Natural and human forcing in recent geomorphic change; case studies in the Rio de la Plata basin

An analysis of geomorphic system`s response to change in human and natural drivers in some areas within the Rio de la Plata basin is presented The aim is to determine whether an acceleration of geomorphic processes has taken place in recent years and, if so, to what extent it is due to natural (climate) or human (land-use) drivers Study areas of different size, socio-economic and geomorphic conditions have been selected: the Rio de la Plata estuary and three sub-basins within its watershed Sediment cores were extracted and dated ((210)Pb) to determine sedimentation rates since the end of the 19th century. Rates were compared with time series on rainfall as well as human drivers such as population, GDP, livestock load, crop area, energy consumption or cement consumption, all of them related to human capacity to disturb land surface Data on river discharge were also gathered Results obtained indicate that sedimentation rates during the last century have remained essentially constant in a remote Andean basin, whereas they show important increases in the other two, particularly one located by the Sao Paulo metropolitan area Rates in the estuary are somewhere in between It appears that there is an intensification of denudation/sedimentation processes within the basin. Rainfall remained stable or varied very slightly during the period analysed and does not seem to explain increases of sedimentation rates observed. Human drivers, particularly those more directly related to capacity to disturb land surface (GDP, energy or cement consumption) show variations that suggest human forcing is a more likely explanation for the observed change in geomorphic processes It appears that a marked increase in denudation, of a ""technological"" nature, is taking place in this basin and leading to an acceleration of sediment supply This is coherent with similar increases observed in other regions (C) 2010 Elsevier B V All rights reserved

Planejamento para o fechamento prematuro de minas

Several mining companies operating in Brazil have been preparing mine closure plans describing end of life actions to ensure long term physical stability, land rehabilitation and, to a certain extent, socioeconomic measures. Most Brazilian and international guidelines, however, skip early closure and only feature guidance to closure planning after reserve depletion. In this paper, two cases of early closure in Australia are reviewed, causes for early closure are explored, criteria to evaluate preparedness to early mine closure are proposed and tested in two mines. It concludes that, despite recent advances, planning for mine closure seldom take account of early closure risks.

Effect of Ti and C additions on structural and magnetic properties of (Pr,Nd)-Fe-B nanocrystalline magnetic materials

Effects of titanium carbide (TiC) addition on structural and magnetic properties of isotropic (Pr,Nd)-Fe-B nanocrystalline magnetic materials have been investigated. In this work, we investigate the effect of TiC addition on a (Pr,Nd)-poor and B-rich composition, as well as on a B-poor and (Nd, Pr)-rich composition. Rapidly solidified (Pr, Nd)-Fe-B alloys were prepared by melt-spinning. The compositions studied were (Pr(1-x)Nd(x))(4)Fe(78)B(18) (x = 0, 0.5, and 1) with addition of 3 at% TiC. Unlike the (Pr(x)Nd(1-x))(9.5)Fe(84.5)B(6) materials that present excellent values for coercive. field and energy product, the (Pr,Nd)-poor and B-rich composition alloys with TiC addition present lower values. Rietveld analysis of X-ray data and Mossbauer spectroscopy revealed that samples are predominantly composed of Fe(3)B and alpha-Fe. For the RE-rich compositions (Pr(x)Nd(1-x))(9.5)Fe(84.5)B(6) (x = 0.1, 0.25, 0.5, 0.75, and 1) with the addition of 3 at% TiC, the highest coercive field and energy product (8.4 kOe and 14.4 MGOe, respectively) were obtained for the composition Pr(9.5)Fe(84.5)B(6). (c) 2008 Elsevier B.V. All rights reserved.

Structure of a Population of Hydromedusa maximiliani (Testudines, Chelidae) from Parque Estadual da Serra do Mar, an Atlantic Rainforest Preserve in Southeastern Brazil

We studied the structure of a population of Hydromedusa maximiliani associated with a stream in Parque Estadual da Serra do Mar, Nucleo Itutinga-Piloes, southeastern Brazil, between October 2004 and October 2005. Twenty-five individuals were captured, and a population size of 43.72 +/- 23.7 individuals was estimated. This value is similar to that of the population of Parque Estadual Carlos Botelho, another Atlantic forest reserve of southeastern Brazil. Males were recaptured more frequently than females, suggesting higher activity and/or greater movement of males.

Underground systems of Asteraceae species from the Brazilian Cerrado

Underground systems of Asteraceac species from the Brazilian Cerrado. The aim or this study was to describe the underground systems structure, the origin of the shoot buds, and to identify the storage reserve of seven Asteraceae species in order to understand the adaptive strategies of these species in burned Cerrado areas and their higher frequency in the floristic Surveys for herbaceous and undershrub layers of this biome. The subterranean systems types-diffuse underground system, rhizophore, tuberous roots, and xylopodium-varied among the studied species, but all of them have high shoot bud-forming potential. Fructans of the inulin type were detected as storage substances. The presence of these characteristics on the underground systems Could explain the frequency of these species in the floristic surveys from the Brazilian Cerrado, in which Fire and seasonal drought are frequent. It is possible that the belowground bud banks in the Cerrado biome are as important as demonstrated in North American prairies where fire is also frequent. However, in the Cerrado, as demonstrated here, there are types of underground systems other than rhizomes that are usually described in the prairie. Understanding the anatomical features of these plants is one of the steps to appropriate conservation management of these species in the Cerrado.

New species of Anastrepha Schiner (Diptera, Tephritidae) from remnant area of the Atlantic Rain Forest and surroundings in the state of Espirito Santo, Brazil

Four new species of Anastrepha Schiner were collected in McPhail-type traps hung in trees in a natural reserve and in commercial papaya orchards in Linhares, Espirito Santo state, Brazil. They are described and named herein as follows: Anastrepha atlantica n. sp., Anastrepha glochin n. sp., Anastrepha linharensis n. sp. and Anastrepha martinsi n. sp. Only the latter was collected in traps hung in papaya orchards. The classification of these species in species groups of Anastrepha is also discussed.

Fruit flies (Diptera, Tephritidae) and their associations with native host plants in a remnant area of the highly endangered Atlantic Rain Forest in the State of Espirito Santo, Brazil

The results presented in this paper refer to a host survey, lasting approximately three and a half years (February 2003-july 2006), undertaken in the Vale do Rio Doce Natural Reserve, a remnant area of the highly endangered Atlantic Rain Forest located in Linhares County, State of Espirito Santo, Brazil. A total of 330 fruit samples were collected from native plants, representing 248 species and 51 plant families. Myrtaceae was the most diverse family with 54 sampled species. Twenty-eight plant species, from ten families, are hosts of ten Anastrepha species and of Ceratitis capitata (Wiedemann). Among 33 associations between host plants and fruit flies, 20 constitute new records, including the records of host plants for A. fumipennis Lima and A. nascimentoi Zucchi. The findings were discussed in the light of their implications for rain forest conservation efforts and the study of evolutionary relationships between fruit flies and their hosts.

Cloning, characterization and functional analysis of a 1-FEH cDNA from Vernonia herbacea (Vell.) Rusby

Variations in the inulin contents have been detected in rhizophores of Vernonia herbacea during the phenological cycle. These variations indicate the occurrence of active inulin synthesis and depolymerization throughout the cycle and a role for this carbohydrate as a reserve compound. 1-Fructan exohydrolase (1-FEH) is the enzyme responsible for inulin depolymerization, and its activity has been detected in rhizophores of sprouting plants. Defoliation and low temperature are enhancer conditions of this 1-FEH activity. The aim of the present work was the cloning of this enzyme. Rhizophores were collected from plants induced to sprout, followed by storage at 5C. A full length 1-FEH cDNA sequence was obtained by PCR and inverse PCR techniques, and expressed in Pichia pastoris. Cold storage enhances FEH gene expression. Vh1-FEH was shown to be a functional 1-FEH, hydrolyzing predominantly -2,1 linkages, sharing high identity with chicory FEH sequences, and its activity was inhibited by 81 in the presence of 10 mM sucrose. In V. herbacea, low temperature and sucrose play a role in the control of fructan degradation. This is the first study concerning the cloning and functional analysis of a 1-FEH cDNA of a native species from the Brazilian Cerrado. Results will contribute to understanding the role of fructans in the establishment of a very successful fructan flora of the Brazilian Cerrado, subjected to water limitation and low temperature during winter.

Evaluation of the composition of continuously-cultivated Arthrospira (Spirulina) platensis using ammonium chloride as nitrogen source

This work is focused on the influence of dilution rate (0.08 <= D <= 0.32 d(1)) on the continuous cultivation and biomass composition of Arthrospira (Spirulina) platensis using three different concentrations of ammonium chloride (c(No) = 1.0, 5.0 and 10 mol m (3)) as nitrogen source. At c(No) = 1.0 and 5.0 mol m (3) the biomass protein content was an increasing function of D, whereas, when using c(No) = 10 mol m (3), the highest protein content (72.5%) was obtained at D = 0.12 d (1). An overall evaluation of the process showed that biomass protein content increased with the rate of nitrogen supply (D c(No)) up to 72.5% at D c(No) = 1.20 mol m (3) d (1). Biomass lipid content was an increasing function of D only when the nitrogen source was the limiting factor for the growth (D c(No) <= 0.32 mol m (-3) d (1)), which occurred solely with c(No), = 1.0 mol m (3). Under such conditions, A. platensis reduced its nitrogen reserve in the form of proteins, while maintaining almost unvaried its lipid content. The latter was affected only when the concentration of nitrogen was extremely low (c(No) = 1.0 mol m (3)). The most abundant fatty acids were the palmitic (45.8 +/- 5.20%) and the gamma-linolenic (20.1 +/- 2.00%) ones. No significant alteration in the profiles either of saturated or unsaturated fatty acids was observed with c(No) <= 5.0 mol m (3), prevailing those with 16 and 18 carbons. (C) 2010 Elsevier Ltd. All rights reserved.

Trypanocidal activity of quinonemethide triterpenoids from Cheiloclinium cognatum (Hippocrateaceae)

We report the trypanocidal activity of quinonemethide triterpenoids isolated from root extracts of Cheiloclinium cognatum, a plant of the Hippocrateaceae family, collected in the Cerrado Reserve at Universidade Federal de Goias, Brazil. The trypanocidal activity assays showed an effect on the blood trypomastigote forms of the Y strain of Trypanosoma cruzi where tingenone and tingenol demonstrated activity on the parasite. Their structures were elucidated on the basis of spectral data, particularly COSY, HMQC and HMBC experiments, and chemical transformations.

Identification of a juvenile hormone esterase-like gene in the honey bee, Apis mellifera L. - Expression analysis and functional assays

Tight control over circulating juvenile hormone (JH) levels is of prime importance in an insect`s life cycle. Consequently, enzymes involved in JH metabolism, especially juvenile hormone esterases (JHEs), play major roles during metamorphosis and reproduction. In the highly eusocial Hymenoptera, JH has been co-opted into additional functions, primarily in the development of the queen and worker castes and in age-related behavioral development of workers. Within a set of 21 carboxylesterases predicted in the honey bee genome we identified one gene (Amjhe-like) that contained the main functional motifs of insect JHEs. Its transcript levels during larval development showed a maximum at the switch from feeding to spinning behavior, coinciding with a JH titer minimum. In adult workers, the highest levels were observed in nurse bees, where a low JH titer is required to prevent the switch to foraging. Functional assays showed that Amjhe-like expression is induced by JH-III and suppressed by 20-hydroxyecdysone. RNAi-mediated silencing of Amjhe-like gene function resulted in a six-fold increase in the JH titer in adult worker bees. The temporal profile of Amjhe-like expression in larval and adult workers, the pattern of hormonal regulation and the knockdown phenotype are consistent with the function of this gene as an authentic JHE. (C) 2008 Elsevier Inc. All rights reserved.

Menstrual and hormonal alterations in juvenile systemic lupus erythematosus

Menstrual cycles of 30 patients with juvenile systemic lupus erythematosus (JSLE) were compared with 30 age-matched controls. The mean age of patients with JSLE and controls was similar (17.4 +/- 3.2 vs 17.06 +/- 2.08 years, P = 0.66). The mean menarche age was higher in JSLE than controls (13.13 +/- 1.4 vs 11.56 +/- 1.5 years, P = 0.0008). On the contrary, the mean maternal menarche age was similar in both groups (P = 0.62). Menstrual abnormalities and longer length cycles were more frequently observed in JSLE than controls (63% vs 10%, P = 0.0001; 23% vs 0%, P = 0.0105, respectively). The median of follicle stimulating hormone was significantly higher in patients with JSLE compared with controls (4.6 vs 3.4 IU/L, P = 0.0207), and the median of progesterone was lower (32.5 vs 70 ng/mL, P = 0.0033). The median Of luteinizing hormone was lower in patients with JSLE with menstrual abnormalities versus normal cycles (2.9 vs 5.5 IU/L, P = 0.019) and both had a high percentage of decreased progesterone levels (63% vs 73%, P = 0.70). Our findings support the notion that menstrual disturbances are frequent and may be associated with pituitary dysfunction leading to a decreased progesterone production. We also reported that in spite of premature ovarian failure being a rare event in JSLE the follicular reserve seems to be low regardless of intravenous cyclophosphamide treatment. Lupus (2009) 18, 38-43.

Hormone profile in juvenile systemic lupus erythematosus with previous or current amenorrhea

To identify the underlying mechanism of amenorrhea in juvenile systemic lupus erythematosus (JSLE) patients, thirty-five (11.7%) JSLE patients with current or previous amenorrhea were consecutively selected among the 298 post-menarche patients followed in 12 Brazilian pediatric rheumatology centers. Pituitary gonadotrophins [follicle-stimulating hormone (FSH) and luteinizing hormone (LH)] and estradiol were evaluated in 32/35 patients, and prolactin and total testosterone in 29/35 patients. Patient`s medical records were carefully reviewed according to demographic, clinical and therapeutic findings. The mean duration of amenorrhea was 7.2 +/- A 3.6 months. Low FSH or LH was observed in 7/32 (22%) JSLE patients and normal FSH or LH in 25 (78%). Remarkably, low levels of FSH or LH were associated with higher frequency of current amenorrhea (57% vs. 0%, P = 0.001), higher median disease activity (SLEDAI) and damage (SLICC/ACR-DI) (18 vs. 4, P = 0.011; 2 vs. 0, P = 0.037, respectively) and higher median current dose of prednisone (60 vs. 10 mg/day, P = 0.0001) compared to normal FSH or LH JSLE patients. None of them had decreased ovarian reserve and premature ovarian failure. Six of 29 (21%) patients had high levels of prolactin, and none had current amenorrhea. No correlations were observed between levels of prolactin and SLEDAI, and levels of prolactin and SLICC/ACR-DI scores (Spearman`s coefficient). We have identified that amenorrhea in JSLE is associated with high dose of corticosteroids indicated for active disease due to hypothalamic-pituitary-ovary axis suppression.

Menstrual and hormonal alterations in juvenile dermatomyositis

Objective To evaluate age at menarche, menstrual cycles and hormone profile in juvenile dermatomyositis (JDM) patients and controls. Methods Twelve consecutive JDM patients were compared to 24 age-matched healthy subjects. Age at menarche and age of maternal menarche were recorded. Menstrual cycle was evaluated prospectively for 6 consecutive months and the mean cycle length and flow were calculated. The hormone profile was collected on the last menstrual cycle. Demographic data, clinical features, muscle enzymes, JDM scores and treatment were analysed. Results The median of current age of JDM patients and controls was similar (18 vs. 17 years, p=0.99). The median age at menarche of the JDM patients was higher than in the control group (13 vs. 11 years, p=0.02) whereas the median age of maternal menarche was alike in both groups (12 vs. 13 years, p=0.67). Menstrual disturbances were not observed, except for one patient who had longer length of menstrual cycle. The median of follicle stimulating hormone (FSH) was significantly higher in JDM patients compared to controls (4.5 vs. 3.0 IU/L, p=0.02) and none of them had premature ovarian failure (POF). The median of progesterone was significantly lower in JDM patients (0.3 vs. 0.7 ng/mL, p=0.01) with a higher frequency of decreased progesterone compared to controls (75% vs. 29%, p=0.01). Conclusions Our study identifies in JDM patients delayed menarche with normal cycles and low follicular reserve. The decreased progesterone levels may suggest an underlying subclinical corpus luteum dysfunction in this disease.

Qualitative and Quantitative Real Time Myocardial Contrast Echocardiography for Detecting Hibernating Myocardium

Background: Real time myocardial contrast echocardiography (RTMCE) is an emerging imaging modality for assessing myocardial perfusion that allows for noninvasive quantification of regional myocardial blood flow (MBF). Aim: We sought to assess the value of qualitative analysis of myocardial perfusion and quantitative assessment of myocardial blood flow (MBF) by RTMCE for predicting regional function recovery in patients with ischemic heart disease who underwent coronary artery bypass grafting (CABG). Methods: Twenty-four patients with coronary disease and left ventricular systolic dysfunction (ejection fraction < 45%) underwent RTMCE before and 3 months after CABG. RTMCE was performed using continuous intravenous infusion of commercially available contrast agent with low mechanical index power modulation imaging. Viability was defined by qualitative assessment of myocardial perfusion as homogenous opacification at rest in >= 2 segments of anterior or >= 1 segment of posterior territory. Viability by quantitative assessment of MBF was determined by receiver-operating characteristics curve analysis. Results: Regional function recovery was observed in 74% of territories considered viable by qualitative analysis of myocardial perfusion and 40% of nonviable (P = 0.03). Sensitivity, specificity, positive and negative predictive values of qualitative RTMCE for detecting regional function recovery were 74%, 60%, 77%, and 56%, respectively. Cutoff value of MBF for predicting regional function recovery was 1.76 (AUC = 0.77; 95% CI = 0.62-0.92). MBF obtained by RTMCE had sensitivity of 91%, specificity of 50%, positive predictive value of 75%, and negative predictive value of 78%. Conclusion: Qualitative and quantitative RTMCE provide good accuracy for predicting regional function recovery after CABG. Determination of MBF increases the sensitivity for detecting hibernating myocardium. (Echocardiography 2011;28:342-349).