The upper cretaceousLacazina limestone in the Basco-Cantabrian and Iberian basins of northern Spain: Cold-water grain associations in warm-water environments

Summary The Upper Santonian to Lower CampanianLacazina Limestone consists of massive, often amalgamated beds of packstones and grainstones which were deposited in a shallow marine environment. The most abundant skeletal components are miliolid foraminifera, echinoderm, bivalve and bryozoan fragments, peloids and sparse red algae. Small, solitary corals only occur sporadically. Hermatypic corals, sponges and green algae are missing. The series which reaches thicknesses between 60 m and 160 m, was sampled at intervals of 0.5 m at five localities. The petrographic features throughout the series are mainly a product of changing depositional energy. The limestones are well cemented. Diagenesis is characterized by a transition from marine phreatic to burial cementation. Syntaxial and blocky calcite cements predominate over early acicular to bladed and microgranular cements. The faunal association within theLacazina Limestone exhibits features typical for temperate water i.e.foramol carbonates. On the other hand, oxygen (δ¹⁸O =-1.7 to −6.3 ‰ PDB) and carbon (δ¹³C to 3.0‰ PDB) isotope values of diagentically unaltered bivalve shells indicate warm surface waters corresponding better to the palaeogeographical situation of theLacazina Limestone. Nutrient-surplus is proposed as a limiting factor preventing the development of reefs and finally ofchlorozoan sediments. In the sense of sequence stratigraphy, theLacazina Limestone is interpreted to contain transgressive and highstand systems tracts. This interpretation fits well into theHaq-Vail-curve. The series shows no visible high-frequency cyclicity in the field. Several cycles were found by means of principle component analysis and spectral analysis. Their relationships to the Milankovitch spectrum are discussed. The ammonite fauna of the unit and of preceding sediments (late Coniacian to early Campanian) is described and some inoceramids are figured. They permit—for the first time—the exact dating of theLacazina Limestone in the Basco-Cantabrian Basin (BCB) and throw light on a prominent faunal change at the Coniacian/Santonian boundary. The Cenomanian to Coniacian ammonite faunas which were dominated by endemic Tethyan pseudoceratitic faunas are replaced by cosmopolitan species dominated by Madagascan elements. This drastic change permits speculations about the installation of a new oceanic current system in the Santonian.     

Ern?hrungsphysiologie des Blaunackenmausvogels (Urocolius macrourus pulcher)

Zusammenfassung Beim Blaunackenmausvogel (Urocolius macrourus pulcher) wurde die Ausnutzung der verschiedenen Nährstoffe (Fette, Eiweiße, Kohlenhydrate) und die Assimilationseffizienz des Gesamtfutters untersucht. Mausvögel sind Vegetarier und hauptsächlich frugivor. Im Versuch erhielten die Vögel vier Diäten: I. Mischfutter (Bananen, Salat, gekochtes Ei, gekochter Reis, Apfel); II. Bananen; III. Fruchtfutter (Pfirsiche und Birnen); IV. Eiweißfutter (Quark und gekochtes Weißei). Die minimalen Darmpassagezeiten betrugen für alle vier Diäten zusammengefaßt zwischen 6 und 18 min. Damit kommen die Mausvögel an die Werte für Nektarfresser heran (unter 15 min). Der Darmtrakt ist mit 19,0 ±2,4 cm (n = 16) für einen Vogel dieser Körpermasse ( 56,4 ±2,7 g; 49,2 ±2,9 g) extrem kurz und zeigt den für Fruchtfresser typischen einfachen Bau. Blinddärme fehlen. Die mittlere Gesamteffizienz für die vier Diäten liegt bei 71,0 %. Die Werte variieren in einem relativ engen Bereich zwischen 65,9 % (Banane) und 74,0 % (Mischfutter). Damit sind Blaunackenmausvögel innerhalb der Vögel als relativ schlechte Nahrungsverwerter zu bezeichnen. Für Fruchtfresser allgemein werden allerdings noch niedrigere Werte zwischen 30 % und 70 % angegeben. Die Assimilationsrate der einzelnen Nährstoffe hängt in starkem Maße vom Angebot im Futter ab. Die Zusammensetzung der assimilierten Nahrung zeigt, daß Kohlenhydrate mit 89,0–91,1 % den weitaus größten Anteil am Energiestoffwechsel haben. Vermutlich werden nur gelöste oder leicht verdauliche Einfachzucker bzw. Stärken verwertet. Zellulose wird praktisch ungenutzt ausgeschieden. Fette und Proteine spielen unter Normalbedingungen nur eine untergeordnete Rolle. Der Energieumsatz ist nahrungsabhängig und beträgt 62,5 J/g·h bei der Bananendiät, 69,2 J/g·h bei der Fruchtdiät, 87,3 J/g·h bei der Eiweißdiät und 99,6 J/g·h beim Mischfutter.

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Nutrient physiology of the Blue-naped Mousebird (Urocolius macrourus pulcher)

Blue-naped Mousebirds were fed with four different diets: I. mixed food (bananas, salad, boiled eggs, boiled rice, apples); II. bananas only; III. soft fruits (pears and peaches); and IV. food enriched with protein (curd cheese and egg-white). The minimal times for food passage through the digestive tract were 6–18 min altogether. This is similar to the data known from nectarivorous birds (<15 min). The intestines are extremely short (19,0 ±2,4 cm; n = 16) and simple-structured, without specialization and without any caeca. The overall efficiency for the diets with 71,0 %, ranging between 65,9 % (bananas) and 74,0 % (mixed food), is relatively low. However, for frugivorous birds in general, far lower efficiencies are recorded (30–70 %). The assimilation efficiencies of nutrients depend on their amount in food and the physiological and seasonal requirements. The composition of the assimilated food shows that carbohydrates, having the largest part with 89,0–91,1 %, are most important for energy supply. Presumably, the birds utilize only sugars being easy to digest, because cellulose is removed. Fat and protein are playing a subordinate role in metabolism. The metabolic turnover differs with the diet and ranges between 62,5 J/g·h (bananas), 69,2 J/g·h (fruits), 87,3 J/g·h (protein food) and 99,6 J/g·h (mixed food).

     

Ein Vogelruf, dessen Form sich im Jahresablauf ?ndert: der Verbeugungstriller bei der Brandente (Tadorna tadorna)

Zusammenfassung Der Verbeugungstriller männlicher Brandenten, eine epigame Lautäußerung, weist sowohl in syntaktischen wie auch phonetischen Parametern zyklische jahreszeitliche Veränderungen auf. Die Gesamtdauer der Lautäußerung vergrößert sich allmählich im Laufe des Frühjahrs. Dafür sind eine Verlängerung des tonalen Eingangselements und eine Vermehrung der Elemente der abschließenden Phrase verantwortlich. Dagegen verkürzt sich das 2. Element gleichzeitig. In allen untersuchten Elementen erhöht sich die Tonhöhe parallel zur Verlängerung des Rufes. Diese Veränderungen des Ausdrucksverhaltens geben vermutlich Änderungen innerer Zustandsgrößen wieder.

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Seasonally changing bird call: the trill call of male Shelducks (Tadorna tadorna)

Both syntactic and phonetic features of the trill call accompanying the whistle-shake in adult male Shelducks are subject to cyclic annual changes. In the course of spring, the duration of the whole call increases gradually. This is caused by a prolongation of the first call element and insertion of additive elements in the final phrase. In contrast the second element is shortened by about 10 ms. At the same time, the pitch of all measured elements is raised. These findings are discussed in the framework of hormonal regulation and communicative function.

     

A new approach for rhizosphere research by X-ray microanalysis of microliter soil solutions

Lolium perenne growing with high root density on a fine nylon mesh (Kuchenbuch and Jungk, 1982) caused the development of element gradients in the rhizosphere below the mesh. Micro-liter soil solutions from 2-mg soil samples were sprayed onto Formvar-coated grids and analyzed by X-ray microanalysis in a transmission electron microscope. The results were comparable to those obtained by flame photometry and atomic absorption spectrometry (AAS) of conventional soil solutions from 1 g soil. X-ray microanalysis of micro-soil solutions allows the application of different extraction procedures to even small amounts of soil usually available from rhizosphere experiments. Information about soil buffering characteristics in the rhizosphere can thus be obtained. Aluminum accumulation in the rhizosphere of small segments of single Picea abies fine roots grown in undisturbed natural forest soil could be detected with this technique.     

Spotlight on phytochrome nomenclature

These recommendations for genes encoding phytochromes were developed independently by Quail et al., but are broadly consistent with the Commission's guidelines. Their original article, kindly provided in advance of publication, appeared as a Letter to the Editor inPlant Cell (6:468–471, 1994) and is published with permission of the American Society of Plant Physiologists.     

Isolation of humic acid from the brown algaPilayella littoralis

A standard humic acid extraction procedure has been used to isolate dark brown organic residues from samples of the macroscopic marine brown algaPilayella littoralis. The residues are insoluble in water, but soluble at high pH, and are similar in elemental composition, ash content, UV-visible, IR, PMR and X-Ray fluorescence spectra, X-Ray diffractograms and scanning electron micrographs to residues of a humic acid isolated from municipal compost. These results indicate thatPilayella produces humic acids.Author for correspondence     

Characterization of a class Ib gene of the rat major histocompatibility complex

The cDNA and a partial genomic sequence of a rat class I major histocompatibility (RT1) gene, 11/3R, is reported here. The sequence contains several unique amino acid residues at certain positions, mutations in exon 7 (which is not expressed), a mutation of the canonical exon 8 stop codon to a sense codon, and includes a long 3 unstranslated region (utr). The structure of exon 7 differs from that found in most rat class I genes and resembles exon 7 of most H-2K,D,L.Q genes. Parts of the 3 noncoding region are homologous to the RT1.A-4 and certain H-2 genes. Expression is detectable by northern blot analysis in mitogen-stimulated lymphocytes only, by polymerase chain reaction (PCR) in each tissue tested. After transfection into L cells 11/3R can be shown to be expressible at the cell surface. Probes derived from the 3 noncoding part crosshybridize with a number of restriction fragments which map to the RT1.C region, thus defining a subfamily of RT1.C region genes. Several members of this subfamily are deleted in the M1 RT1 mutant. The 11/3R gene presents typical features of a class Ib gene. Aspects of evolution and the potential of the gene are discussed.The nucleotide sequence data reported in this paper have been submitted to the GenBank molecule sequence data base and have been assigned the accession numbers X67503 ande X67504.