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81.
82.
Disturbances, elevation, topography and spatial proximity drive vegetation patterns along an altitudinal gradient of a top biodiversity hotspot 总被引:1,自引:0,他引:1
Pedro V. Eisenlohr Luciana F. Alves Luís Carlos Bernacci Maíra C. G. Padgurschi Roseli B. Torres Eduardo M. B. Prata Flavio Antonio M. dos Santos Marco Antônio Assis Eliana Ramos André Luís C. Rochelle Fernando R. Martins Mariana C. R. Campos Fernando Pedroni Maryland Sanchez Larissa S. Pereira Simone A. Vieira José Ataliba M. A. Gomes Jorge Y. Tamashiro Marcos A. S. Scaranello Cora J. Caron Carlos Alfredo Joly 《Biodiversity and Conservation》2013,22(12):2767-2783
The correlation between vegetation patterns (species distribution and richness) and altitudinal variation has been widely reported for tropical forests, thereby providing theoretical basis for biodiversity conservation. However, this relationship may have been oversimplified, as many other factors may influence vegetation patterns, such as disturbances, topography and geographic distance. Considering these other factors, our primary question was: is there a vegetation pattern associated with substantial altitudinal variation (10–1,093 m a.s.l.) in the Atlantic Rainforest—a top hotspot for biodiversity conservation—and, if so, what are the main factors driving this pattern? We addressed this question by sampling 11 1-ha plots, applying multivariate methods, correlations and variance partitioning. The Restinga (forest on sandbanks along the coastal plains of Brazil) and a lowland area that was selectively logged 40 years ago were floristically isolated from the other plots. The maximum species richness (>200 spp. per hectare) occurred at approximately 350 m a.s.l. (submontane forest). Gaps, multiple stemmed trees, average elevation and the standard deviation of the slope significantly affected the vegetation pattern. Spatial proximity also influenced the vegetation pattern as a structuring environmental variable or via dispersal constraints. Our results clarify, for the first time, the key variables that drive species distribution and richness across a large altitudinal range within the Atlantic Rainforest. 相似文献
83.
Berta Lúcia Pereira Villagra Eduardo Pereira Cabral Gomes Robyn J. Burnham Sergio Romaniuc Neto 《Biodiversity and Conservation》2013,22(11):2505-2517
Climbing plant community composition and abundance was compared between the Alto da Serra de Paranapiacaba Biological Reserve (ASPRB) and the Nascentes de Paranapiacaba Municipal Natural Park (NPMNP), two protected areas in the largest Atlantic Forest remnant, southeastern Brazil. Climbing plants ≥1 cm in diameter were sampled in 52 quadrats of 10 × 20 m (1.04 ha). From these data we calculated the Shannon–Wiener diversity index, calculated abundance and importance values for families, performed a principal coordinate analysis, and created a similarity dendrogram (TWINSPAN). The composition and abundance of species between ASPRB and NPMNP differed significantly due to the successional state of the ASPRB forest, which was affected by more recent disturbance. There we found 34 species, while in the NPMNP, species richness was 72, with only 24 species in common. The two areas formed two groups corresponding to two distinct floristic subsets. These montane forests were characterized by a predominance of species of the Asteraceae. The high species richness, floristic composition, and community composition reflect the greater degree of conservation in the area of NPMNP. The high density and community composition of climbers in the more conserved area of rainforest may be due to the low intensity of disturbance. 相似文献
84.
Andréa Helena Vidal André Mariano Batista Ellen Cordeiro Bento da Silva Wilton Arruda Gomes Marina Arruda Pelinca Sildivane Valcácia Silva Maria Madalena Pessoa Guerra 《Small Ruminant Research》2013,109(1):47-51
The aim of this study was to evaluate the effect of different concentrations of soybean lecithin (SL) in extenders for sperm goat cryopreservation. Sexually mature male Saanen goats (n = 4) were used, and the ejaculates were obtained using an artificial vagina method. The semen samples were pooled and diluted in a skim milk-based extender (control group; CG) or Tris extender supplemented with SL at different concentrations (G1 = 0.04%, SL G2 = 0.08% SL and G3 = 0.16%) for a final concentration of 240 × 106 spermatozoa/mL. The semen samples were packed in straws (0.25 mL), frozen using an automated system and stored in liquid nitrogen (?196 °C). After thawing (37 °C/30 s), the samples were evaluated for sperm quality parameters, including sperm motility, membrane integrity, acrosome integrity and mitochondrial activity. No significant difference was observed among the experimental and control groups for all of the parameters (P > 0.05). However, even though the control group presented a significantly lower mitochondrial membrane potential compared to fresh semen (P < 0.05), the same did not occur for the extender supplemented with soybean lecithin, that is, it did not differ from fresh sperm (P > 0.05). The extender containing soybean lecithin at different concentrations preserved the sperm quality parameters in a manner similar to the conventional skim milk-based extender. Thus, it is concluded that an extender containing soybean lecithin as the lipoprotein source can be used for freezing goat semen. 相似文献
85.
Filumena Maria Gomes S. V. Subramanian Ana Maria de Ulh?a Escobar Maria Helena Valente Sandra Josefina Ferraz Ellero Grisi Alexandra Brentani Günther Fink 《PloS one》2013,8(6)
Background
A growing literature suggests that low birth weight increases the risk of poor health outcomes in adulthood. We tested this hypothesis among young adults living in São Paulo State, Brazil.Methods and Findings
To identify the effects of low birth weight on young adulthood outcomes, a medical assessment of 297 individuals born between 1977 and 1989 was conducted at a primary care unit in São Paulo State, Brazil. We analyzed body mass index (BMI), waist-hip ratio, blood pressure, fasting glucose and total cholesterol levels using linear and logistic regressions. Low birth was negatively associated with BMI (β = −2.0, 95% CI: −3.69, −0.27, p = 0.02), fasting glucose levels (β = −1.9, 95% CI: −3.9, −0.07, p = 0.05), waist-hip ratio (β = −0.03, 95% CI: −0.07, −0.01, p = 0.10), systolic blood pressure (β = −3.32, 95% CI: −7.60, 0.96, p = 0.12), and total cholesterol levels (β = −3.19, 95% CI: −16.43, 10.05, p = 0.636). Low birth weight was also associated with lower odds of young adults being overweight and obese, but neither association was statistically significant. Weight gain in the first 12 months of life was associated with higher adult BMI (β = 0.79, 95% CI: −0.0455, 1.623, p = 0.064) and blood pressure (β = 2.79, 95% CI: 0.22, 5.35, p = 0.034). No associations were found between low birth weight and early life (catch-up) growth.Conclusions
Low birth weight was not associated with poor health outcomes among young adults in Brazil. These results appear inconsistent with the original Barker hypothesis, but will need to be corroborated in larger samples with longer follow-ups to allow a more general evaluation of the validity of the hypothesis in low and middle income countries. 相似文献86.
Anti‐HSV‐1 and HSV‐2 Flavonoids and a New Kaempferol Triglycoside from the Medicinal Plant Kalanchoe daigremontiana 下载免费PDF全文
Fernanda Gouvêa Gomes Ürményi Georgia do Nascimento Saraiva Livia Marques Casanova Amanda dos Santos Matos Luiza Maria de Magalhães Camargo Maria Teresa Villela Romanos Sônia Soares Costa 《化学与生物多样性》2016,13(12):1707-1714
Kalanchoe daigremontiana (Crassulaceae) is a medicinal plant native to Madagascar. The aim of this study was to investigate the flavonoid content of an aqueous leaf extract from K. daigremontiana (Kd), and assess its antiherpetic potential. The major flavonoid, kaempferol 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside ( 1 ), was isolated from the AcOEt fraction (Kd‐AC). The BuOH‐soluble fraction afforded quercetin 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside ( 2 ) and the new kaempferol 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside‐7‐O‐β‐d ‐glucopyranoside ( 3 ), named daigremontrioside. The crude extract, Kd‐AC fraction, flavonoids 1 and 2 were evaluated using acyclovir‐sensitive strains of HSV‐1 and HSV‐2. Kd‐AC was highly active against HSV‐1 (EC50 = 0.97 μg/ml, SI > 206.1) and HSV‐2 (EC50 = 0.72 μg/ml, SI > 277.7). Flavonoids 1 and 2 showed anti‐HSV‐1 (EC50 = 7.4 μg/ml; SI > 27 and EC50 = 5.8 μg/ml; SI > 8.6, respectively) and anti‐HSV‐2 (EC50 = 9.0 μg/ml; SI > 22.2 and EC50 = 36.2 μg/ml; SI > 5.5, respectively) activities, suggesting the contribution of additional substances to the antiviral activity. 相似文献
87.
Evaluation of dental enamel caries assessment using Quantitative Light Induced Fluorescence and Optical Coherence Tomography 下载免费PDF全文
Ana Marly Araújo Maia Anderson Zanardi de Freitas Sergio de L. Campello Anderson Stevens Leônidas Gomes Lena Karlsson 《Journal of biophotonics》2016,9(6):596-602
An in vitro study of morphological alterations between sound dental structure and artificially induced white spot lesions in human teeth, was performed through the loss of fluorescence by Quantitative Light‐Induced Fluorescence (QLF) and the alterations of the light attenuation coefficient by Optical Coherence Tomography (OCT). To analyze the OCT images using a commercially available system, a special algorithm was applied, whereas the QLF images were analyzed using the software available in the commercial system employed. When analyzing the sound region against white spot lesions region by QLF, a reduction in the fluorescence intensity was observed, whilst an increase of light attenuation by the OCT system occurred. Comparison of the percentage of alteration between optical properties of sound and artificial enamel caries regions showed that OCT processed images through the attenuation of light enhanced the tooth optical alterations more than fluorescence detected by QLF System.
88.
Alexandre Costa Adilson Luís Pereira Silva Rommel Bezerra Viana Auro Atsushi Tanaka Jaldyr de Jesus Gomes VarelaJr 《Journal of molecular modeling》2016,22(9):217
Theoretical chemistry calculations using the Density Functional Theory (DFT) were carried out to understand the interaction between oxygen (O2) and MnN4 type manganese-based complexes during the formation of MnN4-O2 adducts. In order to understand how this interaction is affected by different macrocyclic ligands, O2 was bonded to manganese-porphyrin (MnP), manganese-octamethylporphyrin (MnOMP), manganese-tetraaza[14]annulene (MnTAA), manganese-dibenzo [b,i] [1, 4, 8, 11]-tetraaza [14] annulene (MnDBTAA), manganese-2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,10-tetraene ([(tim)Mn]2+), and manganese-2,3,9,10-tetraphenyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,10-tetraene ([(ph-tim)Mn]2+). The binding and activation of the oxygen molecule was facilitated by an increasing trend in the O-O bond lengths and a decreasing one in the O-O vibrational frequency, with preference for the O2 side-on interaction among MnN4 macrocycles. The catalytic activities of the MnN4 complexes toward the O2 binding process increased in the following order: [(ph-tim)Mn]2+?<?MnP?<?MnOMP?<?MnDBTAA?<?MnTAA?<?[(tim)Mn]2+. Therefore, it was concluded that the [(tim)Mn]2+complex was the most active for the binding and activation of molecular oxygen. 相似文献
89.
Determinant Factors of Untreated Dental Caries and Lesion Activity in Preschool Children Using ICDAS
Tássia Cristina de Almeida Pinto-Sarmento Mauro Henrique Abreu Monalisa Cesarino Gomes Edja Maria Melo de Brito Costa Carolina Castro Martins Ana Flávia Granville-Garcia Saul Martins Paiva 《PloS one》2016,11(2)
The aim of the present study was to investigate determinant factors associated with the presence of dental caries and lesion activity in preschool children. A population-based, cross-sectional study was carried out with 843 children of aged three to five years enrolled at public and private preschools in the city of Campina Grande, Brazil. A questionnaire addressing socio-demographic data and oral health care was self-administered by parents/caregivers. Three dentists previously calibrated examined the children for the diagnosis of dental caries and lesion activity using the International Caries Detection and Assessment System (ICDAS). Nutritional status was evaluated based on the body mass index. Logistic regression analysis for complex samples was performed (α = 5%). The prevalence of dental caries was 66.3%. Among the children with caries, 88.0% had active lesions. Dental caries was more prevalent in girls (OR = 1.53, 95%CI: 1.05–2.23), in children from families with a monthly household income ≤US$312.50 (OR = 2.38, 95%CI: 1.65–3.43) and those whose mothers had up to eight years of schooling (OR = 1.55, 95%CI: 1.07–2.23). Lesion activity was significantly associated with mother’s schooling ≤ 8 years (OR = 2.15, 95%CI: 1.15–4.00). The prevalence rates of dental caries and lesion activity were high and mainly associated with a lower socioeconomic status and mother’s schooling. 相似文献