140 research outputs found
Flandrian, a formation or just a name?
The name Flandrian is now used to indicate deposits of the FIandrian transgression or of the Holocene is a whole, particular in Anglo-Saxon literature. As most geological connotations, Flandrian has changed significance and chronostratigraphic age since it was created in 1885 by RUTOT and VAN DEN BROECX. At that time, Flandrian was a pleistocene "assise" which occurred at the end of long series of quaternary and tertiary stages. Therefore, it completed and still completes the geological traditions of the cenozoic sequence. Substages the Flandrian, as Calais and Dunkerque, are generally used, although there only exist type areas of both series instead of type localities. 'Work is going to define the type section in both areas of the Flemish Coastal Plain. It would be useful to re-establish the Flandrian stage on basis of these new investigations, as the last chronostratigraphic member of a continuous series in the cenozoic stratigraphical sequence
Application de la mĂ©thode de rĂ©trodiffusion des Ă©lectrons Ă la mesure en continu des faibles Ă©paisseurs de revĂȘtements lĂ©gers sur mĂ©taux ou alliages lĂ©gers
Le problĂšme envisagĂ© concerne la mesure en continu des faibles Ă©paisseurs de revĂȘtements organiques sur mĂ©taux ou alliages lĂ©gers. Nous Ă©tudions les caractĂ©ristiques d'une jauge Ă rĂ©trodiffusion ÎČ opĂ©rant sous atmosphĂšre d'hĂ©lium. Nous montrons que le fait de travailler sous hĂ©lium amĂ©liore les rĂ©sultats de façon trĂšs importante. L'influence de l'Ă©nergie de la source radio-active et du numĂ©ro atomique du revĂȘtement sont examinĂ©s. Les rĂ©sultats obtenus concernent Ă©galement la prĂ©cision, le temps de mesure ainsi que la surface de l'Ă©chantillon sous investigation
A model for the generic alpha relaxation of viscous liquids
Dielectric measurements on molecular liquids just above the glass transition
indicate that alpha relaxation is characterized by a generic high-frequency
loss varying as , whereas deviations from this come from one or
more low-lying beta processes [Olsen et al, Phys. Rev. Lett. {\bf 86} (2001)
1271]. Assuming that long-wavelength fluctuations dominate the dynamics, a
model for the dielectric alpha relaxation based on the simplest coupling
between the density and dipole density fields is proposed here. The model,
which is solved in second order perturbation theory in the Gaussian
approximation, reproduces the generic features of alpha relaxation
La formation d'Herzeele: un nouveau stratotype du pleistocene moyen marin de la mer du Nord
The Herzeele Brickyard (Northern France) offers a permanently well exposed outcrop of continental and marine deposits which are reaching a total thickness of 6 m and are overlying the Ypresian clay of eocene age, occuring at about 8 m N.G.F.Three marine phases represented by tidal flat and brackish sediments may be readily distinguished. The tidal flat sediments have previously been recognized in the area of Izenberge (Belgium) from which locality the name "Izenberge Cardium Sands" has been derived. The marine sediments may be subdivised into units of different lithology: the lower sandy unit, the middle loamy-clayey unit and the upper sandy clayey unit which latter is characterized by the abundance of Cardium edule and Macoma balthica. The marine phases are furthermore separated by continental deposits amongst which peat layers are occurring. The cover sediments are represented by eolian sands and loams interfering with palaeosoils. The series of sediments underlying these cover deposits is named the "Herzeele Formation" which represents a lithostratigraphical unit in the southern North Sea basin. The analysis of the heavy mineral content points to a change in sediment origin occuring after the lower marine sedimentation. The middle and upper marine units contain an increasing content of green hornblende and epidote. Some volcanic minerals were observed at different levels. The clay analyses by means of X-ray diffraction indicate that the different lithostratigraphical units bear polymineralic clay assemblages within which the smectitic fraction is predominant. Greene-Kelly's (1953) Li-test yielded a further detailed analysis of the smectitic components: beidellite, montmorillonite-like. minerals as well as random mixed-layers illite-smectites. The analysis indicates a stratigraphical - mineralogical subdivision of the section which coincides with the lithostratigraphical one.The pollen analytical data show that the whole of the Herzeele Formation most probably belongs to the second half of the Holsteinian interglacial, except for the very base composed of glauconiferous sands. It may readily be seen that the forest evolved from a mesocratic phase, characterized by a Quercetum mixtum with Picea, towards a telocratic phase during which the forest became dominated by Abies. Within the peat which is resting upon the glauconiferous sands, the pollen grains of Taxus, are very abundant in the overlying clay however, this species declines gradually and disappears at the top of the upper marine unit. These evidences are corresponding with the first half of the so-called Abies- zone. Buxus and Vitis, both undergo the same evolution. The only Tertiary relict, Pterocarya, made a short appearance at the top of the upper marine unit, while Azolla filiculoides, was only discovered in the Quercetum zone. The diatom analyses indicate the conditions of brackish and marine sedimentation in a tidal environment. Although the magnetostratigraphical approach of deep-sea and lake sediments has proven to be successful, its application to continental and especially coastal sediments is hampered by the very nature of these sediments (large variation of sedimentation rate, depositional environment, lithology, a.o.) The palaeomagnetical study of the Herzeele Formation reveals a striking difference inmagnetic behaviour between the upper and lower beds separated by the lowermost peat layer. The upper beds are characterized by a strong dispersion of the magnetisation directions and a low intensity. Therefore identification of clear-cut magnetozone(s) is not possible for the moment being. As to the extension of the Herzeele Formation in Belgium, it was only found south of the river Yzer. The comparison with the area of Izenberge itself did not reveal any lithostratigraphical correlation with the Herzeele Formation. The situation of the stratum (former shoreline) at this type-locality gives prove of the importance of the palaeographical evolution since the Lower Pleistocene with the formation of the southern North Sea basin and probably the early opening of the Strait of Dover as well. Therefore this stratum is considered as a landmark and a witness of several interglacial marine transgressions which are attributed to the Holsteinian and to the upper part of the "Cromerian complex"
Juvenile hemochromatosis caused by a novel combination of hemojuvelin G320V/R176C mutations in a 5-year old girl
A multi-technique approach, based on mobile/portable laser instruments, for the in situ pigment characterization of stone sculptures on the island of Crete dating from Venetian and Ottoman period
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Shareholder activism in the UK: types of activists, forms of activism, and their impact on a targetâs performance
Considering the recent rapid expansion of shareholder activism phenomenon in the United Kingdom (UK) and the vast amount of resources committed to it by corporations, government and investors, its effectiveness has become a crucial subject for investigation. This article analyzes organizational outcomes of shareholder activism in the UK. This research is based on a unique comprehensive database of shareholder activism events during the period of 1998â2008. We provide a detailed account of different types of activists, activism strategies and shareholder demands associated with the events of activism. Our findings show that the effectiveness of shareholder activism in terms of abnormal stock-market returns varies dramatically depending on its form, type of investor and the nature of investor proposals
A prospective study of postmenopausal hormone use and ovarian cancer risk
The relationship between postmenopausal hormone use (PMH) and ovarian cancer risk is unclear, particularly for specific hormone formulations, but recent studies suggest that there is a positive association. We conducted a prospective observational study with 82â905 postmenopausal women, including 389 ovarian cancers, in the Nurses' Health Study from 1976 to 2002. Compared with never users of PMH, both current and past users of â©Ÿ5 years had a significantly elevated risk of ovarian cancer (RR=1.41, 95% confidence interval (CI) 1.07â1.86 and relative risk (RR)=1.52, 95% CI 1.01â2.27, respectively). Examined by hormone type in continuous years, use of unopposed estrogen was associated with a significant increase in the risk of epithelial ovarian cancer (P for trend <0.001; RR for 5-year increment of use=1.25, 95% CI 1.12â1.38). Use of estrogen plus progestin (RR for 5-year increment of use=1.04, 95% CI 0.82â1.32) was not significantly associated with ovarian cancer risk. Generally, results were similar for serous tumours (RR for 5-year increment of unopposed estrogen use=1.23, 95% CI 1.07â1.40) and slightly stronger for endometrioid tumours (RR for 5-year increment of unopposed estrogen use=1.53, 95% CI 1.20â1.94). Recency of use was not significantly associated with ovarian cancer risk, but statistical power was limited here
Travelers With Cutaneous Leishmaniasis Cured Without Systemic Therapy
Guidelines recommend wound care and/or local therapy as first-line treatment for cutaneous leishmaniasis. An analysis of a referral treatment program in 135 travelers showed that this approach was feasible in 62% of patients, with positive outcome in 83% of evaluable patient
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