. After that the algorithm just searches the words of the same length. Our experimental results depend mainly on comparing the performance of our algorithm with the well-known pattern matching algorithms such as Boyer–Moor's and Boyer–Moor–Galil's. The comparison between our algorithm and others are done in terms of the number of characters compared for different sizes of text. The output results show that our algorithm performs better than the others in terms of this parameter.
REMOTE SENSING TECHNOLOGIES IN POST-DISASTER DAMAGE ASSESSMENT
Authors: YAMAZAKI FUMIO , MATSUOKA MASASHI
Published: October 2007

This paper highlights the recent applications of remote sensing technologies in post-disaster damage assessment, especially in the 2004 Indian Ocean tsunami and the 2006 Central Java earthquake. After the 2004 Indian Ocean tsunami, satellite images which captured the affected areas before and after the event were fully employed in field investigations and in tsunami damage mapping. Since the affected areas are vast, moderate resolution satellite images were quite effective in change detection due to the tsunami. Using high-resolution optical satellite images acquired before and after the 2006 Central Java earthquake, the areas of building damage were extracted based on pixel-based and object-based land cover classifications and their accuracy was compared with visual inspection results. In the Central Java earthquake, ALOS/PALSAR captured a SAR image of the affected area one day after the event as well as pre-event times. Taking the difference of the pre-event correlation and the pre-and-post event correlation, the areas affected by the earthquake were also identified. From these examples, the use of proper satellite imagery is suggested considering the area to cover, sensor type, spatial resolution, satellite's retake time etc., in post-disaster damage assessment.
A Theory for the Separation of Liquid Mixtures by Laser Radiation
Authors: Hassanov H. G.
Published: October 2007

A theory for the separation of liquid mixtures under the action of electromagnetic waves is developed. The theory considers physical specifications that take place during the separation. It is shown that at certain extreme value of the radiation intensity the maximum of mixture separation could be observed. This extreme value depends on the parameters of falling waves and medium studied. The effect of the liquid convection on the mixture separation is investigated. It is established that convection reduces the separation. Thus, laminar flow is much more preferable for the mixture separation than turbulent one.
A Novel Variant of Ileal Bile Acid Binding Protein Is Up-regulated through Nuclear Factor-κB Activation in Colorectal Adenocarcinoma
Authors: Fang Changming , Dean Jarrod , Smith Jeffrey W.
Published: October 2007

Ileal bile acid binding protein (IBABP) is the only cytosolic protein known to bind and transport bile acids. Because IBABP is reportedly up-regulated in colorectal cancer, it has been suggested as a link between bile acids and the risk of colorectal cancer. However, in this study, we show that IBABP is not up-regulated. Rather, a novel transcript of the IBABP gene, which encodes an additional 49 NH2-terminal amino acid residues, is up-regulated in colorectal cancer (P < 0.001). The novel transcript, called IBABP-L, is also distinct from IBABP because its transcription is controlled by nuclear factor-κB (NF-κB) rather than by the farnesoid X receptor. Most significantly, IBABP-L is necessary for the survival of HCT116 colon cancer cells in the presence of physiologic levels of the secondary bile acid deoxycholate. Collectively, the studies point toward a unique bile acid response pathway involving NF-κB and IBABP-L that could be useful for diagnosis and could potentially be targeted for therapeutic benefit. [Cancer Res 2007;67(19):9039–46]
The Activity of Zoledronic Acid on Neuroblastoma Bone Metastasis Involves Inhibition of Osteoclasts and Tumor Cell Survival and Proliferation
Authors: Peng Hongjun , Sohara Yasuyoshi , Moats Rex A. , Nelson Marvin D. , Groshen Susan G. , Ye Wei , Reynolds C. Patrick , DeClerck Yves A.
Published: October 2007

Metastasis to the bone is seen in 56% of patients with neuroblastoma and contributes to morbidity and mortality. Using a murine model of bone invasion, we have reported previously that neuroblastoma cells invade the bone by activating osteoclasts. Here, we investigated the antitumoral and antiosteolytic activities of zoledronic acid, a bisphosphonate inhibitor of osteoclasts, in combination with cytotoxic chemotherapy in our model. We first show that zoledronic acid given at the same time (early prevention) or 2 weeks after tumor cell injection (late prevention) significantly prevented the formation of severe osteolytic lesions. It also prevented formation of these lesions when given 4 weeks after tumor cell injection (intervention) when combined with chemotherapy including cyclophosphamide and topotecan. The combination of zoledronic acid + cyclophosphamide/topotecan also significantly improved survival (P < 0.001). In mice treated with zoledronic acid, we observed a marked inhibition of osteoclasts inside the bone associated with a decrease in tumor cell proliferation and increase in tumor cell apoptosis. In vitro, zoledronic acid inhibited neuroblastoma cell proliferation and induced apoptosis, and these effects were significantly enhanced by the addition of 4-hydroxyperoxycyclophosphamide (4-HC). The proapoptotic effect of zoledronic acid and zoledronic acid in combination with 4-HC on tumor cells was associated with an increase in caspase-3 activity and a decrease in phosphorylated Bcl-2, Bcl-2, and Bcl-XL expression. Zoledronic acid inhibited the association of Ras with the plasma membrane and activation of c-Raf, Akt, and extracellular signal-regulated kinase 1/2. The data indicate that zoledronic acid, in addition to inhibiting osteoclasts, is active against tumor cells and suggest that zoledronic acid in combination with cytotoxic chemotherapy may be effective in children with neuroblastoma that has metastasized to the bone. [Cancer Res 2007;67(19):9346–55]