Manganese Defective Clustering: Influence on the Spectroscopic Features of Ceria-Based Nanomaterials.

The influence of manganese modification on the spectroscopic features of manganese-doped CeO2 systems synthesized by the microwave-assisted hydrothermal route and their correlation with the presence of O defective structures were verified, focusing on their interaction with poisonous atmospheres. Raman and electron paramagnetic resonance studies confirmed the presence of defective clusters formed by dipoles and/or quadrupoles. The number of paramagnetic species was found to be inversely proportional to the doping concentration, resulting in an increase in the Mn2+ signal, likely due to the reduction of Mn3+ species after the interaction with CO. X-ray photoelectron spectroscopy data showed the pure system with 33% of its cerium species in the Ce3+ configuration, with an abrupt decrease to 19%, after the first modification with Mn, suggesting that 14% of the Ce3+ species are donating one electron to the Mn2+ ions, thus becoming nonparamagnetic Ce4+ species. On the contrary, 58% of the manganese species remain in the Mn2+ configuration with five unpaired electrons, corroborating the paramagnetic feature of the samples seen in the electron paramagnetic resonance study.

Salivary biomarkers present in patients with periodontitis without clinical distinction: findings from a meta-analysis.

BACKGROUND: A new classification for periodontitis has been adopted in clinical practice. However, there are still discussions regarding this new classification and difficulties in its adoption, both by professionals and researchers. Thus, this study aimed to evaluate which salivary biomarkers are present in periodontitis, following the new classification of periodontal diseases through meta-analysis. MATERIAL AND METHODS: A literature search was carried out in the scientific databases: PubMed, Scielo and Google scholar to select studies. The selection of studies was followed by two authors upon reading of the title, abstract and full text. The necessary data were collected and statistical analyses were performed using the Review Manager statistical software version 5.4, with calculation of Mean Difference, heterogeneity (I²) and funnel plot with P < 0.05. RESULTS: After following the selection criteria, 9 articles were selected for comparison. The studies address the presence of biomarkers in the saliva of patients with periodontitis and their possible use in the monitoring and diagnosis of the disease. For the meta-analytic comparison, a sample size of 1,983 individuals was used. Statistical analyses showed that nitric oxide, IL-6, IL-1B and osteoprotegerin are substances that are significantly present in patients with periodontitis (P < 0.05). CONCLUSIONS: IL-6, nitric oxide, IL-1B, TNF-α and osteoprotegerin are among the most present biomarkers in patients with periodontitis, and may be used in the future as a monitoring of periodontal disease. The present study also revealed that there was no statistically significant difference in the concentration of these biomarkers for clinical distinction from periodontitis.

Measuring liveweight changes in lactating dairy ewes with an automated walk-over-weighing system.

Monitoring liveweight (LW) is an important part of sound management practices at the individual and flock level (e.g., controlling for nutritional status based on body condition, reproduction, and health-related issues), but it is time consuming and stressful. To our knowledge, no literature has reported on the evaluation of automated weighing systems in dairy sheep as an alternative to conventional static scales. The objective of this research was to evaluate the practical feasibility of using an automated walk-over-weighing (WoW) prototype to measure daily LW changes in dairy ewes without human intervention. We used adult Lacaune dairy ewes in 2 complementary trials conducted indoors. Trial 1 aimed at evaluating the repeatability, precision, and accuracy of LW measures recorded using WoW scales compared with a static scale (the gold standard). Forty-two adult ewes (LW ± standard deviation = 71.3 ± 10.4 kg) were randomly drafted from the main flock and used in a 1-day session. The trial included 3 passages. In each passage, ewes were weighed first on a static scale; once a static position was achieved and LW recorded, they continued the circuit and immediately traversed the WoW scale for an automated LW record. Trial 2 aimed to demonstrate the feasibility of using the WoW device under real-world conditions in a dairy sheep-farming system. The WoW scale was installed in the exit race of the milking parlor and evaluated over 7 wk with adult ewes in mid lactation (n = 93; LW 78.5 ± 8.1 kg). Once the ewes were acclimated to the WoW system, 1 group of ewes (n = 48) continued to receive the same feeding regimen (controls), and the other group (n = 45) underwent a nutritional challenge [challenged; 2 wk of undernutrition and then back to control regimen (refeeding) for 1 wk]. We evaluated the ability of the WoW to detect small changes in LW. We collected LW data (2 weighings per ewe per day) from the WoW after each of the 2 milking sessions (morning and evening). We also obtained LW values by weighing the ewes using a static scale once a week. The automated WoW system showed substantial agreement with the gold standard when assessed using Lin's concordance correlation coefficient and Bland and Altman's method, largely due to high repeatability. The WoW system was adequate for detecting small daily variations in LW during undernutrition and refeeding periods. Misbehaviors resulted in spurious WoW values in trial 2, requiring us to use filtration methods to exclude outlier weights and allow meaningful assessment of small LW changes. The WoW system evaluated here is an alternative to the static scales conventionally used on dairy sheep farms. If sound filtration of raw data is applied, WoW could contribute to the close (daily) monitoring of individual LW without operator intervention (i.e., voluntary weighing) and taking animal welfare into account (i.e., no stress related to the weighing session on static scales).

Could formaldehyde induce mutagenic and cytotoxic effects in buccal epithelial cells during anatomy classes?

BACKGROUND: Due to increased formaldehyde exposure, carcinogenic to humans, several researches have been studying the potential toxicity and the safe levels for human beings. The aim of this study was to investigate mutagenicity and cytotoxicity in buccal epithelial exfoliated cells (BEC) of students subjected to formaldehyde (FA) during anatomy classes. MATERIAL AND METHODS: BEC were collected periodically from 17 volunteers of undergraduate programs, who had participated in practical anatomy classes, before and after FA exposure. Cells were stained according to Feulgen method and then micronucleus test was applied. A total of 1,500 cells were assessed per individual in this study for the micronucleus frequency and other parameters of cytotoxicity. RESULTS: There was statistically significant increase in number of micronucleated BEC after FA exposure (after 1 month p=.034 and after 3.5 months p=.017). However, FA exposure caused no significant increase in other nuclear alterations closely related to cytotoxicity (p≥.05). CONCLUSIONS: FA induced mutagenicity during anatomy classes. Cell death increased, but it was not statistically significant. Efforts have to be made to improve air quality and reduce exposures during anatomy classes.

Effect of delayed scanning on imaging and on the diagnostic accuracy of vertical root fractures in two photostimulable phosphor plates digital systems.

AIM: To evaluate the influence of delayed scanning on images obtained with two PSPs digital systems and on the diagnostic accuracy of vertical root fracture (VRF) by means of objective and subjective analyses. METHODOLOGY: Forty single-rooted human teeth were divided into two groups, one without VRFs and another with VRFs induced by a universal testing machine. Two digital systems (VistaScan(®) and Express(®) ) were used to radiograph all teeth, and the resulting plates were scanned at four time-points: T0-immediately, T1-30 min, T2-2 h and T3-4 h after exposure. An aluminium (Al) wedge was used to evaluate the change in mean grey values as each scan was delayed. Three observers screened all images for VRFs, and one-fourth of the sample was revaluated after thirty days. Areas under the receiver operating characteristic (ROC) curve, sensitivity, specificity and accuracy values were compared by anova. RESULTS: Intra- and interobserver agreement ranged from moderate to substantial and fair to moderate, respectively. There was no significant difference amongst scan delays with regard to sensitivity, specificity and accuracy; however, there were significant differences in the area under the ROC curve, with the 4-h delayed scan being associated with lower values compared to the others (P = 0.019). As for objective analysis, there was a significant difference amongst all different scanning time-points for the two systems (P = 0.001), except between the 30-min and 2-h delayed scans in the VistaScan(®) system. CONCLUSION: Whilst delayed scanning caused changes to the density of images acquired with the systems studied, it did not seem to interfere with VRF diagnosis except when scanning was delayed for 4 h, which should therefore be avoided.

Digital radiographs displayed on different devices: effect on the detection of vertical root fractures.

AIM: To evaluate whether the type of display device affects the detection of vertical root fractures (VRFs) on digital radiographs in unfilled canals and canals with fibreglass posts. METHODOLOGY: Forty single-rooted human teeth were decoronated, and the root canals were prepared. The teeth were divided into 2 groups: controls (20 teeth) and with VRF (20 teeth). The VRFs were induced using an universal testing machine. Periapical radiographs of all teeth, with canal unfilled or with a fibreglass post, were obtained using the parallel technique in 3 directions (ortho-, mesio- and distoradial) on storage phosphor plates (VistaScan®). All images were evaluated and re-evaluated after 30 days by 3 examiners on a 5-point scale using 4 different devices (notebook display with full high definition resolution, desktop display with a standard resolution, 8-inch Android(™) tablet with high definition resolution and a 9.7-inch iPad® tablet with Retina resolution). Areas under ROC curves, sensitivity, specificity and accuracy values were compared by anova. RESULTS: The weighted kappa values for intra- and interobserver reproducibility were 0.55-0.88 and 0.31-0.65, respectively. There was a significant difference (P < 0.05) in relation to the area under the ROC curve, specificity and sensitivity when unfilled canals were compared with canals with a fibreglass post; however, no difference was observed for the different devices studied. CONCLUSIONS: The type of display device did not affect the detection of VRFs. Thus, the detection of VRFs can be performed using different screen sizes and resolutions.

Impact of root fillings and posts on the diagnostic ability of three intra-oral digital radiographic systems in detecting vertical root fractures.

AIM: To evaluate (i) the accuracy of three intra-oral digital systems in detecting vertical root fractures (VRFs); and (ii) the influence of different intracanal conditions (without filling, filled with Gutta-percha and metal or fibreglass post). METHODOLOGY: Forty single-rooted human teeth were decoronated and the root canals prepared. VRFs were induced using a universal testing machine on 20 teeth. Radiographic images were obtained using the paralleling technique with three different horizontal angulations on conventional E/F film, two storage phosphor plates (Digora Optime and VistaScan) and one sensor system (SnapShot). All teeth were radiographed with all intracanal conditions tested. All images were evaluated by five examiners. After 30 days, 25% of the images were reviewed. Areas under ROC curves, sensitivity, specificity, accuracy, positive predictive and negative predictive values were compared by anova. RESULTS: The weighted kappa values for intra- and interobserver reproducibility were 0.48-0.74 and 0.57-0.66, respectively. The sensitivity revealed a significant difference between imaging modalities, with higher values for SnapShot (0.53) and VistaScan (0.46), followed by the film (0.41) and Digora (0.38). The area under the ROC curve for SnapShot (0.82) was greater than for the other systems in the teeth with a fibreglass post (VistaScan: 0.70; Digora: 0.64; film: 0.60). CONCLUSION: All systems gave a similar performance for detecting VRFs; all gave a good performance in the absence of intracanal materials, but performed less well in the presence of a metal post or Gutta-percha. In teeth with a fibreglass post, digital systems with higher resolution should be used.

The 'Sharpen' filter improves the radiographic detection of vertical root fractures.

AIM: To compare the diagnostic accuracy of digital enhancement filters in the diagnosis of vertical root fractures. METHODOLOGY: The sample consisted of 40 single-rooted teeth randomly divided into two groups: experimental and control. Vertical root fractures were induced in the experimental group using a universal testing machine. All teeth were individually radiographed with three different horizontal angles using the Digora Optime(®) digital system. Three observers separately examined the original and filtered images (3D Emboss, Negative, Sharpen and Shadow). The area under Receiver Operating Characteristic curve values (Az) for each protocol were compared by one-way anova with post hoc Bonferroni test. The significance level was set at 5%. RESULTS: The highest Az value was obtained using the Sharpen filter, with significant differences from the original and other filtered images (P < 0.05). The 3D Emboss filter had the lowest Az value, which was significantly different from the other filtered images (P < 0.05). CONCLUSION: When using the Digora Optime(®) system, the 'Sharpen' filter is recommended to improve the radiographic detection of vertical root fractures.

Preimplantation development of in vitro-produced bovine embryos treated with hydroxychloroquine.

Hydroxychloroquine (HCQ) is a safe antimalarial drug but its overdosage or inappropriate use, such as during the pandemic, may cause adverse effects once this drug is considered a potent inhibitor of autophagy. Information about HCQ's effects on the reproductive field, including gametes and initial embryos, is limited. In this study, we evaluated the effect of HCQ (1, 6, 12, and 24 µM) on pre-implantation embryo development, autophagy, and apoptosis of bovine embryos produced in vitro. A dose-response experiment showed a reduction (p < 0.05) in cleavage only at the highest concentration. Blastocyst rate was gradually reduced (p < 0.05) with the increase of HCQ dosage starting at 6 µM, with no embryo formation occurring at 24 µM. Further analysis showed that embryos treated with 12 µM of HCQ had a higher (p < 0.05) accumulation of acidic autophagic vesicles on Days 5 and 7 of development and a higher (p < 0.01) apoptotic index on Day 7. To our knowledge, this is the first study to evaluate the effects of HCQ on embryo pre-implantation development in mammals. The results contribute with more information related to the study of autophagy in embryology as well as add some discussion on HCQ toxicology and its effects on reproductive cells.

Evaluation of an ELISA for canine leishmaniasis immunodiagnostic using recombinant proteins.

The present work describes the isolation and purification of two Leishmania chagasi (= syn. Leishmania infantum) recombinant proteins, rLci2B and rLci1A, and their use in the development of an immunoassay for the diagnostic of canine leishmaniasis. After protein expression and cell disruption, rLci2B was purified by immobilized metal affinity chromatography followed by size exclusion chromatography, whereas rLci1A, expressed as an inclusion body, was treated with urea and purified by anion-exchange chromatography. Homogeneities were ascertained by denaturing gel electrophoresis (MW (rLci2B) = 46,370; MW(rLci1A) = 88,400), isoelectric focusing (pI (rLci2B) = 5·91; pI (rLci1A) = 6·01) and Western blot. An indirect ELISA was developed using the purified antigens rLci2B and rLci1A and a leishmaniasis canine serum panel (n = 256). The ELISA showed 100% sensitivity and 95% specificity for rLci2B and 96% sensitivity and 92% specificity for rLci1A. The purified proteins did not present cross-reactivity with sera from dogs infected with Trypanosoma caninum, Babesia canis and Ehrlichia canis. Cross-reaction was verified with sera from dogs infected with Leishmania brasiliensis (11·7% for rLci2B and 2·9% for rLci1A). Based on ELISA results, it is suggested the use of rLci2B and rLci1A as antigens in an alternative serological assay for diagnostic of canine leishmania.

Monitoring and Treatment of Juvenile Idiopathic Arthritis-associated Uveitis: Brazilian Evidence-based Practice Guidelines.

PURPOSE: To present a national guideline for ophthalmologic care and surveillance of juvenile idiopathic arthritis-associated uveitis (JIA-uveitis). METHODS: Review article based on medical literature and the experience of an Expert Committee composed of members of the Brazilian Society of Pediatric Ophthalmology/Brazilian Council of Ophthalmology and the Brazilian Society of Pediatrics/Brazilian Society of Rheumatology. Studies with a high level of evidence were selected by searching the PubMed/Medline database. The final document was approved by the experts. RESULTS: The main recommendations are that children/adolescents with JIA should undergo screening according to their risk factors. Ophthalmological checkups should also consider ocular inflammation and therapy. Topical glucocorticoids should be the first line of therapy, with systemic glucocorticoids acting as bridge treatments in severe uveitis. Methotrexate should be the first-line systemic therapy and anti-tumor necrosis factor (anti-TNF alpha) the second for uncontrolled uveitis. CONCLUSIONS: This evidence-based guideline for JIA-uveitis will be useful for both ophthalmology and rheumatology practice.

The economic impact of severe asthma to low-income families.

BACKGROUND: To estimate the direct and indirect costs of severe asthma and the economic impact of its management to low-income families in Salvador, Brazil. METHODS: One hundred and ninety-seven patients with severe asthma and referred to a state-funded asthma center providing free treatment were evaluated. At registration, they were asked about family cost-events in the previous year and had a baseline assessment of lung function, symptoms and quality of life. During the subsequent year, they were reassessed prospectively. RESULTS: One hundred-eighty patients concluded a 12-month follow-up. Eighty-four percent were female patients, and the median family income was US$ 2955/year. Forty-seven percent of family members had lost their jobs because of asthma. Total cost of asthma management took 29% of family income. After proper treatment, asthma control scores improved by 50% and quality of life by 74%. The income of the families increased by US$ 711/year, as their members went back to work. The total cost of asthma to the families was reduced by a median US$ 789/family/year. Consequently, an annual surplus of US$ 1500/family became available. CONCLUSIONS: Family costs of severe asthma consumed over one-fourth of the family income of the underprivileged population in a middle-income country. Adequate management brings major economic benefit to individuals and families.

Spermatogonial morphology, kinetics and niches in hamsters exposed to short- and long-photoperiod.

Previous studies have shown that under short photoperiod exposure spermatogenesis in golden hamster regresses leading to sexual inactivity. It is known that this regression is related to changes in somatic and germ cells (spermatocytes and spermatids). However, the photoperiod effects on spermatogonial biology have not been studied in detail yet. In this regard, this study was carried out to investigate the morphology, kinetics and niches of different spermatogonial types in golden hamsters under long- and short-photoperiod. Six spermatogonial generations such as type A undifferentiated (A(und)), type A differentiating (A(1), A(2), A(3)), intermediate (In) and type B spermatogonia were characterized, and were morphologically similar irrespective of the photoperiod exposure. The short photoperiod was inhibitory to A(und) spermatogonia and preleptotene but had no effect on the number of differentiating (A(1) to B) spermatogonia. In golden hamsters exposed to stimulatory-photoperiod, the interstitial components were positioned mainly in triangular areas around the seminiferous tubules and, in this situation, the A(und) spermatogonia were clearly positioned in niches (p < 0.05) in all stages studied. On the other hand, during the inhibitory-photoperiod where the seminiferous tubules have smaller diameter, the interstitial components were more homogenously distributed and the triangular areas were not clearly observed. In this case, the niches were identified only at stage VII (p < 0.05), although there was a trend of being positioned in niches area in all the stages studied. Thus, these findings suggest that the A(und) spermatogonia location in the seminiferous epithelium and the niche position are directly related to the position of the interstitial components.

Lack of control of severe asthma is associated with co-existence of moderate-to-severe rhinitis.

BACKGROUND: Retrospective studies provide evidence that rhinitis is associated with more severe asthma. The aim of this study was to evaluate prospectively whether rhinitis is a predictor of increased asthma severity. METHODS: Five hundred and fifty-seven patients with severe asthma were enrolled. During 1 year of follow-up, each patient was evaluated every 3 months with a record of emergency room visits and supply of topical corticosteroids for asthma and rhinitis. In the 1 year of follow-up visit, the patients were checked for rhinitis diagnosis, severity and answered questionnaires for asthma symptoms and quality of life. RESULTS: Eighty-two (15%) patients had no rhinitis, 299 (54%) had mild rhinitis and 176 (31%) moderate/severe rhinitis. In logistic regression models, moderate/severe rhinitis was a predictor for any emergency room visit in the follow-up period [3.83 (2.00-7.35)], for the presence of uncontrolled asthma after 1 year of follow-up [12.68 (1.73-92.85)], for <10% improvement of the airway obstruction [2.94 (1.48-5.85)] and <50% reduction in the number of emergency room visits [2.90 (1.02-8.26)] in the year of follow-up. It was also associated with a smaller chance of more than 90% reduction in the number of emergency room visits in the year of follow-up [0.27 (0.12-0.60)]. In a multivariate linear regression model, severity of rhinitis was positively correlated with a score of asthma severity and inversely correlated to an index of quality of life. CONCLUSIONS: In a population with severe asthma, moderate/severe rhinitis is a strong predictor for greater severity of asthma.

Persistent effects of pre-Columbian plant domestication on Amazonian forest composition.

The extent to which pre-Columbian societies altered Amazonian landscapes is hotly debated. We performed a basin-wide analysis of pre-Columbian impacts on Amazonian forests by overlaying known archaeological sites in Amazonia with the distributions and abundances of 85 woody species domesticated by pre-Columbian peoples. Domesticated species are five times more likely than nondomesticated species to be hyperdominant. Across the basin, the relative abundance and richness of domesticated species increase in forests on and around archaeological sites. In southwestern and eastern Amazonia, distance to archaeological sites strongly influences the relative abundance and richness of domesticated species. Our analyses indicate that modern tree communities in Amazonia are structured to an important extent by a long history of plant domestication by Amazonian peoples.

Inter-site variation in allometry and wood density of Goupia glabra Aubl. in Amazonia.

The present study aims to compare the allometry and wood density of Goupia glabra Aubl. (Goupiaceae) in two different terra-firme sites in Amazonian forest. A total of 65 trees ≥ 10 cm DBH was sampled in both sites, with 39 trees in Nova Olinda do Norte (NOlinda, near the Amazon River) and 29 trees in Apuí (near the southern edge of the Amazon forest). Except for the relationship between DBH (diameter at breast height) and Ht (total height), allometric relationships for G.glabra differed significantly between sites. Apuí had lower intercept and greater slope for log10 (DBH) versus log10 (Hs - stem height), and, conversely, greater intercept and lower slope for log10 (DBH) versus log10 (Ch - crown height). The slope differed significantly between the sites for DBH versus Cd (crown diameter), with greater slope found for NOlinda. Mean basic wood density in Apuí was 8.8% lower than in NOlinda. Our findings highlight the variation in adaptive strategy of G. glabra due to environmental differences between sites. This is probably because of different canopy-understory light gradients, which result in differentiation of resource allocation between vertical and horizontal growth, which, in turn, affects mechanical support related to wood density. We also hypothesize that differences in soil fertility and disturbance regimes between sites may act concomitantly with light.

Influence of CBCT enhancement filters on diagnosis of vertical root fractures: a simulation study in endodontically treated teeth with and without intracanal posts.

OBJECTIVES: To evaluate the influence of CBCT enhancement filters on the diagnosis of vertical root fractures (VRFs) in teeth with and without metal posts. METHODS: The crowns of 40 uniradicular human teeth were removed and all roots were prepared. 20 teeth were randomly selected, and VRFs were induced using a universal testing machine. The i-CAT (Imaging Sciences International, Hatfield, PA) CBCT was used to scan teeth with and without intracanal metal posts using the following parameters: 0.2 voxel size, 8 × 8-cm scan size and acquisition time of 26.9 s. Images were evaluated by three observers with and without the use of the following filters: S9, smooth, smooth 3 × 3, sharpen, sharpen-mild and sharpen 3 × 3. RESULTS: Intra- and interobserver agreement ranged from poor to moderate. Images with and without CBCT filters did not show significant differences regarding the area under the receiver operating characteristic curve, as well as sensitivity (p > 0.05). As for accuracy, the sharpen-mild filter was superior to the sharpen (p = 0.03), but these filters did not differ from all others. For specificity, S9, smooth and original images were superior to sharpen (p < 0.01). Results for teeth without posts differed from those for teeth with metal posts in all cases (p < 0.05). CONCLUSIONS: The use of enhancement filters in CBCT images has no influence on the diagnosis of VRFs in teeth with metal posts, and their use is not justified.

Extracellular proteolytic processing of Aspergillus awamori GAI into GAII is supported by physico-chemical evidence.

The proportion of glucoamylases, GAI and GAII, in the culture supernatant of Aspergillus awamori fermentations depends on the medium C/N ratio in such a way that the transformation of GAI into GAII is favored by the existence of a surplus of the carbon source in the growth medium. This condition also favors the appearance of the proteolytic activity. The authors report the observation that the shift in the isoenzyme proportion was concomitant to the peak of proteolytic activity. A peptide that may have resulted from the continuous degradation of the GAI C-terminal peptide, Gp-1, was isolated by gel filtration and purified by reverse-phase chromatography. This peptide matched with the region G14-A34 of the substrate-binding domain of GAI, thus reinforcing the hypothesis of the extracellular proteolytic processing of GAI.

Glucoamylase isoenzymes tailoring through medium composition.

Two major glucoamylase isoenzymes (GAI and GAII) have been identified in culture supernatants of Aspergillus awamori. It has been suggested that a stepwise degradation of a native enzyme during the fermentation by proteases and/or glucosidases results in the formation of isoenzymes that have different characteristics concerning substrate specificity and stability to pH and temperature. In this study, the glucoamylase isoenzymes produced by Aspergillus awamori using liquid media with C/N 10 (2.0% starch, 0.45% (NH4)2 SO4) and C/N 26 (5.2% starch, 0.45% (NH4)2 SO4) were analyzed. In both cases, GAI and GAII were characterized concerning its hydrolitic activities, mol wt, and isoeletric point. Using HPLC gel filtration and FPLC chromatofocusing, it was obtained for GAI a mol wt of 110,000 Da, pi 3.45 and for GAII a mol wt of 86,000 Da, pI 3.65. A different isoenzymes proportion was observed by the use of the two C/N ratios. In the lower carbohydrate content, fermentation of the GAI form predominated, whereas in the C/N 26 medium, GAII was prevalent. Gel eletrophoresis, amino acid analysis, and structural data confirmed that both preparations were glucoamylases with a high degree of homogeneity.

Inter-site variation in allometry and wood density of Goupia glabra Aubl. in Amazonia

Abstract The present study aims to compare the allometry and wood density of Goupia glabra Aubl. (Goupiaceae) in two different terra-firme sites in Amazonian forest. A total of 65 trees 10 cm DBH was sampled in both sites, with 39 trees in Nova Olinda do Norte (NOlinda, near the Amazon River) and 29 trees in Apuí (near the southern edge of the Amazon forest). Except for the relationship between DBH (diameter at breast height) and Ht (total height), allometric relationships for G.glabra differed significantly between sites. Apuí had lower intercept and greater slope for log10 (DBH) versus log10 (Hs stem height), and, conversely, greater intercept and lower slope for log10 (DBH) versus log10 (Ch crown height). The slope differed significantly between the sites for DBH versus Cd (crown diameter), with greater slope found for NOlinda. Mean basic wood density in Apuí was 8.8% lower than in NOlinda. Our findings highlight the variation in adaptive strategy of G. glabra due to environmental differences between sites. This is probably because of different canopy-understory light gradients, which result in differentiation of resource allocation between vertical and horizontal growth, which, in turn, affects mechanical support related to wood density. We also hypothesize that differences in soil fertility and disturbance regimes between sites may act concomitantly with light.

Resumo O presente estudo tem como objetivo comparar a alometria e a densidade da madeira de Goupia glabra em dois diferentes sítios de floresta de terra firme na Amazonia. Um total de 65 árvores com DAP 10 cm foi amostrado em ambos os sítios, sendo 39 árvores em Nova Olinda do Norte (NOlinda, próximo ao rio Amazonas) e 29 em Apuí (próximo à borda sul da Amazônia). Exceto para a relação entre o DBH (diâmetro a altura do peito) e a Ht (altura total), as relações alométricas para G. glabra diferiu significativamente entre os sítios. Apuí apresentou menor intercepto e maior inclinação para a relação log10 (DBH) versus log10 (Hs altura do fuste) e, ao contrário, maior intercepto e menor inclinação para log10 (DBH) versus log10 (Ch altura da copa). A inclinação diferiu significativamente entre os sítios para DBH versus Cd (diâmetro da copa), com maior inclinação encontrada para NOlinda. A densidade básica média da madeira in Apuí foi 8.8% menor do que em NOlinda. Os resultados deste estudo destacam a variação na estratégia adaptativa de G. glabra devido às diferenças ambientais entre os sítios. Isto é provavelmente consequência dos diferentes gradientes de luz o que resulta na diferenciação na alocação de recursos entre o crescimento vertical e horizontal o que, por sua vez, afeta o suporte mecânico relacionado à densidade da madeira. Nós também levantamos a hipótese de que as diferenças em termos de fertilidade e regimes de distúrbios entre os sítios podem agir concomitantemente com o regime de luz.