Use of levoglucosan, potassium, and water-soluble organic carbon to characterize the origins of biomass-burning aerosols

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Blue-greenish acrochaetioid algae in freshwater habitats are Chantransia stages of Batrachospermales sensu lato (Rhodophyta)

Fourteen culture isolates of freshwater acrochaetioid algae from distinct regions around the world were analysed, including the reddish species Audouinella hermannii, the dubious blue-greenish species A. pygmaea, and Chantransia stages from distinct taxonomic origins in the Batrachospermales sensu lato (Batrachospermaceae, Lemaneaceae and Thoreaceae). Four isolates (two 'Chantransia' stages and two species of Audouinella, A. hermannii and A. pygmaea) were tested under experimental conditions of temperature (10-25°C), irradiance (65 and 300 μmol photons m-2 s-1) and photoperiod (16:8 h and 8:16 h light/dark cycles). Plant colour is proposed as the only vegetative character that can be unequivocally applied to distinguish Audouinella from 'Chantransia', blue-greenish representing Chantransia stages and reddish applying to true Audouinella species (also forming reproductive structures other than monosporangia, e.g. tetrasporangia). Some isolates of A. pygmaea were proven to be unequivocally 'Chantransia stages owing either to production of juvenile gametophytes or to derivation from carpospores. No association of the morphology of A. pygmaea was found with any particular species, thus it should be regarded as a complex involving many species of the Batrachospermales sensu lato, as is also the case with A. macrospora. We therefore recommend that all blue-greenish acrochaetioid algae in freshwater habitats be considered as Chantransia stages of members of the Batrachospermales, and that the informal descriptors pygmaea and macrospora be used to distinguish the two discernable morphologies. Induction of gametophytes occurred under much wider conditions than previously reported, reinforcing the conclusion that requirements are probably species-specific. Although phenotypic plasticity was in evidence, with temperature, irradiance and photoperiod affecting morphology, no alga showed variation outside the limits based on traditional taxonomic studies. No overall trend was observed for vegetative or reproductive characters in response to temperature, irradiance and photoperiod for all the algae tested, only for specific algae or characters. Effects of temperature and irradiance on morphological characters were more evident, as well as strong interactions between these variables, whereas few differences were generally found in response to photoperiod and irradiance.

Biosynthetic origins of the isoprene units of 4-nerolidylcatechol in Potomorphe umbellata

The biosynthetic origins of the isoprene units of 4-nerolidylcatechol (1), the major constituent of Potomorphe umbellata, have been studied through feeding experiments with [14C]- and [13C]-glucose, and with precursors of the mevalonic acid and triose/pyruvate pathways, namely, [2- 14C]-mevalonolactone and [U-14C]-glyceraldehyde-3- phosphate, respectively. The pattern of incorporation of label from [1- 13C]-glucose into 1 was determined by quantitative 13C NMR spectroscopy. The labelling pattern revealed that the additive was specifically incorporated, and that the isoprene units of the sesquiterpenoid moiety of 4-nerolidylcatechol were derived from both the mevalonic acid and the triose/pyruvate pathways. The results indicate that both plastidic and cytoplasmic pathways are able to provide isopentenyl diphosphate units for the biosynthesis of 1. ©2005 Sociedade Brasileira de Química.

The crisis in Central America: its origins, scope and consequences

Includes bibliography

Crisis en Centroamérica: orígenes, alcances y consecuencias = Crisis in Central America: its origins, scope and consequences

Incluye Bibliografía

Debt accumulation in the Caribbean: origins, consequences and strategies

Includes bibliography

Biotechnology: origins and development in the Caribbean

Includes bibliography

Single Origin of Sex Chromosomes and Multiple Origins of B Chromosomes in Fish Genus Characidium

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Properties of films obtained from biopolymers of different origins for skin lesions therapy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genome-wide association study and ancestral origins of the slick-hair coat in tropically adapted cattle

The slick hair coat (SLICK) is a dominantly inherited trait typically associated with tropically adapted cattle that are from Criollo descent through Spanish colonization of cattle into the New World. The trait is of interest relative to climate change, due to its association with improved thermo-tolerance and subsequent increased productivity. Previous studies localized the SLICK locus to a 4 cM region on chromosome (BTA) 20 and identified signatures of selection in this region derived from Senepol cattle. The current study compares three slick-haired Criollo-derived breeds including Senepol, Carora, and Romosinuano and three additional slick-haired cross-bred lineages to non-slick ancestral breeds. Genome-wide association (GWA), haplotype analysis, signatures of selection, runs of homozygosity (ROH), and identity by state (IBS) calculations were used to identify a 0.8 Mb (37.7-38.5 Mb) consensus region for the SLICK locus on BTA20 in which contains SKP2 and SPEF2 as possible candidate genes. Three specific haplotype patterns are identified in slick individuals, all with zero frequency in non-slick individuals. Admixture analysis identified common genetic patterns between the three slick breeds at the SLICK locus. Principal component analysis (PCA) and admixture results show Senepol and Romosinuano sharing a higher degree of genetic similarity to one another with a much lesser degree of similarity to Carora. Variation in GWA, haplotype analysis, and IBS calculations with accompanying population structure information supports potentially two mutations, one common to Senepol and Romosinuano and another in Carora, effecting genes contained within our refined location for the SLICK locus.

A model to explain spermatophore implantation in cephalopods (Mollusca: Cephalopoda) and a discussion on its evolutionary origins and significance

Male coleoid cephalopods produce spermatophores that can attach autonomously on the female's body during a complex process of evagination called the spermatophoric reaction, during which the ejaculatory apparatus and spiral filament of the spermatophore are everted and exposed to the external milieu. In some deepwater cephalopods, the reaction leads to the intradermal implantation of the spermatophore, a hitherto enigmatic phenomenon. The present study builds upon several lines of evidence to propose that spermatophore implantation is probably achieved through the combination of (1) an evaginating-tube mechanism performed by the everting ejaculatory apparatus and (2) the anchorage provided by the spiral filament's stellate particles. The proposed theoretical model assumes that, as it is exposed to the external milieu, each whorl of the spiral filament anchors to the surrounding tissue by means of its sharp stellate particles. As the ejaculatory apparatus tip continues evaginating, it grows in diameter and stretches lengthwise, enlarging the diameter of the whorl and propelling it, consequently tearing and pushing the anchored tissue outward and backward, and opening space for the next whorl to attach. After the ejaculatory apparatus has been everted and has perforated tissue, the cement body is extruded, possibly aiding in final attachment, and the sperm mass comes to lie inside the female tissue, encompassed by the everted ejaculatory apparatus tube. It is proposed that this unique, efficient spermatophore attachment mechanism possibly evolved in intimate relationship with the adoption of an active mode of life by coleoids. The possible roles of predation pressure and sperm competition in the evolution of this mechanism are also discussed. (c) 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 711726.

Characterization of aflatoxigenic and non-aflatoxigenic strains of Aspergillus section Flavi isolated from corn grains of different geographic origins in Brazil

Aflatoxins can cause great economic losses and serious risks to humans and animals health. The largest aflatoxin producers belong to Aspergillus section Flavi and can occur naturally in food commodities. Studies showed that molecular tools as well as the type of sclerotia produced by the strains could be helpful for identification of Aspergillus species and could be correlated with levels of toxin production. The purpose of this work was to characterize the genetic diversity using AFLP technique, the type of sclerotia and the ability of aflatoxin production by isolated strains from corn of different origins in Brazil, and to verify whether qPCR based on aflR and aflP genes is appropriate for estimating the level of aflatoxin production. All the 75 strains were classified as A. flavus and the AFLP technique showed a wide intraspecific variability within them. Regarding sclerotia production, 34% were classified as S and 66% as L type. Among the aflatoxin-producers, 52.8% produced aflatoxin B-1, while 47.2% aflatoxins B-1 and B-2. Statistical analysis showed no correlation between sclerotia production and aflatoxigenicty, and no correlation between the phylogenetic clusters and aflatoxin production. Concerning the relative expression of aflR and aflP, Pearson's correlation test demonstrated low positive correlation between the expression of the aflR and aflP genes and the production of AFB(1) and AFB(2), but showed high positive correlation between aflR and aflP expression. In contrast to the other reference strains, A. oryzae ATCC 7282 showed no amplification of aflR and aflP. The results highlight the need for detection of reliable and reproducible markers with a high positive correlation with aflatoxin production.

Use of levoglucosan, potassium, and water-soluble organic carbon to characterize the origins of biomass-burning aerosols

Three chemical species related to biomass burning, levoglucosan, potassium and water-soluble organic carbon (WSOC), were measured in aerosol samples collected in a rural area on the outskirts of the municipality of Ourinhos (Sao Paulo State, Brazil). This region is representative of the rural interior of the State, where the economy is based on agro-industrial production, and the most important crop is sugar cane. The manual harvesting process requires that the cane be first burned to remove excess foliage, leading to large emissions of particulate materials to the atmosphere. Most of the levoglucosan (68-89%) was present in small particles (<1.5 mu m), and its concentration in total aerosol ranged from 25 to 1186 ng m(-3). The highest values were found at night, when most of the biomass burning occurs. In contrast, WSOC showed no diurnal pattern, with an average concentration of 5.38 +/- 2.97 mu g m(-3) (n = 27). A significant linear correlation between levoglucosan and WSOC (r = 0.54; n = 26; p < 0.0001) confirmed that biomass burning was in fact an important source of WSOC in the study region. A moderate (but significant) linear correlation between levoglucosan and potassium concentrations (r = 0.62; n = 40; p < 0.0001) was indicative of the influence of other sources of potassium in the study region, such as soil resuspension and fertilizers. When only the fine particles (<1.5 pm; typical of biomass burning) were considered, the linear coefficient increased to 0.91 (n = 9). In this case, the average levoglucosan/K+ ratio was 0.24, which may be typical of biomass burning in the study region. This ratio is about 5 times lower than that previously found for Amazon aerosol collected during the day, when flaming combustion prevails. This suggests that the levoglucosan/K+ ratio may be especially helpful for characterization of the type of vegetation burned (such as crops or forest), when biomass-burning is the dominant source of potassium. The relatively high concentrations of WSOC (and inorganic ions) suggest an important influence on the formation of cloud condensation nuclei, which is likely to affect cloud formation and precipitation patterns. (C) 2012 Elsevier Ltd. All rights reserved.

Multiple independent origins of mitochondrial control region duplications in the order Psittaciformes

mitochondrial genomes are generally thought to be under selection for compactness, due to their small size, consistent gene content, and a lack of introns or intergenic spacers. As more animal mitochondrial genomes are fully sequenced, rearrangements and partial duplications are being identified with increasing frequency, particularly in birds (Class Ayes). In this study, we investigate the evolutionary history of mitochondrial control region states within the avian order Psittaciformes (parrots and cockatoos). To this aim, we reconstructed a comprehensive multi-locus phylogeny of parrots, used PCR of three diagnostic fragments to classify the mitochondrial control region state as single or duplicated, and mapped these states onto the phylogeny. We further sequenced 44 selected species to validate these inferences of control region state. Ancestral state reconstruction using a range of weighting schemes identified six independent origins of mitochondrial control region duplications within Psittaciformes. Analysis of sequence data showed that varying levels of mitochondrial gene and tRNA homology and degradation were present within a given clade exhibiting duplications. Levels of divergence between control regions within an individual varied from 0-10.9% with the differences occurring mainly between 51 and 225 nucleotides 3' of the goose hairpin in domain I. Further investigations into the fates of duplicated mitochondrial genes, the potential costs and benefits of having a second control region, and the complex relationship between evolutionary rates, selection, and time since duplication are needed to fully explain these patterns in the mitochondrial genome. (C) 2012 Elsevier Inc. All rights reserved.