The ammonite fauna of the type Maastrichtian with a revision of Ammonites colligatus BINKHORST, 1861

A revision of the ammonites from Maastricht and adjacent parts of Limburg and Liège based on the BINKHORST Collection in the Museum für Naturkunde, Berlin, the collections of the Institut Royal des Sciences naturelles de Belgique, Brussels, (including material described by A. DE GROSSOUVRE in 1908) and the Natuurhistorisch Museum, Maastricht, revealed the following sequence of faunas. The youngest Campanian ammonite from the Vaals Formation is a specimen of Hopliloplacenticeras marroti (COQUAND, 1859) from Vijlen, Cotessen (Zuid-Limburg, The Netherlands); this is a typical lower Upper Campanian species. The Zeven Wegen Chalk yields Baculites at several localities and upper Upper Campanian Hopliloplacenticeras coesfeldiense (SCHLUETER, 1867) and Trachyscaphites spiniger (SCHLUETER, 1872) at Vijlenerbosch (Zuid-Limburg, The Netherlands): these are Bostrychoceras polyplocum Zone species. An unspecified horizon within the Gulpen Formation of Schneeberg, north of Vaals yields the lower Lower Maastrichtian Acanthoscaphites tridens (KNER, 1848); the same species occurs at Vaals. No ammonites were seen from the Beutenaken Chalk, but the Vijlen Chalk yields phosphatised and unphosphatised Baculites at a number of localities, Hoploscaphites tenuistriatus (KNER, 1848) at Mesch (Zuid-Limburg, The Netherlands), and there is a record of Pachydiscus sp. from Hallembaye, Liège. No ammonites were seen from the Lixhe or Lanaye Chalks. The base of the Valkenburg Chalk yields phosphatised Baculites anceps LAMARCK, 1822, and phosphatised Baculites sp. at the Blankenberg Quarry, Cadier en Keer (Zuid-Limburg, The Netherlands). No ammonites were seen from the Gronsveld, Schiepersberg or Emael Chalks. Ammonites known to be from the Nekum Chalk, mostly from the environs of Maastricht, are Anapachydiscus fresvillensis (SEUNES, 1890). Diplomoceras cylindraceum (DEFRANCE, 1816), Baculites vertebralis LAMARCK, 1801, B. anceps LAMARCK, 1822 and Hoploscaphites constrictus (J. SOWERBY. 1817). There are two records of Sphenodiscus binkhorsti BOEHM, 1898 from this unit. Ammonites known to be from the Meerssen Chalk are Nostoceras sp., Diplomoceras cylindraceum (DEFRANCE, 1816), Baculites vertebralis LAMARCK, 1801, B. anceps LAMARCK, 1822 and Hoploscaphites constrictus (J. SOWERBY, 1817). The upper part of the Meerssen Chalk only yields frequent Sphenodiscus binkhorsti BOEHM, 1898 and the crassus form of Hoploscaphites constrictus. A single specimen of Eubaculites lyelli (d'ORBIGNY, 1847) from Maastricht is from either the Nekum of the Meerssen Chalk. Ammonites from the upper part of the "Calcaire de Kunraed" are Saghalinites sp., Pachydiscus (Pachydiscus) gollevillensis (d'ORBIGNY, 1850), P. (P.) cf. jacquoti SEUNES, 1890, Anapachydiscus fresvillensis (SEUNES, 1890), Glyptoxoceras cf. subcompressum (FORBES, 1846), G. cf. circulare SHIMIZU, 1935, G. sp., Diplomoceras cylindraceum (DEFRANCE, 1816), Baculites vertebralis LAMARCK, 1801, which is common, B. anceps LAMARCK, 1822, Hoploscaphites constrictus (J. SOWERBY, 1817), H. felderi sp. nov., H. pungens (BINKHORST, 1861). Acanthoscaphites verneuilianus (d'ORBIGNY, 1841) and Acanthoscaphites sp. These ammonites records are in accord with recent work on the belemnites of the region (SCHULZ and SCHMID, 1983) that has shown the Zeven Wegen to Beutenaken Chalk to be Lower Maastrichtian, the Vijlen to lower Meerssen Chalk to be Upper Maastrichtian, Belemnitella junior Zone and only the upper part of the Meerssen Chalk to be Upper Maastrichtian, Belemnella casimirovensis Zone. The upper part of the "Calcaire de Kunraed" yields Upper Maastrichtian ammonites that show it to be older than the upper part of the Meerssen Chalk, compatible with microfaunal work by VILLAIN (1977) and the presence of belemnites of the Belemnitella junior Zone but not of the Belemnella casimirovensis Zone. Also included in this work is a revision of the classic Maastrichtian ammonite Pachydiscus colligatus BINKHORST, 1861. The syntypes are shown to belong to two genera, Pachydiscus and Anapachydiscus, and to at least four species. The lectotype, herein designated in accordance with customary useage, is shown to be from the Upper Campanian of Jauche (Brabant, Belgium)

Structural and synthetic insights on oxidative homocouplings of alkynes mediated by alkali-metal manganates

Exploiting bimetallic cooperation alkali-metal manganate (II) complexes can efficiently promote oxidative homocoupling of terminal alkynes furnishing an array of conjugated 1,3-diynes. The influence of the alkali-metal on these C−C bond forming processes has been studied by preparing and structurally characterizing the alkali-metal tetra(alkyl) manganates [(TMEDA)2Na2Mn(CH2SiMe3)4] and [(PMDETA)2K2Mn(CH2SiMe3)4]. Reactivity studies using phenylacetylene as a model substrate have revealed that for the homocoupling to take place initial metalation of the alkyne is required. In this regard, the lack of basicity of neutral Mn(CH2SiMe3)2 precludes the formation of the diyne. Contrastingly, the tetra(alkyl) alkali-metal manganates behave as polybasic reagents, being able to easily deprotonate phenylacetylene yielding [{(THF)4Na2Mn(C≡CPh)4}∞] and [(THF)4Li2Mn(C≡CPh)4]. Controlled exposure of [{(THF)4Na2Mn(C≡CPh)4}∞] and [(THF)4Li2Mn(C≡CPh)4] to dry air confirmed their intermediary in formation of 1,4-diphenyl-1,3-butadiyne in excellent yields. While the Na/Mn(II) partnership proved to be the most efficient in stoichiometric transformations, under catalytic regimes, the combination of MC≡CAr (M= Li, Na) and MnCl2 (6 mol %) only works for lithium, most likely due to the degradation of alkynylsodiums under the aerobic reaction conditions.</p

Forage type influences milk yield and ruminal responses to wheat adaptation in late-lactation dairy cows

peer-reviewedThe effects of different wheat adaptation strategies on ruminal fluid pH, dry matter intake (DMI) and energy-corrected milk (ECM) were measured in 28 late-lactation dairy cows. Cows were fed either perennial ryegrass (PRG) hay or alfalfa hay and had no previous wheat adaptation. Wheat was gradually substituted for forage in 3 even increments, over 6 or 11 d, until wheat made up 40% of DMI (∼8 kg of dry matter/cow per day). We found no differences in DMI between adaptation strategies (6 or 11 d) within forage type; however, cows fed alfalfa hay consumed more overall and produced more ECM. The rate of ruminal pH decline after feeding, as well as the decrease in mean, minimum, and maximum ruminal pH with every additional kilogram of wheat was greater for cows fed alfalfa hay. Cows fed alfalfa hay and on the 6-d adaptation strategy had the lowest mean and minimum ruminal fluid pH on 3 consecutive days and were the only treatment group to record pH values below 6.0. Despite ruminal pH declining to levels typically considered low, no other measured parameters indicated compromised fermentation or acidosis. Rather, cows fed alfalfa hay and adapted to wheat over 6 d had greater ECM yields than cows on the 11-d strategy. This was due to the 6-d adaptation strategy increasing the metabolizable energy intake in a shorter period than the 11-d strategy, as substituting wheat for alfalfa hay caused a substantial increase in the metabolizable energy concentration of the diet. We found no difference in ECM between adaptation strategies when PRG hay was fed, as there was no difference in metabolizable energy intake. The higher metabolizable energy concentration and lower intake of the PRG hay meant the increase in metabolizable energy intake with the substitution of wheat was less pronounced for cows consuming PRG hay compared with alfalfa hay. Neither forage type nor adaptation strategy affected time spent ruminating. The higher intakes likely contributed to the lower ruminal pH values from the alfalfa hay treatments. However, both forages allowed the rumen contents to resist the large declines in ruminal pH typically seen during rapid grain adaptation. Depending on the choice of base forage, rapid grain introduction may not result in poor adaptation. In situations where high-energy grains are substituted for a low-energy, high-fiber basal forage, rapid introduction could prove beneficial over gradual strategies

ZZ--Z′Z' mixing and oblique corrections in an SU(3)×U(1){\rm SU(3) \times U(1)} model

A global fit for experiments is included in this revised version.Comment: IFP-460-UNC, TRI-PP-93-11, 20 pages, 2 figures are appende

The spectral gap for some spin chains with discrete symmetry breaking

We prove that for any finite set of generalized valence bond solid (GVBS) states of a quantum spin chain there exists a translation invariant finite-range Hamiltonian for which this set is the set of ground states. This result implies that there are GVBS models with arbitrary broken discrete symmetries that are described as combinations of lattice translations, lattice reflections, and local unitary or anti-unitary transformations. We also show that all GVBS models that satisfy some natural conditions have a spectral gap. The existence of a spectral gap is obtained by applying a simple and quite general strategy for proving lower bounds on the spectral gap of the generator of a classical or quantum spin dynamics. This general scheme is interesting in its own right and therefore, although the basic idea is not new, we present it in a system-independent setting. The results are illustrated with an number of examples.Comment: 48 pages, Plain TeX, BN26/Oct/9

Evaluation of the n-alkane technique for estimating herbage dry matter intake of dairy cows offered herbage harvested at two different stages of growth in summer and autumn

peer-reviewedThe n-alkane technique for estimating herbage dry matter intake (DMI) of dairy cows was investigated in this experiment. Eight Holstein-Friesian dairy cows were offered perennial ryegrass ad libitum that had been harvested at two different herbage masses and during two different seasons, in order to assess the effect of herbage mass and season on the accuracy of the n-alkane technique. Two pre-harvested herbage mass treatments (low, target 1500 kg DM/ha versus high, target 4000 kg DM/ha, measured above 4 cm), were investigated in a crossover factorial arrangement within each of two seasons (summer versus autumn), in Ireland. Each season consisted of two periods, each 12 days in length. Cows were housed in individual metabolism stalls to allow for accurate determination of measured DMI. Herbage DMI was estimated, with the n-alkane technique, by dosing cows twice daily with a C32 n-alkane. Pre-harvest herbage mass and season did not affect the n-alkane estimated DMI, although lack of season and herbage mass effects may have been masked by variation that occurred between swards within the same herbage mass and season. However, there were a number of differences between summer and autumn in the fecal recovery rates of a number of n-alkanes suggesting that the effect of season requires further investigation prior to the application of recovery rates from literature values when investigating diet selection and botanical composition. Overall, the n-alkane technique provided good estimates of DMI; the discrepancy had a standard deviation due to sward of 1.2 and 1.0 kg DM/cow per day, and hence potential bias of up to twice this, and a measurement error standard deviation of 1.3 and 1.0 kg DM/cow per day, for the C33/C32 and C31/C32 n-alkane pair methods respectively. Two n-alkane pairs were tested, and C33/C32 n-alkane provided the most precise estimates of DMI, compared with the C31/C32 n-alkane pair. This research provides some strong evidence for future use of the n-alkane technique including that the accuracy of the technique has not been influenced by contemporary changes to herbage management, is not affected by seasonal changes, and overall is an accurate and precise technique for estimating DMI.This research was funded by Teagasc Core Funding (Ireland) and the Irish Dairy Levy Research fund (Ireland). The Department of Economic Development, Jobs, Transport and Resources (Australia), Dairy Australia (Australia) and The University of Melbourne (Australia) supported the travel costs in order to conduct this research

Variation in feeding behavior and milk production among dairy cows when supplemented with 2 amounts of mixed ration in combination with 2 amounts of pasture

peer-reviewedVariation in feeding behavior and milk production of grazing dairy cows fed a mixed ration was measured. Experiments were conducted in spring (early lactation) and autumn (late lactation) with 48 Holstein-Friesian dairy cows. Pasture allowance (low vs. high) and amounts of supplement (low vs. high) were applied to determine the effect on variation among cows in feeding behavior and milk production. The experiments investigated 4 dietary treatments in a 2×2 factorial arrangement of treatments. Daily pasture allowances were 15kg of DM/cow per day (low) and 37kg of DM/cow per day (high; to ground level); and 12kg of DM/cow per day (low) and 31kg of DM/cow per day (high; to ground level), for the spring and autumn experiments, respectively. Supplements were offered at 6kg of DM/cow per day (low) and 14kg of DM/cow per day (high); and 6kg of DM/cow per day (low) and 12kg of DM/cow per day (high), for the spring and autumn experiments, respectively. There were 2groups of 6 cows per treatment. All treatments received a partial mixed ration, defined as a total mixed ration fed between periods of grazing that contained wheat grain, corn grain, alfalfa hay, and canola meal. The grain-to-forage ratio of the supplements was 78:22 (DM basis) in both spring and autumn. In both experiments, the pre-experimental period was 14d followed by a 10-d experimental period. The variation among cows within a group in feeding behavior was influenced by the amount of supplement but not the amount of pasture offered. The variation among cows in pasture eating time approximately doubled when the amount of supplement offered increased, indicating that to reduce the variability among cows, supplement feeding management strategies need to be considered. Increasing pasture allowance had no effect on pasture eating time although pasture intake increased as a result of increased grazing intensity compared with the low pasture allowance. However, increasing the amount of supplement in the partial mixed ration feeding system reduced pasture eating time by 51min/cow per day

Ammonite Faunal Dynamics Across Bio-Events During the Mid-and Late Cretaceous Along the Russian Pacific Coast

Jagt−Yazykova, E.A. 2012. Ammonite faunal dynamics across bio−events during the mid − and Late Cretaceous along th

Evaluation of the n-alkane technique for estimating the individual intake of dairy cows consuming diets containing herbage and a partial mixed ration

peer-reviewedEstimation of dry matter intake (DMI) using the n-alkane technique was evaluated in lactating dairy cows fed fresh herbage and a partial mixed ration (PMR). Four dietary treatments were investigated in a 2 × 2 factorial experiment using 16 Holstein-Friesian dairy cows. Dietary treatments were combinations of low and high amounts of fresh herbage (8 or 14 kg DM/cow per day) and PMR supplement (6 or 12 kg DM/cow per day). The pre-experimental period was 14 days followed by a 10-day experimental period. Cows were housed in individual metabolism stalls to allow for accurate measurement of DMI and total fecal output. Fecal n-alkane recovery rates were calculated to determine the most accurate corrections for incomplete fecal n-alkane recovery. The n-alkane technique accurately estimated DMI when corrected for incomplete fecal recovery using both published recovery rates and recovery rates calculated in this experiment. The most accurate application of recovery rates was with those calculated for each combination of dietary treatments, compared with using an average recovery rate. This research has important implications for the future use of the n-alkane technique, especially in PMR feeding systems. The discrepancy between estimated (when treatment recovery rates were applied) and measured herbage DMI increased with the amount of herbage offered but was not affected by amount of PMR. It was also found that the recovery rates of all natural n-alkanes increased as the amount of herbage increased. This research demonstrates that the n-alkane technique can be used to accurately estimate individual cow intake when fresh herbage and PMR are offered separately, evidenced by strong Lin’s concordance estimates