scholarly journals Investigating Possible Gastroliths in a Referred Specimen of Bohaiornis guoi (Aves: Enantiornithes)

2021 ◽  
Vol 9 ◽  
Author(s):  
Shumin Liu ◽  
Zhiheng Li ◽  
Alida M. Bailleul ◽  
Min Wang ◽  
Jingmai O’Connor
Keyword(s):  
Digestive System ◽  
Multidisciplinary Approach ◽  
Direct Evidence ◽  
Soft Tissues ◽  
Indirect Evidence ◽  
Stomach Contents ◽  
Gastric Mill ◽  
Limited Evidence ◽  
X Ray ◽  
Two Samples

Gastroliths, where preserved, can provide indirect evidence regarding diet in extinct avian and non-avian dinosaurs. Masses of gastroliths consistent with the presence of a gastric mill are preserved in many Early Cretaceous Jehol birds mostly belonging to the Ornithuromorpha. Gastroliths are also present in basal birds Sapeornis and Jeholornis in which herbivory is supported by direct evidence these taxa consumed seeds in the form of crop or stomach contents. Although gastroliths have been correlated with herbivory in non-avian dinosaurs, the presence of gastroliths and bone together in Ambopteryx calls this association in to question. Despite being known from greater numbers of specimens than other avian lineages, no unequivocal direct or indirect evidence of diet has been recovered from Jehol deposits for the Enantiornithes. A referred specimen of Bohaiornis guoi IVPP V17963 was described as preserving a small number of gastroliths interpreted as rangle, gastroliths whose function is cleaning the stomach in extant raptorial birds. However, based on comparison with gastroliths in other Jehol birds, it has alternatively been suggested that the identified structures are not ingested stones at all but some unusual mineral precipitate. Considering the limited evidence regarding diet in Enantiornithes and the importance of accurately identifying the traces in Bohaiornis in order to understand the enantiornithine digestive system, we extracted two samples of these purported gastroliths and explored these traces using computerized laminography scanning, scanning electron microscopy, energy dispersive x-ray spectroscopy, ground sections, and body size to gastral mass regressions. Similar analyses were conducted on gastroliths extracted from undisputed gastral masses of two Jehol ornithuromorphs and the non-avian pennaraptoran Caudipteryx. The combined results contradict the hypothesis that these traces are gastroliths and supports the interpretation they are mineral precipitate, most likely authigenic quartz (chalcedony). Although authigenesis is commonly responsible for the preservation of soft tissues, it is unclear if these traces record part of the tissues of this Bohaiornis. This study highlights the importance of a multidisciplinary approach in understanding unusual traces in the fossil record and reveal a previously unidentified taphonomic phenomenon in fossils from Jehol deposits.

scholarly journals Structural Transformations and Their Precursors

1983 ◽  
Vol 36 (4) ◽  
pp. 553 ◽  
Author(s):  
TR Finlayson
Keyword(s):  
Thermal Expansion ◽  
Electron Diffraction ◽  
Physical Properties ◽  
Elastic Constants ◽  
Direct Evidence ◽  
Indirect Evidence ◽  
Structural Transformations ◽  
X Ray ◽  
Kinetics Of

For a number of materials which exhibit a change of structure on being cooled below a certain temperature Tm, some physical properties display anomalous behaviour at temperatures above Tm. The particular structural transformations in mind have been broadly classified as 'martensitic' and the anomalous physical properties as 'precursive phenomena'. Some debate exists regarding the role of the precursive phenomenon in the kinetics of the structural transformation. The most direct evidence for 'martensite precursors' is obtained from electron diffraction, although various indirect evidence is contained in X-ray, neutron and y-ray diffraction and various physical properties, for example, elastic constants and thermal expansion. In this paper current understanding of 'martensite precursors' is reviewed and examples of data from the A15 structure compounds V 3Si and Nb3Sn,. In-TI and TiNi alloys are discussed.

scholarly journals TUBERCULOUS MENINGITIS

2012 ◽  
Vol 19 (04) ◽  
pp. 449-454
Author(s):  
SAID AMIN ◽  
Muhammad USMAN ◽  
MUHAMMAD NOOR WAZIR
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Tuberculous Meningitis ◽  
Direct Evidence ◽  
Indirect Evidence ◽  
Mantoux Test ◽  
Meningeal Enhancement ◽  
X Ray ◽  
Computed Tomographic ◽  
Group 2 ◽  
Group 1

Objective: To evaluate the role of cerebrospinal fluid (CSF) polymerase chain reaction (PCR) for Mycobacterium Tuberculosis inrapid diagnosis of tuberculous meningitis (TBM). Study Design: Prospective observational study. Place and Duration of Study: Medical A unitHayat Abad Medical complex Peshawar from 1st September 2010 to 30th August 2011. Methodology: A total of 20 Patients having fever,constitutional symptoms (malaise, vague ill health, headache, vomiting), nuchal rigidity with altered mental and behavior changes weresuspected as TBM and hence included in the study. Patients were divided into two groups based on direct and indirect evidence of tuberculosisin central nervous system (CNS) of patients. Group1: Patients having direct evidence of mycobacterial infection in CNS as Acid Fast Bacillismear positive in CSF. Group 2: Patients with indirect evidence of TB in CNS in form of typical CSF findings of TBM, positive sputum smear forAcid fast bacilli (AFB) or computed tomographic (CT) Scan brain findings suggestive of TBM or evidence of TB in x-ray chest or family History oftuberculosis and/or history of contact with TB patients or positive Mantoux Test or evidence of TB elsewhere in the body. Results: Out of total 20patients, 3 (15%) belonged to Group 1 having direct evidence of TBM the remaining 17 (85%) patients belonged to Group 2. Female patientswere 60% while 40% patients were male. Mean age was 35.8 years. All patients had fever and headache. Productive cough was present in 40%patients. Thirty five percent had lost weight. Contact with TB patients was revealed in 35% patients. Signs of meningeal irritation were elicited in90% patients. Cranial nerve palsies were seen in 25% patients, 10% had hemiparesis while 35% had impairment of consciousness. X-ray chestwas normal in 65%.Computed tomographic scan was showing meningeal enhancement in 30% patients, hydrocephalus in 15% patients,meningeal enhancement plus hydrocephalus in 55% patients and infarct in 15% patients. Three patients were enrolled in group 1 and all hadPCR positive for mycobacterium tuberculosis. Of 17 patient in group 2, 64% patients had positive CSF PCR. Conclusions: Tuberculousmeningitis is an important serious extrapulmonary complication of TB, related with high mortality and morbidity. The prompt and accuratediagnosis of TBM is a daunting challenge. CSF PCR for Mycobacterium tuberculosis is an excellent test for rapid diagnosis of TBM.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

Electron holography of interfaces in electroceramics

1993 ◽  
Vol 51 ◽  
pp. 1088-1089
Author(s):  
Vinayak P. Dravid ◽  
V. Ravikumar ◽  
Richard Plass
Keyword(s):  
Space Charge ◽  
Direct Evidence ◽  
Materials Science ◽  
Theoretical Work ◽  
Electron Holography ◽  
Resolution Limit ◽  
Interference Phenomenon ◽  
X Ray ◽  
Electron Sources ◽  
Science Community

With the advent of coherent electron sources with cold field emission guns (cFEGs), it has become possible to utilize the coherent interference phenomenon and perform “practical” electron holography. Historically, holography was envisioned to extent the resolution limit by compensating coherent aberrations. Indeed such work has been done with reasonable success in a few laboratories around the world. However, it is the ability of electron holography to map electrical and magnetic fields which has caught considerable attention of materials science community.There has been considerable theoretical work on formation of space charge on surfaces and internal interfaces. In particular, formation and nature of space charge have important implications for the performance of numerous electroceramics which derive their useful properties from electrically active grain boundaries. Bonnell and coworkers, in their elegant STM experiments provided the direct evidence for GB space charge and its sign, while Chiang et al. used the indirect but powerful technique of x-ray microchemical profiling across GBs to infer the nature of space charge.

Nutrition as an important component of treatment and rehabilitation in cancer patients

2020 ◽  
pp. 15-22
Author(s):  
T.F. Tatarchuk ◽  
◽  
E.G. Manzhalii ◽  
D.V. Pominchuk ◽  
T.S. Shevchuk ◽  
...  
Keyword(s):  
Cancer Patients ◽  
High Frequency ◽  
Nutritional Support ◽  
Digestive System ◽  
Multidisciplinary Approach ◽  
Dietary Factors ◽  
Protective Activity ◽  
Macro And Micronutrients ◽  
Diet And Lifestyle ◽  
Cachexia Syndrome

The article deals with the importance of nutritional support for cancer patients. The high frequency of malnutrition and impaired absorption of macro and micronutrients in cancer patients and, which, at its maximum, is anorexia-cachexia syndrome, is the direct cause of the patient’s death. The progression of the tumor process is always accompanied by a violation of nutritional status, which is manifested in changes in weight, weakness, decreased physical activity, and disorders of the digestive system. It is estimated that about half of cancer-related deaths can be prevented, many of which are due to diet and lifestyle. Dietary factors can be involved in the initiation of tumor growth (carcinogens), promote growth, or have protective activity against the development of cancer. Therefore, nutritional support is one of the important components of a multidisciplinary approach in the treatment of cancer. Based on the analysis of the literature, the main tasks of nutritional support, indications, methods and criteria for the effectiveness of therapeutic nutrition are determined for the practitioner, a brief overview of the diets that are used by cancer patients is presented, and a list of anticarcinogenic products is compiled. Key words: anticarcinogenic products, diet, nutritional support, cancer patient, cancer prevention, nutrition.

scholarly journals Why heel spurs are traction spurs after all

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Johann Zwirner ◽  
Aqeeda Singh ◽  
Francesca Templer ◽  
Benjamin Ondruschka ◽  
Niels Hammer
Keyword(s):  
Achilles Tendon ◽  
Soft Tissues ◽  
Plantar Fascia ◽  
Trabecular Architecture ◽  
Pathological Findings ◽  
Traction Forces ◽  
X Ray ◽  
Developmental Mechanism ◽  
Common Features ◽  
Compressive Loads

AbstractIt is unclear whether plantar and posterior heel spurs are truly pathological findings and whether they are stimulated by traction or compression forces. Previous histological investigations focused on either one of the two spur locations, thereby potentially overlooking common features that refer to a uniform developmental mechanism. In this study, 19 feet from 16 cadavers were X-ray scanned to preselect calcanei with either plantar or posterior spurs. Subsequently, seven plantar and posterior spurs were histologically assessed. Five spur-free Achilles tendon and three plantar fascia entheses served as controls. Plantar spurs were located either intra- or supra-fascial whereas all Achilles spurs were intra-fascial. Both spur types consistently presented a trabecular architecture without a particular pattern, fibrocartilage at the tendinous entheses and the orientation of the spur tips was in line with the course of the attached soft tissues. Spurs of both entities revealed tapered areas close to their bases with bulky tips. Achilles and plantar heel spurs seem to be non-pathological calcaneal exostoses, which are likely results of traction forces. Both spur types revealed commonalities such as their trabecular architecture or the tip direction in relation to the attached soft tissues. Morphologically, heel spurs seem poorly adapted to compressive loads.

Two examples of quantitative analysis by simulated X-ray powder diffraction patterns

Clay Minerals ◽  
1982 ◽  
Vol 17 (4) ◽  
pp. 393-399
Author(s):  
C. E. Corbato ◽  
R. T. Tettenhorst
Keyword(s):  
Quantitative Analysis ◽  
Pattern Matching ◽  
Powder Diffraction ◽  
X Ray ◽  
Quantitative Estimates ◽  
Powder Diffractometer ◽  
Alternative Method ◽  
Two Samples ◽  
Natural Mixture ◽  
Diffraction Patterns

AbstractQuantitative estimates were made by visually matching computer-simulated with experimental X-ray powder diffractometer patterns for two samples. One was a natural mixture of dickite and nacrite in about equal proportions. The second sample contained mostly quartz with corundum and mullite in small (0.5–1%) amounts. Percentages deduced from pattern matching agreed to within ±10% of the weight fractions of the components determined by an alternative method of analysis.

scholarly journals Anisotropy of the galaxy cluster X-ray luminosity–temperature relation

2018 ◽  
Vol 611 ◽  
pp. A50 ◽  
Author(s):  
Konstantinos Migkas ◽  
Thomas H. Reiprich
Keyword(s):  
Galaxy Clusters ◽  
Statistical Significance ◽  
Cosmological Parameters ◽  
Galaxy Cluster ◽  
Luminosity Distance ◽  
Temperature Relation ◽  
X Ray ◽  
Two Samples ◽  
The Galaxy ◽  
Group A

We introduce a new test to study the cosmological principle with galaxy clusters. Galaxy clusters exhibit a tight correlation between the luminosity and temperature of the X-ray-emitting intracluster medium. While the luminosity measurement depends on cosmological parameters through the luminosity distance, the temperature determination is cosmology-independent. We exploit this property to test the isotropy of the luminosity distance over the full extragalactic sky, through the normalization a of the LX–T scaling relation and the cosmological parameters Ωm and H0. To this end, we use two almost independent galaxy cluster samples: the ASCA Cluster Catalog (ACC) and the XMM Cluster Survey (XCS-DR1). Interestingly enough, these two samples appear to have the same pattern for a with respect to the Galactic longitude. More specifically, we identify one sky region within l ~ (−15°, 90°) (Group A) that shares very different best-fit values for the normalization of the LX–T relation for both ACC and XCS-DR1 samples. We use the Bootstrap and Jackknife methods to assess the statistical significance of these results. We find the deviation of Group A, compared to the rest of the sky in terms of a, to be ~2.7σ for ACC and ~3.1σ for XCS-DR1. This tension is not significantly relieved after excluding possible outliers and is not attributed to different redshift (z), temperature (T), or distributions of observable uncertainties. Moreover, a redshift conversion to the cosmic microwave background (CMB) frame does not have an important impact on our results. Using also the HIFLUGCS sample, we show that a possible excess of cool-core clusters in this region, is not able to explain the obtained deviations. Furthermore, we tested for a dependence of the results on supercluster environment, where the fraction of disturbed clusters might be enhanced, possibly affecting the LX–T relation. We indeed find a trend in the XCS-DR1 sample for supercluster members to be underluminous compared to field clusters. However, the fraction of supercluster members is similar in the different sky regions, so this cannot explain the observed differences, either. Constraining Ωm and H0 via the redshift evolution of LX–T and the luminosity distance via the flux–luminosity conversion, we obtain approximately the same deviation amplitudes as for a. It is interesting that the general observed behavior of Ωm for the sky regions that coincide with the CMB dipole is similar to what was found with other cosmological probes such as supernovae Ia. The reason for this behavior remains to be identified.

Phase Formation in FeOx-SiO2-Cu2O-ZnO-FeS System during Melts Crystallization

2010 ◽  
Vol 297-301 ◽  
pp. 602-607
Author(s):  
Evgeny N. Selivanov ◽  
R.I. Gulyaeva ◽  
N.I. Selmenskich
Keyword(s):  
Cooling Rate ◽  
Phase Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Samples ◽  
And Calorimetry

The phase formation in oxide-sulphidic systems was studied with the use of X-ray diffraction, mineralography, combined thermogravimetry and calorimetry, in addition to Х-ray spectral microanalysis. The purpose of this work was to estimate the effect of cooling rate of melts in FeOx-SiO2-Cu2O-ZnO-FeS systems on structure and content of the resulting phases. Test subjects were two samples having following compositions (wt. %): I - 40.5 Fe, 2.41 S, 0.87 Cu, 3.87 Zn, 32.1 SiO2 and II - 40.7 Fe, 3.05 S, 8.55 Cu, 4.1 Zn and 19.5 SiO2. Cooling rate of the melts was changed from 0.3 up to 900оС/s.

Sign in / Sign up

Export Citation Format

Share Document