Carbohydrate Structural Units in Glycosphingolipids as Receptors for Gal and GalNAc Reactive Lectins

Glycosphingolipids (GSLs) contain many carbohydrate epitopes or crypto-glycotopes for Gal and GalNAc reactive lectins. Many of them are in the nervous system and function as important receptors in various life processes. During the past two decades, 11 mammalian structural units have been used to express the binding domain of applied lectins. They are: F, GalNAc1 3GalNAc; A, GalNAc1 3Gal; T, Gal1 3GalNAc; I, Gal1 3GlcNAc; II, Gal1 4GlcNAc; B, Gal1 3Gal; E, Gal1 4Gal; L, Gal1 4Glc; P, GalNAc1 3Gal; S, GalNAc1 4Gal, and Tn, GalNAc1 Ser(Thr). Although 10 of them occur in GSLs, only 3 (L , S , and T ) are found in human brain, and 2 (L and II ) are present in the inner structures of human blood group active GSLs. In the families of gangliosides, L and II represent 55% of the total structural units, while the other three units (T , P , and S ) constitute the rest. To facilitate the selection of lectins that could serve as structural probes, the carbohydrate binding specificities of Gal/GalNAc reactive lectins have been classified according to their highest affinity for the structural units and their binding properties expressed by decreasing order of reactivity. Hence, the binding relation between GSLs and Gal/GalNAc specific lectins can be established.     

Nucleotide sequence evidence of the unicentric origin of the βC mutation in Africa

Summary The origin of the ^C mutation was studied by characterizing nucleotide sequence polymorphisms on ^C chromosomes of patients from various African countries. In the majority of cases, the ^C mutation was found in linkage disequilibrium with a single chromosomal structure as defined by classical RFLP haplotypes, intergenic nucleotide sequence polymorphisms immediately upstream of the -globin gene, and intragenic -globin gene polymorphisms (frameworks). In addition, three atypical variant chromosomes carrying the ^C mutation were observed, and are most probably explained either by a meiotic recombination (two cases) or by one nucleotide substitution occurring in an unstable array of tandemly repeated sequences (one case). These data demonstrate the unicentric origin of the ^C mutation in central West Africa, with subsequent mutational modification in a small number of instances. The data also supports gene flow of the ^C chromosome from subsaharan Africa to North Africa.     

The organ-specific rRNA gene number in Drosophila hydei is controlled by sex heterochromatin

Genotypes of Drosophila hydei having deficiencies of specific sections of X or Y chromosomal heterochromatin are characterized by heterogeneous rRNA gene numbers in their nonpolyploid organs. Depending on which sex heterochromatin portion is deleted, the rDNA amount in either brain or thoracic muscle cells or in both is increased threefold. This rDNA overreplication cannot be a compensation for a deficiency in ribosomal gene number, since the phenomenon also occurs in genotypes with a high initial rRNA gene numbers.     

Solution conformations of proline rings in proteins studied by NMR spectroscopy

Summary Three different conformations of proline rings in a protein in solution, Up, Down and Twist, have been distinguished, and stereospecific assignments of the pyrrolidine -, - and -hydrogens have been made on the basis of ¹H-¹H vicinal coupling constant patterns and intraresidue NOEs. For all three conformations, interhydrogen distances in the pairs -³, ³-³, ²-², ²-², and ³-³ (2.3 Å) are shorter than those in the pairs -², ²-³, ³-², ²-³, and ³-² (2.7–3.0 Å), resulting in stronger NOESY cross peaks. For the Up conformation, the ³-² and ²-³ spin-spin coupling constants are small (<3 Hz), and weak cross peaks are obtained in a short-mixing-time (10 ms) TOCSY spectrum; all other vicinal coupling constants are in the range 5–12 Hz, and result in medium to strong TOCSY cross peaks. For the Down form, the -², ²-³, and ³-² vicinal coupling constants are small, leading to weak TOCSY cross peaks; all other couplings again are in the range 5–12 Hz, and result in medium to strong TOCSY cross peaks. In the case of a Twist conformation, dynamically averaged coupling constants are anticipated. The procedure has been applied to bovine pancreatic trypsin inhibitor and Cucurbita maxima trypsin inhibitor-V, and ring conformations of all prolines in the two proteins have been determined.     

UDP-galactose:lactosylceramide α-galactosyltransferase activity in human placenta

The activity of UDP-Gal: LacCer galactosyltransferase in human placenta was studied by using crude homogenate and Triton CF-54 extract as the source of enzyme. Transfer of galactose to lactosylceramide was optimal in the presence of 0.1% Triton CF-54 and Mn²⁺ at pH 6.3, and the reaction product was susceptible to -galactosidase.Abbreviations LacCer lactosylceramide (Gal1-4Glc1-1Cer) - Gb₃ globotriaosylceramide (Gal1-4Gal1-4Glc1-1Cer) - Gb₄ globoside (GalNAc1-3Gal1-4Gal1-4Glc1-1Cer) - TLC thin-layer chromatography - GC/MS gas chromatography/mass spectrometry - NMR nuclear magnetic resonance - EDTA ethylenediamine tetraacetic acid - CHAPS 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate     

Genetic characterization of a new splice variant of the β2 subunit of the voltage-dependent calcium channel

This study reports a novel splice variant form of the voltage-dependent calcium channel ₂ subunit (_2g). This variant is composed of the conserved amino-terminal sequences of the _2a subunit, but lacks the -subunit interaction domain (BID), which is thought essential for interactions with the ₁ subunit. Gene structure analysis revealed that this gene was composed of 13 translated exons spread over 107 kb of the genome. The gene structure of the ₂ subunit was similar in exon-intron organization to the murine ₃ and human ₄ subunits. Electrophysiological evaluation revealed that _2a and _2g affected channel properties in different ways. The _2a subunit increased the peak amplitude, but failed to increase channel inactivation, while _2g had no significant effects on either the peak current amplitude or channel inactivation. Other subunits, such as ₃ and ₄, significantly increased the peak current and accelerated current inactivation.     

A structural model for elongation factor 1 (EF-1) and phosphorylation by protein kinase CKII

EF-1a binds aminoacyl-tRNA to the ribosome with the hydrolysis of GTP; the complex facilitates the exchange of GDP for GTP to initiate another round of elongation. To examine the subunit structure of EF-1 and phosphorylation by protein kinase CKII, recombinant , , and subunits from rabbit were expressed in E. coli and the subunits were reconstituted into partial and complete complexes and analyzed by gel filtration. To determine the availability of the and subunits for phosphorylation by CKII, the subunits and the reconstituted complexes were examined as substrates for CKII. Formation of the nucleotide exchange complex increased the rate of phosphorylation of the subunit and reduced the Km, while addition of to or the complex inhibited phosphorylation by CKII. However, a had little effect on phosphorylation of . Thus, the and subunits in EF-1 were differentially phosphorylated by CKII, in that phosphorylation of was altered by association with other subunits, while the site on was always available for phosphorylation by CKII. From the availability of the subunits for phosphorylation by CKII and the composition of the reconstituted partial and complete complexes, a model for the subunit structure of EF-1 consisting of (22)2 is proposed and discussed.     

Einige Bemerkungen über die Ersatzgeschlechtstiere vonReticulitermes

Zusammenfassung An Laboratoriumszuchten vonReticulitermes lucifugus Rossi undReticulitermes flavipes Kollar (aus den Hamburger Befallsgebieten) werden Beobachtungen zur Biologie der Ersatzgeschlechtstiere mitgeteilt. Für die Durchführung dieser Beobachtungen wurden besondere Schaunester eingerichtet. Folgende Punkte der beobachteten Verhaltensweisen werden hier hervorgehoben: Die Nymphen der Ersatzgeschlechtstiere sammeln sich stets in Herden von 80–100 Einzeltieren und werden von einer Gruppe Arbeiter (als Hütehunde) bewacht. Die Arbeiter halten die Nymphen auf einem engen Raum zusammen und versuchen andere Nestgenossen von den Nymphen fernzuhalten. Alle ein bis zwei Tage wechseln die Herden ihren Standort. Das Weiterziehen geschieht gleichfalls in Form von Herden.Die Ernährung der Nymphen geschieht auf stomodealem Wege durch die Arbeiter. *** DIRECT SUPPORT *** A0180089 00007     

Polymorphism of the HLA DR1 haplotype in the Israeli population investigated at the serological,cellular, and genomic levels

In the present report, we used serological, cellular, and restriction fragment length polymorphism (RFLP) to investigate the DR1 haplotype in the Israeli population. We describe an Israeli homozygous typing cell (HTC), HLA-DwLVA, which defines a new lymphocyte-activating determinant associated with Bw65, DR1 and distinct from Dwl. The parents of this donor, non-Ashkenazi Algerian Jews, are first cousins and share HLA-Cw8, Bw65, BfS, DR1, DQw1, DPw4. No specificity could be assigned to HLA-DwLVA using the 91 Ninth Workshop HTCs. Two families and forty unrelated DR1 individuals were studied with DwLVA and a panel of DR1/Dw1 HTCs. HLA-DwLVA showed segregation as a single determinant within families. This new specificity was present in 24 out of 40 (60%) unrelated DR1 individuals, indicating that in the Israeli population DwLVA is the main lymphocyte-defined determinant associated with the serologically defined DRI specificity, in contrast to non-Jewish Caucasoids where DR1 is significantly associated with Dw1. The vast majority of DwLVA-positive carriers were also Bw65 carriers, indicating that Bw65, DR1, DwLVA may represent a typical allele combination in the Israeli population. The RFLP analysis established the correlation of certain RFLPs with Dw1 and DwLVA. In addition, we describe a cluster of RFLPs that may correspond to a new Dw subtype associated with DR1, for which no serological and cellular reagents have been described so far.     

Charles Darwin's theory of evolution: A review of our present understanding

The paper characterizes Darwin's theory, providing a synthesis of recent historical investigations in this area. Darwin's reading of Malthus led him to appreciate the importance of population pressures, and subsequently of natural selection, with the help of the wedge metaphor. But, in itself, natural selection did not furnish an adequate account of the origin of species, for which a principle of divergence was needed. Initially, Darwin attributed this to geographical isolation, but later, following his work on barnacles which underscored the significance of variation, and arising from his work on botanical arithmetic, he supposed that diversity allowed more places to be occupied in a given region. So isolation was not regarded as essential. Large regions with intense competition, and with ample variation spread by blending, would facilitate speciation. The notion of place was different from niche, and it is questioned whether Darwin's views on ecology were as modern as is commonly supposed. Two notions of struggle are found in Darwin's theory; and three notions of variation. Criticisms of his theory led him to emphasize the importance of variation over a range of forms. Hence the theory was populational rather than typological. The theory required a Lamarckian notion of inheritable changes initiated by the environment as a source of variation. Also, Darwin deployed a use/habit theory; and the notion of sexual selection. Selection normally acted at the level of the individual, though kin selection was possible. Group selection was hinted at for man. Darwin's thinking (and also the exposition of his theory) was generally guided by the domestic-organism analogy, which satisfied his methodological requirement of a vera causa principle.     

Characterization of the effectors required for stable inheritance of Streptococcus pyogenes pSM19035-derived plasmids in Bacillus subtilis

The low-copy-number and broad-host-range pSM19035-derived plasmid pBT233 is stably inherited in Bacillus subtilis cells. Two distinct regions, segA and segB, enhance the segregational stability of the plasmid. Both regions function in a replicon-independent manner. The maximization of random plasmid segregation is accomplished by the recombination proficiency of the host or the presence of the pBT233 segA region. The segA region contains two open reading frames (or) [ and ]. Inactivation or deletion of or results in SegA^– plasmids. Better than random segregation requires an active segB region. The segB region contains two ors (or and or). Inactivation of either of the orfs does not lead to an increase in cell death, but or^– plasmids are randomly segregated. These results suggest that pBT233 stabilization relies on a complex system involving resolution of plasmid oligomers (segA) and on the function(s) encoded by the segB region.     

Zur Brutbiologie des Seggenrohrs?ngers(Acrocephalus paludicola)

Zusammenfassung In der vorliegenden Arbeit werden Beobachtungen ausgewertet, die in den letzten Jahren in einer Seggenrohrsängerpopulation der Mark Brandenburg gesammelt wurden. Brutbiotop ist eine Großseggenwiese. und haben getrennte Reviere, wobei sich -Reviere, -Reviere und auch - und -Reviere zum Teil sehr erheblich überlagern. Keinem konnte ein bestimmtes zugeordnet werden, sie leben also in Keinehe. versuchen, aus der Nestnähe zu vertreiben. Aggressive Handlungen zwischen benachbarten konnten nicht festgestellt werden. Ihre Singflüge unterscheiden sich von denen der Schilfrohrsänger. 28 Eier maßen im Durchschnitt 17,76×13,14 mm. Nur die brüten und Füttern. Die durchschnittliche Fütterungsfrequenz liegt bei 19,7 Fütterungen pro Stunde, die tägliche Aktivitätszeit der ist im Juli etwa 1 Stunde kürzer als im Juni. 13–14 Tage nach dem Schlüpfen verlassen die Jungen das Nest. In der Nestlingsnahrung ist bei Julibruten der hohe Heuschreckenanteil auffällig. Nachdem die Jungen selbständig sind, streunen sie im Brutbiotop umher. Zweitbruten sind sehr wahrscheinlich, konnten aber noch nicht nachgewiesen werden.

---

Summary Observations made during the last years on a population of the Aquatic Warbler (Acrocephalus paludicola) in Brandenburg, Germany, gave the following results:In a sedge meadow, withCarex elata the dominant species, males and females ofAcrocephalus paludicola held separate territories, those of males as well of females sometimes considerably overlapping territories held by other individuals of the same or the opposite sex. In no case a certain male could be considered as having formed a firm pair bond with a certain female: on the contrary, the relations between the sexes were very loose, and probably the birds are even promiscuous. Females try to chase away males from the neighbourhood of their nests. Aggressiveness between neighbouring males has not been observed. The display flights of the males are different from those of the Sedge Warbler(A. schoenobaenus). 28 eggs measure on the average 17,76×13,14 mm. Females alone incubate and feed the young, at an average rate of 19,7 times per hour. The young leave the nest 13–14 days after hatching. Young reared in July are fed a great amount of grasshoppers. Second broods probably occur, but could not be proved.

     

Primary structure of the hemoglobin beta-chain of rose-ringed parakeet (Psittacula krameri)

The primary structure of Rose-ringed Parakeet hemoglobin -chain was established, completing the analysis of this hemoglobin. Comparisons with other avian -chains show variations smaller than those for the corresponding -chains. There are 11 amino acid exchanges in relationship to the only other characterized psittaciform -chain, and a total of 35 positions are affected by differences among all avian -chains analyzed (versus 61 for the -chains). At three positions, the Psittacula -chain has residues unique to this species. Three ₁₁ contacts are modified, by substitutions at positions 51, 116, and 125.     

Characterization of human chromosomal unit fibers

A structural component of mitotic chromosomes that partially explains the compaction of DNA within mitotic chromosomes is suggested on the basis of the occurrence of long, regular cylindrical structures in preparations of isolated human chromosomes. These structures, unit fibers, of a rather constant diameter of about 4,000 Å have been postulated to be formed by coiling of the 250T2–300 Å solenoid chromatin fiber that itself is formed by coiling of the 100 Å string of nucleosome fiber. The human chromatid would thus be composed by a hierarchy of helices with contraction ratios for DNA at each level of coiling of 7 (string of nucleosomes), 5 (solenoid) and 40 (4,000 Å unit fiber or super-solenoid) which results in an overall contraction ratio for DNA in the unit fiber structures of about 1,400, which is approximately 5-fold less than the final contraction of DNA in intact chromatids of condensed metaphase chromosomes. The present report concerns more detailed studies with respect to the dimensions and cytochemical properties of the unit fiber structures observed in preparations of isolated human mitotic chromosomes that provide direct and indirect evidence in support of their super-solenoid structure and relate to known properties of human mitotic chromosomes.     

Chromophore assignment in phycoerythrocyanin from Mastigocladus laminosus

The component spectra (maxima of absorption, circular and linear dichroism) of individual chromophores have been assigned for phycoerythrocyanin (PEC) trimer, monomer(s), and its subunits (-PEC and -PEC) by titration with p-chloromercury-benzene-sulfonate (PCMS), linear dichroism and photochemical transformations, as well as by deconvolution using a bilin line-shape spectrum based on the -84 phycoviolobilin-chromophore in the -subunit. The level ordering PVB--84 PCB--155 PCB--84 is the same irrespective of aggregation. Two different monomers () were observed. In 4 M urea, the spectra are appropriately weighted sums of the subunit spectra, whereas in the monomer obtained in 1 M KSCN, both -chromophores are red-shifted by 4–5 nm. Formation of trimer ()_{_3}gives considerable spectral changes: (1) the absorption is narrowed, which has been rationalized by excitonic coupling between neighbouring monomers, (2) the short wavelength part in the CD spectrum is missing and (3) a fourth band (+) at 528 in the LD spectrum appears. A deconvolution of the trimeric aggregation state using only the bilin line-shape model is not possible.     

β2-Adrenoceptor activation by zinterol causes protein phosphorylation,contractile effects and relaxant effects through a cAMP pathway in human atrium

Evidence from ventricular preparations of cat, sheep, rat and dog suggests that both ₁-adrenoceptors (₁AR) and ₂-adrenoceptors (₂AR) mediate positive inotropic effects but that only ₁AR do it through activation of a cAMP pathway. On the other hand, our evidence has shown that both ₁ AR and ₂ AR hasten relaxation of isolated human myocardium consistent with a common cAMP pathway. We have now investigated in the isolated human right atrial appendage, a tissue whose -AR comprise around 2/3 of ₁AR and 1/3 of ₂AR, whether or not ₂AR-mediated effects occur via activation of a cAMP pathway. We carried out experiments on atria obtained from patients without advanced heart failure undergoing open heart surgery. To activate ₂AR, we used the ₂AR-selective ligand zinterol. Experiments were carried out on paced atrial strips (1 Hz) and tissue homogenates and membrane particles. Zinterol caused positive inotropic and lusitropic (i.e. reduction of t_1:2 of relaxation) effects with EC₅₀ values of 3 and 2 nM, respectively. The zinterol-evoked effects were unaffected by the AR-selective antagonist CGP 20712A (300 nM) but blocked surmountably by the ₂AR-selective antagonist ICI 118551 (50 nM) which reduced both EC₅₀ values to 1 M. Zinterol stimulated adenylyl cyclase activity with an EC₅₀ of 30 nM and intrinsic activity of 0.75 with respect to (–)-isoprenaline (600 M); the effects were resistant to blockade by CGP 20712A (300 nM) but antagonised surmountably by ICI 118551 (50 nM). Zinterol bound to membrane PAR labelled with (–)-[¹²⁵I] cyanopindolol with higher affinity for ₂AR than for - 1 AR; the binding to ₂AR but not to - BAR was reduced by GTPyS (10 M). In the presence of CGP 20712A (300 nM) (–)-isoprenaline (400 M); (to activate both ₁AR and ₂AR maximally) and zinterol (10 M); increased contractile force 3.4-fold and 2.5-fold respectively and reduced relaxation tut by 32% and 18% respectively. These effects of (–)-isoprenaline and zinterol were associated (5 min incubation) with phosphorylation (pmol P/mg supernatant protein) of troponin I and C-protein to values of 8.4 ± 2.0 vs 12.4 ± 2.3 and 10.1 ± 2.5 vs 8.6 ± 1.6 respectively. (–)-Isoprenaline and zinterol also caused phosphorylation of phospholamban (1.8 ± 0.3 vs 0.4 ± 0.1 pmol P/mg respectively) specifically at serine residues. We conclude that in human atrial myocardium activation of both ₁AR and ₂AR leads to cAMP-dependent phosphorylation of proteins involved in augmenting both contractility and relaxation.     

Agonistisches Verhalten, Territorialverhalten und Balz der Zwergtrappe (Tetrax tetrax)

Zusammenfassung 1980–1984 wurden in Südfrankreich und Portugal Untersuchungen zum agonistischen Verhalten, Territorialverhalten und zur Balz der ZwergtrappeTetrax tetrax durchgeführt.Während der Fortpflanzungsperiode kommt es zwischen Zwergtrappen- häufig zu agonistischen Auseinandersetzungen. Ausdruck aggressiver Erregung ist enges Anlegen des Halsgefieders, Langstrecken des Halses, und nur beim Aufrichten und dachartiges Falten der Schwanzfedern. Aggressive Verhaltensweisen sind Drohen durch Hinlaufen oder -fliegen zu Reviereindringlingen, seitliches Drohen gleichstarker , und nur, wenn Verhaltensweisen niedrigerer Intensität nicht zur Unterlegenheit eines der Rivalen führen, Schnabelkämpfe.Rufen dient der Markierung eines Reviers. Die Intensität des Rufens wird durch die Anwesenheit von nicht beeinflußt, die Anwesenheit fremder nahe der Reviergrenze führt jedoch zu einem deutlichen Anstieg. Die Rufbewegung macht eine gewisse optische Signalwirkung, vor allem auf kurze Distanz, zusätzlich zur akustischen Wirkung, wahrscheinlich.Fliegende erzeugen mit den Schwingen (besondere Struktur der 7. Handschwinge) ein pfeifendes Geräusch, das während der Fortpflanzungszeit Bedeutung in der innerartlichen Kommunikation hat. Es zeigt sowohl als auch den Anflug eines weiteren an und löst damit territoriale bzw. aggressive Verhaltensweisen oder Flucht aus. Weitere Bedeutung erlangt es als Element des Territorialen Flügelschlagens und der Sprungbalz.Über ihrem Revier fliegen territoriale stets mit leicht hochgebogenem Kopf und verhaltenen, flachen Flügelschlägen. Deutungen dieses Fluges als Imponierflug zur besseren Darstellung des auffällig gefärbten Halsgefieders bzw. als Suchflug zum leichteren Auffinden und Verjagen von Reviereindringlingen werden diskutiert.Territoriales Flügelschlagen beginnt mit Fußtrampeln, das sich beschleunigt und in einen Ruf überleitet. Gleichzeitig schlägt das dreimal sehr schnell und flach mit den Flügeln, hebt jedoch nicht vom Boden ab. Alle Elemente des Verhaltens sind deutlich zu hören. Der Verstärkung der beim Fußtrampeln erzeugten Klopfgeräusche dienen Balzplätze, die entweder auf akustisch besonders geeignetem Boden angelegt oder durch das Fußtrampeln der sekundär verbessert werden.Territoriales Flügelschlagen wird ausschließlich in niedrigen Lichtintensitäten während kurzer Zeit in der Morgen- und Abenddämmerung gezeigt. Die Anwesenheit von hat keinen Einfluß auf seine Intensität. Es ist eine territoriale Verhaltensweise mit akustischem Signal und wird als ritualisiertes Anlaufen gegen einen Reviereindringling bzw. ritualisiertes Auffliegen eines Revier- zum Eindringling hin gedeutet. Optische Komponenten kommen in der deckenden Vegetation kaum zur Geltung. können wegen der relativ geringen Reichweite der Signale nicht angelockt werden.Sprungbalz tritt zeitlich streng getrennt vom Territorialen Flügelschlagen in wesentlich höheren Lichtintensitäten auf; seine Intensität hängt ab von Kontakten zu . Sie ähnelt zwar in der Ausführung dem Territorialen Flügelschlagen, der Vogel hebt sich jedoch während der langsameren Flügelschläge durch einen Sprung vom Boden ab, und das Fußtrampeln ist wesentlich weniger intensiv. Charakteristische Flügelbewegungen während des Balzsprunges exponieren schwarzweiße Gefiederpartien bis in 65 cm Höhe. Sprungbalz erhöht im Vergleich zu Territorialem Flügelschlagen stark die optische Auffälligkeit eines ; die Sprunghöhe garantiert zusammen mit der Lage der Balzplätze bei geringstmöglichem Energieaufwand eine maximale Sichtbarkeit des über der umgebenden Vegetation. Sowohl die zeitliche Korrelation der Sprungbalz mit den Aktivitäten der als auch die Art der Interaktionen mit während Sprungbalzphasen machen deutlich, daß diese Verhaltensweise ins Paarungsrevier zieht.Das Hennenjagen dient der Stimulierung der zur Kopulation. Das läuft in charakteristischer Körperhaltung schnell hinter einem her, hat dabei den Kopf tief in die aufgerichtete Halskrause eingezogen, hält oft ruckartig an und ruft unter Zurseitewerfen des Kopfes. Kopulationen sind sehr kurz. Offensichtlich kann das Hennenjagen die sonst sehr ausgeprägte Abwehr des gegen das unterdrücken und zur Kopulationsbereitschaft führen. Die Kopulation selbst jedoch hebt diesen Effekt wieder auf, so daß nach 1–2 Sekunden das abwehrt oder flieht.

---

Agonistic behaviour, territorial behaviour and courtship display of the Little Bustard (Tetrax tetrax)

Summary From 1980 to 1984 studies were made of the agonistic, territorial and courtship behaviour of the Little Bustard in Southern France and Portugal. The behaviour patterns are described in detail, the signals involved are analysed, and factors which could have led to their evolution are discussed.In the reproductive period agonistic encounters between males happen remarkably often. Aggressive excitement is expressed in both sexes by compression of the neck-feathers and stretching of the neck, and in the female by the erection and lateral folding of the tail-feathers. There are several kinds of threat behaviour in territorial encounters: running or flying towards intruders; lateral threat behaviour (if both males are of similar strength); and bill-fighting which only occurs if aggressive behaviour of a lower intensity has not led to the submission of one of the rivals. Calling is a territorial behaviour and serves to mark a territory. The frequency of calls is not affected by the presence of females, but the presence of other males close to the territory borders can result in a marked increase in calling frequency. In addition to the acoustic signal, the call involves a sharp neck-jerk which may act as an optical signal, at least over short distances.In flight males produce a whistling sound by means of the specially adapted 7th primary feather on their wings. This sound has important meaning in intraspecific communication during the reproductive period: it announces a flying male to other males as well as to females, and causes territorial and aggressive behaviour, or fleeing of these birds. The flight sound is also an important element of the behaviour patterns territorial wingbeat display and jumping display. Within their territories males always fly with the neck raised at a slight angle and with suppressed, shallow wing-beats. Two interpretations of this flight are discussed: that it serves to advertise the conspicuously coloured neck-feathers in a display; or that it is a search flight for locating and chasing-off intruders.Territorial wingbeat display begins with an accelerating foot-stamping and leads into a call. During the call the male performs three very fast, whistling wing-beats but remains on the ground. The combined elements, foot-stamping, calling and whistling wings, produce a unique and distinctive acoustic signal. The foot-stamping is only performed at special display sites where the sound is amplified by the substrate structure. At such sites, the soil typically has trapped pockets of air below a compacted surface which may result from the repeated defecating and stamping of the male on the same spot. Territorial wingbeat display behaviour is only performed for short periods in low light intensities at dawn and dusk. The presence of females has no effect on the intensity of the behaviour which serves a territorial function. It is interpreted to be a ritualisation of the aggressive running or flying of a territorial male towards an intruder. Optical elements of this behaviour cannot have much importance because the body and wings of the bird are rarely visible above the vegetation. Territorial wingbeat display behaviour cannot be seen over long distances and from this reason cannot serve to attract females into a males territory.Jumping display is only performed at much higher light intensities than territorial wingbeat display so the two never occur at the same time of day. The intensity of the behaviour increases markedly in the presence of females in sharp contrast to the territorial wingbeat display. The jumping display is performed in a similar way to the territorial wingbeat display except that the foot-stamping is much less intensive, the wing-beats are slower, and the bird jumps off the ground during the wing-beats. During the jumping display the black and white patterns on the body and wings are clearly visible and the behaviour increases the conspicuousness of the male markedly. The jump, advertising the wing-pattern up to a height of 65 cm, together with the specific location of the display site, ensures that maximum visibility of the male above the vegetation is achieved at minimum energetic cost. Activities of the females and their interactions with males during the jumping periods indicate that this behaviour serves to attract females to the males territory.The chasing of females is also a courtship behaviour and serves in stimulating and preparing females for copulation. In a characteristic posture with the head retracted into the neck-collar, the male rapidly runs behind the female, repeatedly stopping abruptly and calling whilst throwing its head and body sideways. Copulations are performed very quickly and only happen after a female has been chased for some time. Under certain preconditions chasing suppresses the aggressive and defence behaviour of the female which normally characterises encounters with males, and thus leads to readiness for copulation. Copulation itself removes this effect and after only one or two seconds aggression leads to the escape of the female.

     

Modulation of natural killer activity by thymosin alpha 1 and interferon

Summary A single injection of -interferon (-IFN) (30 000 units/mouse), a major biological modifier of natural killer (NK) cytolytic activity, strongly stimulated NK activity in normal mice, as expected, while the same treatment did not statistically alter the NK response in cyclophosphamide (CY)-suppressed animals.We investigated the possibility of thymosin ₁ cooperating with -IFN in boosting NK activity in CY-suppressed animals.The results show that treatment with thymosin ₁ (200 g/kg) for 4 days, followed by a single injection of -IFN 24 h before testing, strongly restored NK activity in CY-suppressed mice. Thymosin ₁ was, moreover, able to accelerate the recovery rate of NK activity in bone marrow reconstituted murine chimeras.Taken together the data support the concept that the synergic effect between thymosin ₁ and -IFN could be the result of effects on differentiation of the NK lineage at different levels.     

Geochemical controls for Al, Fe, Mn, Cd, Cu, Pb, and Zn during experimental acidification and recovery of Little Rock Lake, WI, USA

Concentrations of Al, Fe, Mn, Cd, Cu, Pb, and Zn were measured in thereference and treatment basins of Little Rock Lake (Vilas County, Wisconsin), alow-alkalinity, seepage system (pH 6.1, alkalinity25eq/L) during six years of a whole-basinacidificationand the first four years of the lake's recovery. The treatment basin wasacidified with H₂SO₄ in three two-year steps to pH5.6, 5.1, and 4.7. By the end of year 4 of recovery, treatmentbasin pH increased to 5.3 as a result of internal alkalinity generation.During acidification, dissolved Mn and Fe (0.4mpore-size filters) increased at pH 5.6; dissolved Al, Cd, and Zn becameelevated at pH 5.1; and dissolved Pb at pH 4.7. Dissolved Cu remainedsimilar in both basins to pH 4.7. Al, Fe and Mn levels declinedsignificantly during the recovery period, approaching values at pH 5.3intermediate between the concentrations at pH 5.6 and 5.1 during acidification.Dissolved Al and Fe in the reference basin were near the equilibrium levels forsolubility of gibbsite (Al(OH)₃) and amorphousFe(OH)₃(s).The acidified basin was undersaturated relative to gibbsite, and dissolved Alwas limited by pH disequilibrium between the water column and sediments andpossibly by Al-DOC precipitation. Dissolved Fe apparently was controlled bysolubility of amorphous Fe(OH)₃(s) and Fe-DOC precipitation.Dissolved Mn levels in both basins were consistent with manganite[-MnOOH(s)] solubility. Elevated levels of Cd, Pb, and Zn in thetreatment basin during acidification probably resulted from less efficientscavenging of atmospherically-deposited Cd, Pb, and Zn by settling particles.