Contribution of Monsoon Asia to the carbon budget of the biosphere,past and future

The High Resolution Biosphere Model (HRBM), which has been developed by the group of the author, was used to investigate the carbon balance of the vegetation and the soil in the ecosystems of Monsoon Asia in comparison to the rest of the world. The HRBM is a global grid-based (0.5 degree resolution) model with a monthly time step. It includes modules for natural vegetation, land use, vegetation fires, vegetation composition. A historical carbon budget was calculated for the period 1860–1978 and, on a global scale, validated using atmospheric CO₂ data. Based on the per-country development of the population and their requirements, different reasonable scenarios were used to investigate the potential impacts of land use and deforestation in the period 1990–2050. The HRBM calculates considerable contributions of Monsoon Asia to the global CO₂ emissions due to land use changes in the past. Between 1860 and 1978, about 1/4 of the global releases from land use changes came from South Asian and Southeast Asian biota. The future contributions in the period 1990–2050 depend on the assumed development of the agricultural methods. If the intensity of agriculture and the agricultural productivity will stay the same as in the 1980s, there will be a strong need to increase agricultural areas, and thus deforestation will dominate. If there will be a change over to intensive methods of agricultural production, the presently used areas might be sufficient to provide resources to the growing population.     

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     

Stress and Age Related Spots with Immunoreactivity to Ubiquitin-Antibody at Protoplast Surfaces

Mesophyll protoplasts from primary leaves of 2, 3, and 4 weekold Viciafaba L. plants and from not expanded leaves of 2 weekold plants were incubated with rabbit anti-ubiquitin antibodyand FITC labeled goat anti-rabbit IgG. Dependent on age of theplant material, an increase in size and number of immunoreactivespots at protoplast surfaces were observed, when incubationswere performed after 16 h storage to allow protoplast to recover.A relationship between isolation stress and the intensity ofimmunolabeling was demonstrated for protoplasts from not expandedleaves. Furthermore, the surface of isolation stressed protoplastsshowed an increasing number of immunoreactive spots when plantswere previously exposed to water deficiency conditions for 1,2 or 4 days. Water deficiency conditions and isolation stressare therefore thought to induce ubiquitination of surface locatedproteins. A phenomenon, which seemed to be normally correlatedwith early events of senescence. (Received October 28, 1993; Accepted February 21, 1994)     

Modification of sialic acids by 9-O-acetylation is detected in human leucocytes using the lectin property of influenza C virus

Influenza C virus spike glycoprotein HEF specifically recognizesglycoconjugates containing 9-O-acetyl-N-acetylneuraminic acid.The same protein also contains an esterase activity. Takingadvantage of these two properties, influenza C virus was usedas a very sensitive probe for the detection of traces of 9-O-acetyl-N-acetylneuraminicacid in human leucocytes. The binding of influenza C virus toleucocyte glycoproteins and gangliosides separated by sodiumdodecyl sulphate–polyacrylamide gel electrophoresis andthin-layer chromatography, respectively, was assayed using achromogenic esterase substrate. In this way, glycoproteins ofB-lymphocytes and T-lymphocytes were found to contain 9-O-acetylatedsialic acids. Of the various 9-O-acetylated gangliosides detected,one had the characteristics of 9-O-acetylated G^D3. The identificationof 9-O-acetylated sialic acids on distinct glycoproteins andglycolipids should be helpful in assigning a physiological roleto this sugar. O-acetylation gangliosides influenza C virus lymphocytes sialic acids     

Carbon distribution in grass (Festuca pratensis L.) during regrowth after cutting—utilization of stored and newly assimilated carbon

Distribution of net assimilated C in meadow fescue (Fectuca pratensi L.) was followed before and after cutting of the shoots. Plants were continuously labelled in a growth chamber with ¹⁴C-labelled CO₂ in the atmosphere from seedling to cutting and with ¹³C-labelled CO₂ in the atmosphere during regrowth after the cutting. Labelled C, both ¹⁴C and ¹³C, was determined at the end of the two growth periods in shoots, crowns, roots, soil and rhizosphere respiration. Distribution of net assimilated C followed almost the same pattern at the end of the two growth periods, i.e. at the end of the ¹⁴C- and the ¹³C-labelling periods. Shoots retained 71–73% of net assimilated C while 9% was detected in the roots and 11–14% was released from the roots, determined as labelled C in soil and as rhizosphere respiration. At the end of the 2nd growth period, after cutting and regrowth, 21% of the residual plant ¹⁴C at cutting (¹⁴C in crowns and roots) was found in the new shoot biomass. A minor part of the residual plant ¹⁴C, 12%, was lost from the plants. The decreases in ¹⁴C in crowns and roots during the regrowth period suggest that ¹⁴C in both crowns and roots was translocated to new shoot tissue. Approximately half of the total root C at the end of the regrowth period after cutting was ¹³C-labelled C and thus represents new root growth. Root death after cutting could not be determined in this experiment, since the decline in root ¹⁴C during the regrowth period may also be assigned to root respiration, root exudation and translocation to the shoots. ei]{gnH}{fnLambers} ei]{gnA C}{fnBorstlap}     

Application of High Enzyme Activities Present in Clostridium Thermoaceticum for the Efficient Regeneration of NADPH, NADP+, NADH AND NAD+

Crude extracts of Clostridium thermoaceticum DSM 521 contain various AMAPORs (artificial mediator accepting pyridine nucleotide oxidoreductases). The specific activities of this mixture of AMAPORs is about 8-9 U mg^-1 protein (µmoles mg^-1 min^-1) for NADPH and 3-4 U mg^-1 protein for NADH formation with reduced methylviologen (MV⁺⁺) as electron donor. These AMAPOR-activities are only slightly oxygen sensitive. The reoxidation of NADPH and NADH with carboxamido-methylviologen is catalysed by crude extracts with 2.0 and 1.6 U mg^-1 protein, respectively. The same crude extracts also catalyse the dehydrogenation of reduced pyridine nucleotides with suitable quinones such as anthraquinone-2,6-disulphonate. The reduced quinone can be reoxidised by dioxygen.

The K_m-values of these enzymes for the pyridine nucleotides and also for the artificial electron mediators are in a suitable range for preparative transformations.

Furthermore the crude extract of C. thermoaceticum contains about 2.5 U mg^-1 protein of an NADP⁺-dependent formate dehydrogenase (FDH), which is suitable for NADPH and/or MV⁺⁺ regeneration. The regeneration of MV⁺⁺ with FDH and formate as electron donor proceeds with a specific activity of about 5 U mg^-1 protein of the crude extract. The reduced viologen in turn reduces NAD(P)⁺ by AMAPOR. The formate dehydrogenase is sensitive to oxygen.

Examples of compounds which have been prepared by combination of AMAPORs or formate dehydrogenase with an oxidoreductase are: (S)-3-hydroxycarboxylates, esters of (S)-3-hydroxycarboxylates, (1R,2S)-1-hydroxypropane-tricarboxylate (D_s-(+)-isocitrate), L_s-(-)-isocitrate and 6-phosphogluconate.     

Monoclonal antibody uptake in B-cell lymphomas: Experimental studies in nude mouse xenografts

Accumulation of radiolabelled monoclonal antibodies (mAb) in human B-lymphoma xenografts was found to result in two distinct patterns. The basic elements leading to these patterns were elucidated by autoradiographic and immunohistological analysis applied to the nude mouse xenografts BJAB and OCI.LY1. With BJAB, accumulation occurred exclusively in peripheral cell layers of the lymphoma nodule, while central areas were not accessible irrespective of mAb dose. This feature was the consequence of an inefficient transport across intratumoral vessels together with peripheral mAb supply through a subcapsular pseudosinus. With OCI.LY1, intratumoral vessels showed generalized leakiness. Furthermore, interstitial transport was operative to a fair extent, such that in early images multiple sites of mAb extravasation were obvious, which coalesced during the course of prolonged uptake. The pattern of peripheral mAb uptake resulted in a low overall tumour uptake, while multifocal uptake yielded substantial accumulation values.     

Involvement of Ubiquitin in Phosphoenolpyruvate Carboxylase Degradation

Western immunoblot analysis of protein extracts prepared from epidermal peels, whole leaves, and mesophyll protoplasts with ubiquitin and PEPCase antibodies indicated ubiquitinated PEPCase bands and degradation products only in crude extracts which have been obtained in the presence of the proteolysis inhibitors leupeptin and hemin. After ammonium sulfate precipitation and further purification, PEPCase forms were stable and not ubiquitinated. It is assumed, that only a certain part of PEPCase is degraded via the ubiquitin-dependent proteolysis.     

Chemical agents that inhibit pollen development: effects of the phenyl-cinnoline carboxylates SC-1058 and SC-1271 on the ultrastructure of developing wheat anthers (Triticum aestivum L. var Yecora rojò)

Summary Phenylcinnoline carboxylate compounds SC-1058 and SC-1271 cause complete male sterility in wheat when applied at suitable dosages at the pre-meiotic stage of anther development. Anthers from treated and untreated plants were compared using light and electron microscopy from the pre-meiotic stage through the formation of nearly mature pollen. Overall anther development is gradually slowed in treated plants and pollen development is generally arrested in the late prevacuolate or early vacuolate microspore stage, although the first pollen mitosis does sometimes occur. The sporopollenin-containing exine walls are thinner, and show abnormally developed foot and tectum layers with sparse connecting baculi. Microspore cytoplasm degenerates and the cells eventually collapse. At the early, prevacuolate, free microspore stage treated tapetal cells hypertrophy, expanding into the locule. They contain abnormally large vacuoles that appear to form from the fusion of secretory vesicles, and some vacuoles contain electrondense deposits. The sporopollenin-containing orbicular wall and Ubisch bodies are retarded in their development and are structurally deformed. Acetolysis of whole anthers and of thick sections shows that the sporopollen-in-containing structures of treated materials are greatly reduced in thickness and are less rigid than in the control. We conclude that application of these compounds causes interference with the secretory function of tapetal cells which supplies sporopollenin cell-wall polymers to the exine of the microspores and to the tapetal orbicular wall and associated Ubisch bodies. Interference with the tapetal secretion of other nutrients required for microspore development is strongly suggested.