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A series of radiocarbon dates for Early Bronze Age contexts from the excavations at Kouphovouno are published for the first time. By adopting a Bayesian modelling approach, the 14C estimates allow greater precision in arriving at an absolute chronology for the period. The opportunity is taken to place these dates as part of the more general development of the Early Bronze period. The sequence for mainland Greece is compared with the recently revised dating of the Early Cycladic period. The new data support a lower chronology than that advocated in recent publications.
On 26 November 2010, an outbreak of scombroid fish poisoning occurred in the French Armed Forces in Dakar, Senegal. This chemical intoxication, due to high histamine concentration in fish, is often mistaken for an allergic reaction. A case-control study was undertaken including the 71 cases and 78 randomly selected controls among lunch attendees. The usual symptoms for scombroid fish poisoning were observed in cases, i.e. flushing (85·9%), headache (83·1%), rapid/weak pulse (59·1%) and diarrhoea (47·9%). Symptoms occurred from within a few minutes to up to 3 h following the meal. Most patients quickly recovered with antihistamine and/or symptomatic treatment. Tuna was the only food item positively associated with illness (odds ratio 36·3, 95% confidence interval 6·3–210·0), with the risk of illness increasing with the quantity of fish consumed. No bacterial contamination was found in leftover food, but histamine concentration in tuna was found to be 4900 mg/kg, almost 50-fold higher than the concentration allowed by European regulations. This report is unique because of the large size of the case series – to our knowledge, the largest event of scombroid fish poisoning ever reported – and the chemical and bacteriological analyses results obtained on leftover food.
Ce travail présente une technique de détection et de suivi de l’endommagement dans les
structures en matériaux composites. Les mécanismes d’endommagement dans ces matériaux sont
complexes. Dès lors que l’on souhaite modéliser le comportement d’une structure, il est
important de comprendre comment celle-ci s’endommage. La méthode optique d’observation
in-situ proposée est appliquée au cas d’une plaque trouée.
In developing countries, vaccination against highly pathogenic avian influenza subtype H5N1 (HPAI) in free-range poultry flocks is usually implemented as periodic campaigns and newborn chicks are generally not vaccinated by farmers between vaccination passes. The demographic population turnover leads to a continuous decrease in the population immunity rate (PIR) over time. We present a simple Leslie matrix model for estimating population turnover and PIR dynamics in a hypothetical small-size vaccinated free-range poultry population. Four different vaccination scenarios were identified assuming necessary procedures to achieve immunity. The results indicate that high levels of population immunity are difficult to sustain. Assuming an animal immunity response of 80% after vaccination and a constant population size, PIR 4 months after vaccination was ⩽30% in all the scenarios. Predictions averaged over time showed mean PIR between 36% and 48%, which is below the population immunity thresholds for eradication approximated from R0 estimates.
The frequency response of the h.f. quadrupole probe is calculated to be used as a diagnostic tool for measurements of electron density and temperature. In §2 the magnetic field is assumed to be zero, and ion motions are neglected. For a Maxwellian plasma, the so-called ‘Landau wave approximation’ is compared with various more sophisticated treatments, such as numerical integration or super-Cauchy and multiple water-bag models. The range of validity of this approximation is shown to be large, and the results can be applied to the most interesting parts of the experimental observations. All results previously established are recovered with greater speed. Having studied various disturbances (collisions, inhomogeneity and relative motion of the probe with respect to the plasma), it is deduced that the best way to determine the electron temperature is to use the anti-resonances due to beating between the Landau wave and the cold plasma field. In § 3 we describe the quadrupole probe, launched in December 1971 as part of the CISASPE rocket experiment. To deduce the electron density and temperature from these measurements, it is necessary to consider the influence of a static magnetic field, such as the earth's magnetic field. The general case could be treated by numerical integration, though with great difficulty, but it is shown that in most ionospheric conditions, in the vicinity of the upper hybrid frequency ωT the above treatment is again possible, the plasma frequency simply being replaced by ωT, and the thermal velocity slightly modified. These assumptions are used to deduce the electron density and temperature profiles.
A final report is presented here on the excavation of four Areas at the prehistoric site of Kouphovouno, Sparta, Lakonia. Areas A and D were excavated as trials in 2001 and lie outside the land purchased by the BSA for the main campaigns, so they could not be excavated further, whilst Areas E and F had extensive deposits of historic date and were not further explored as being outside the remit of the main Kouphovouno Project. The excavations have yielded important Neolithic and Early Helladic II deposits, plus Bronze Age burials and later Roman remains. After summarising the aims of the Project and mentioning earlier work at the site, the report gives an account of the stratigraphy and finds and includes specialist reports on the human and animal bones, the ceramics, the chipped and ground stone and other finds. Also discussed is the relationship between the surface remains reported in BSA 99 and the excavated material.
A multidisciplinary research programme was developed to get a scientific expertise for the quality assessment of products obtained from cloned livestock. Thirty-seven bovine Holstein female clones of five different genotypes and their products were analysed in comparison with 38 control animals obtained by conventional artificial insemination and raised under the same conditions at the same experimental farm. Animal evaluation included over 150 criteria and more than 10 000 measurements to check the physiological status and health over a 3-year period. All the parameters studied were in the normal range for age and breed, but some significant differences were detected between clone and control groups in terms of delayed onset of puberty in clones, higher neutrophil counts in haematology or lower biochemical plasma concentrations of gamma glutamyl transferase. Milk and meat analyses were conformable to expected values. We, however, found some differences in fatty acid (FA) composition of milk and muscle suggesting a possible deviation in lipid metabolism as assessed by higher delta-9 desaturase activity indexes in both milk and muscles from clones compared with controls. Repeated muscle biopsies in the semitendinosus muscle of the same animals demonstrated a higher oxidative activity in muscle of young clones (8 months of age) compared with controls, suggesting a delayed muscle maturation in clones. Nutritional evaluation of milk and meat using the rat feeding trials did not show any difference between clone and control products for food intake, growth rate, body composition of the rats, nor for possible allergenicity. Possible reactivation of bovine endogenous retroviruses (BERVs) was analysed and compared between normal and cloned cattle. As expected, these BERV sequences are not transcribed and no RNA was detected in the blood of clones, donor animals or controls; therefore, it may be assumed that the sanitary risk associated with BERV sequences is not higher in cattle derived from somatic nuclear transfer than in cattle born from conventional reproduction. Our results confirm that the quality and safety of products (milk and meat) from adult and clinically healthy cloned cattle is globally similar to normal animals. However, from a strictly biological point of view, the slightly delayed maturation we observed in the muscle of clones together with some marginal differences identified in FA composition of both muscle and milk, point to the need for more refined analysis to totally exclude any risks from the consumption of those products.
An experimental study has been performed at CRM with impinging burners to heat
quickly low carbon steels without oxidizing their surfaces. The thermal performances
of various burners (maximum heat transfer of ~370 kW/m2 on impinged surface)
were studied and compared to data collected from classical direct flame furnaces.
Simulations permit to consider an interesting reduction of furnace size. The surface
characterization indicates the possibility to heat steel strip without oxidizing up
to 840°C. It would then be possible to anneal steel strips at higher temperature
than it is actually performed in the direct flame furnaces.
This is the final report on the intensive survey at Kouphovouno, the prehistoric settlement just south of Sparta, in 1999–2000. As well as a total collection of the artefacts on the surface, there was a magnetometer survey of the site and a programme of environmental studies, for which a series of cores was taken. The site was first occupied in the 6th millennium and covered 4–5 ha in the Middle, Late/Final Neolithic and Early Helladic periods. Occupation continued in the Middle and Late Helladic periods and there is also evidence of Classical-Hellenistic and Roman activity. As well as pottery, the artefacts included chipped and polished stone tools. An analytical programme has investigated the source of the raw materials used for the latter.
The production of new steel grades - such as dual phase and TRIP steels -
requires improvements to both process and equipment of continuous galvanizing lines.
In particular, progress has to be obtained in cooling technology in order to get the
desired mechanical properties. This paper presents a study of design parameters allowing
the optimization of fast gas multi-jet cooling systems. The thermal study involves
the application of infrared thermography and three-dimensional numerical simulations.
Furthermore, a dynamic study is performed in order to reduce steel strip vibration.
We have characterised the changes in preimplantation embryos that occur in the mRNA population during the transition from maternal to zygotic control of embryogenesis. We connected the mRNA differential display method and RT-PCR based method that allows amplification of the whole population of messengers. In the early stages of development we have further characterised the level of individual mRNAs with the help of semiquantitative RT-PCR used with specific primers. This report concerns four of 12 cDNA fragments that appeared to be differentially expressed between the 4- and late 8-cell stages. A transcript corresponding to fragment no. 1/12 appears to be analogous to the maternal mRNA since it is abundant in 1-, 2-, 4- and 8-cell embryos and rapidly decreases in the later stages. A similar pattern of expression was revealed in the transcript corresponding to fragment no. 8/9. A transcript corresponding to fragment no. 20/8 is newly synthesised from the embryonic genome at the late 8-cell stage and its amount rapidly increases during the following stages. This messenger shows a 91.7% identity with mRNA for human S3A ribosomal protein and 92.2% identity with mRNA for Felis domesticus S3A ribosomal protein. A transcript corresponding to fragment no. 8/19 is stage-specific, being newly synthesised from an embryonic genome at the late 8-cell stage and decreasing in the later stages. This messenger shows 86.6% identity with a mouse mRNA for proline-rich protein and 91.6% identity with human mRNA for KIAA-0058 gene. A complex of these molecular markers represents a suitable tool for answering questions concerning the molecular control of major gene activation during bovine embryogenesis.
In bovine conceptuses, the trophoblast elongates rapidly from the 13th to the 19th day of pregnancy, while the embryonic disc differentiates to set up the primary germ layers and the axis of the fetus. Observations on pregnancies of cloned fetuses underline placental abnormalities which could originate from earlier gene deregulations occurring during this long pre-implantation period. To allow screenings with individual trophoblasts we used amplification protocols involving either PCR or in vitro transcription steps. For that purpose we used a bovine-specific macro-array starting from a cDNA library generated on early in vivo elongating conceptuses. RNAs from adult somatic tissues were used to compare hybridisation patterns generated with amplified and unamplified polyA+ probes.
The aim of the study was to evaluate differences between cows in the “quality” of their oocytes defined as their ability to support embryonic development. Ten cows from the same herd, all primiparous and non-pregnant were submitted for oocyte collection by Ovum-Pick Up (OPU). The oocytes were matured in vitro and fertilised with semen from the same bull. In vitro embryo development, both quantitatively (percentages showing cleavage and forming blastocysts) and qualitatively (differential cell counting in blastocysts) was determined at the blastocyst stage (Day 7). The number of oocytes collected, the number of blastocysts obtained and the blastocyst formation rate varied between cows (P<0.001). The mean percentage of inner cell mass cells tended to higher for embryos derived from one cow. These results provide evidence that the quality of the oocytes was influenced by their maternal origin. Follicular growth also varied between cows.
We present a thermodynamic study of the critical magnetic properties of La1.2Sr1.8Mn2O7, including the determination of the fundamental characteristics of a magnetic system: anisotropy, critical exponents and crossovers in the vicinity of the Curie temperature, TC∼108K. It appears that two-dimensional correlations above TC do not spread very fast, and that thus the critical fluctuations regime occurs in a moderately narrow temperature range, assessing the three- dimensional nature of the ferromagnetic ordering.
Hormonally active compounds of different origins such as polychlorinated biphenyls (PCBs) and their derivatives are widely dispersed in the environment by various industrial processes. They represent a threat to human health since their toxic effects can result from biological accumulation of low doses of active compound during extended periods of exposure. Critical doses for a cytotoxic effect have been determined using cellular models such as cultured hepatocytes but it is still not known if lower doses can affect in vitro cell functions before any toxic effect can be detected. To address this issue we have used a functional genomic approach to characterize changes in the profile of genes expressed by cultured bovine fibroblasts exposed during only 26 hours to concentrations as low as 10-10 to 10-12 molar of TCDD
Zirconium nitride films on silicon substrates have been prepared by DC magnetron enhanced reactive sputtering in a N2/Ar gas mixture under various experimental conditions. The films properties (chemical composition, structure, morphology and optical response) were investigated and related to the experimental conditions. It is shown that these properties are strongly related to the target current density which governs the deposition rate, to the deposit thickness, to the nitrogen partial pressure and to the residual gas contamination. The objective of this paper is to detect the minimum film thickness threshold under which a zirconium nitride coating cannot be used in decorative applications.
The nanostructure and local strain of \111] FCC Co/Cu and Co/Ni multilayers is studied by means of nuclear magnetic resonance. The atomic topology of the interface can be deduced from the NMR spectrum, the local strains from the shift in the hyperfine fields. The results show that the Co/Cu interface is a mixed monolayer and that the Co layers, including the interface, have uniform (tensile) strain inversely proportional to the Co thickness (within experimental error) with the proportionality constant depending on the Cu thickness. In Co/Ni the interface consists of two mixed layers and the Co layers have uniform compressive strain inversely proportional to the Co thickness.
We have studied the morphology and magnetic phase transitions of monolayer-range Fe films on a reconstructed Au(001) surface using the combination of High-Resolution Low-Energy Electron Diffraction (HRLEED) and Surface Magneto-Optic Kerr Effect (SMOKE) techniques. Through the measurement of energy dependent angular profiles of the specularly diffracted beam, we discovered a simple method to determine not only the interfacial spacings (Fe-Au and Fe-Fe) but also to detect the build up of the second layer. For a one-level (2-D) Fe films with coverage of ∼ 0.6 monolayer (ML) perpendicular magnetization was observed. For a 1 ML equivalent 3-D film both perpendicular and in-plane magnetization were observed. The magnetic phase transitions of these magnetic islands showed finite size broadening effect. The perpendicular saturation magnetization decreases with temperature above 100°C but never vanishes and the magnetization curve has no hysteresis loop above ∼ 120°C. The implication of superparamagnetism is discussed.
By means of light scattering from spin waves and magnetooptical Kerr measurements we investigated the exchange interaction of two Fe films across a Cr film as a function of the Cr thickness dCr.
Using good quality epitaxial samples with a special wedge geometry of the interspacer we observed up to four full periods of the long range oscillations of the exchange, including its ferromagnetic parts. At room temperatures the damping of the oscillations does not follow the d-2Crpendence predicted by zero-temperature RKKY-type theory.
After a special e-beam treatment of the samples a short-range oscillation with a period around a lattice constant of Cr are discovered. The value of coupling in the maximum in this case shows considerable temperature dependence.
The analysis of domain patterns and M(H) curves reveals the existence of a noncollinear interaction, which causes a configuration where the magnetizations of two Fe films are perpendicular to each other.