121 research outputs found
Proceedings of the European MOOC stakeholder summit 2015
RESCIF is a French-speaking network with 14 faculties of technology from the North and from the South. One of their research themes is water and four partner institutions decided to build together a MOOC as tentative tool for disseminating knowledge and contribute to education of southern engineers. This MOOC “Rivers and Men” is thus an example of collaborative work. The paper gives some facts about the building process and the success of the course. Some reflections are proposed about the target and the actual audience and some preliminary conclusions are drawn about advantages and limitations of such collaborative approach
A case of hemorrhage at the junctions of the posterior intercostal arteries-a vital sign?
The authors present the case of a 58-year-old man found hanging from a radiator by his shoelaces. The time of death was approximately 6Â h before the body was discovered. An autopsy was performed approximately 24Â h after the body was found, which revealed hemorrhages in the thoracic aorta at the junctions of the posterior intercostal arteries. Before autopsy, a routine whole-body CT scan was performed. Histologic examination of the aorta and the posterior intercostal arteries revealed a fresh hemorrhage into the tunica adventitia of the aorta. To our knowledge, there is no case description of such findings in hanged persons in the literature. Conclusion: Hemorrhages into the tunica adventitia of the junction of the posterior costal arteries may occur in association with suicidal hanging. The significance of these hemorrhages as a sign of vitality may be debated
Human and livestock faecal biomarkers at the prehistorical encampment site of Ullafelsen in the Fotsch Valley, Stubai Alps, Austria – potential and limitations
The Ullafelsen at 1869 m above sea level (a.s.l.) in the Tyrolean Stubai Alps next to Innsbruck is an important (geo)archeological reference site for the Mesolithic period. Buried fireplaces on the Ullafelsen plateau were dated at 10.9 to 9.5 ka cal BP and demonstrate together with thousands of flint stone artifacts the presence of hunter-gatherers during the Early Holocene. Grazing livestock has been a predominant anthropozoological impact in the Fotsch Valley presumably since the Bronze Age (4.2–2.8 ka). In order to study the human and/or livestock faeces input on the Ullafelsen, we carried out steroid analyses on 2 modern ruminant faeces samples from cattle and sheep, 37 soil samples from seven archeological soil profiles, and 9 soil samples from five non-archeological soil profiles from the Fotsch Valley used as reference sites. The dominance of 5β-stigmastanol and deoxycholic acid in modern cattle and sheep faeces can be used as markers for the input of ruminant faeces in soils. The OAh horizons, which have accumulated and developed since the Mesolithic, revealed high contents of steroids (sterols, stanols, stanones and bile acids); the eluvial light layer (E (LL)) horizon coinciding with the Mesolithic living floor is characterized by medium contents of steroids. By contrast, the subsoil horizons Bh, Bs and BvCv contain low contents of faecal biomarkers, indicating that leaching of steroids into the podsolic subsoils is not an important factor. High content of 5β-stigmastanol and deoxycholic acid in all soil samples gives evidence for faeces input of ruminants. The steroid patterns and ratios indicate a negligible input of human faeces on the Ullafelsen. In conclusion, our results reflect a strong faeces input by livestock, rather than by humans as found for other Anthrosols such as Amazonian dark earths. Further studies need to focus on the question of the exact timing of faeces deposition
Diagnostic accuracy of coronary artery stenosis and thrombosis assessment using unenhanced multiplanar 3D post-mortem cardiac magnetic resonance imaging.
BACKGROUND
A 3D sequence was introduced to unenhanced post-mortem cardiac magnetic resonance imaging (PMCMR) to enable multiplanar coronary artery image analysis and to investigate its diagnostic accuracy for the diagnosis of coronary artery stenosis and thrombosis.
MATERIALS AND METHODS
NÂ =Â 200 forensic cases with suspected coronary artery pathology underwent 3 Tesla PMCMR (sequence used: T2 weighted transversal 3D turbo spin echo) before autopsy. Main coronary artery stenosis and thrombosis were assessed in PMCMR by multiplanar image analysis by two observers. Coronary artery histology was determined as the gold standard and compared to PMCMR. Sensitivity, specificity, negative (NPV) and positive predictive values (PPV) with 95% confidence intervals were calculated.
RESULTS
For all coronary arteries combined, sensitivity was 75% (PPV 73%) for the diagnosis of stenosis and 72% (PPV 71%) for the diagnosis of thrombosis. Specificity was 92% (NPV 90%) for correct diagnosis of non-existing stenosis and 97% (NPV 97%) for non-existing thrombosis. Sensitivity for correct diagnosis of different degrees of stenosis ranged between 67% and 80% (PPVs 67-82%); specificity ranged between 96% and 99% (NPVs 96-99%).
CONCLUSION
Multiplanar PMCMR coronary artery stenosis and thrombosis assessment based on an unenhanced T2 weighted 3D sequence provide moderate sensitivity and high specificity for the diagnosis of coronary artery stenosis and/or thrombosis. Hence, 3D T2w PMCMR cannot reliably detect existing coronary artery stenosis and thrombosis but may be particularly useful for the exclusion of stenosis or thrombosis of the main coronary arteries
Holocene landscape evolution, palaeoclimate and human impact in the Fotsch Valley, Stubai Alps, Austria: Interrogating biomarkers, stable isotopes, macrofossils and palynological indicators from a subalpine mire archive
Peatlands are receiving increasing attention in palaeoenvironmental research and represent very useful terrestrial archives for reconstructing vegetation, climate and human history. Previous palaeoenvironmental studies in the Fotsch Valley, Stubai Alps, Austria, focused on geoarchaeological investigations on the Ullafelsen representing a very important prehistorical encampment site used by Mesolithic hunter-gatherers (10.9–9.5 cal. kyr BP). In order to contribute to a better understanding of the landscape evolution of the Fotsch Valley, we here studied the close-by subalpine ‘Potsdamer Hütte Mire’ by applying radiocarbon dating as well as elemental, biomarker, compound-specific stable isotope, palynological and macrofossil analyses on bulk peat samples. The calculated age-depth model using R Bacon indicates the beginning of peat formation during the Early Holocene and shows a strongly reduced peat accumulation rate (PAR) from 170 to 121 cm depth (8.5–2.1 cal. kyr BP) and/or a striking hiatus. Results of leaf wax-derived n-alkane biomarkers as well as macrofossils and palynological indicators reflect the local presence of coniferous trees and the synchronous expansion of deciduous trees during the Early Holocene. The above-mentioned strongly reduced PAR and/or hiatus coincides with the Neolithic, the Bronze and the Iron Age, and goes hand in hand with strong changes in vegetation and an increase of micro-charcoal and black carbon. Despite age uncertainties, these changes can be explained with strongly increasing human and livestock activities in form of deforestation, domestic fires and the beginning of Alpine pastoralism. The latter is confirmed by the finding of pasture and cultural indicator pollen (Cerealia-type, Rumex, Plantago lanceolata, Poaceae) occurring since the Middle to Late Bronze Age. The oxygen isotope composition of sugar biomarkers (δ18Osugars) likely reflects the dry versus humid climatic variability associated with the Holocene climatic optimum during the Mesolithic, the Roman Age, the Late Antique Little Ice Age, the Middle Ages and the Little Ice Age
A Hubble Space Telescope Study of Lyman Limit Systems: Census and Evolution
We present a survey for optically thick Lyman limit absorbers at z<2.6 using
archival Hubble Space Telescope observations with the Faint Object Spectrograph
and Space Telescope Imaging Spectrograph. We identify 206 Lyman limit systems
(LLSs) increasing the number of catalogued LLSs at z<2.6 by a factor of ~10. We
compile a statistical sample of 50 tau_LLS > 2 LLSs drawn from 249 QSO sight
lines that avoid known targeting biases. The incidence of such LLSs per unit
redshift, l(z)=dn/dz, at these redshifts is well described by a single power
law, l(z) = C1 (1+z)^gamma, with gamma=1.33 +/- 0.61 at z<2.6, or with
gamma=1.83 +/- 0.21 over the redshift range 0.2 < z < 4.9. The incidence of
LLSs per absorption distance, l(X), decreases by a factor of ~1.5 over the ~0.6
Gyr from z=4.9 to 3.5; l(X) evolves much more slowly at low redshifts,
decreasing by a similar factor over the ~8 Gyr from z=2.6 to 0.25. We show that
the column density distribution function, f(N(HI)), at low redshift is not well
fitted by a single power law index (f(N(HI)) = C2 N(HI)^(-beta)) over the
column density range 13 17.2. While low and high
redshift f(N(HI)) distributions are consistent for log N(HI)>19.0, there is
some evidence that f(N(HI)) evolves with z for log N(HI) < 17.7, possibly due
to the evolution of the UV background and galactic feedback. Assuming LLSs are
associated with individual galaxies, we show that the physical cross section of
the optically thick envelopes of galaxies decreased by a factor of ~9 from z~5
to 2 and has remained relatively constant since that time. We argue that a
significant fraction of the observed population of LLSs arises in the
circumgalactic gas of sub-L* galaxies.Comment: Accepted by Ap
Effects of the Czech Propolis on Sperm Mitochondrial Function
Propolis is a natural product that honeybees collect from various plants. It is known for its beneficial pharmacological effects. The aim of our study was to evaluate the impact of propolis on human sperm motility, mitochondrial respiratory activity, and membrane potential. Semen samples from 10 normozoospermic donors were processed according to the World Health Organization criteria. Propolis effects on the sperm motility and mitochondrial activity parameters were tested in the fresh ejaculate and purified spermatozoa. Propolis preserved progressive motility of spermatozoa in the native semen samples. Oxygen consumption determined in purified permeabilized spermatozoa by high-resolution respirometry in the presence of adenosine diphosphate and substrates of complex I and complex II (state OXPHOS I+II ) was significantly increased in the propolis-treated samples. Propolis also increased uncoupled respiration in the presence of rotenone (state ETS II ) and complex IV activity, but it did not influence state LEAK induced by oligomycin. Mitochondrial membrane potential was not affected by propolis. This study demonstrates that propolis maintains sperm motility in the native ejaculates and increases activities of mitochondrial respiratory complexes II and IV without affecting mitochondrial membrane potential. The data suggest that propolis improves the total mitochondrial respiratory efficiency in the human spermatozoa in vitro thereby having potential to improve sperm motility
Effects of the Czech Propolis on Sperm Mitochondrial Function
Propolis is a natural product that honeybees collect from various plants. It is known for its beneficial pharmacological effects. The aim of our study was to evaluate the impact of propolis on human sperm motility, mitochondrial respiratory activity, and membrane potential. Semen samples from 10 normozoospermic donors were processed according to the World Health Organization criteria. Propolis effects on the sperm motility and mitochondrial activity parameters were tested in the fresh ejaculate and purified spermatozoa. Propolis preserved progressive motility of spermatozoa in the native semen samples. Oxygen consumption determined in purified permeabilized spermatozoa by high-resolution respirometry in the presence of adenosine diphosphate and substrates of complex I and complex II (state OXPHOSI+II) was significantly increased in the propolis-treated samples. Propolis also increased uncoupled respiration in the presence of rotenone (state ETSII) and complex IV activity, but it did not influence state LEAK induced by oligomycin. Mitochondrial membrane potential was not affected by propolis. This study demonstrates that propolis maintains sperm motility in the native ejaculates and increases activities of mitochondrial respiratory complexes II and IV without affecting mitochondrial membrane potential. The data suggest that propolis improves the total mitochondrial respiratory efficiency in the human spermatozoa in vitro thereby having potential to improve sperm motility
The High Velocity Gas toward Messier 5: Tracing Feedback Flows in the Inner Galaxy
We present Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope
Imaging Spectrograph (STIS E140M) observations of the post-asymptotic giant
branch star ZNG 1 in the globular cluster Messier 5 (l=3.9, b=+47.7; d=7.5 kpc,
z=+5.3 kpc). High velocity absorption is seen in C IV, Si IV, O VI, and lower
ionization species at LSR velocities of -140 and -110 km/s. We conclude that
this gas is not circumstellar on the basis of photoionization models and path
length arguments. Thus, the high velocity gas along the ZNG 1 sight line is the
first evidence that highly-ionized HVCs can be found near the Galactic disk. We
measure the metallicity of these HVCs to be [O/H]=+0.22\pm0.10, the highest of
any known HVC. Given the clouds' metallicity and distance constraints, we
conclude that these HVCs have a Galactic origin. This sight line probes gas
toward the inner Galaxy, and we discuss the possibility that these HVCs may be
related to a Galactic nuclear wind or Galactic fountain circulation in the
inner regions of the Milky Way.Comment: 23 pages, 11 figures, 7 table
Diagnosis of pulmonary infarction in post-mortem computed tomography and post-mortem magnetic resonance imaging-a technical note.
Pulmonary thromboembolism may be accompanied by pulmonary infarction. Even though pulmonary thromboembolism (PTE) is a frequently found cause of death at autopsy, pulmonary infarction accompanying PTE is a less common finding and may therefore easily be misinterpreted as infectious or cancerous lung disease. Appearance of pulmonary infarction in post-mortem imaging and acquisition parameters helping to identify pulmonary infarctions are not described yet. Based on a case of a 50-year-old man who died due to PTE and presented pulmonary infarction, we suggest using a pulmonary algorithm in post-mortem computed tomography combined with post-mortem magnetic resonance imaging of the lungs using conventional T1- and T2-weighted sequences
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