A study on relations of vegetation,climate and soils in Shanxi province,China

Relationships of vegetation, climate and soils in Shanxi plateau wereanalyzed by use of Canonical Correspondence Analysis (CCA). Shanxi province,located at 34°35–40°43 N, 110°15–114°33 E, was divided into a series of rectangular districts of30 latitude by 20 longitude. Areas of vegetation formations and soil types ineach district were measured carefully using fine grain on the vegetation andsoil maps of Shanxi. Climatic data were mean values of 25 years records in eachdistrict. Three data matrices of climate, vegetation and soil were combined byCCA. The results showed that the distribution of vegetation is closely relatedto the variety of climates and to soils distribution.     

Inverse relationship between poly (ADP-ribose) polymerase activity and 2′,5′-oligoadenylates core level in estrogen-treated immature rat

Summary The activity of poly (ADP-ribose) polymerase (ADPRP) and the content of 2,5-oligodenylates core (2,5A_n; n = 2,3 and 4) were measured in homogenates of the uterus and of the liver of immature rats immediately before (time 0) or at different times after injection of estradiol-valerate. ADPRP activity increased gradualy, starting 6 hours after estrogen injection, for about 4 days. Instead, the content of 2,5 A_n decreased by about 50% within 6 hours, and thereafter more slowly for 4 days to about 20% of starting values. Estrogen increased ADPRP activity and decreased 2,5A_n concentration also in the kidney and in the cardiac muscle of the same animals, but not in the skeletal muscle, where neither of the two parameters was affected. Injection of vehicle only (sesame oil) had no effect on ADPRP activity nor on 2,5A_n content of immature rat tissues.     

Observation of a distinct transition in the mode of interconversion of ring pucker conformers in non-crystalline d-ribose-2'-d from 2H NMR spin-alignment

Internal motions of d-ribose selectively ²H-labeled at the 2 position were measured using solid state ²H NMR experiments. A sample of d-ribose-2 -d was prepared in a hydrated, non-crystalline state to eliminate effects of crystal-packing. Between temperatures of –74 and –60°C the C2–H2 bond was observed to undergo two kinds of motions which were similar to those of C2–H2/H2 found previously in crystalline deoxythymidine (Hiyama et al. (1989) J. Am. Chem. Soc., 111, 8609–8613): (1) Nanosecond motion of small angular displacement with an apparent activation energy of 3.6 ± 0.7 kcal mol^–1, and (2) millisecond to microsecond motion of large amplitude with an apparent activation energy 4 kcal mol^–1. At –74°C, the slow, large-amplitude motion was best characterized as a two-site jump with a correlation time on the millisecond time scale, whereas at –60°C it was diffusive on the microsecond time scale. The slow, large-amplitude motions of the C2–H2 bond are most likely from interconversions between C2-endo and C3-endo by way of the O4-endo conformation, whereas the fast, small-amplitude motions are probably librations of the C2–H2 bond within the C2-endo and C3-endo potential energy minima.     

Potential importance of protozoan grazing on the accumulation of polychlorinated biphenyls (PCBs) in the pelagic food web

Experiments were conducted to study the distribution of three selectedpolychlorinated biphenyl (PCB) congeners within the microbial food web attwo different nutrient levels; control and nutrient enriched. The objectivewas to quantify the uptake of PCBs through grazing by protozoa. The¹⁴C-PCBs tested were 4-chlorobiphenyl (IUPAC # 3),2,2,5,5-tetrachlorobiphenyl (IUPAC # 52), and2,2,4,4,5,5-hexachlorobiphenyl (IUPAC # 153). EachPCB was incubated in triplicate seawater samples at 20 idref;Cover one week. Daily, samples were separated into four fractions; <0.2µm (dissolved), 0.2-2 µm (bacteria), 2-10 µm(flagellate), and > 10 µm (microplankton; phytoplankton andprotozoa) by selective filtration. Of the PCB fraction that initiallyadsorbed to particles, 60–100% was associated to the bacterialfraction and 0–5% to the microplankton fraction. The totaluptake was highest in the nutrient enriched samples, but when normalized tothe carbon biomass the concentration was lower or equal to the control inall particle fractions. The recovery of the PCBs in the particulatefractions depended on the degree of chlorination, as the highest values wereobserved for the 2,2,4,4,5,5-hexachlorobiphenyl and thelowest for the 4-chlorobiphenyl. The concentrations in the bacterial andflagellate fractions decreased over the first 48–96 hours whilst theconcentration increased in the highest trophic level (>10 µmfraction). Approximately 75% of the increase in concentration of the2,2,4,4,5,5-hexachlorobiphenyl in the > 10 µmfraction was estimated to be the result of bacterivory. Our results indicatethe microbial food web can contribute to a rapid uptake of higherchlorinated PCBs, particularly in oligotrophic ecosystems where thebacterial biomass dominates.     

Phagostimulation of the mediterranean fruit fly, Ceratitis capitata by ribonucleotides and related compounds

Females of the medfly, Ceratitis capitata, prefer sucrose solutions containing ribonucleotides to sucrose solutions without them. The order of preference for the nucleotides was: 5GMP>GTP>5CMP>5IMP >dGMP>5UMP>5AMP>5XMP=ATP=2 & 3GMP=RP>3AMP.2AMP, guanosine, inosine, adenine and 5TMP produced no significant stimulation. Females sterilized by irradiation showed reduced attraction to 5GMP as compared to non-irradiated females.Optimal molecular configuration for phagostimulation includes: phosphorylation at the 5 position of the ribose, free hydroxyl groups at 2 and 3 on the ribose, and an NH₂ group at the 2 position of the aromatic ring of purine.It is proposed that the 5GMP in yeast hydrolyzate can be used as a measure of the suitability of the hydrolyzate as a bait.

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Résumé La femelle de la mouche méditerranéenne des fruits, Ceratitis capitata, préfère les solutions de sucrose contenant des ribonucléotides aux simples solutions de sucrose. Lórdre de préférence pour les nucléotides est le suivant: 5GMP>GTP>5CMP>5IMP >dGMP>5UMP>5AMP>5XMP=ATP =2 & 3GMP=RP>3AMP.Le 2AMP, la guanosine, l'inosine, l'adénine et le 5TMP provoquent une stimulation significative. Les femelles montrent aprés stérilisation par irradiation une attirance réduite pour le 5GMP par comparaison avec les femelles non-irradiées.La configuration moléculaire optimale pour la phagostimulation comprend: la phosphorylation en position 5 du ribose; des groupes hydroxyles libres en 2 et 3 sur le ribose; et un groupe NH₂ en position 2 sur le noyau aromatique.Nous proposons que le 5GMP dans l'hydrolysat de levure puisse être utilisé pour mesurer la capacité de l'hydrolysat comme appât.

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Abbreviations 5AMP Adenosine 5-monophosphate - 3AMP Adenosine 3-monophosphate - 2AMP Adenosine 2-monophosphate - dAMP 2-deoxyadenosine 5-monophosphate - ADP Adenosine 5-diphosphate - ATP Adenosine 5-triphosphate - 5GMP Guanosine 5-monophosphate - 2GMP Guanosine 2-monophosphate - 3GMP Guanosine 3-monophosphate - dGMP 2-deoxyguanosine 5-monophosphate - GDP Guanosine 5-diphosphate - GTP Guanosine 5-triphosphate - 5IMP Inosine 5-monophosphate - IDP Inosine 5-diphosphate - ITP Inosine 5-triphosphate - 5XMP Xanthosine 5-monophosphate - 5CMP Cytidine 5-monophosphate - dCMP 2 deoxycytidine 5-monophosphate - CTP Cytidine 5-triphosphate - 5UMP Uridine 5-monophosphate - 5TMP Thymidine 5-monophosphate - RP Ribose 5 monophosphate     

Pre-moult foraging trips and moult locations of Emperor penguins at the Mawson Coast

The movements of nine breeding adult emperor penguins Aptenodytes forsteri from two colonies, Auster (67° 23S 64° 04E) and Taylor Glacier (67° 28S 60° 54E), were determined by satellite telemetry on their pre-moult foraging trips. While preparing for their annual moult the penguins travelled for 22–38 days and reached distances of up to 618 km from the colony. Six of the nine tracked penguins were followed to three different moult locations all to the west of their breeding colonies and near other known emperor penguins colonies, such as Kloa Point (66°38S, 59°23E) and Fold Island (67°17S, 59°23E). Sea-ice conditions changed throughout the tracking period; as the birds travelled north the sea-ice contracted south.     

Annual growth of the cockle Clinocardium ciliatum in the Norwegian Arctic (Svalbard area)

The Svalbard Islands are influenced by warm Atlantic water in the south and west, and cold Arctic water in the east. Ice cover, and hence the location of the highly productive marginal ice zone, varies both intra and interannually. Part of the primary production accumulates on the bottom and is utilized by the benthos. In this study, the annual growth of the cockle Clinocardium ciliatum (Fabricius, 1780) from three sites in Svalbard waters is reported. Moffen, the site in the north (80° 01 N, 13° 48 E) is located in the northernmost areas influenced by Atlantic water. The Storfjorden site (77° 10 N, 20° 09 E) is situated in cold Arctic water masses, and the Bear Island site (74° 50 N, 18° 54 E) is in the Polar front area where Atlantic and Arctic water masses meet. Annual growth of cockles was analysed retrospectively by measuring external growth increments, which gave annual growth records from the 1970s to 1996. Shell height for age for different year classes was highest at the Storfjorden site, and lowest at Bear Island. Periods of high growth occurred at Storfjorden and Bear Island during the 1980s while the beginning of 1990s was characterized by low growth. At Moffen, growth was more variable between single years. Several factors are influencing the growth of C. ciliatum in the Svalbard area and growth cannot be coupled to only one environmental factor like ice cover.     

Some properties of 2-5A binding/nucleolytic activities in gel filtered rabbit reticulocyte lysates

Rabbit reticulocyte lysates, gel filtered on Sephadex G-25 with or without ATP (or its analogs), were preincubated at 37°C and their subsequent binding to p₃A₄,3-[³²P]pCp was studied. Lysates filtered without ATP or in the presence of 0.1 mM 8-bromo-ATP, 1,N⁶-etheno-ATP, or ITP showed a time-dependent decrease in binding activity. This decrease was completely prevented when lysates were filtered with 0.1 mM ATP, 2-deoxy-ATP, --methylene-ATP, or ATP--S. The stability of binding provided by ATP or 2-deoxy-ATP analogs corresponds to a more active 2–5A dependent endonucleolytic (RNAase L) activity based on studies using [³H] viral mRNA. Chromatography on heparin-agarose showed that ATP-supplemented gel-filtered reticulocyte lysates had a different p₃A₄,3-[³²P]pCp binding activity elution-profile than lysates gel-filtered in the absence of ATP. Covalent cross-linking of periodate-oxidized p₃A₄,3-[³²P]pC to gelfiltered lysates, preincubated at 0°C or 37°C for 30 min, showed the following results: (1) all lysates gave a major cross-linking of the radioactive ligand to an 80 000 dalton polypeptide, regardless of the temperature of preincubation, (2) Iysates gel-filtered without ATP, with 0.1 mM ITP, or --methylene-ATP, showed a significant reduction in the cross-linking of the 80 000 dalton protein, after preincubation at 37°C for 30 min. This decrease was accompanied by an increase in the labeling of two smaller polypeptides.Abbreviations used 2 5-oligoadenylates oligonucleotides consisting of 5-adenylic acid residues joined by a 2 5-phosphodiester linkage     

Effect of nucleosides and nucleotides and the relationship between cellular adenosine 3′∶5′-cyclic monophosphate (cyclic AMP) and germ tube formation in Candida albicans

A yeast-mycelium (Y-M) transition in Candida albicans was induced by exogenous yeast extract, adenosine, adenosine 5-monophosphate (AMP), adenosine 5-diphosphate (ADP), adenosine 35 cyclic monophosphate (cAMP) and its analogue N⁶, O²-dibutyryl adenosine 35-cyclic monophosphate (dbcAMP) in defined liquid medium at 25°C. Adenosine 5-triphosphate (ATP) was found to delay germ tube formation in yeast cells, whereas the cAMP phosphodiesterase inhibitors, theophylline and caffeine, induced a Y-M transition. Intracellular and extracellular cyclic AMP levels increased during the yeast-mycelium transition and maximum levels of intracellular cyclic AMP coincided with maximum germ tube formation. Of the many inducers and inhibitors of germ tube and mycelium formation in C. albicans tested, including incubation at 37°C or in the presence of 1.5mM CaCl₂, the calmodulin inhibitor calmidazolium (R24571) added together with CaCl₂ induced the highest intra- and extracellular cyclic AMP levels. These results confirm the involvement of cyclic AMP in the yeast-mycelium transition of C. albicans.     

Observations on the reduction of non-activated carboxylates by Clostridium formicoaceticum with carbon monoxide or formate and the influence of various viologens

Crude extracts or supernatants of broken cells of Clostridium formicoaceticum reduce unbranched, branched, saturated and unsaturated carboxylates at the expense of carbon monoxide to the corresponding alcohols. The presence of viologens with redox potentials varying from E ₀=-295 to-650 mV decreased the rate of propionate reduction. The more the propionate reduction was diminished the more formate was formed from carbon monoxide. The lowest propionate reduction and highest formate formation was observed with methylviologen. The carbon-carbon double bond of E-2-methyl-butenoate was only hydrogenated when a viologen was present. Formate as electron donor led only in the presence of viologens to the formation of propanol from propionate. The reduction of propionate at the expense of a reduced viologen can be followed in cuvettes. With respect to propionate Michaelis Menten behavior was observed. Experiments are described which lead to the assumption that the carboxylates are reduced in a non-activated form. That would be new type of biological reduction.Non-standard abbreviations glc Gas liquid chromatography - HPLC high performance liquid chromatography - RP reverse phase; Mediators (the figures in parenthesis of the mediators are redox potentials E ₀ in mV) - CAV²⁺ carbamoylmethylviologen, 1,1-carbamoyl-4,4-dipyridinium dication (E ₀=-296 mV) - BV²⁺ benzylviologen, 1,1-dibenzyl-4,4-dipyridinium dication (E ₀=-360 mV) - MV methylviologen, 1,1-dimethyl-4,4-dipyridinium-dication (E ₀=-444 mV) - DMDQ²⁺ dimethyldiquat, 4,4-dimethyl-2,2-dipyridino-1,1-ethylendication (E ₀=-514 mV) - TMV²⁺ tetramethylviologen, 1,1,4,4-tetramethyl-4,4-dipyridinium dication (E ₀=-550 mV) - PDQ²⁺ propyldiquat, 2,2-dipyridino-1,1-propenyl dication (E ₀=-550 mV) - DMPDQ²⁺ dimethylpropyldiquat, 4,4-dimethyl-2,2-dipyridino-1,1-propenyl dication (E ₀=-656 mV) - PN productivity number=mmol product (obtained by the uptake of one pair of electrons) x (biocatalyst (dry weight) kg)^-1×h^-1     

Formation of nucleoside 5′-phosphoramidates under potentially prebiological conditions

Summary Adenosine 5-phosphoramidates form when solutions containing adenosine 5-polyphosphates p_nA (n 3) or P₁, P₂-diadenosine 5-diphosphate and amines are allowed to dry out. Mg ions catalyze these reactions. We have studied systems containing ammonia, imidazole, glycine, ethylenediamine and histamine. The yields of adenosine 5-phosphoramidates range from 10–50 % based on the nucleotide. The prebiotic significance of the reactions is discussed.Abbreviations Im imidazole - hist histamine - gly glycine - en ethylenediamine - CDI 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride - EDTA ethylenediaminetetraacetic acid - A adenosine - P_n (n = 1, 2 ) linear polyphosphate containing n phosphate residues - p_nA adenosine 5-polyphosphate containing n phosphate residues - ADP adenosine 5-diphosphate - ATP adenosine 5-triphosphate - AppA P₁, P₂-diadenosine 5-diphosphate - gly-pA adenylyl-(5N)-glycine - ImpA adenosine 5-phosphorimidazolide - NH₂-pA adenosine 5-phosphoramidate - en-pA adenylyl-(5N)-ethylenediamine - hist (NH) - pA adenosine 5-phospho-[2-(4-imidazolyl)-ethylamide] - hist(Im)-pA adenosine 5-phospho-[4-(2-aminoethyl)-imidazolide] - enP_1,2 phosphoramidates of ethylenediamine derived from H₃PO₄ and H₄P₂O₇     

Poly(U)-directed peptide-bond formation from the 2′(3′)-glycyl esters of adenosine derivatives

Summary The self-condensation of 2(3)-O-glycyl esters of adenosine, adenosine-5-(O-methylphosphate) and P₁, P₂-diadenosine-5-pyrophosphate in 6.2 mM solutions at pH 8.0 and -5°C in the presence of 12.5 mM poly(U) yields approximately 3 times as much diketopiperazine as reactions without poly(U). As the concentration of 2(3)-O-(glycyl)-P₁, P₂-diadenosine-5-pyrophosphate is decreased from 6.2 mM to 1.5 mM the yield of diketopiperazine in the presence of poly(U) decreases slightly from 6.6% to 5.2%, whereas, in the absence of poly(U) the yield of diketopiperazine decreases substantially from 2.4% to 0.75%. The enhanced yield of diketopiperazine that is attributed to the template action of poly(U) is temperature dependent and is observed only at temperatures below 10°C (5°C to -5°C) for 6.2 mM 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate) and below 23°C (15°C to -5°C) for 6.2 mM 2(3)-O-(glycyl)-P₁, P₂-diadenosine-5-pyrophosphate. The absence of a template effect at high temperatures is attributed to the melting of the organized helices. The hydrolysis half-lives at pH 8.0 and -5°C of 2(3)-O-(glycyl)-adenosine, 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate), 2(3)-O-(glycyl)-P₁, P₂-diadenosine-5-pyrophosphate, and 5-O-(glycyl)-adenosine in the presence of poly(U) are substantially larger than their half-lives in the absence of poly(U). The condensation of 2(3)-O-(glycyl)-adenosine yields 5% of 5-O-(glycyl)-adenosine in the presence of poly(U) compared to 0.7% in the absence of poly(U).Abbreviations DKP diketopiperazine - (gly)₂ glycylglycine - (gly)₃ glycylglycylglycine - AppA-gly 2(3)-O-(glycyl)-P₁, P₂-diadenosine-5-pyrophosphate - MepA-gly 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate) - Ado-2(3)-gly 2(3)-O-(glycyl)-adenosine - Ado-5-gly 5-O-(glycyl)-adenosine - Boc-gly N-tert-butyloxycarbonylglycine - AppA P₁, P₂-diadenosine-5-pyrophosphate - MepA adenosine-5-(O-methylphosphate) - AppA-Boc-gly 2(3)-O-(Boc-glycyl)-P₁, P₂-diadenosine-5-pyrophosphate - Ado-5-Boc-gly 5-O-(Boc-glycyl)-adenosine - Ado-2(3)-Boc-gly 2(3)-O-(Boc-glycyl)-adenosine     

Correction of the published sequence for the human proteolipid protein gene

Summary In the human proteolipid protein gene, the base sequence of the intronic region 5 to exon 6 was found to be 5-ctctttcattttcctgcag-3 and not 5-ctctttt-cattttcctgcag-3 as previously reported.     

Pyridoxal 5′-phosphate binds to a lysine residue in the adenosine 3′-phosphate 5′-phosphosulfate recognition site of glycolipid sulfotransferase from human renal cancer cells

In the course of characterization of glycolipid sulfotransferase from human renal cancer cells, the manner of inhibition of sulfotransferase activity with pyridoxal 5-phosphate was investigated. Incubation of a partially purified sulfotransferase preparation with pyridoxal 5-phosphate followed by reduction with NaBH₄ resulted in an irreversible inactivation of the enzyme. When adenosine 3-phosphate 5-phosphosulfate was co-incubated with pyridoxal 5-phosphate, the enzyme was protected against this inactivation. Furthermore, pyridoxal 5-phosphate was found to behave as a competitive inhibitor with respect to adenosine 3-phosphate 5-phosphosulfate with aK _i value of 287 µm. These results suggest that pyridoxal 5-phosphate modified a lysine residue in the adenosine 3-phosphate 5-phosphosulfate-recognizing site of the sulfotransferase.     

Carotenoid pigments of Stigmatella aurantiaca (Myxobacterales)

Summary The two main carotenoids of Stigmatella aurantiaca were identified as 1,2-dihydro-1-hydroxy-3,4-dehydro-torulene glucoside (myxobactin) and 1,2-dihydro-1-hydroxy-4-keto-torulene glucoside (myxobacton). Both pigments occur as monoesters of various fatty acids. The structural formulas were established by chemical and chromatographical analysis and by visible, infrared, and mass spectroscopy.     

Cleavage of nucleotides by Ce4+ and the lanthanide metal complexes

The cleavage of adenosine-5-monophosphate (5-AMP) and guanosine-5-monophosphate (5-GMP) by Ce⁴⁺ and lanthanide complex of 2-carboxyethylgermanium sesquioxide (Ge-132) in acidic and near neutral conditions was investigated by NMR , HPLC and measuring the liberated inorganic phosphate at 37°C and 50°C. The results showed that 5-GMP and 5-AMP was converted to guanine (G), 5-monophosphate (depurination of 5-GMP), ribose (depurination and dephosphorylation of 5-GMP), phosphate and adenine (A), 5-monophosphate (depurination of 5-AMP), ribose (depurination and dephosphorylation of 5-AMP), phosphate respectively by Ce⁴⁺. In presence of lanthanide complexes, 5-GMP and 5-AMP were converted to guanosine (Guo) and phosphate and adenosine (Ado) and phosphate respectively. The mechanism of cleaving 5-GMP and 5-AMP is hydrolytic scission     

Prebiotic Formation of ADP and ATP from AMP,Calcium Phosphates and Cyanate in Aqueous Solution

Adenosine-5-triphosphate was synthesized by the phosphorylation of adenosine-5-diphosphate in aqueous solution containing cyanate as a condensing reagent and insoluble calcium phosphate produced from phosphate and calcium chloride. In a similar manner, adenosine-5-diphosphate was synthesized from adenosine-5-monophosphate. When the experiment was carried out in the conditions of 4 °C and pH 5.75, the formation of adenosine-5-diphosphate and adenosine-5-triphosphate from adenosine-5-monophosphate was observed in the yields of 19 and 7%, respectively. The other nucleoside-5-triphosphates were also produced from their respective diphosphates.     

Continuous production of 5′-ribonucleotides from yeast RNA by hydrolysis with immobilized 5′-phosphodiesterase and 5′-adenylate deaminase

The production of 5-IMP and 5-GMP by enzymatic conversion from RNA using a continuous two packed-bed reactor was investigated. 5-Phosphodiesterase (5PD) and 5-adenylate deaminase (5AD) were immobilized in an acrylic resin to produce derivatives with about 15 U/g of support. The kinetic properties of the enzymes were described by Michaelis-Menten models: no significant differences were found in the K _m value of the free and immobilized 5AD (60 and 20 m, respectively), whereas for 5PD the K _m value was one order of magnitude higher for the immobilized enzyme (4.85 mg RNA/ml), probably due to diffusional limitations. Both enzymes remained stable after 8 h of use in a continuous packed-bed reactor whereas the half lives of the free enzymes were 193 min and 240 min at 40°C and 70°C for 5AD and 5PD, respectively. A procedure is proposed for the design of a continuous two packed-bed column process.F. Olmedo and F. Iturbe are with the Depto. de Alimentos y Biotecnologia, Facultad de Química, UNAM, México 04510, D.F., Mexico. J. Gomez-Hernández is with the Depto. de Biotecnología, UAM-1, Apdo. Postal 55-535, México 09340, D.F., Mexico. A. López-Munguía is with the Instituto de Biotecnología, Apartado Postal 510-3, Cuernavaca, Mor. 62271, Mexico     

Photosynthetic activities of a membrane preparation of the thermophilic cyanobacterium Mastigocladus laminosus

Photosynthetically active membranes have been prepared from the thermophilic cyanobacterium Mastigogladus laminosus by treatment with lysozyme. The membranes were active in electron transport through photosystem I and II as well as in photophosphorylation and proton uptake. Cells were grown at 40°, 45° and 55°C respectively. The temperature optimum of oxygen evolution of whole cells was about 10°C higher than the growth temperature. In isolated membranes the temperature optimum for cyclic photophosphorylation was identical to the growth temperature of the cells whereas the optimum for photosystem II electron transport never exceeded 40°C. Photophosphorylation was inhibited by N, N-dicyclohexyl carbodiimide (DCCD), carbonyl-cyanide-m-chlorophenylhydrazone and NH₄Cl, whereas proton uptake was enhanced by DCCD. Electron transport was slightly inhibited by these treatments. The membranes could be stored for several weeks at-20°C in 50% glycerol without any loss in the activities.Abbreviations DPIP 2,6-dichlorophenolindophenol - CCCP Carbonyl-cyanide-m-chlorophenylhydrazone - DCCD N,N-dicyclohexyl carbodiimide - PMS N-methylphenazonium methosulfate - DCMU 3-(3-4-dichlorophenyl)-1,1-dimethylurea - TMP 20 mM Tris-HCl buffer pH 7.8, 10 mM MgCl₂, 5 mM phosphate buffer pH 7.8     

The Humboldt penguinSpheniscus humboldti: a migratory bird?

Until recently, the endangered Humboldt penguin was considered a sedentary bird, which remained near its breeding colonies throughout the year. In this pilot study we used five satellite transmitters on Humboldt penguins during the austral winter and were able to track one bird from Pan de Azúcar Island (26°09S, 70°40W), Northern Chile to Iquique (20°12S, 70°07W), a distance of 640 km, between May 24 and June 26, 1996. While a 35 km protection zone around breeding islands might be helpful to prevent competition of penguins with fisheries during the summer months, this might not improve the survival of migrating birds in the winter. Further studies are required to determine the extent of migration and to confirm the recorded travelling route and landing locations in order to detect possible threats to Humboldt penguins from fishing and other industries throughout the year.

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Zusammenfassung Während noch vor wenigen Jahrzehnten Millionen Humboldtpinguine die Küsten Perus und Chiles bevölkerten, wird die Art heute als gefährdet eingestuft. Die Fischerei stellt die größte Bedrohung für diese Tierart dar, deren Gesamtbestand sich nach letzten Schätzungen nur noch auf 10 000 Individuen beläuft. Wir setzten im Südherbst 1996 fünf Argos-Satellitensender ein, um festzustellen, ob Humboldtpinguine des Naturschutzgebietes Pan de Azúcar (26°09S) im Winter ortstreu bleiben oder saisonale Wanderungen durchführen. Während sich vier der Vögel im Untersuchungszeitraum (18–74 Tage) nicht weiter als 87 km von ihrer Brutinsel entfernten, wanderte ein Vogel im Juni 1996 nach Norden bis vor die Stadt Iquique (20° 12S, 640 km vom Ausgangspunkt entfernt). Obwohl die in einer früheren Studie ermittelte Größe eines marinen Schutzgebietes von 35 km Durchmesser rund um die Brutinsel in den Sommermonaten ausreichend sein mag, belegen die neuen Ergebnisse, daß weitere Untersuchungen über das Wanderverhalten der Humboldtpinguine als Grundlage für einen effektiven Artenschutz unerläßlich sind.