bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic relationships among species of the genus Bothrops based on RAPD markers
Authors: Grazziotin Felipe , Echeverrigaray Sergio
Published: December 2006

The genetic relationships among 11 species of Bothrops found in Brazil were determined using random amplified fragment (RAPD) information. A total of 239 amplified bands were scored using 20 aleatory primers. Most of the bands (88.7%) were polymorphic. Phylogenetic analysis of the data determined three similarity groups within Bothrops: Group I- B. alternatus, B. neuwiedi, B. cotiara, and B. jararacusu; Group II- B. insularis, B. jararaca, and B. erythromelas; and Group III- B. moojeni, B. leucurus, and B. atrox. These groups coincided with those obtained by other methods, indicating that RAPD's could be a useful tool for the evaluation of genetic relationships at the interspecific level.
Effect of feeding methods on the astaxanthin production by Phaffia rhodozyma in fed-batch process
Authors: Moriel Danilo Gomes , Chociai Miriam Blumel , Machado Iara Maria Pereira , Fontana José Domingos , Bonfim Tania Maria Bordin
Published: December 2006

The effect of feeding methods on the production of astaxanthin by the yeast Phaffia rhodozyma ATCC 24202 was studied, using continuous and pulsed fed-batch processes and low cost materials as substrates (sugar cane juice and urea). In continuous fed-batch processes, a cellular astaxanthin concentration of 383.73 µg/g biomass was obtained. But in pulsed fed-batch processes a reduction in the cellular astaxanthin concentration (303.34 µg/g biomass) was observed. Thus the continuous fed-batch processes could be an alternative to industrial production of astaxanthin, allowing an increase in the biomass productivity without losses on astaxanthin production by the yeast.
Biology of Chirocentrodon bleekerianus (Poey, 1867) (Clupeiformes: Pristigasteridae) in a continental shelf region of southern Brazil
Authors: Corrêa Carlos Eduardo , Chaves Paulo de Tarso , Guimarães Paulo Ricardo Bittencourt
Published: December 2006

This study provides information on the biology of C. bleekerianus from Paraná State coast, Brazil, assembling data about its abundance, size structure, diet and reproduction. Monthly collections were accomplished in 1999 and 2000 in the internal continental shelf, with trawl net. The catch-per-unit-effort did not vary significantly among the seasons. In the summer, the individuals were larger, followed by autumn, spring and winter. C. bleekerianus was predominantly planktivorous and the most frequent items in its diet were copepods followed by diatomaceous algae. Seasonal variation in the frequency values of the gonad maturation stages, gonadossomatic index and gonadal condition factor indicated that the reproductive period encompassed spring and summer. The mean total length at first maturity of females was estimated to be 76 mm.
Egg Development of Paralichthys orbignyanus (Valenciennes, 1839)
Authors: Cerqueira Vinicius Ronzani
Published: December 2006

Eggs of the Southern Brazilian flounder Paralichthys orbignyanus were obtained through spawning induction and reared in laboratory. The eggs released were free-floating or pelagic. Other important characteristics were: spherical shape, smooth chorion, narrow perivitelline space, and a single oil globule. Egg and oil globule diameter were about 0.792 ± 0.008 mm and 0.114 ± 0.003 mm, respectively. The blastodisc was observed approximately 1 h after fertilization and followed by blastodisc cleavage. Blastula stage started after about 5 h and gastrula stage after 9 h. Approximately 20 h after fertilization, blastopore closure was observed. Neurula or early embryo occurred after 24 h. Cardiac beats and movements of the free embryonic tail were recorded after 40 h of incubation. Hatching occurred after an incubation period of 40-50 h at temperatures ranging from 18 to 20 ºC. Newly hatched larvae were about 2.04 ± 0.024 mm long and quite undeveloped, with a large yolk sac with a posterior oil globule and sparse pigmentation. These results were greatly similar to those obtained by previous studies regarding congener species. This is one of the first steps towards the artificial propagation of this species under controlled conditions.
Biodiversity assessment of benthic macroinvertebrates along a reservoir cascade in the lower São Francisco river (northeastern Brazil)
Authors: Callisto M. , Goulart M. , Barbosa F. A. R. , Rocha O.
Published: December 2006

In order to verify the cascade-system effect in benthic macroinvertebrate communities, and the implications for policy making and proposals for conservation and sustainable use of the lower portion of São Francisco river basin (Bahia State, Brazil), a three-reservoir cascade system including two stretches downstream were studied during dry (June, 1997) and rainy (March, 1998) periods. The dominant groups found were Mollusca (Melanoides tuberculata), Oligochaeta, and Chironomidae larvae. Low Shannon-Wiener and Pielou index values were found, but with no significant difference between the sampling periods. However, density and taxonomic richness were significantly different (t(0.05; 31) = -2.1945; p < 0.05; e t(0.05; 31) = -3.0600; p < 0.01) between the sampling periods, with a reduction in the number of taxaand macroinvertebrate abundance during the rainy period. An increasing gradient in benthic macroinvertebrate community structures was noted along the reservoir cascade from the first reservoir (Apolônio Sales), followed by a decrease downstream from the third reservoir of the system (Xingó). Despite the negative consequences of rapid proliferation of dams, which have caused widespread loss of freshwater habitats, the reservoir cascade system promoted an increase in benthic macroinvertebrate diversity, due to water-quality improvement along the system.
Preliminary notes on yeasts associated with necrotic cactus stems from different localities in Brazil
Authors: Moraes E. M. , Rosa C. A. , Sene F. M.
Published: December 2006

The yeast species found in necrotic stems of three columnar cacti (Pilosocereus machrisii, Pilosocereus vilaboensis, and Praecereus euchlorus)at eight localities in Brazil were described and a similarity analysis using Sorensen distances was used to compare the composition of yeast species at these localities. Of 56 necrotic cactus stems sampled,32 produced yeast colonies. Ten species of yeast or yeast-like microorganisms were identified from 53 isolates, with Pichia cactophila, Candida sonorensis, Geotrichum sp., and Sporopachydermia cereana being the most common. The remaining species occurred in low proportions in the cacti surveyed. The similarity analysis provided a dendogram (UPGMA) that clustered the yeast communities from different cactus species and indicated that host cactus species was unimportant in this clustering.
Oyster condition index in Crassostrea rhizophorae (Guilding, 1828) from a heavy-metal polluted coastal lagoon
Authors: Rebelo M. F. , Amaral M. C. R. , Pfeiffer W. C.
Published: December 2006

The condition index (CI) of oysters represents an ecophysiological approach to estimate meat quality and yield in cultured bivalve mollusks. In the present study, the CI of oysters from a heavy-metal polluted bay was analyzed with respect to Zn and Cd contamination in soft tissues, spawning, and polychaete infestation. The CI was calculated through a new technique based on molds made to measure the volume of oyster-shell internal cavities. The higher CI values (over 9 in the dry season) were probably related availability of suspended particles rich in organic matter in the bay, while the rapid reduction in the CI from one season to the next at some stations suggests the effect of spawning. Polychaete infestation was considered low (18.7%) and produced no clear CI effects. The Cd in the oyster tissue collected during the rainy season was weak, although still significantly correlated with the CI (r = -0.36; p < 0.05). All other comparisons of CI and metal concentrations demonstrated a non-significant correlation. The CI variations observed on the temporal and spatial scale were likely to have been caused by availability of organic matter and spawning, rather than spionid infestation or metal body burdens.
Evidence indicating participation of the serotonergic system in controlling feeding behavior in Coturnix japonica (Galliformes: Aves)
Authors: Reis L. C. , Almeida A. C. , Cedraz-Mercez P. L. , Olivares E. L. , Marinho Jr. A. , Thomaz C. M.
Published: December 2006

We investigated participation of the brain serotonergic system in food intake control by using oral and systemic administration of serotonin precursors in quails (Coturnix japonica). Dietary supplemental tryptophan (0.1-50.0 g/kg) provoked a dose-dependent inhibition of food intake during a 5-h observation period, which persisted up to 24 h for doses of 30.0 and 50.0 g/kg. Normally fed and fasted animals treated with hydroxytryptophan (12.5-50.0 mg/kg) by the intracoelomic route showed an acute inhibition of food intake. Hypophagia in fasted birds was only effective when the precursor was administered immediately before food presentation. A similar response was obtained by administering serotonin (0.125-2.5 mg/kg, sc), with animals showing a hypnogenic response within the first ten minutes after administration, suggesting that, in contrast to mammals, the amine crosses the blood-brain barrier in quails. Administration of hydroxytryptophan at all doses tested induced significant dipsogenic behavior despite the concomitant hypnogenic response. The results suggest the involvement of serotonergic pathways in food intake control in quails and also show, for the first time, hypnogenic action induced by serotonin and a hyperdipsic effect elicited by hydroxytryptophan.
Characterization of adenosine deaminase (ADA) in Hemolymph of Biomphalaria glabrata
Authors: Vale M. R. , Pereira R. V. , Almeida S. M. , Almeida Y. M. , Nunes S. F. L. C.
Published: December 2006

Adenosine is an important signaling molecule for many cellular events. Adenosine deaminase (ADA) is a key enzyme for the control of extra- and intra-cellular levels of adenosine. Activity of ADA was detected in hemolymph of B. glabrata and its optimum assay conditions were determined experimentally. The pH variation from 6.2 to 7.8 caused no significant change in ADA activity. Using adenosine as a substrate, the apparent Km at pH 6.8 was 734 µmols.L-1. Highest activity was found at 37ºC. Standard assay conditions were established as being 15 minutes of incubation time, 0.4 µL of pure hemolymph per assay, pH 6.8, and 37ºC. This enzyme showed activities of 834 ± 67 µmol.min-1.L-1 (25ºC) and 2029 ± 74 µmol.min-1.L-1 (37ºC), exceeding those in healthy human serum by 40 and 100 times, respectively. Higher incubation temperature caused a decrease in activity of 20% at 43ºC or 70% at 50ºC for 15 minutes. The ADA lost from 26 to 78% of its activity when hemolymph was pre-incubated at 50ºC for 2 or 15 minutes, respectively. Since the ADA from hemolymph presented high levels, it can be concluded that in healthy and fed animals, adenosine is maintained at low concentrations. In addition, the small variation in activity over the 6.2 to 7.8 range of pH suggests that adenosine is maintained at low levels in hemolymph even under adverse conditions, in which the pH is altered.
Fusos extremos na era da ressonância magnética: características clínicas, eletrográficas e de neuroimagem
Authors: Maia Maria Goretti Lima , Caboclo Luís Otávio Sales Ferreira , Carrete Jr. Henrique , Garzon Eliana , Sakamoto Américo Ceiki , Yacubian Elza Márcia Targas
Published: December 2006

OBJETIVOS: Fusos Extremos (FE) foram descritos por Gibbs e Gibbs em 1962. São tipicamente observados em crianças menores de cinco anos, ocorrendo em 0,05% de crianças normais e em 5 a 18% das crianças com retardo mental ou paralisia cerebral. Nesse estudo, descrevemos as características clínicas e neurofisiológicas de 5 pacientes com FE, correlacionando esses achados com os aspectos de neuroimagem, através de exame de ressonância magnética (RM) de encéfalo. PACIENTES E MÉTODOS: Foram selecionados inicialmente oito pacientes do ambulatório de epilepsia infantil da UNIFESP, que apresentavam fusos extremos em pelo me-nos um exame de eletroencefalograma (EEG). Dos oito, foram selecionados cinco (três do sexo feminino) que tinham RM de encéfalo disponível para análise. Foram verificados as características clínicas, o desenvolvimento neuropsicomotor e os achados neurofisiológicos, bem como os achados da RM de encéfalo. RESULTADOS: A idade dos pacientes variou de 2 a 16 anos. Os cinco pacientes apresentavam déficits cognitivos, e três apresentavam déficits motores associados. Todas as crianças tinham diagnóstico de epilepsia, sendo que em três as crises estavam controladas com drogas antiepilépticas (DAE) enquanto em dois, eram refratárias ao tratamento clínico. Em apenas um paciente a RM foi normal. Nos demais, os achados foram: paquigiria bilateral, atrofia cortical difusa, lesão focal occipital direita e atrofia frontal bilateral. A freqüência dos FE variou de 8,9 a 16 Hz, a amplitude de 67 a 256 µV. Em três pacientes, além dos FE foi observada atividade rápida de localização frontal. CONCLUSÃO: FE são raramente observados em crianças normais, mas podem ocorrer com maior freqüência naquelas com retardo mental ou paralisia cerebral. FE não parecem estar associados a epilepsia, mas em nossa série todos as crianças tinham diagnóstico de epilepsia, bem como retardo mental. O estudo com RM mostrou que FE podem ocorrer em crianças com anormalidades estruturais definidas bem como naquelas com neuroimagem normal, sugerindo que esse padrão se associa à retardo mental, mas não a etiologias específicas.
Indole-3-acetic acid metabolism in normal and dwarf micropropagated banana plants (Musa spp. AAA)
Authors: Zaffari Gilmar Roberto , Peres Lázaro Eustáquio Pereira , Tcacenco Fernando Adami , Kerbauy Gilberto Barbante
Published: December 2006

Nanism is one of the most frequent type of mutant in micropropagated banana plants from the Cavendish subgroup. The present study aimed at studying some of the hormone factors involved in this type of mutation. Rhizomes from normal and dwarf plants from the cultivar Grand Naine were incubated for 5 d in the presence of [³H]-L-tryptophan, [³H]-indole-3-acetic acid and gibberellin, to quantify the endogenous levels of indole-3-acetic acid-ester, indole-3-acetic acid-amide, free indole-3-acetic acid, and cytokinins. The endogenous levels of indole-3-acetic acid and its ester- and amide-conjugated forms were measured in normal and dwarf plants incubated for 30 d with gibberellin, indole-3-acetic acid, and L- and D-tryptophan. In normal plants, the use of [³H]-L-tryptophan resulted in higher levels of radioactivity in the retention times corresponding to indole-3-acetic acid, indole-3-acetic acid-aspartate, indole-3-acetic acid-glycine and indole-3-acetic acid-alanine. These values were higher than those observed in dwarf plants. Higher quantities of radioactive indole-3-acetic acid and of amide-forms in dwarf plants occurred in rhizomes treated with [³H]-L-tryptophan and gibberellin simultaneously. The endogenous levels of total cytokinins were the same in both materials, while the levels of indole-3-acetic acid in normal plants were 1.5 times higher than in dwarf plants. Moreover, in these ones application of tryptophan and gibberellin coincided in an increase in the levels of free indole-3-acetic acid in dwarf plants and to a decrease in the levels of indole-3-acetic acid-ester and indole-3-acetic acid-amide.
Cadmium-Zinc interactions in a hydroponic system using Ceratophyllum demersum L.: adaptive ecophysiology, biochemistry and molecular toxicology
Authors: Aravind Parameswaran , Prasad Majeti Narasimba Vara
Published: December 2006

The interaction between an essential micronutrient, Zn and a toxic non-essential element, Cd has been comprehensively reviewed based on our experiments conducted with Ceratophyllum demersum L. in a hydroponic system. Since Cd and Zn belong to the group IIB transition elements and show similarities in chemistry, geochemistry and environmental properties, it would be one of the elemental pairs of choice to investigate metal-metal interactions. Evidence in support of the protective role of Zn against Cd toxicity in Ceratophyllum demersum L. is presented in this review. Based on our experimental results, we conclude that the antioxidant properties of Zn play an important role in counteracting Cd toxicity.
Ethylene production and acc oxidase gene expression during fruit ripening of Coffea arabica L.
Authors: Pereira Luiz Filipe Protasio , Galvão Rafaelo M. , Kobayashi Adilson K. , Cação Sandra Maria B. , Vieira Luiz Gonzaga Esteves
Published: December 2006

The phytohormone ethylene is involved in several physiological and developmental processes in higher plants, including ripening of fruits, abscission of organs and tissues, senescence, wound response as well as in other abiotic stresses. The enzyme 1-aminocyclopropane-1-carboxylate oxidase (ACO) catalyzes the last step of ethylene biosynthesis. The production of ethylene and the expression of a Coffea arabica ACO gene during the last stages of fruit maturation were investigated. A rapid increase of ethylene production at the green-yellow stage of fruit ripening, after the end of endosperm formation, and a decrease of ethylene production at the cherry stage indicates a climacteric phase during ripening. An ACC oxidase (Ca-ACO) from coffee fruit cDNA was cloned and characterized using primers previously reported. The cDNA is homologous to previously described ACC oxidase cDNA in Coffea. The nucleotide and amino acid deduced sequences of the clone showed high homology with ACO from climacteric fruits. Northern blots were performed to determine the Ca-ACO transcription pattern from different tissues and from fruits at different ripening stages. Coffee fruits at an early ripening stage (green) showed the lowest level of Ca-ACO transcript accumulation. The transcript levels of Ca-ACO did not change significantly during the later stages, suggesting the presence of post- transcriptional control mechanisms. These results, taken together, strongly suggest a climacteric nature of coffee fruit ripening.
Ripening of "Pedro Sato" guava: study on its climacteric or non-climacteric nature
Authors: Azzolini Marisa , Jacomino Angelo Pedro , Bron Ilana Urbano , Kluge Ricardo Alfredo , Schiavinato Marlene Aparecida
Published: December 2006

Guava (Psidium guajava L.) is a tropical fruit exhibiting rapid post-harvest ripening. However, the physiological basis involved in the ripening process of guava is not totally clear, which makes it difficult to develop technologies to enhance fruit storability. Two experiments were carried out with the objective of determining the ripening behavior of 'Pedro Sato' guavas. In the first experiment, guava fruits at three maturity stages (I - dark green, II - light green and III - yellow-green) were stored at room temperature (23 ± 1°C and 85 ± 5 % RH). The respiratory rate, ethylene production, pulp and skin colours, and firmness were evaluated. In the second experiment, ethylene and 1-methylcyclopropene (1-MCP) were applied to guavas at the light green maturity stage and the ripening behaviour during storage at room temperature was studied. Fruits from all maturity stages showed a gradual increase in the respiratory rate and ethylene production. The intense changes in pulp and skin colours and in firmness preceded the maximum respiratory rate and ethylene production. 1-MCP reduced the rate of ripening, while the application of ethylene did not promote this process. These results do not permit the classification of 'Pedro Sato' guava as a traditional climacteric fruit.
Bone defect regeneration with bioactive glass implantation in rats
Authors: Macedo Nelson Luiz de , Matuda Fábio da Silva , Macedo Luís Guilherme Scavonne de , Gonzales Michel Borges , Ouchi Suzana Martins , Carvalho Yasmin Rodarte
Published: December 2006

The main goal of this study was to histologically evaluate the healing of surgically created defects on the tibiae of adult male rats after implantation of two types of bioactive glass. Sixteen adult Wistar rats (body weight of 300g) were divided into two groups: PerioGlas (PG) (n=8) and BioGran (BG) (n=8). Unicortical bone defects with 3-mm diameter were performed in both tibiae of the animals and filled with two types of glass particles. The rats were then sacrificed at 7, 14, 30 and 60 days, and the tissues were prepared for histological processing, sectioning, and staining with hematoxylin and eosin, as well as Mallory trichrome, and analyzed under light microscope. Within 7-14 days, both groups presented connective tissue septa with new bone formation, more intense in the PG group. In the subsequent periods (30 and 60 days), both groups presented more mature bone tissue around the glass particles. Bone trabeculae formed in all experimental periods were juxtaposed to the glass particles. It can be concluded that both materials promoted comparable bone formation over the entire extension of the defect, independently of the size of the granules, thus confirming their biological osteoconductive property.
Dental fluorosis in children attending basic health units
Authors: Gonini Cristiane de Andrade Janene , Morita Maria Celeste
Published: December 2006

OBJECTIVES: The purpose of this study was to determine the prevalence and severity of dental fluorosis among patients attending basic health units in Londrina. METHODS: Five basic health units of the urban area were randomly selected and 434 children attending these units, born between 1986 and 1989 (9 to 12 years of age), were examined. Diagnosis of dental fluorosis was performed by means of the Thylstrup and Fejerskov (TF) Index. Oral examinations were carried out by 5 previously trained dentists with the patients lying in the dental chair, under artificial light, preceded by prophylaxis, isolation with cotton rolls and air-drying of the teeth. Ten percent of the sample was reexamined and an almost perfect agreement on diagnostic criteria was obtained either on the intra-examiner or inter-examiner evaluation (K=1.00, p<0.0001). RESULTS: The observed prevalence of dental fluorosis was 91.0%, and 87.8% of the individuals were classified as TF grade 2 or less. CONCLUSIONS: Despite of the low severity, the high prevalence observed shows the need for regular screening of dental fluorosis in Londrina; establishment of procedures to prevent the overutilization of fluoride both by the professionals and the population; sanitary surveillance of fluoride levels in water supply and also in all sources of fluoride available; besides the need for further studies to understand the factors associated to dental fluorosis among children living in Londrina.
Occlusal stabilization appliance: evaluation of its efficacy in the treatment of temporomandibular disorders
Authors: Tanaka Elisa Emi , Arita Emiko Saito , Shibayama Bunji
Published: December 2006

Occlusal stabilization appliances or splints are the most widely employed method for treatment of temporomandibular disorders (TMD). Magnetic Resonance Imaging (MRI) is the most indicated imaging modality to evaluate the components of the temporomandibular joint (TMJ). Forty patients with signs and symptoms of temporomandibular disorders were treated with splints for a mean period of 12 months, comprising regular semimonthly follow-ups. After stabilization of the clinical status, occlusal adjustments and MRI evaluation were performed. It was concluded that the success of this kind of treatment are related to the total (70%) or partial improvement (22.5%) of painful symptomatology and to the functional reestablishment of the craniomandibular complex. The MRI allowed evaluation and also the conclusion that the splints provide conditions for the organism to develop means to resist to the temporomandibular disorders by means of elimination of several etiologic factors. Moreover, after treatment the patients are able to cope with disc displacements with larger or smaller tolerance.
Elimination of intracanal infection in dogs' teeth with induced periapical lesions after rotary instrumentation: influence of different calcium hydroxide pastes
Authors: Soares Janir Alves , Leonardo Mário Roberto , Silva Léa Assed Bezerra da , Tanomaru Filho Mário , Ito Izabel Yoko
Published: December 2006

The aim of this study was to evaluate the antiseptic efficacy of rotary instrumentation associated with calcium hydroxide-based pastes prepared with different vehicles and antiseptics. Chronic periapical lesions were experimentally induced in 72 premolar root canals of four dogs. Under controlled asepsis, after initial microbiological sampling (A1), the root canals were instrumented using the ProFile system in conjunction with 5.25% sodium hypochlorite and the intracanal medication was placed. Four experimental groups were formed according to the pastes used: group 1- Calen (n=18), group 2- Calen+CPMC (n=20), group 3- Ca(OH)2 p.a.+ anaesthetic solution (n=16) and group 4- Ca(OH)2 p.a.+ 2% chlorhexidine digluconate (n=18). After 21 days, the pastes were removed; the canals were emptied and 96 hours later a second microbiological sample was obtained (A2). The incidence of positive microbiological cultures and the number of cfus in stages A1 and A2 were compared statistically by the Wilcoxon test while the influence of the different treatments in intracanal infection was evaluated by Kruskal-Wallis test at 5% significance level (p<0.05). Large numbers of strict and facultative anaerobes, and viridans group streptococci were found in 100% of root canals of A1 samples. Among A2 samples, all treatments showed significant reduction of cfus and positive cultures (p<0.05), but only groups 3 and 4 showed 100% of root canals free of microorganisms. Rotary instrumentation plus NaOCl 5.25% associated with intracanal medication produced a drastic reduction or elimination of intracanal microbiota, whose performance was not influenced by the nature of the vehicle or the antiseptic added to the Ca(OH)2 p.a.
Radiographic study of the prevalence of apical periodontitis and endodontic tratment in the adult population of São Luís, MA, Brazil
Authors: Terças Analúcia Guerra , Oliveira Ana Emília Figueiredo de , Lopes Fernanda Ferreira , Maia Filho Etevaldo Matos
Published: December 2006

This study investigated the prevalence of apical periodontitis (AP) and its association with endodontically treated teeth in residents of São Luís, MA, Brazil. Two-hundred complete series of periapical radiographs taken over a 10-year period (1993-2003) were retrieved from the files of four prosthesists and five periodontists. The Periapical Index (PAI) was used and the age range, sex, tooth groups, location and association with endodontic treatment (ET) were also analyzed. The Cohen Kappa and Chi-square tests were used for statistical analysis. Out of 200 patients, 135 presented at least one case of AP, which corresponds to a prevalence of 67.5%. Of the 5008 teeth examined, 296 had AP and 553 had ET. Therefore, considering the total number of teeth, AP and ET prevalences were 5.9% and 11%, respectively. Of the 553 endodontically treated teeth, 235 (42.5%) were associated with AP. Chi-square test showed a strong correlation between AP and ET (p<0.05). The 40-year-old age group was significantly the most prevalent (p<0.05). There was no association between AP and patient's sex (p>0.05). The maxillary incisors were the most affected group of teeth (p<0.05). AP had predilection for the maxilla and was strongly associated with endodontically treated teeth (p<0.05). The prevalence of apical periodontitis and endodontically treated teeth with AP was high and similar to the results of studies performed in other countries.
Comparative evaluation of antimicrobial action of MTA, calcium hydroxide and Portland cement
Authors: Ribeiro Caroline Sousa , Kuteken Fernanda Akemi , Hirata Júnior Raphael , Scelza Miriam F. Zaccaro
Published: December 2006

The present study aimed to evaluate and compare the antimicrobial effect of MTA Dentsply, MTA Angelus, Calcium Hydroxide and Portland cement. Four reference bacterial strains were used: Pseudomonas aeruginosa, Escherichia coli, Bacteroides fragilis, and Enterococcus faecalis. Plates containing Mueller-Hinton agar supplemented with 5% sheep blood, hemin, and menadione were inoculated with the bacterial suspensions. Subsequently, wells were prepared and immediately filled with materials and incubated at 37ºC for 48 hours under anaerobic conditions, except P. aeruginosa. The diameters of inhibition zones were measured, and data analyzed using ANOVA and the Tukey test with 1% level of significance. MTA Dentsply, MTA Angelus and Portland cement inhibited the growth of P. aeruginosa. Calcium Hydroxide was effective against P. aeruginosa and B. fragillis. Under anaerobic conditions, which may hamper the formation of reactive oxygen species, the materials failed to inhibit E. faecalis, and E. coli.
Influence of different methods of cervical flaring on establishment of working length
Authors: Lazzaretti Dieison Nardi , Camargo Bernardo Alievi , Della Bona Alvaro , Fornari Volmir João , Vanni José Roberto , Baratto Filho Flares
Published: December 2006

OBJECTIVE: to investigate the influence of three different rotary systems for cervical flaring on establishment of the real working length. MATERIAL AND METHODS: Thirty mandibular first molars were submitted to conventional endodontic access and initial working length measurement, followed by irrigation/suction of the pulp chamber with 5% sodium hypochlorite. Teeth were randomly divided into 3 groups (n=10) and cervical flaring of the mesiobuccal canals were performed using one of the following instrument systems: Group 1 - Gates-Glidden burs; Group 2 - Orifice Openers; Group 3 - La Axxess system. Two subsequent numbers of instruments of each rotary system were used and the final working length was recorded. A digital calyper was used to record the working length, in millimeters, to investigate a possible discrepancy between initial and final measurements. RESULTS: Analysis of variance (Anova) na Tukey test revealed statistical difference between Group 1 and Groups 2 and 3 (p£ 0.05). CONCLUSIONS: all groups presented shorter working length after cervical flaring; groups prepared with instruments La Axxes and Orifice Opener presented the best results among the systems studied.
Histomicrobiologic aspects of the root canal system and periapical lesions in dogs' teeth after rotary instrumentation and intracanal dressing with Ca(OH)2 pastes
Authors: Soares Janir Alves , Leonardo Mário Roberto , Silva Léa Assed Bezerra da , Tanomaru Filho Mário , Ito Izabel Yoko
Published: December 2006

OBJECTIVE: The purpose of this study was to evaluate the distribution of microorganisms in the root canal system (RCS) and periapical lesions of dogs' teeth after rotary instrumentation and placement of different calcium hydroxide [Ca(OH)2]-based intracanal dressings. MATERIALS AND METHODS: Chronic periapical lesions were experimentally induced in 80 premolar roots of four dogs. Instrumentation was undertaken using the ProFile rotary system and irrigation with 5.25% sodium hypochlorite. The following Ca(OH)2-based pastes were applied for 21 days: group 1 - Calen (n=18); group 2 - Calen+CPMC (n=20); group 3 - Ca(OH)2 p.a. + anaesthetic solution (n=16) and group 4 - Ca(OH)2 p.a.+ 2% chlorhexidine digluconate (n=18). Eight root canals without endodontic treatment constituted the control group. Histological sections were obtained and stained with Brown & Brenn staining technique to evaluate the presence of microorganisms in the main root canal, ramifications of the apical delta and secondary canals, apical cementoplasts, dentinal tubules, areas of cemental resorption and periapical lesions. The results were analyzed statistically by the Mann-Whitney U test (p<0.05). RESULTS: The control group showed the highest prevalence of microorganisms in all sites evaluated. Gram-positive cocci, bacilli and filaments were the most frequent morphotypes. Similar microbial distribution patterns in the RCS and areas of cementum resorption were observed in all groups (p>0.05). The percentage of RCS sites containing microorganisms in groups 1, 2, 3, 4 and control were: 67.6%, 62.5%, 78.2%, 62.0% and 87.6%, respectively. CONCLUSION: In conclusion, the histomicrobiological analysis showed that the rotary instrumentation and the different calcium hydroxide pastes employed did not effectively eliminate the infection from the RCS and periapical lesions. However, several bacteria seen in the histological sections were probably dead or were inactivated by the biomechanical preparation and calcium hydroxide-based intracanal dressing.
Influence of root embedment material and periodontal ligament simulation on fracture resistance tests
Authors: Soares Carlos José , Pizi Eliane Cristina Gava , Fonseca Rodrigo Borges , Martins Luis Roberto Marcondes
Published: December 2006

The aim of this study was to evaluate the influence of the embedment material and periodontal ligament simulation on fracture resistance of bovine teeth. Eighty bovine incisor teeth were randomized into 8 groups (n = 10), embedded in acrylic or polystyrene resin using 4 types of periodontal ligament simulation: 1 - absence of the ligament; 2 - polyether impression material; 3 - polysulfide impression material; 4 - polyurethane elastomeric material. The specimens were stored at 37°C and 100% humidity for 24 hours. Specimens were submitted to tangential load on the palatal surface at 0.5 mm/minute crosshead speed until fracture. The fracture modes were analyzed as follows: 1 - coronal fracture; 2 - cemento-enamel junction fracture; 3 - partial root fracture; 4 - total root fracture. Statistical analyses by two-way ANOVA and Tukey's test were applied (p < 0.05). The results showed that root embedment method and periodontal ligament simulation have a significant effect on fracture resistance. Artificial periodontal ligament modified the fracture modes.
Influence of carbamide peroxide-based bleaching agents on the bond strength of resin-enamel/dentin interfaces
Authors: Cavalli Vanessa , Carvalho Ricardo Marins de , Giannini Marcelo
Published: December 2006

In this bond strength study, a bleaching agent containing 10% carbamide peroxide was applied over composite-teeth bonded interfaces of two adhesive systems applied to enamel and dentin. Sixteen human third molars were used for bonding procedures. Single Bond (SB) and Clearfil SE Bond (CB) were applied to enamel and dentin according to the manufacturers' instructions. A resin composite cube-like structure was incrementally built on the bonded surfaces. The restored teeth were sectioned into 0.7 mm thick slices that were trimmed at enamel or dentin bonded interfaces to an hourglass shape with a cross-sectional area of approximately 0.5 mm². Specimens were assigned to 8 groups (n = 10) according to the following factors under study: dental substrate (enamel and dentin); adhesive system (SB and CB) and treatment (10% carbamide peroxide and not bleached/control). The bleaching gel (Opalescence) was applied at the bonded interfaces for 6 hours during 14 days and after daily treatment specimens were stored in artificial saliva. Unbleached specimens were stored in artificial saliva for 14 days. Specimens were tested for tension and the data were analyzed by three-way ANOVA and Tukey's test (p < 0.05). Enamel tensile bond strength of CB was reduced after carbamide peroxide application. The bleaching treatment did not alter dentin bond strength of both adhesives. The results suggest that bleaching significantly affects bond strength of CB to enamel, but no influence on bond strength to dentin was noted for both adhesive systems.
CT interpretation of craniofacial anomalies: a comparative analysis by undergraduate dental students
Authors: Gaia Bruno Felipe , Perella Andréia , Cara Ana Cláudia Ballet de , Antunes José Leopoldo Ferreira , Cavalcanti Marcelo Gusmão Paraiso
Published: December 2006

The aim of this study was to evaluate the accuracy and reproducibility of computed tomography (CT) image interpretation made in axial slices (2D-CT) and 3D reconstructed images (3D-CT) of patients with craniofacial anomalies. The analyses were made by undergraduate dental students, and compared with the diagnoses considered upon surgical intervention. Computed tomography of 43 patients were analyzed independently by three calibrated examiners (undergraduate students) with, respectively, one, two, and three semesters of experience in craniofacial CT training and interpretation. The analysis of 2D-CT and 3D-CT images were performed at distinct times using an independent workstation associated with a specific computer graphics software for volumetric images. The analysis of inter-examiner agreement and of the agreement between observers and the gold standard was performed using the Kappa test. The accuracy evaluation presented a progressively higher value for examiners with progressively broader experience in 2D-CT and 3D-CT image interpretation. 3D-CT analyses allowed a higher inter-examiner agreement (1 - 0.896) than 2D-CT analyses (1 - 0.614). 3D-CT was considered more precise and accurate than 2D-CT for all students' evaluations. The reproducibility and accuracy varied according to the experience in CT interpretation, and the most experienced student achieved results closer to the gold standard.
Hydroelectric power without water storage
Authors: Shaw T. L.
Published: December 2006

Although reservoirs benefit the performance of hydropower schemes there is no overriding operational need for them. Wind and solar power projects function well without storage, as will the planned range of marine energy devices. This paper reviews the equivalent features of ‘run-of-river’ hydro schemes which in essence operate in response to rainfall, that is, according to the variation of river flow resulting from the natural release of water from catchments.
Reducing carbon dioxide emissions from UK road transport
Authors: Simpson B. J.
Published: December 2006

Several cases of extreme local weather conditions since the storms of October 1987 have served as reminders of some of the possible consequences of global warming, recently more usually, although less precisely, referred to as ‘climate change’. Carbon dioxide emissions have been identified as the principal likely culprit and road traffic is the only major source from the UK which is increasing in amount. Local authorities may feel impotent to make a significant contribution to a solution, but example is a worthwhile motive. A local authority can contribute in several ways: implementation of improved vehicle technologies; adopting road speed limits and upholding them; promotion of driving styles which are more sensitive to their environmental effects and of improved vehicle maintenance; policies to change mode of travel and transport and to reduce the amount of travel by several means, including fuller use of vehicles. Many of the ways of reducing carbon dioxide discharges locally will have other environmental benefits. The implementation of cleaner travel lags behind the science to allow it; local authorities have an important role to play in reducing the gap. Average vehicle loadings are low, especially for personal travel; there is much scope for improved environmental performance, and for public transport there are issues relating to value for public spending. Reductions in the amount of travel can also contribute to several government policies relating to social exclusion, promotion of sustainable communities and supporting town centre activities.
Impact of transport policies on energy use and emissions
Authors: Nepal S. M.
Published: December 2006

There are numerous mid-sized cities in the developing world and most of them lack effective urban management and transportation policies. Though city efforts to reduce global warming potential (GWP) emissions may be low in the global context, effective transportation policies in cities will have obvious results. Taking the Kathmandu Valley as a case study, this paper makes an attempt to analyse the implication of different transportation policies for reducing vehicular emissions and energy consumption. This paper estimates and analyses current and future trends of energy demand and environmental emissions, especially CO2 and PM10 from passenger road transportation in the Kathmandu Valley. The study is based on the primary data collected at the busiest and longest inner city road. It uses the long range energy alternatives planning system framework to construct future scenarios up to 2025. It analyses future scenario implications mainly dealing with the introduction of trolley buses, promotion of public transportation, discouraging private vehicles and low occupancy public vehicles, increasing vehicular speed, and other transportation policies. The study estimated that the 637 million passenger-kilometres traveled in the study route during 2004 resulted in 34·8 million kg of CO2 emissions. The travel demand is estimated to multiply by 7·8 with a corresponding twelve-fold increase in CO2 emissions and a ten-fold increase in total suspended particles (TSP) emissions in the study route from 2004 to 2024 under a non-intervention scenario. This scenario analysis suggests that discouraging private vehicles, thereby promoting mass transportation operated by electricity, can reduce CO2 by 43·7% and TSP by 43·8% compared with a scenario of non-intervention. In addition to transportation policies, effective land-use planning and encouragement of nonmotorised transport can have more positive impacts. Since Nepal is the Himalayan Kingdom, having many glaciers and snow-fed rivers, it is in great risk of global warming. Therefore change should begin immediately.
The environmental importance of front gardens
Authors: Alexander D. A.
Published: December 2006

The environmental importance of front gardens is examined in the context of climate change. Domestic front gardens help to absorb carbon dioxide, soak up rainfall and thus reduce flooding risks, provide open spaces for pleasant townscapes, protect biodiversity reserves and help conserve energy through shade and shelter. The continuing loss of front gardens is a result of increasing car ownership, off-street parking pressures, changes in garden fashion, wider lifestyle changes and perhaps also the absence in some cultures of any garden tradition. At a time of climatic uncertainty there are many positive ways in which a multi-purpose approach to front gardens can allow parking while retaining a green garden. The planning system is needed to ensure national awareness of the environmental importance of front gardens. The significance of their increasing loss and a multiple-use approach to alleviate the problems caused by current trends are discussed.
Hydrobia ulvaefeeding rates: A novel way to assess sediment toxicity
Authors: Shipp Emily , Grant Alastair
Published: December 2006

Standard acute toxicity tests are widely used to assess contaminated sediments. However, such tests last 10 d or more and only provide information regarding lethality. Here, we present data concerning the use of a 28-d growth test and a 24-h test using feeding rate, as measured by egestion rate, of the marine snail Hydrobia ulvae. The test was used to assess the toxicity of estuarine sediments from a gradient of heavy metal contamination, and its sensitivity and ease of use were compared with those of 10-d tests using the amphipod crustacean Corophium volutator. Mortality of C. volutator and H. ulvae in 10-d lethal toxicity tests showed similar patterns of sensitivity. Lethality tests with both species showed no effects when carried out using sediments from a number of sites at which ecological impacts are known to occur. By contrast, growth over 28 d in H. ulvae was reduced at all sites where other studies have detected adverse ecological effects. Feeding rate after 24 h also was decreased at moderately contaminated sites where sediments were not acutely toxic, and it was a very good predictor of 28-d growth (r2 = 0.74). Both tests were straightforward to carry out, so H. ulvae has considerable potential as a test organism for chronic toxicity.
Plasma membrane surface potential (ψpm) as a determinant of ion bioavailability: A critical analysis of new and published toxicological studies and a simplified method for the computation of plant ψpm
Authors: Kinraide Thomas B.
Published: December 2006

Plasma membranes (PMs) are negatively charged, and this creates a negative PM surface electrical potential ψPM) that is also controlled by the ionic composition of the bathing medium. The ψPM controls the distribution of ions between the PM surface and the medium so that negative potentials increase the surface activity of cations and decrease the surface activity of anions. All cations reduce the negativity of ψPM, and these common ions are effective in the following order: Al3+ > H+ > Cu2+ > Ca2+ ≈ Mg2+ > Na+ ≈ K+. These ions, especially H+, Ca2+, and Mg2+, are known to reduce the uptake and biotic effectiveness of cations and to have the opposite effects on anions. Toxicologists commonly interpret the interactions between toxic cations (commonly metals) and ameliorative cations (commonly H+, Ca2+, and Mg2+) as competitions for binding sites at a PM surface ligand. The ψPM is rarely considered in this biotic ligand model, which incorporates the free ion activity model. The thesis of this article is that ψPM effects are likely to be more important to bioavailability than site-specific competition. Furthermore, ψPM effects could give the false appearance of competition even when it does not occur. The electrostatic approach can account for the bioavailability of anions, whereas the biotic ligand model cannot, and it can account for interactions among cations when competition does not occur. Finally, a simplified procedure is presented for the computation of ψPM for plants, and the possible use of ψPM in a general assessment of the bioavailability of ions is considered.
Epifluorescence microscopy and image analysis of high-level polycyclic aromatic hydrocarbon contamination in soils
Authors: Roper J. Chadwick , Brown Denise M. , Sullivan Michelle A. , Schoonhoven Robert , Swenberg James A. , Pfaender Frederic K.
Published: December 2006

Interactions between polycyclic aromatic hydrocarbons (PAHs) and soil are an important determinant of their chemical availability and transport. Laboratory examination of microscale PAH–soil interaction is limited by the availability of methods for particle-scale observation. Inverted epifluorescence microscopy, combined with digital photography and computer image analysis, was evaluated for specificity and linearity using dissolved PAHs. A pyrene filter (excitation wavelength, 360–400 nm; emission wavelength, 450–520 nm) gave nonspecific PAH fluorescence, and bias for fluoranthene, benzo[b]fluoranthene, benzo[g, h, i]perylene, and benz[a]anthracene was quantified in comparison to that for pyrene. Concentrations ranging from 1 to 10 mM for anthracene, fluoranthene, and pyrene and from 1 to 50 mM for naphthalene produced a linear response with low interpixel variability. Liquid-phase analyses validated use of the technique for the descriptive analysis of PAH distribution in solid samples, but liquid-phase calibration was not quantitative for spiked or field-contaminated soils. The mean luminance for three field soils was proportional to the values predicted from their chemically measured concentrations and to values from spiked, aged, uncontaminated materials. Image analysis of laboratory- and field-contaminated samples determined the area distribution of fluorescent intensity and the size of fluorescent areas exceeding a threshold luminance. These qualitative descriptions of the microscale spatial distribution of PAH contamination are presented as potential endpoints for future research on biogeochemical interactions in heavily contaminated solids.