Subject: Navigation and orientation

Research Notes on Avian Biology 1994: Selected Contributions from the 21st International Ornithological CongressMorphology and Physiology: Orientation

Subject: Navigation and orientation     

BLOEM: A spatially explicit model of bioenergy and carbon capture and storage,applied to Brazil

Bioenergy could play a major role in decarbonizing energy systems in the context of the Paris Agreement. Large-scale bioenergy deployment could be related to sustainability issues and requires major infrastructure investments. It, therefore, needs to be studied carefully. The Bioenergy and Land Optimization Spatially Explicit Model (BLOEM) presented here allows for assessing different bioenergy pathways while encompassing various dimensions that influence their optimal deployment. In this study, BLOEM was applied to the Brazilian context by coupling it with the Brazilian Land Use and Energy Systems (BLUES) model. This allowed investigating the most cost-effective ways of attending future bioenergy supply projections and studying the role of recovered degraded pasture lands in improving land availability in a sustainable and competitive manner. The results show optimizing for limiting deforestation and minimizing logistics costs results in different outcomes. It also indicates that recovering degraded pasture lands is attractive from both logistics and climate perspectives. The systemic approach of BLOEM provides spatial results, highlighting the trade-offs between crop allocation, land use and the logistics dynamics between production, conversion, and demand, providing valuable insights for regional and national climate policy design. This makes it a useful tool for mapping sustainable bioenergy value chain pathways.     

The effect of post-hypoxia on roots inSenecio andMyosotis species related to the glutathione system

This paper shows the effect of re-aeration following hypoxic pretreatment on the glutathione system in plants with different flooding tolerance. Re-aeration of hypoxically pretreated roots led to an increase of TBA-rm content indicating an accelerated lipid peroxidation (post-anoxic injury). Re-admission of oxygen resulted in a clear increase in the content of total glutathione in both flooding-intolerant speciesMyosotis arvensis andSenecio jacobaea. Simultaneously, the high ratio between reduced (GSH) and oxidized (GSSG) glutathione decreased in these species upon the onset of re-aeration, while the tolerantMyosotis palustris andSenecio aquaticus showed only little changes in contents of GSH and GSSG. An imbalance in GSH/GSSG ratio reflects oxidative stress. The glutathione reductase (GR) reacted very differently in the investigated genera. The metabolic response to varying oxygen pressure is much stronger in the flooding-intolerant species compared to species naturally growing in wetlands. The present results suggest that glutathione system is an important component in overcoming oxidative stress.     

Urinary excretion of mercury, copper and zinc in subjects exposed to mercury vapour

The excretion of mercury, copper and zinc in urine, and mercury in whole blood andplasma, was determined in 40 chloralkali workers exposed to mercury vapour and 40age-matched referents. The Hg concentrations in whole blood, plasma and urine werehigher in the exposed group (35 nmol l, 30 nmol l,and 11.5 nmol mmol creatinine, respectively) in comparison with thereference group (15 nmol l, 6.3 nmol l, and 1.8nmol mmol creatinine, respectively). The urinary copper excretionwas similar in the two groups, while U-Zn excretion was significantly higher (P = 0.04)in the exposed group, median 0.83 mmol mmol creatinine versus 0.76mnmol mmol creatinine in the reference group. In a subgroup of exposedworkers with current U-Hg above 11.5 nmol lmmolcreatinine (20 mg g creatinine) the medianU-Zn was 1.1 mmol mmol creatinine. In both groups smokers had highU-Zn levels than non smokers. When both U-Hg and smoking were taken into account in alinear regression model, there was a significant association between U-Hg and U-Zn inthe combined group of exposed and referents (P = 0.002). This study indicates thatmercury exposure in humans, as in animals, causes increased urinary excretion of zinc.The mechanisms may be induced synthesis of metallothionein in the kidneys, displacementof Zn from preexisting metallothionein by Hg, or a decreased reabsorption of zinc in thekidneys owing to a slight tubular dysfunction.     

Avian feather development: relationships between morphogenesis and keratinization

Morphogenesis and expression of the alpha and beta keratin polypeptides are controlled by epidermal-dermal interactions during development of avian skin derivatives. We have examined the relationship between morphogenesis of the embryonic feather and expression of the feather alpha and beta keratins by routine histology, indirect-immunofluorescence, and SDS-PAGE. Initially beta keratins are expressed only in the feather sheath. Following barb ridge morphogenesis beta keratins can be detected in the barb ridge, coincident with the differentiation of barb ridge cells into eight distinct morphological types. Beta keratinization occurs in gradients; from feather apex to base, and from periphery of the barb ridge to the interior. The onset of beta keratinization in the barb ridges is paralleled by an increase in the major feather beta keratin polypeptides, as detected by SDS-PAGE. The alpha keratins are present in both the periderm and feather sheath at early stages of feather development, but become greatly reduced after hatching, when the down feather emerges from the sheath.     

Apolipoprotein A-IV polymorphism in man

Summary In man, apolipoprotein A-IV is characterized by a genetically determined polymorphism controlled by two codominant alleles. Two isoforms of this apolipoprotein, designated A-IV-1 and A-IV-2, can be identified by isoelectric focusing. Among 1000 healthy factory workers participating in an epidemiological study, A-IV-1 (genotype 1-1) was observed in 85%; A-IV-2 (genotype 2-2), in 0.5%; and A-IV-1 in combination with A-IV-2 (genotype 1–2), in 14%. In four nonrelated subjects, an apolipoprotein A-IV variant (A-IV-Münster), characterized by a slightly more basic isoelectric focusing behavior than A-IV-2, was detected in combination either with A-IV-1 or A-IV-2. Mendelian inheritance of this variant could be demonstrated.     

Genetic control of human apolipoprotein E polymorphism: Comparison of one-and two-dimensional techniques of isoprotein analysis

Summary Genetic polymorphism of human apolipoprotein E (apo E) has previously been demonstrated by one-dimensional isoelectric focusing (Utermann et al. 1977b) and by two-dimensional electrophoresis of apolipoproteins (Zannis et al. 1981), but the relationship between the results obtained by these methods remained unclear. We therefore performed comparative phenotyping by one-dimensional and two-dimensional electrophoresis. Apoproteins from very low-density lipoproteins (apo VLDL) prepared by ultracentrifugation or from an apo Erich lipoprotein fraction prepared by heparin/Mg⁺⁺ precipitation, were used as a source of apo E. Six common phenotypes designated apo E-4/4, apo E-N/N, apo E-D/D, apo E-4/N, apo E-4/D, and apo E-N/D were differentiated irrespective of the technique used or the source of apolipoproteins, but the two-dimensional electrophoresis of apo VLDL and apo VLDL which had been treated with neuraminidase was the key for the correct genetic interpretation of those phenotypes exhibiting the E4 isoform of the protein. Each phenotype is characterized by the presence of either one or two of three major isoforms E2, E3, and E4 and by the presence of several minor sialylated forms of these proteins (apo E_s) that have higher apparent molecular weights. The unsialylated major isoform apo E2 does not only differ in charge but also has a higher apparent mol.wt. (about 34,500) than the major isoforms apo E3 and apo E4 (mol. wt. about 33,000). Family studies including 90 matings with a total of 203 offspring confirmed the genetic one locus model of Zannis et al. (1981). Apo E phenotypes are controlled by three autosomal codominant alleles apo E^d, apo Eⁿ, and apo E⁴ that specify for the E2, E3, and E4 isoforms respectively. Phenotypes apo E-D/D,-N/N, and-4/4 represent homozygotes and phenotypes apo E-4/N,-4/D, and-N/D heterozygotes for these alleles.The frequencies of apo E alleles in 1031 blood donors were apo E⁴=0.150, apo Eⁿ=0.773, and apo E^d=0.077. Homozygosity for the allele apo E^d is associated with hyperlipoproteinemia type III. Hence a large number of the population (about 1%) are at risk for this specific lipoprotein disorder that is associated with premature atherosclerosis and xanthomatosis.     

Biological activity of the antitumor protein neocarzinostatin coupled to a monoclonal antibody by N-succinimidyl 3-(2-pyridyldithio)-propionate

The chromophore free apoprotein of neocarzinostatin was coupled to monoclonal IgG₁ antibody using N-Succinimidyl 3-(2-pyridyldithio)-propionate as heterobifunctional reagent. After coupling active chromophore was reassociated with the apoprotein. We present here experimental evidence that the hybrid protein retains biological activity as measured by the degradation of T2-DNA and bacteriostatic action.     

cell clones and pattern formation: Studies onsevenless,a mutant ofDrosophila melanogaster

Summary sev ^LY3,the only existing allele at thesev locus (1–33,2±0,2), behaves as strongly hypomorph or even as amorph. Ommatidia in asev compound eye have only seven receptor cells, the position of the R7 pattern element being vacant. Various criteria showing that the missing cell is R7 have been verified. These include (i) anatomical characteristics ofsev ommatidia; (ii) behaviour of central R cells insev rdgB double mutants; (iii) medullary projection of central R cell axons; and (iv) mitotic pattern ofsev imaginal discs. The analysis of morphogeneticsev-sev ⁺ mosaics has shown thatsev is expressed autonomously by R7 cells, indicating that thesev phenotype is not due to asev genotype of ommatidial pattern elements other than R7. The study of third instarsev imaginal discs has not brought any direct evidence for death of clustered presumptive R7 cells; however, clonal analysis of the developingsev compound eye has given evidence of developmental parameters comparable to those ofsev ⁺, therefore favouring the hypothesis that R7 cells die insev mutants. On the other hand,sev ⁺ seems to be required for the determination of the R7 cells, since thesev phenotype cannot be uncovered during the last mitoses of heterozygous mutant cells.