35 research outputs found
Taphonomic differentiation of Oxfordian ammonites from the Cracow Upland, Poland
Taphonomic analysis of Lower and Middle Oxfordian ammonites from the Cracow Upland, southern Poland (localities at Podłęże, Zalas, Młynka) revealed differences in ammonite preservation. The studied ammonites, usually termed as external and internal moulds, show a more complex state of preservation. In the Middle Oxfordian glauconitic marls, ammonites are preserved as internal moulds with neomorphic calcite shells showing relics of the original internal structure. In the Middle Oxfordian platy peloidal limestones, ammonites are preserved mostly as external moulds, without septal suture, however under microscope might show relics of internal whorls and septa and/or subtle differences in sediment filling phragmocone chambers. In sponge–microbial bioherms and biostromes, ammonite internal moulds have shells, which in contrast to ammonites from glauconitic marls are not strictly neomorphic ones, but originated by shell dissolution and subsequent filling of moldic porosity by calcite cement. In sponge–microbial nodular limestones, the ammonites are strongly deformed and the outer wall is usually removed by dissolution under pressure. Other important taphonomic differences include the rate of compaction (highest in platy limestones), sedimentary infillings, microborings, encrustations and preservation of siphuncular tubes. The majority of the ammonites appear to be phragmocones; aptychi in all facies are rare. Siphuncular tubes are fossilized exclusively in oppeliids, only in specimens from glauconitic marls and platy limestones, although their other taphonomic attributes are different. Tubes seem to have fossilized due to microbially mediated phosphatization that could be favoured by a set of parameters which operated rather at the scale of ammonoid carcasses: closed, poorly oxygenated conditions, and reduced pH. Taphonomic processes were controlled by the sedimentary environment (fragmentation, sedimentary filling, phosphatization of siphuncular tubes), as well as by early and late diagenesis (neomorphic transformation, dissolution, cementation, compaction) influenced by lithology
Materiały i konstrukcja wybranych reliefów Henryka Stażewskiego
The first reliefs appeared in the achievements of Henryk Stażewski around 1956. Artist made these objects in large quantities to the mid seventies. Each new series was built in a slightly different way, sometimes with the use of new materials. The kind of material often decides about character of works of art, as it is in metal reliefs. Similarly, a way to combine elements is very significant, for example can makes an impression of mysterious play of light and shadows, especially exposed in the white reliefs. Analyzing the importance of material and structure in the works of Henryk Stażewski, it can be concluded, that these are equivalent to other means of artistic expression, which reflect artist’s thoughts. The essay presents seven reliefs from the subsequent series, focusing primarily on its technical construction. The main aim was to show how the way of performing this works of art had been changing and prove that this was consequent and fluent process, where each component has its origin in the earlier works. Knowledge about the used materials and structures let the receivers better know the works of Stażewski and get new information, which are often hidden in them. Looking into the relief we can find many surprises. Artist assumed that accurate recipient would observe them from different points, reaching even deep inside of it. This is supported by the fact that the layer of color is also on parts hidden under the geometric elements. Artist often changed his compositions and colors of his works. The remains of his previous actions can sometimes be found under the surface of the paint and sometimes in hollows of relief.
Improving detection of foraminifera by cathodoluminescence
Cathodoluminescence (CL) studies of Lower-Middle Oxfordian marls and limestones, as well as clasts from the uppermost Turonian-?Early Coniacian conglomerates of the Cracow Upland (southern Poland), reveal that the CL view of foraminifers from some lithologies differs from that in transmitted light. In particular, the CL technique revealed abundant tests of planktonic species Globuligerina oxfordiana in the Middle Oxfordian glauconitic marls, which under transmitted light are either poorly visible or remain completely undetected. Bright red-orange luminescence characterizes originally hyaline aragonitic tests of G. oxfordiana, but also several calcitic benthic species, in spite of their different taxonomic position and original test structure and mineralogy. In sponge microbial boundstones, foraminifers generally do not show the CL emission, or show a weak luminescence. Similarly, Late Cretaceous foraminifera represented mostly by planktonic taxa were detected or their view was clearly improved
under CL only in some clasts from the uppermost Turonian-?Early Coniacian conglomerates filling karstic cavities. In other clasts, foraminifera are clearly visible only under normal transmitted light, therefore the luminescence signature is highly spatially variable. These results indicate a strong influence of lithology and diagenesis and rather
minor effects of shell structure on luminescence of microfossils. The CL technique can be a useful tool in the detection and documentation of abundance patterns of foraminifers that are poorly preserved under transmitted light
Biokinetics of ^{131}I after endogenous and exogenous stimulation of TSH in patients with DTC
BACKGROUND: The effective radioiodine treatment of patients with DTC is possible only after raising the TSH value over 30 μUI/ml. This effect might be obtained by either endogenous or exogenous stimulation. The aim of this study was to evaluate differences in 131I biokinetics of selected regions of interest (ROIs) in cases of endogenous and exogenous stimulation.
MATERIAL AND METHODS: Two groups of 50 patients were enrolled in the study. All patients were treated with 3.7 GBq of 131I; the first group after thyroid hormone withdrawal (THW), the second group after rhTSH administration (rhTSH). On the basis of post-treatment images, the uptake ratios over selected ROIs (thyroid remnants, mediastinum, liver, stomach, abdomen, and whole-body) were compared between groups.
RESULTS: In the case of uptake over the whole-body and the liver, statistically significant higher values were received for the THW group. For the remaining regions, the differences between groups were statistically insignificant, but uptake ratios in the rhTSH group were generally numerically lower compared to the THW group.
CONCLUSIONS: The revealed difference in radioiodine biokinetics after thyroid hormone withdrawal or administration of recombinant human TSH may influence many important aspects of patients with DTC treatment, such as the choice of proper therapeutic scheme, the cost of therapy, and the dose assessment
Biokinetics of 131I after endogenous and exogenous stimulation of TSH in patients with DTC
BACKGROUND: The effective radioiodine treatment of patients
with DTC is possible only after raising the TSH value over
30 μUI/ml. This effect might be obtained by either endogenous
or exogenous stimulation. The aim of this study was to evaluate
differences in 131I biokinetics of selected regions of interest (ROIs)
in cases of endogenous and exogenous stimulation.
MATERIAL AND METHODS: Two groups of 50 patients were
enrolled in the study. All patients were treated with 3.7 GBq of
131I; the first group after thyroid hormone withdrawal (THW), the
second group after rhTSH administration (rhTSH). On the basis
of post-treatment images, the uptake ratios over selected ROIs
(thyroid remnants, mediastinum, liver, stomach, abdomen, and
whole-body) were compared between groups.
RESULTS: In the case of uptake over the whole-body and the
liver, statistically significant higher values were received for the
THW group. For the remaining regions, the differences between
groups were statistically insignificant, but uptake ratios in the
rhTSH group were generally numerically lower compared to
the THW group.
CONCLUSIONS: The revealed difference in radioiodine biokinetics
after thyroid hormone withdrawal or administration of
recombinant human TSH may influence many important aspects
of patients with DTC treatment, such as the choice of proper therapeutic
scheme, the cost of therapy, and the dose assessment.
Nuclear Med Rev 2010; 13, 2: 55–5
A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.
The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world