3,859 research outputs found
Significance of the Sm-Nd isotopic systematics of the Akilia Association
Samarium-Neodymium analyses were carried out on fourteen samples of basic to ultrabasic metavolcanics from several enclaves of the Amitsoq gneisses (T = to or approximately 3,700 Ma). Field observations suggest that all the analyzed rocks belong to the pre-Amitsoq Akilia Association. Consequently, a minimum age of 3,700 Ma is postulated for the emplacement of their protoliths. When all the data points are put together in a conventional isochron diagram, no clear isochron relationship can be discerned. However, the points seem to fall within a band broadly corresponding to an age of 3,600 Ma. The isotopic results are difficult to interpret satisfactorily. Two contrasting interpretations are offered and summarized: (1) data scatter as a result of open system behavior; and (2) data scatter due to a melange of data sets defining two distinct isochrons
Gastric Ulceration, Appetite and Feeding Practices in Standardbred Racehorses in the Czech Republic
The objective of our study was to determine the prevalence of poor appetite and its correlation with the prevalence of gastric ulceration, and to evaluate relation between feeding management (feeding frequency and feeding regularity) and gastric ulceration in a group of 54 Standardbred racehorses in training. Prevalence of gastric ulceration in the group of horses with poor general appetite was 94.8%. Prevalence of gastric ulceration in the group of horses with good general appetite was 48.6%. Significant association between poor general appetite and squamous gastric ulcer presence was observed (p < 0.001). Gastric ulceration was found in 75.0% of horses fed twice daily and in 57.9% horses fed three times a day. Fifty seven point nine per cent of regularly fed horses had gastric ulcers. Irregularly fed horses were ulcer-positive in 75.0%. Thus no significant association between feeding frequency or regularity and the occurrence of gastric ulcers was found
FREKUENSI TRAIT THALASSEMIA-b DI AMBON, MALUKI
Genetic screening for D-thalassemia trait was carried out in Ambon population of the Moluccas, a population genetically related with other eastern Indonesian populations with strong Melanesian influence where HbE gene frequency is very low. Blood specimens were collected from 92 adult healthy unrelated individuals consists of 32 males and 60 females mostly student nurses participated in the study.
Three blood indices, hemoglobin concentration, packed cell volume and MCHC were normal. However, increase of HbA2 concentration was observed in six individuals (6.5%). Unlike the previous study, not even single individual with abnormally structural hemoglobin was found in this study. The occurrence of carrier of this genetic traits comparable with previous studies in Java, again confirms the interaction of 13-thalassemia and HbE distribution in malaria endemic region.
Further measures include premarital genetic counseling should be considered to avoid public health problem that may be created in the future.
Key words : genetic screening, B-thalassemia trait, malaria endemic, premarital genetic counselin
Crossover Between Universality Classes in the Statistics of Rare Events in Disordered Conductors
The crossover from orthogonal to the unitary universality classes in the
distribution of the anomalously localized states (ALS) in two-dimensional
disordered conductors is traced as a function of magnetic field. We demonstrate
that the microscopic origin of the crossover is the change in the symmetry of
the underlying disorder configurations, that are responsible for ALS. These
disorder configurations are of weak magnitude (compared to the Fermi energy)
and of small size (compared to the mean free path). We find their shape
explicitly by means of the direct optimal fluctuation method.Comment: 7 pages including 2 figure
2-factors with k cycles in Hamiltonian graphs
A well known generalisation of Dirac’s theorem states that if a graph G on n ≥ 4k vertices has minimum
degree at least n/2 then G contains a 2-factor consisting of exactly k cycles. This is easily seen to
be tight in terms of the bound on the minimum degree. However, if one assumes in addition that
G is Hamiltonian it has been conjectured that the bound on the minimum degree may be relaxed.
This was indeed shown to be true by S´ark¨ozy. In subsequent papers, the minimum degree bound has
been improved, most recently to (2/5 + ε)n by DeBiasio, Ferrara, and Morris. On the other hand no
lower bounds close to this are known, and all papers on this topic ask whether the minimum degree
needs to be linear. We answer this question, by showing that the required minimum degree for large
Hamiltonian graphs to have a 2-factor consisting of a fixed number of cycles is sublinear in n
Vergleichende Untersuchungen zur Regulierung des Kartoffelkäfers (Leptinotarsa decemlineata Say) mit Pyrethrum/Rapsöl-, Neemöl- und Bacillus thuringiensis-Präparaten
The Colorado Potato Beetle is one of the most important pests of potatoes. The effect of various plant protection products with neem oil (NeemAzal-T/S), pyrethrum/rape oil (Spruzit Neu) and Bacillus thuringiensis-B.t.t.(Novodor Neu) against this pest was compared in a field experiment 2004. Neem oil and B.t.t. reduced the number of Colorado Potato Beetle larvae as well as the losses of plant material due to feeding by beetle larvae significantly in the same way. Beneficial arthropods were not affected. The application of pyrethrum/rape oil has shown in this experiment no significant effect to reduce the number of Colorado Potato Beetles. However, the number of beneficial arthropods was reduced from 2.2 individuals/plant (untreated control) to 1.0 individual/plant
Entwicklung und Darstellung von Strategieoptionen zur Behandlung von Saatgut im ökologischen Landbau
Zur Erzeugung gesunden Saatgutes steht im Öko-Landbau neben präventiven Maßnahmen eine Reihe verschiedener Saatgutbehandlungsverfahren zur Verfügung (physikalische Methoden, Pflanzenextrakte, Naturstoffe und Mikroorganismenpräparate), die jedoch für die zahlreichen, wichtigen Wirt/Pathogen-Kombinationen nicht hinreichend untersucht waren. Inhalt und Ziel dieses Verbundvorhabens war es, Erfolg versprechende, aber hinsichtlich Handhabbarkeit und Wirksamkeit bislang nicht ausreichend untersuchte Varianten zu überprüfen sowie Schwellenwerte zu ermitteln, die eine Saatgutbehandlung indizieren.
Um eine schnelle Übertragbarkeit wirksamer Verfahren in die Praxis zu ermöglichen, wurden neben den physikalischen Verfahren überwiegend gelistete Pflanzenstärkungsmittel untersucht.
Im ersten Untersuchungsschritt wurden Klimakammer- und Gewächshausversuche angelegt. Ansätze, die sich unter diesen Modellbedingungen für die Praxistestung als geeignet erwiesen, wurden in Feldversuchen (Projekt 03OE127/2) überprüft.
Für wichtige Wirt/Pathogen-Kombinationen konnten unter Modellbedingungen Behandlungsvarianten mit guten Wirkungen ausgewählt werden, die keine bis geringe negative Auswirkungen auf die Keimfähigkeit hatten. Bei Sommergerste mit Netzflecken oder Streifenkrankheit sowie bei Haferflugbrand konnten nach Behandlung mit Heißwasser, LEBERMOOSER, Ethanol, Milsana flüssig, Serenade und/oder Cedomon gute bis sehr gute Wirkungen erreicht werden. An Winterweizen mit Fusarium spp., Stagonospora nodorum bzw. Schneeschimmel sowie Winterroggen mit Schneeschimmel wurde eine Wirkung vor allem durch FZB 53, Warm- oder Heißwasserbehandlung und LEBERMOOSER erreicht.
Von den besonders schwer zu bekämpfenden Krankheiten wurden Anthraknose an Lupine und Ascochyta pisi an Erbse mit Feuchtheißluft reduziert, jedoch war die Wirkung nicht ausreichend
First IBEX observations of the terrestrial plasma sheet and a possible disconnection event
The Interstellar Boundary Explorer (IBEX) mission has recently provided the first all-sky maps of energetic neutral atoms (ENAs) emitted from the edge of the heliosphere as well as the first observations of ENAs from the Moon and from the magnetosheath stagnation region at the nose of the magnetosphere. This study provides the first IBEX images of the ENA emissions from the nightside magnetosphere and plasma sheet. We show images from two IBEX orbits: one that displays typical plasma sheet emissions, which correlate reasonably well with a model magnetic field, and a second that shows a significant intensification that may indicate a near-Earth (similar to 10 R(E) behind the Earth) disconnection event. IBEX observations from similar to 0.5-6 keV indicate the simultaneous addition of both a hot (several keV) and colder (similar to 700 eV) component during the intensification; if IBEX directly observed magnetic reconnection in the magnetotail, the hot component may signify the plasma energization
More evidence of localization in the low-lying Dirac spectrum
We have extended our computation of the inverse participation ratio of
low-lying (asqtad) Dirac eigenvectors in quenched SU(3). The scaling dimension
of the confining manifold is clearer and very near 3. We have also computed the
2-point correlator which further characterizes the localization.Comment: presented at Lattice2005(Topology and Confinement), Dublin, July
25-30, 2005, 6 pages, 3 figures, to appear in Proceedings of Scienc
Ontogeny of synaptophysin and synaptoporin in the central nervous system
The expression of the synaptic vesicle antigens synaptophysin (SY) and synaptoporin (SO) was studied in the rat striatum, which contains a nearly homogeneous population of GABAergic neurons. In situ hybridization revealed high levels of SY transcripts in the striatal anlage from embryonic day (E) 14 until birth. In contrast. SO hybridization signals were low, and no immunoreactive cell bodies were detected at these stages of development. At E 14, SY-immunoreactivity was restricted to perikarya. In later prenatal stages of development SY-immunoreactivity appeared in puncta (identified as terminals containing immunostained synaptic vesicles), fibers, thick fiber bundles and ‘patches’. In postnatal and adult animals, perikarya of striatal neurons exhibited immunoreaction for SO; ultrastructurally SO antigen was found in the Golgi apparatus and in multivesicular bodies. SO-positive boutons were rare in the striatum. In the neuropil, numerous presynaptic terminals positive for SY were observed. Our data indicate that the expression of synaptic vesicle proteins in GABAergic neurons of the striatum is developmentally regulated. Whereas SY is prevalent during embryonic development, SO is the major synaptic vesicle antigen expressed postnatally by striatal neurons which project to the globus pallidus and the substantia nigra. In contrast synapses of striatal afferents (predominantly from cortex, thalamus and substantia nigra) contain SY
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