Temporal variation of the phytoplankton community at short sampling intervals in the Mundaú reservoir, Northeastern Brazil

The aim of this study was to determine how abiotic factors drive the phytoplankton community in a water supply reservoir within short sampling intervals. Samples were collected at the subsurface (0.1 m) and bottom of limnetic (8 m) and littoral (2 m) zones in both the dry and rainy seasons. The following abiotic variables were analyzed: water temperature, dissolved oxygen, electrical conductivity, total dissolved solids, turbidity, pH, total nitrogen, nitrite, nitrate, total phosphorus, total dissolved phosphorus and orthophosphate. Phytoplankton biomass was determined from biovolume values. The role abiotic variables play in the dynamics of phytoplankton species was determined by means of Canonical Correspondence Analysis. Algae biomass ranged from 1.17×10(4) to 9.21×10(4) µg.L-1; cyanobacteria had biomass values ranging from 1.07×10(4) to 8.21×10(4) µg.L-1. High availability of phosphorous, nitrogen limitation, alkaline pH and thermal stability all favored cyanobacteria blooms, particularly during the dry season. Temperature, pH, total phosphorous and turbidity were key factors in characterizing the phytoplankton community between sampling times and stations. Of the species studied, Cylindrospermopsis raciborskii populations were dominant in the phytoplankton in both the dry and rainy seasons. We conclude that the phytoplankton was strongly influenced by abiotic variables, particularly in relation to seasonal distribution patterns.

Patterns of distribution of the hermit crab Loxopagurus loxochelis (Moreira, 1901) (Decapoda, Diogenidae) in two coastal areas of southern Brazil

The present study determined the distribution pattern of the hermit crab Loxopagurus loxochelis by a comparison of catch, depth and environmental factors at two separate bays (Caraguatatuba and Ubatuba) of Sao Paulo State, Brazil. The influence of these parameters on the distribution of males, non- ovigerous females and ovigerous females was also evaluated. Crabs were collected monthly, over a period of one year (from July/2002 to June/2003), in seven depths, from 5 to 35 m. Abiotic factors were monitored as follows: superficial and bottom salinity (psu), superficial and bottom temperature (C), organic matter content (%) and sediment composition (%). In total, 366 hermit crabs were sampled in Caraguatatuba and 126 in Ubatuba. The highest frequency of occurrence was verified at 20 m during winter (July) in Caraguatatuba and 25 m during summer (January) in Ubatuba. The highest occurrences were recorded in the regions with bottom salinities ranging from 34 to 36 psu, bottom temperatures from 18 to 24 C and, low percentages of organic matter, gravel and mud; and large proportion of sand in the substrate. There was no significant correlation between the total frequency of organisms and the environmental factors analyzed in both regions. This evidence suggests that other variables as biotic interactions can influence the pattern of distribution of L. loxochelis in the analyzed region, which is considered the limit of the northern distribution of this species.

Reproductive Activity and Survivorship of Liriomyza sativae (Diptera: Agromyzidae) at Different Temperatures and Relative Humidity Levels

We studied a population of Liriomyza sativae Blanchard (Diptera: Agromyzidae) identified by morphological and molecular techniques from the semiarid region of the Brazilian northeast. The influence of temperature and relative humidity on the survival and reproductive parameters of L. sativae in cowpeas (Vigna unguiculata L. Walp.) (Fabales: Fabaceae) was evaluated. We used temperatures of 18, 20, 22, 25, 28, 30, and 32 +/- 1 degrees C (50 +/- 10% RH) and relative humidity values of 30,50,70, and 90 +/- 10% (25 +/- 1 degrees C) under a 14 L:10 D photoperiod. Adult longevity decreased as temperature and relative humidity increased and was greater, in general, for females. The preoviposition and oviposition periods also decreased as temperature increased, whereas relative humidity only caused reductions in the oviposition period at higher levels. Fecundity was similar in the range from 18 to 30 degrees C but decreased at 32 degrees C with respect to relative humidity; the best performances of L. sativae occurred at lower levels. The pattern of oviposition rate changed with temperature and relative humidity. Regardless of temperature and relative humidity, L, sativae laid between 75 and 92% of its eggs on the adaxial surface of the cowpea leaves. This information will be highly useful to design a leafminer production system aimed at the multiplication of natural enemies, as well as for pest management in the field.

Culture-Independent Assessment of Rhizobiales-Related Alphaproteobacteria and the Diversity of Methylobacterium in the Rhizosphere and Rhizoplane of Transgenic Eucalyptus

The rhizosphere is an ecosystem exploited by a variety of organisms involved in plant health and environmental sustainability. Abiotic factors influence microorganism-plant interactions, but the microbial community is also affected by expression of heterologous genes from host plants. In the present work, we assessed the community shifts of Alphaproteobacteria phylogenetically related to the Rhizobiales order (Rhizobiales-like community) in rhizoplane and rhizosphere soils of wild-type and transgenic eucalyptus. A greenhouse experiment was performed and the bacterial communities associated with two wild-type (WT17 and WT18) and four transgenic (TR-9, TR-15, TR-22, and TR-23) eucalyptus plant lines were evaluated. The culture-independent approach consisted of the quantification, by real-time polymerase chain reaction (PCR), of a targeted subset of Alphaproteobacteria and the assessment of its diversity using PCR-denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone libraries. Real-time quantification revealed a lesser density of the targeted community in TR-9 and TR-15 plants and diversity analysis by principal components analysis, based on PCR-DGGE, revealed differences between bacterial communities, not only between transgenic and nontransgenic plants, but also among wild-type plants. The comparison between clone libraries obtained from the transgenic plant TR-15 and wild-type WT17 revealed distinct bacterial communities associated with these plants. In addition, a culturable approach was used to quantify the Methylobacterium spp. in the samples where the identification of isolates, based on 16S rRNA gene sequences, showed similarities to the species Methylobacterium nodulans, Methylobacterium isbiliense, Methylobacterium variable, Methylobacterium fujisawaense, and Methylobacterium radiotolerans. Colonies classified into this genus were not isolated from the rhizosphere but brought in culture from rhizoplane samples, except for one line of the transgenic plants (TR-15). In general, the data suggested that, in most cases, shifts in bacterial communities due to cultivation of transgenic plants are similar to those observed when different wild-type cultivars are compared, although shifts directly correlated to transgenic plant cultivation may be found.

The effect of temperature and fasting period on the viability of free-living females of Rhipicephalus sanguineus (Acari : Ixodidae) under laboratory conditions

Little is known about the effect of temperature on viability of free-living phases of the life cycle of Rhipicephalus sanguineus (Latreille, 1806) despite of its importance as vector of several pathogens. Knowledge of the effect of abiotic factors on the capacity of a given tick species to infest new hosts is important for routine experimental activities under laboratory conditions, and may be relevant to understand the transmission of pathogens. The study evaluates the viability of R. sanguineus females held at 18 +/- 1, 27 +/- 1 and 32 +/- 1 degrees C and 80 +/- 5% RH (saturation deficits of 3.0, 5.3 and 7.2 mmHg, respectively) for three fasting periods (3 and 20 days and the day when female mortality reached approximately 50% after ecdysis), under laboratory conditions. In general, the best result on viability was obtained when rabbits were infested with unfed female ticks after three or 20 fasting days at both 27 +/- 1 and 32 +/- 1 degrees C and 80 +/- 5% RH.

Relief influence on tree species richness in secondary forest fragments of Atlantic Forest, SE, Brazil

(Relief influence on tree species richness in secondary forest fragments of Atlantic Forest, SE, Brazil). The aim of this work was to explore the relationship between tree species richness and morphological characteristics of relief at the Ibiuna Plateau (SE Brazil). We sampled 61 plots of 0.30 ha, systematically established in 20 fragments of secondary forest (2-274 ha) and in three areas within a continuous secondary forest site, Morro Grande Reserve (9,400 ha). At each plot, 100 trees with diameter at breast height > 5 cm were sampled by the point centered quarter method, and total richness and richness per dispersal and succession class were obtained. The relief was characterized by the mean and variance of slope, elevation, aspect and slope location. There was no significant relationship between relief heterogeneity and tree species richness. Relief parameters generally did not affect tree richness, but elevation was particularly important especially in the continuous forest. Despite the limited range of altitudinal variation (150 m), species richness increases with elevation. The highest areas were also those with the largest forest cover and the lowest disturbance degree, which should contribute to the greater richness of those sites. Our results suggest an indirect influence of relief, due to the fact that deforestation is less intense in higher regions, rather than a direct influence of abiotic factors related to the altitudinal gradient.

Relative populations and toxin production by Aspergillus flavus and Fusarium verticillioides in artificially inoculated corn at various stages of development under field conditions

The presence, development and production of mycotoxins by Aspergillus flavus and Fusarium verticillioides were studied in corn ears under field conditions after artificial contamination of corn silks. The planted area was divided into five treatments: T1, inoculated with A.flavus solution containing 1 x 10(8) spores, ears covered; T2, inoculated with F. verticillioides solution containing 1 X 10(8) spores, ears covered; T3, inoculated with E verticillioides plus A. flavus solution containing 1 x 10(8) spores of each, ears covered; T4, sprayed with sterile phosphate-buffered saline, ears covered; TS, non-sprayed silks, uncovered ears. Soil and air samples were also collected and analysed for the occurrence of fungi. Water activity, relative air humidity, rainfall and temperature were determined to assess the correlation between abiotic factors and the presence of fungi in the samples. Contamination with the inoculated fungus predominated in T1 and T2. In the other treatments, F. verticillioides was the most frequently isolated contaminant irrespective of treatment. Considering the production of mycotoxins, a positive relation between the production of fumonisins B-1 and B-2 and the frequency of F. verticillioides was statistically verified in all treatments. (C) 2007 Society of Chemical Industry.

Distribution of fungi and aflatoxins in a stored peanut variety

The objective of the present study was to evaluate the mycoflora and occurrence of aflatoxins in stored peanut samples (hulls and kernels) from Tupa, State of Sao Paulo, Brazil. The samples were analyzed monthly over a period of one year. The results showed a predominance of Fusarium spp. (67.7% in hulls and 25.8% in kernels) and Aspergillus spp. (10.3% in hulls and 21.8% in kernels), and the presence of five other genera. The growth of Aspergillus flavus was mainly influenced by temperature and relative humidity. Analysis of hulls showed that 6.7% of the samples were contaminated with AFB(1) (mean levels 15-23.9 mu g/kg) and AFB(2) (mean levels = 3.3-5.6 mu g/kg); in kernels, 33.3% of the samples were contaminated with AFB(1) (mean levels 7.0-116 mu g/kg) and 28.3% were contaminated with AFB(2) (mean levels = 3.3-45.5 mu g/kg). Analysis of the toxigenic potential revealed that 93.8% of the A. flavus strains isolated were producers of AFB(1) and AFB(2). mu 2007 Elsevier Ltd. All rights reserved.

Mycoflora and fumonisin contamination in Brazilian sorghum from sowing to harvest

BACKGROUND: The aim of this study was to characterise the mycoflora and the presence of fumonisin in sorghum grains, correlating the results with the environment and abiotic factors. RESULTS: Fifty samples (five collections of ten samples each) of sorghum were analysed. All samples were found to be contaminated with fungi, with higher frequencies of Cladosporium spp. (61.8%) and Helminthosporium spp. (33.4%). Fusarium verticillioides was isolated from 15.1% of the samples, with 38% of them being contaminated with fumonisin B(1) (FB(1)) at levels ranging from 50 to 368.78 ng g(-1). Regarding abiotic factors, temperature, water activity and rainfall showed a positive correlation with the frequency of F. verticillioides and FB(1) production. There was a significant positive correlation between relative air humidity and FB(1) production. The results obtained from sexual crosses between standard F mating tester strains and the isolated strains confirmed that the strains isolated were F. verticillioides. CONCLUSION: It can be concluded that the decrease in F. verticillioides and fumonisin contamination occurred owing to atypical climatic factors during the period of sorghum cultivation, when there was any occurrence of rain and the level of water activity of grains did not reach 0.58. (C) 2010 Society of Chemical Industry

Dental caries and related factors in Brazilian children from fluoridated and non-fluoridated areas

PURPOSE: To compare the caries prevalence, saliva buffering capacity (SBC), oral hygiene (OH), dietary habits, family income (FI) and frequency of visits to a dental office (Do) between Brazilian children living in areas with and without fluoridated public water supply. METHODS: Forty-six 5-7-year-old preschoolers were selected in Itatiba, SP, Brazil; 19 were from a fluoridated area, and 27 were from a non-fluoridated area. The caries index was determined according to the World Health Organization criteria, and the SBC was assessed by titration with hydrochloric acid. The FI, frequency of OH and visits to Do were estimated by questionnaire. The dietary habits were assessed with a diet chart. The differences between the groups were analyzed with Mann-Whitney-U tests (α=0.05). RESULTS: Children from the non-fluoridated area showed significantly higher dmft/DMFT than those from the fluoridated area, but they showed significantly lower SBC, OH frequency and FI. No significant differences were observed between the areas for dietary habits and visits to Do. CONCLUSION: Children from fluoridated areas showed higher salivary buffering capacity, family income and oral hygiene frequency as well as lower caries prevalence, supporting the beneficial effect of fluoride in the tap water for caries prevention.

Diagnostic and clinical factors associated with pulpal and periapical pain

A retrospective survey was designed to identify diagnostic subgroups and clinical factors associated with odontogenic pain and discomfort in dental urgency patients. A consecutive sample of 1,765 patients seeking treatment for dental pain at the Urgency Service of the Dental School of the Federal University of Goiás, Brazil, was selected. Inclusion criteria were pulpal or periapical pain that occurred before dental treatment (minimum 6 months after the last dental appointment), and the exclusion criteria were teeth with odontogenic developmental anomalies and missing information or incomplete records. Clinical and radiographic examinations were performed to assess clinical presentation of pain complaints including origin, duration, frequency and location of pain, palpation, percussion and vitality tests, radiographic features, endodontic diagnosis and characteristics of teeth. Chi-square test and multiple logistic regression were used to analyze association between pulpal and periapical pain and independent variables. The most frequent endodontic diagnosis of pulpal pain were symptomatic pulpitis (28.3%) and hyperreactive pulpalgia (14.4%), and the most frequent periapical pain was symptomatic apical periodontitis of infectious origin (26.4%). Regression analysis revealed that closed pulp chamber and caries were highly associated with pulpal pain and, conversely, open pulp chamber was associated with periapical pain (p<0.001). Endodontic diagnosis and local factors associated with pulpal and periapical pain suggest that the important clinical factor of pulpal pain was closed pulp chamber and caries, and of periapical pain was open pulp chamber.

Prevalence and risk factors of apical periodontitis in endodontically treated teeth in a selected population of Brazilian adults

The aim of this study was to assess the prevalence and risk factors of apical periodontitis in endodontically treated teeth in a selected population of Brazilian adults. A total of 1,372 periapical radiographs of endodontically treated teeth were analyzed based on the quality of root filling, status of coronal restoration and presence of posts associated with apical periodontitis (AP). Data were analyzed statistically using odds ratio, confidence intervals and chi-square test. The prevalence of AP with adequate endodontic treatment was low (16.5%). This percentage dropped to 12.1% in cases with adequate root filling and adequate coronal restoration. Teeth with adequate endodontic treatment and poor coronal restoration had an AP prevalence of 27.9%. AP increased to 71.7% in teeth with poor endodontic treatment associated with poor coronal restoration. When poor endodontic treatment was combined with adequate coronal restoration, AP prevalence was 61.8%. The prevalence of AP was low when associated with high technical quality of root canal treatment. Poor coronal restoration increased the risk of AP even when endodontic treatment was adequate (OR=2.80; 95%CI=1.87-4.22). The presence of intracanal posts had no influence on AP prevalence.

Multivariate analysis of the effects of soil parameters and environmental factors on the flavonoid content of leaves of Passiflora incarnata L., Passifloraceae

The aim of the present study was to evaluate the effect of soil characteristics (pH, macro- and micro-nutrients), environmental factors (temperature, humidity, period of the year and time of day of collection) and meteorological conditions (rain, sun, cloud and cloud/rain) on the flavonoid content of leaves of Passiflora incarnata L., Passifloraceae. The total flavonoid contents of leaf samples harvested from plants cultivated or collected under different conditions were quantified by high-performance liquid chromatography with ultraviolet detection (HPLC-UV/PAD). Chemometric treatment of the data by principal component (PCA) and hierarchic cluster analyses (HCA) showed that the samples did not present a specific classification in relation to the environmental and soil variables studied, and that the environmental variables were not significant in describing the data set. However, the levels of the elements Fe, B and Cu present in the soil showed an inverse correlation with the total flavonoid contents of the leaves of P. incarnata.

Association of dental enamel lead levels with risk factors for environmental exposure

OBJECTIVE: To analyze household risk factors associated with high lead levels in surface dental enamel. METHODS: A cross-sectional study was conducted with 160 Brazilian adolescents aged 14-18 years living in poor neighborhoods in the city of Bauru, southeastern Brazil, from August to December 2008. Body lead concentrations were assessed in surface dental enamel acid-etch microbiopsies. Dental enamel lead levels were measured by graphite furnace atomic absorption spectrometry and phosphorus levels were measured by inductively coupled plasma optical emission spectrometry. The parents answered a questionnaire about their children's potential early (05 years old) exposure to well-known lead sources. Logistic regression was used to identify associations between dental enamel lead levels and each environmental risk factor studied. Social and familial covariables were included in the models. RESULTS: The results suggest that the adolescents studied were exposed to lead sources during their first years of life. Risk factors associated with high dental enamel lead levels were living in or close to a contaminated area (OR = 4.49; 95% CI: 1.69;11.97); and member of the household worked in the manufacturing of paints, paint pigments, ceramics or batteries (OR = 3.43; 95% CI: 1.31;9.00). Home-based use of lead-glazed ceramics, low-quality pirated toys, anticorrosive paint on gates and/or sale of used car batteries (OR = 1.31; 95% CI: 0.56;3.03) and smoking (OR = 1.66; 95% CI: 0.52;5.28) were not found to be associated with high dental enamel lead levels. CONCLUSIONS: Surface dental enamel can be used as a marker of past environmental exposure to lead and lead concentrations detected are associated to well-known sources of lead contamination.

Analysis of the prevalence of and factors associated with urinary incontinence among elderly people in the Municipality of São Paulo, Brazil: SABE Study (Health, Wellbeing and Aging)

To investigate the prevalence of urinary incontinence among elderly people living in São Paulo, Brazil and their associated risk factors. The Pan-American Health Organization and World Health Organization coordinated a multicenter study named Health, Wellbeing and Aging (SABE Study) in elderly people (over 60 years old) living in seven countries in Latin America and the Caribbean. In Brazil, the study was carried out in São Paulo in the year 2000. The total Brazilian sample included 2,143 people. The prevalence of self reported urinary incontinence was 11.8% among men and 26.2% for women. It was verified that among those reporting urinary incontinence, 37% also reported stroke and 34% depression. It was found that the greater the dependence that the elderly people presented, the greater the prevalence of urinary incontinence. The associated factors found were depression (odds ratio = 2.49), female (2.42), advanced age (2.35), important functional limitation (2.01). Urinary incontinence is a highly prevalent symptom among the elderly population of the municipality of São Paulo, especially among women. The adoption of preventive measures can reduce the negative effects of urinary incontinence.