The impact of carbon footprinting aggregation on realizing emission reduction targets

A variety of activity-based methods exist for estimating the carbon footprint in transportation. For instance, the greenhouse gas protocol suggests a more aggregate estimation method than the Network for Transport and Environment (NTM) method. In this study, we implement a detailed estimation method based on NTM and different aggregate approaches for transportation carbon emissions in the dynamic lot sizing model. Analytical results show the limitations of aggregate models for both accurate estimation of real emissions and risks of compliance with carbon constraints (e.g., carbon caps). Extensive numerical experimentation shows that the magnitude of errors can be substantial. We provide insights under which limited conditions aggregate estimations can be used safely and when more detailed estimates are appropriate.     

Biogeography of Speciation of Two Sister Species of Neotropical Amazona (Aves,Psittaciformes) Based on Mitochondrial Sequence Data

Coalescent theory provides powerful models for population genetic inference and is now increasingly important in estimates of divergence times and speciation research. We use molecular data and methods based on coalescent theory to investigate whether genetic evidence supports the hypothesis of A. pretrei and A. tucumana as separate species and whether genetic data allow us to assess which allopatric model seems to better explain the diversification process in these taxa. We sampled 13 A. tucumana from two provinces in northern Argentina and 28 A. pretrei from nine localities of Rio Grande do Sul, Brazil. A 491 bp segment of the mitochondrial gene cytochrome c oxidase I was evaluated using the haplotype network and phylogenetic methods. The divergence time and other demographic quantities were estimated using the isolation and migration model based on coalescent theory. The network and phylogenetic reconstructions showed similar results, supporting reciprocal monophyly for these two taxa. The divergence time of lineage separation was estimated to be approximately 1.3 million years ago, which corresponds to the lower Pleistocene. Our results enforce the current taxonomic status for these two Amazon species. They also support that A. pretrei and A. tucumana diverged with little or no gene flow approximately 1.3 million years ago, most likely after the establishment of a small population in the Southern Yungas forest by dispersion of a few founders from the A. pretrei ancestral population. This process may have been favored by habitat corridors formed in hot and humid periods of the Quaternary. Considering that these two species are considered threatened, the results were evaluated for their implications for the conservation of these two species.     

The PHA Test as an Indicator of Phagocytic Activity in a Passerine Bird

Several techniques in ecological immunology have been used to assess bird immunocompetence thus providing useful information to understand the contribution of the immunological system in life-history decisions. The phytohaemagglutinin (PHA)-skin test has been the most widely employed technique being interpreted as the sole result of T lymphocytes proliferation and hence used to evaluate acquired immunological capacity. However, the presence of high numbers of phagocytic cells in the swelling point has cast some doubt about such an assumption. To address this issue, we collected blood from 14 days-old nestlings of spotless starling (Sturnus unicolor), administered subcutaneous PHA immediately after and then measured the swelling response 24 hours later. Differential counts of white blood cells suggested that an intense development of acquired immunological defences was taking place. The phagocytic activity of both heterophiles and monocytes was also very intense as it was the swelling response. Moreover, our results show, for the first time in birds, a positive relationship between the phagocytic activity of both kinds of cells and the swelling response. This broadens the significance of the PHA test from reflecting T lymphocytes proliferation -as previously proposed but still undetermined in vivo- to evaluate phagocytosis as well. In other words, our data suggest that the PHA swelling response may not be considered as the only consequence of processes of specific and induced immunity –T lymphocytes proliferation- but also of constitutive and nonspecific immunity –heterophiles and monocytes phagocytosis. We propose the extensive use of PHA-skin test as an optimal technique to assess immunocompetence.     

Mitochondrial haplotype variability of brown trout populations from Northwestern Iberian Peninsula,a secondary contact area between lineages

Previous studies using mitochondrial markers and microsatellites revealed a new highly differentiated Atlantic lineage of brown trout in the Iberian Peninsula mainly confined to the Upper Duero Basin. Data suggest that Duero lineage (DU) hybridizes with previously described Atlantic (AT) lineages in that basin. However, nuclear and cytogenetic data suggest another hybrid zone between divergent lineages might be present in the Miño Basin, another Atlantic drainage located to the north. Here, we extend those studies by analyzing the mitochondrial haplotype variability of brown trout populations from northwestern Spain, a poorly studied area, to obtain an accurate picture of the distribution of DU. Results show that the DU haplotype is fixed in several isolated populations from the upper course of the Miño River and its main tributary the Sil River. DU haplotype co-occurs with two related AT haplotypes in the Miño Basin revealing a new secondary contact zone. The identification of both longtime stable populations of DU and several other populations showing introgression with widespread AT lineages will be useful for the management and conservation of such an endemic lineage.     

Preparation of Giant Myelin Vesicles and Proteoliposomes to Register Ionic Channels

Abstract: Myelin vesicles, reconstituted liposomes with proteolipid protein (PLP), the main protein component of myelin, and electrophysiological patch-clamp are potentially powerful tools to study the role of myelin in functional ionic channels. However, technical difficulties in the vesiculation of myelin and the small size of the vesicles obtained do not permit the application of micropipettes for current recordings. From a suspension of purified myelin we have prepared oligolamellar vesicles (mean diameter of 144 nm) using the so-called French pressure system. From this preparation we obtained giant myelin vesicles ∼10 µm in mean diameter, using a dehydration-rehydration procedure. Qualitative analysis of proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed no significant loss of any component in these vesicles due to pressure, in comparison with non-vesiculated myelin. A way of preparing giant liposomes of ∼80–100 µm and proteoliposomes of ∼30 µm in mean diameter, using the same dehydration-rehydration procedure, is also reported. Reconstitution of purified PLP in giant liposomes was confirmed by fluorescent labeling of PLP and by fluorescence microscopy. The current recordings from these vesicles prove the validity of these methods and provide significant evidence of the existence of ionic channels in myelin membranes and the possibility that PLP functions as a channel. The physiological significance and characterization of these channels remain yet unresolved. These results have a special significance for elucidating the molecular role of myelin in the regulation of neural activity and in the brain ion microenvironment.     

Vitamin content of four marine microalgae. Potential use as source of vitamins in nutrition

Summary Certain marine microalgae contain water-and lipid-soluble vitamins and can be used as food supplements or food ingredients. A number of vitamins are present in higher concentrations in the microalgae than in conventional foods traditionally considered rich in them. Ingestion of relatively small quantities of microalgae can cover the requirements for some vitamins in animal nutrition, including human nutrition, while supplementing others. Marine microalgae can thus be considered to represent a non-conventional source of vitamins or a vitamin supplement for animal or human nutrition.     

Proteolytic activities in yeast after UV irradiation

Summary Specific proteolytic activities are known to be induced in Escherichia coli following irradiation. Consequently it seemed of interest to investigate whether variations in proteinase activities occur in yeast.Among the five most well known proteinases of Saccharomyces cerevisiae, we have found that proteinase B activity increases up to three times in wild-type RAD ⁺ yeast cells after a dose of 50 Jm^-2 of 254 nm ultraviolet light (40% survival). Carboxypeptidase Y and aminopeptidase I (leucin aminopeptidase) activities were only moderately increased. Proteinase A activity was only slightly enhanced, while aminopeptidase II (lysin aminopeptidase) was unaffected in both RAD ⁺ strains studied.The observed post UV-increase in proteinase B activity was inhibited by cycloheximide and was dose dependent. Increases in proteinase B levels were independent of the activation method used to destroy the proteinase B-inhibitor complex present in the crude yeast extracts.A standard method for comparison of the postirradiation levels among different proteinases, strains and methods of activation is presented.Abbreviations UV Ultraviolet - BRIJ-35 Polyoxyethylene-23-lauryl ether - EDTA Ethylene diamine tetraacetic acid - EGTA Ethylene glycol bis (-aminoethyl ether) tetraacetic acid - MOPS 3-[N-morpholine]propansulfonic acid - HEPES N-2-Hydroxyethylpiperazine-N-2-ethansulfonic acid - Tris Tris(hydroxy methyl)amino methane - BTPNA N-benzoyl-L-tyrosine-p-nitroanilide - CP.Y Carboxypeptidase Y - Leu.AP Leucin amino peptidase - Lys.AP Lysin amino peptidase - DMFA Dimethyl formamide - CHX Cycloheximide - PMSF Phenylmethyl sulfonyl fluoride - TCA Trichloroacetic acid Code Number of Enzymes EC. 3.4.23.8 Proteinase A - EC. 3.4.22.9 Proteinase B - EC. 3.4.12.8 Carboxypeptidase Y - EC. 3.4.24.4 Thermolysin - EC. 3.4.23.1 Pepsin A     

Preference for medium dense grass tussocks byHippodamia convergens [Col.: Coccinellidae]

The preference in the choice of hibernacula of the convergent lady beetle,Hippodamia convergens Guérin-Meneville, was investigated with regard to morphological aspects of 2 introduced range grasses,Panicum coloratum (L.), andEragrostis curvula (Schrad.) Beetles strongly preferred tussocks with a ratio in the range of 1.0–3.0 stems per cm² for lovegrass. Preference for klein grass tussocks ranging from 110–130 stems/clump was found. No preference was shown for a particular tussock circumference. It was demonstrated that tussocks could successfully be designated as suitable for beetle aggregation.