Cloud condensation nuclei from biomass burning during the Amazonian dry-to-wet transition season

Aircraft measurements of cloud condensation nuclei (CCN) during the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) were conducted over the Southwestern Amazon region in September-October 2002, to emphasize the dry-to-wet transition season. The CCN concentrations were measured for values within the range 0.1-1.0% of supersaturation. The CCN concentration inside the boundary layer revealed a general decreasing trend during the transition from the end of the dry season to the onset of the wet season. Clean and polluted areas showed large differences. The differences were not so strong at high levels in the troposphere and there was evidence supporting the semi-direct aerosol effect in suppressing convection through the evaporation of clouds by aerosol absorption. The measurements also showed a diurnal cycle following biomass burning activity. Although biomass burning was the most important source of CCN, it was seen as a source of relatively efficient CCN, since the increase was significant only at high supersaturations.

Impact of biomass burning aerosols on precipitation in the Amazon: A modeling case study

A study of the potential role of aerosols in modifying clouds and precipitation is presented using a numerical atmospheric model. Measurements of cloud condensation nuclei (CCN) and cloud size distribution properties taken in the southwestern Amazon region during the transition from dry to wet seasons were used as guidelines to define the microphysical parameters for the simulations. Numerical simulations were carried out using the Brazilian Development on Regional Atmospheric Modeling System, and the results presented considerable sensitivity to changes in these parameters. High CCN concentrations, typical of polluted days, were found to result in increases or decreases in total precipitation, depending on the level of pollution used as a reference, showing a complexity that parallels the aerosol-precipitation interaction. Our results show that on the grids evaluated, higher CCN concentrations reduced low-to-moderate rainfall rates and increased high rainfall rates. The principal consequence of the increased pollution was a change from a warm to a cold rain process, which affected the maximum and overall mean accumulated precipitation. Under polluted conditions, cloud cover diminished, allowing greater amounts of solar radiation to reach the surface. Aerosol absorption of radiation in the lower layers of the atmosphere delayed convective evolution but produced higher maximum rainfall rates due to increased instability. In addition, the intensity of the surface sensible heat flux, as well as that of the latent heat flux, was reduced by the lower temperature difference between surface and air, producing greater energy stores at the surface.

Constraining the orbital orientation of eta Carinae from H Paschen lines

During the past decade, several observational and theoretical works have provided evidence of the binary nature of eta Carinae. Nevertheless, there is still no direct determination of the orbital parameters, and the different current models give contradictory results. The orbit is, in general, assumed to coincide with the Homunculus equator although the observations are not conclusive. Among all systems, eta Car has the advantage that it is possible to observe both the direct emission of line transitions in the central source and its reflection by the Homunculus, which is dependent on the orbital inclination. In this work, we studied the orbital phase-dependent hydrogen Paschen spectra reflected by the south-east lobe of the Homunculus to constrain the orbital parameters of eta Car and determine its inclination with respect to the Homunculus axis. Assuming that the emission excess originates in the wind-wind shock region, we were able to model the latitude dependence of the spectral line profiles. For the first time, we were able to estimate the orbital inclination of eta Car with respect to the observer and to the Homunculus axis. The best fit occurs for an orbital inclination to the line of sight of i similar to 60 degrees +/- 10 degrees, and i* similar to 35 degrees +/- 10 degrees with respect to the Homunculus axis, indicating that the angular momenta of the central object and the orbit are not aligned. We were also able to fix the phase angle of conjunction as similar to -40 degrees, showing that periastron passage occurs shortly after conjunction.

Baroreflex sensitivity and oxidative stress in the LDL receptor knockout mice

This study alms at observing the effect of low-density lipoprotein (LDL) receptor deficiency in cholesterol blood levels, baroreflex sensitivity (BRS), nitric oxide (NO) bioavailability, and oxidative stress. The lack of LDL receptors in mice significantly increased the cholesterol blood levels (179 +/- 35 vs. 109 +/- 13 mg/dL) in the knockout (KO) mice compared to control. There was no difference in basal mean arterial pressure and heart rate between the groups. However, in KO mice the BRS was significantly attenuated and the antioxidant enzyme activities, measured in erythrocytes and heart, were significantly decreased. On the other hand, the oxidative damage measured by chemiluminescence and carbonyls was increased, while total plasma nitrate levels were lower in KO mice, indicating a decrease in NO availability. In conclusion, these results indicate that the lack of LDL receptor increased cholesterol blood levels, induced oxidative stress and decreased BRS. (C) 2008 Elsevier GmbH. All rights reserved.

Bioethanol from lignocelluloses: Status and perspectives in Brazil

The National Alcohol Program - ProAlcool, created by the government of Brazil in 1975 resulted less dependency on fossil fuels. The addition of 25% ethanol to gasoline reduced the import of 550 million barrels oil and also reduced the emission CO(2) by 110 million tons. Today, 44% of the Brazilian energy matrix is renewable and 13.5% is derived from sugarcane. Brazil has a land area of 851 million hectares, of which 54% are preserved, including the Amazon forest (350 million hectares). From the land available for agriculture (340 million hectares), only 0.9% is occupied by sugarcane as energy crop, showing a great expansion potential. Studies have shown that in the coming years, ethanol yield per hectare of sugarcane, which presently is 6000 L/ha, could reach 10,000 L/ha, if 50% of the produced bagasse would be converted to ethanol. This article describes the efforts of different Brazilian institutions and research groups on second generation bioethanol production, especially from sugarcane bagasse. (C) 2009 Elsevier Ltd. All rights reserved.

Human Stem Cell Cultures from Cleft Lip/Palate Patients Show Enrichment of Transcripts Involved in Extracellular Matrix Modeling By Comparison to Controls

Nonsyndromic cleft lip and palate (NSCL/P) is a complex disease resulting from failure of fusion of facial primordia, a complex developmental process that includes the epithelial-mesenchymal transition (EMT). Detection of differential gene transcription between NSCL/P patients and control individuals offers an interesting alternative for investigating pathways involved in disease manifestation. Here we compared the transcriptome of 6 dental pulp stem cell (DPSC) cultures from NSCL/P patients and 6 controls. Eighty-seven differentially expressed genes (DEGs) were identified. The most significant putative gene network comprised 13 out of 87 DEGs of which 8 encode extracellular proteins: ACAN, COL4A1, COL4A2, GDF15, IGF2, MMP1, MMP3 and PDGFa. Through clustering analyses we also observed that MMP3, ACAN, COL4A1 and COL4A2 exhibit co-regulated expression. Interestingly, it is known that MMP3 cleavages a wide range of extracellular proteins, including the collagens IV, V, IX, X, proteoglycans, fibronectin and laminin. It is also capable of activating other MMPs. Moreover, MMP3 had previously been associated with NSCL/P. The same general pattern was observed in a further sample, confirming involvement of synchronized gene expression patterns which differed between NSCL/P patients and controls. These results show the robustness of our methodology for the detection of differentially expressed genes using the RankProd method. In conclusion, DPSCs from NSCL/P patients exhibit gene expression signatures involving genes associated with mechanisms of extracellular matrix modeling and palate EMT processes which differ from those observed in controls. This comparative approach should lead to a more rapid identification of gene networks predisposing to this complex malformation syndrome than conventional gene mapping technologies.

Is there any risk in a symbiotic species associating with an endangered one? A case of a phoronid worm growing on a Ceriantheomorphe tube

The conservation of emblematic threatened species is in highlight nowadays. Interestingly, few invertebrate groups attract scientific attention on this issue while they constitute the vast majority of animal biodiversity. Nevertheless, many invertebrate species are nowadays at risk of extinction. This means that plenty of species are currently disappearing out of sight. During a survey in the southwestern Atlantic Ocean tubes of an endangered species of cerianthid were sampled. This study reports for the very first time the occurrence of the species Phoronis australis in southwestern Atlantic waters and the association of phoronids with the genus Ceriantheomorphe. This raises questions on mutual extinction risks for symbiotic species and also on the criteria for their inclusion on Red Lists.

Taxonomic review of Haliclystus antarcticus Pfeffer, 1889 (Stauromedusae, Staurozoa, Cnidaria), with remarks on the genus Haliclystus Clark, 1863

Difficulties concerning the taxonomy of stauromedusae are long known, and there is a clear need for taxonomic revision of the genus Haliclystus, as well as the reevaluation of some species. Haliclystus antarcticus Pfeffer, 1889 is recorded from Admiralty Bay, King George Island, Antarctic Peninsula. Due to the lack of detailed information on this species, we provide a redescription, presenting new data on the cnidome, morphometry, geographical distribution and intraspecific variation. Based on these characters, we propose that our specimens and Haliclystus auricula from Chile and Argentina are synonymous and should be classified as H. antarcticus. We also review the worldwide distribution of the genus Haliclystus Clark, 1863 and discuss taxonomic issues, concluding that some characters traditionally used in the taxonomy of the group should be used cautiously.

A comparative study of cleaning activity of two reef fishes at Fernando de Noronha Archipelago, tropical West Atlantic

Cleaner fishes are usually classified as obligate or facultative cleaners according to their diet and the extent to which their nutritional requirements in the different ontogenetic stages are gained from cleaning. While obligate cleaners clean throughout their lives and ingest mainly food taken from the clients` body surface, facultative cleaners clean only as juveniles and have a broader diet. In addition, some facultative cleaners may experience a relatively higher predation risk, and thus rarely interact with piscivorous fishes. Despite these acknowledged differences, there are very few studies that compare cleaning activity of obligate and facultative cleaners within the same area. Cleaning activity of the obligate cleaner goby Elacatinus cf. randalli and the facultative cleaner wrasse Thalassoma noronhanum were comparatively examined at Fernando de Noronha Archipelago, tropical West Atlantic. The client assemblage attended by the two cleaners differed, as the goby attended a slightly greater diversity of species (22), mostly piscivores and zoobenthivores, and the wrasse attended fewer species (19), mostly planktivores. Chromis multilineata was the most common client species of both cleaners, although body size (which is expected to be positively correlated to clients` ectoparasite load) of C. multilineata individuals attended by the goby was larger than that of the individuals attended by the wrasse. Despite such differences, T. noronhanum showed a surprisingly species-rich client assemblage when compared with other cleaners of the genus Thalassoma. In addition, the frequency and time spent on cleaning interactions, as well as the number of client species attended per 10-min period, was similar for both cleaner species, which indicate that they have important yet complimentary ecological roles in the reef community at Fernando de Noronha Archipelago.

Expression of alpha-synuclein is increased in the hippocampus of rats with high levels of innate anxiety

A genomic region neighboring the alpha-synuclein gene, on rat chromosome 4, has been associated with anxiety- and alcohol-related behaviors in different rat strains. In this study, we have investigated potential molecular and physiological links between alpha-synuclein and the behavioral differences observed between Lewis (LEW) and Spontaneously Hypertensive (SHR) inbred rats, a genetic model of anxiety. As expected, LEW rats appeared more fearful than SHR rats in three anxiety models: open field, elevated plus maze and light/dark box. Moreover, LEW rats displayed a higher preference for alcohol and consumed higher quantities of alcohol than SHR rats. alpha-Synuclein mRNA and protein concentrations were higher in the hippocampus, but not the hypothalamus of LEW rats. This result inversely correlated with differences in dopamine turnover in the hippocampus of LEW and SHR rats, supporting the hypothesis that alpha-synuclein is important in the downregulation of dopamine neurotransmission. A novel single nucleotide polymorphism was identified in the 30-untranslated region (3`-UTR) of the alpha-synuclein cDNA between these two rat strains. Plasmid constructs based on the LEW 3`-UTR sequence displayed increased expression of a reporter gene in transiently transfected PC12 cells, in accordance with in-vivo findings, suggesting that this nucleotide exchange might participate in the differential expression of alpha-synuclein between LEW and SHR rats. These results are consistent with a novel role for alpha-synuclein in modulating rat anxiety- like behaviors, possibly through dopaminergic mechanisms. Since the behavioral and genetic differences between these two strains are the product of independent evolutionary histories, the possibility that polymorphisms in the alpha-synuclein gene may be associated with vulnerability to anxiety- related disorders in humans requires further investigation. Molecular Psychiatry (2009) 14, 894-905; doi: 10.1038/mp.2008.43; published online 22 April 2008

The effect of DMSA-functionalized magnetic nanoparticles on transendothelial migration of monocytes in the murine lung via a beta(2) integrin-dependent pathway

Magnetic nanoparticles surface-functionalized with meso-2,3-dimercaptosuccinic acid (MNPs-DMSA) constitute an innovative and promising approach for tissue- and cell-targeted delivery of therapeutic drugs in the lung. Transendothelial migration of leukocytes in the lung is a side effect of endovenous administration of MNPs-DMSA. Using cytologic and phenotypic analysis of murine bronchoalveolar lavage cells, we identified monocytes/macrophages as the main subpopulation of leukocytes involved in this process. Moreover, ultrastructural analysis revealed the presence of nanoparticles inside of numerous macrophages from bronchoalveolar lavage. MNPs-DMSA at concentrations as high as 1 X 10(15) nanoparticles/mL had no toxic effects on macrophages, as evidenced by 3-(4, 5-dimethylthiazolyi-2)-2,5-diphenyltetrazolium bromide (MTT) assay. Notably, MNPs-DMSA up-regulated the mRNA expression of E, L- and P-selectin and macrophage-1 antigen in the murine lung. Upregulation of these cell adhesion molecules was associated with an increased concentration of tumor necrosis factor-alpha in lung. Finally, the critical relevance of the beta(2) integrin-dependent pathway in leukocyte transmigration elicited by MNPs-DMSA was demonstrated by use of knockout mice. Our results characterize mechanisms of the pro-inflammatory effects of MNPs-DMSA in the lung, and identify beta(2) integrin-targeted interventions as promising strategies to reduce pulmonary side effects of MNPs-DMSA during biomedical applications. (C) 2009 Elsevier Ltd. All rights reserved.

Analysis of peptides in prohormone convertase 1/3 null mouse brain using quantitative peptidomics

P>Neuropeptides are produced from larger precursors by limited proteolysis, first by endopeptidases and then by carboxypeptidases. Major endopeptidases required for these cleavages include prohormone convertase (PC) 1/3 and PC2. In this study, quantitative peptidomics analysis was used to characterize the specific role PC1/3 plays in this process. Peptides isolated from hypothalamus, amygdala, and striatum of PC1/3 null mice were compared with those from heterozygous and wild-type mice. Extracts were labeled with stable isotopic tags and fractionated by HPLC, after which relative peptide levels were determined using tandem mass spectrometry. In total, 92 peptides were found, of which 35 were known neuropeptides or related peptides derived from 15 distinct secretory pathway proteins: 7B2, chromogranin A and B, cocaine- and amphetamine-regulated transcript, procholecystokinin, proenkephalin, promelanin concentrating hormone, proneurotensin, propituitary adenylate cyclase-activating peptide, proSAAS, prosomatosatin, provasoactive intestinal peptide, provasopressin, secretogranin III, and VGF. Among the peptides derived from these proteins, similar to 1/3 were decreased in the PC1/3 null mice relative to wild-type mice, similar to 1/3 showed no change, and similar to 1/3 increased in PC1/3 null. Cleavage sites were analyzed in peptides that showed no change or that decreased in PC1/3 mice, and these results were compared with peptides that showed no change or decreased in previous peptidomic studies with PC2 null mice. Analysis of these sites showed that while PC1/3 and PC2 have overlapping substrate preferences, there are particular cleavage site residues that distinguish peptides preferred by each PC.

CCP1/Nna1 functions in protein turnover in mouse brain: Implications for cell death in Purkinje cell degeneration mice

Purkinje cell degeneration (pcd) mice have a mutation within the gene encoding cytosolic carboxypeptidase 1 (CCP1/Nna1), which has homology to metallocarboxypeptidases. To assess the function of CCP1/Nna1, quantitative proteomics and peptidomics approaches were used to compare proteins and peptides in mutant and wild-type mice. Hundreds of peptides derived from cytosolic and mitochondrial proteins are greatly elevated in pcd mouse hypothalamus, amygdala, cortex, prefrontal cortex, and striatum. However, the major proteins detected on 2-D gel electrophoresis were present in mutant and wild-type mouse cortex and hypothalamus at comparable levels, and proteasome activity is normal in these brain regions of pcd mice, suggesting that the increase in cellular peptide levels in the pcd mice is due to reduced degradation of the peptides downstream of the proteasome. Both nondegenerating and degenerating regions of pcd mouse brain, but not wild-type mouse brain, show elevated autophagy, which can be triggered by a decrease in amino acid levels. Taken together with previous studies on CCP1/Nna1, these data suggest that CCP1/Nna1 plays a role in protein turnover by cleaving proteasome-generated peptides into amino acids and that decreased peptide turnover in the pcd mice leads to cell death.-Berezniuk, I., Sironi, J., Callaway, M. B., Castro, L. M., Hirata, I. Y., Ferro, E. S., Fricker, L. D. CCP1/Nna1 functions in protein turnover in mouse brain: Implications for cell death in Purkinje cell degeneration mice. FASEB J. 24, 1813-1823 (2010). www.fasebj.org

Hemopressins and other hemoglobin-derived peptides in mouse brain: comparison between brain, blood, and heart peptidome and regulation in Cpefat/fat mice

P>Many hemoglobin-derived peptides are present in mouse brain, and several of these have bioactive properties including the hemopressins, a related series of peptides that bind to cannabinoid CB1 receptors. Although hemoglobin is a major component of red blood cells, it is also present in neurons and glia. To examine whether the hemoglobin-derived peptides in brain are similar to those present in blood and heart, we used a peptidomics approach involving mass spectrometry. Many hemoglobin-derived peptides are found only in brain and not in blood, whereas all hemoglobin-derived peptides found in heart were also seen in blood. Thus, it is likely that the majority of the hemoglobin-derived peptides detected in brain are produced from brain hemoglobin and not erythrocytes. We also examined if the hemopressins and other major hemoglobin-derived peptides were regulated in the Cpefat/fat mouse; previously these mice were reported to have elevated levels of several hemoglobin-derived peptides. Many, but not all of the hemoglobin-derived peptides were elevated in several brain regions of the Cpefat/fat mouse. Taken together, these findings suggest that the post-translational processing of alpha and beta hemoglobin into the hemopressins, as well as other peptides, is up-regulated in some but not all Cpefat/fat mouse brain regions.

Expression Patterns of Cell Adhesion Molecules in Mice`s Lung After Administration of Meso-2,3-Dimercaptosuccinic Acid-Coated Maghemite Nanoparticles

We studied the expression pattern of cell adhesion molecules associated to transendothelial migration of leukocytes in different lung`s vascular compartments after administration of a magnetic fluid sample containing maghemite nanoparticles surface-coated with meso-2,3-dimercaptosuccinic acid. The analyses were conducted in mice 4 and 12 h after endovenous administration of the magnetic fluid in control mice. Firstly, the migratory activity of leukocytes after magnetic fluid surface-coated with meso-2,3-dimercaptosuccinic acid administration was confirmed using broncho-alveolar lavage and light microscopy. Then, the expression of cell adhesion molecules in the lung`s vascular compartments was investigated by immunofluorescence microscopy of frozen sections, using antibodies against L-selectin, P-selectin, E-selectin, macrophage antigen-1, and leukocyte function associated antigen-1. L- and P-selectin showed similar pattern of expression in the pulmonary vasculature in animals treated with magnetic fluid and in the control group. In contrast, macrophage antigen-1 and leukocyte function associated antigen-1 were found in capillary only in animals treated with magnetic fluid surface-coated with meso-2,3-dimercaptosuccinic acid administration. In addition, after magnetic fluid administration E-selectin was found in post-capillary sites. Our findings demonstrated that magnetic fluid surface-coated with meso-2,3-dimercaptosuccinic acid administration exhibits modulation effects on expression patterns of E-selectin, macrophage antigen-1, and leukocyte function associated antigen-1 in the lung`s vascular compartments. These findings are very important in a strategy to reduce the potential toxicity of magnetic fluid surface-coated with meso-2,3-dimercaptosuccinic acid administration for medical applications.