Processing Artifacts Research Articles

Colesevelam and colestipol: novel medication resins in the gastrointestinal tract.

We report the morphologic description of the bile acid sequestrants (BAS) colesevelam and colestipol, as well as the largest series of cholestyramine. Histologically similar medication resins from 4 institutions were prospectively collected over 1 year (26 specimens, 15 patients). Comorbidities included hyperlipidemia (4/15), hypertension (4/15), inflammatory bowel disease (4/15), coronary artery disease (3/15), diarrhea (7/15), hypothyroidism (2/15), and ischemic bowel (1/15). Sites of involvement included the esophagus (1/26), stomach (1/26), small intestine (1/26), ileocecal valve (1/26), and colorectum (22/26). Associated histologic diagnoses included normal (8/26), chronic mucosal injury (11/26), acute inflammation (9/26), erosion/ulceration (6/26), and cytomegalovirus (2/26). The BAS resins were histologically indistinguishable from each other; they were all eosinophilic on hematoxylin and eosin (H&E) and lacked internal "fish-scales." To validate these observations, respective medications were submitted for histologic processing; the processed medications were identical to those in the patient specimens. Rare, irregular "fracture" lines presented diagnostic pitfalls by mimicking the true "fish-scales" of Kayexalate and sevelamer. Clues to the correct identification of BAS include recognition that the "fracture" lines were subtle, irregular, and restricted to large fragments or thick sections, likely representing a processing artifact. Moreover, Kayexalate is violet on H&E and black on acid fast bacillus, and sevelamer characteristically displays a 2-tone color on H&E and is magenta on acid fast bacillus. An association with inflammatory injury was seen (15/26). We believe that the BAS are innocent bystanders in complicated patients, although we cannot exclude their ability to cause mucosal injury in specific settings.

Non-linear dynamical analysis of the Blazhko effect with the Kepler space telescope: the case of V783 Cyg

We present a detailed nonlinear dynamical investigation of the Blazhko modulation of the Kepler RR Lyrae star V783 Cyg (KIC 5559631). We used different techniques to produce modulation curves, including the determination of amplitude maxima, the O-C diagram and the analytical function method. We were able to fit the modulation curves with chaotic signals with the global flow reconstruction method. However, when we investigated the effects of instrumental and data processing artefacts, we found that the chaotic nature of the modulation can not be proved because of the technical problems of data stitching, detrending and sparse sampling. Moreover, we found that a considerable part of the detected cycle-to-cycle variation of the modulation may originate from these effects. According to our results, even the four-year-long, unprecedented Kepler space photometry of V783 Cyg is too short for a reliable nonlinear dynamical analysis aiming at the detection of chaos from the Blazhko modulation. We estimate that two other stars could be suitable for similar analysis in the Kepler sample and in the future TESS and PLATO may provide additional candidates.

Dosimetric effects of residual uncertainties in carbon ion treatment of head chordoma

PurposeTo investigate dose distribution variations due to setup errors and range uncertainties in image-guided carbon ion radiotherapy of head chordoma. Materials and methodsTen treatment plans were retrospectively tested with TRiP98 against ±1.0mm and ±1.0° setup errors, as observed in clinical routine, and 2.6% range uncertainty when 2mm CTV-to-PTV margins were applied. Single-fraction simulations were compared with the total treatment dose in terms of DVH bands, conformity and inhomogeneity. The contribution of image processing artifacts on reported results was also discussed, as a function of the imaging dataset resolution. ResultsResults showed that safety margins grant the conformal target coverage in presence of setup errors with D95CTV variations below 10% in 7 patients out of 10. Instead, the inclusion of range uncertainty yielded to appreciable dose degradation, reporting larger effects for CTV and dose conformity, whereas reduced impact is found on the organ-at-risk. The fractionation scheme positively affects dose conformity and inhomogeneity; conversely its influence on DVH bands is strongly related to the patient anatomy. ConclusionBesides safety margins, setup and range uncertainties lead to non-negligible combined contribution. Systematical treatment plan robustness assessment against expected uncertainties is thus encouraged, selecting beam settings and fractionation schemes where homogeneity is preserved.

Optical coherence tomography--high-resolution tissue imaging, but not histology!

Optical coherence tomography (OCT) is a non-invasive and fast method for retinal in vivo imaging. It was introduced in 1991 and became commercially available in 1996. With higher resolution spectral domain OCT (SD-OCT), all histological retinal layers can be identified with an axial resolution of 1-5 µm today. Numerous papers have correlated OCT and histological images of physiological retina from different species. Reliable attribution of the reflective bands in OCT images to histological layers has been facilitated even for those layers that are displayed differently in OCT and histology, particularly in the outer retina. In contrast, the correlation of OCT and histology of pathologically altered human retina has only rarely been described due to very limited histological availability. The studies that presented such a correlation on animal material were able to identify some artifacts of histological processing. They also showed that OCT reflectivity changes do not necessarily correlate with cell density in the retina, such that a retinal scar, which is rich in fibres, may appear isoreflective to surrounding healthy retina. This issue, however, has mostly been neglected. Morphometric analyses revealed significantly larger diameters in OCT images compared to histology of photocoagulation lesions. Obviously, OCT reflectivity changes indicate a different tissue condition than altered HE-staining properties in histology. While coarse retinal structure alterations may be located and followed very well with OCT, it is almost impossible to derive from an OCT image the histological change that causes the alteration on a cellular level. This leads to frequent misinterpretations of OCT images. This article aims to pinpoint the pitfalls of OCT interpretation with examples from the current literature, and it encourages the reader to be attentive and critical when interpreting OCT images.

Wolbachia Multilocus Sequence Typing of Singly Infected and Multiply Infected Populations of Northern Corn Rootworm (Coleoptera: Chrysomelidae)

Abstract The northern corn rootworm (Diabrotica barberi Smith & Lawrence) in eastern and central North America exhibits at least three distinct populations with respect to Wolbachia infection: uninfected; singly infected; multiply infected. The infected states are associated with different mtDNA haplotypes and reduced mtDNA variability. Multilocus sequence typing (MLST) was used to define strain types and examine the diversity of Wolbachia infecting northern corn rootworm. Four of the five MLST genes (coxA, hcpA, fbpA, and ftsZ) were represented by three alleles each. The remaining MLST gene (gatB) had four to six alleles. The uncertainty arose from whether to call two small clusters new alleles or artifacts of the amplification process. Singly infected individuals had a common set of alleles that defined one strain (wBarB). This strain was also a component of the multiple infections. A second strain (wBarA), restricted to the multiple infections, was defined by alleles that appeared with substantially greater frequency for each of the five loci. By default a third strain would comprise the less frequent third allele of the four loci, but it is not possible to determine to which gatB allele they are linked. Therefore, the strain is not fully defined. The diversity of gatB indicates that four to six Wolbachia strains are present in northern corn rootworm, a number that is similar to the five variants reported previously for the wsp gene. These results also highlight the very real difficulty of using the MLST system to define specific strains in a multiply infected host.

Seasonal variation in the deformation rate in NW Himalayan region

We report GPS measurements of continuous observations from the multi- parametric geophysical observatory (MPGO) at Ghuttu, Garhwal Lesser Himalaya. Other than the evidence of secular motion depicting strain accumulation due to locking of the underneath seismically active detachment, measurements at Ghuttu show annual variation of ±4 mm on horizontal component. Such variations are more prominent in the north coordinate and do not directly correlate with the meteorological parameters such as variations in rainfall, water table, and atmospheric pressure measured at the MPGO observatory. These variations are also not the artefact of data processing and network. They correlate with the water load storage in the Ganga plains, with minimum in dis- placement coinciding with the maximum storage of water in Ganga plains immediately after the monsoon and vice versa. Such variations also appear to cause annual variation in the low-magnitude earthquake frequency in the Himalayan region, being relatively more in the winter period.

Structure and Activity of a New Low-Molecular-Weight Heparin Produced by Enzymatic Ultrafiltration

The standard process for preparing the low-molecular-weight heparin (LMWH) tinzaparin, through the partial enzymatic depolymerization of heparin, results in a reduced yield because of the formation of a high content of undesired disaccharides and tetrasaccharides. An enzymatic ultrafiltration reactor for LMWH preparation was developed to overcome this problem. The behavior, of the heparin oligosaccharides and polysaccharides using various membranes and conditions, was investigated to optimize this reactor. A novel product, LMWH-II, was produced from the controlled depolymerization of heparin using heparin lyase II in this optimized ultrafiltration reactor. Enzymatic ultrafiltration provides easy control and high yields (>80%) of LMWH-II. The molecular weight properties of LMWH-II were similar to other commercial LMWHs. The structure of LMWH-II closely matched heparin's core structural features. Most of the common process artifacts, present in many commercial LWMHs, were eliminated as demonstrated by 1D and 2D nuclear magnetic resonance spectroscopy. The antithrombin III and platelet factor-4 binding affinity of LMWH-II were comparable to commercial LMWHs, as was its in vitro anticoagulant activity.

A Methodology for Exposing Risk in Achieving Emergent System Properties

Determining whether systems achieve desired emergent properties, such as safety or reliability, requires an analysis of the system as a whole, often in later development stages when changes are difficult and costly to implement. In this article we propose the Process Risk Indicator (PRI) methodology for analyzing and evaluating emergent properties early in the development cycle. A fundamental assumption of system engineering is that risk mitigation processes reduce system risks, yet these processes may also be a source of risk: (1) processes may not be appropriate for achieving the desired emergent property; or (2) processes may not be followed appropriately. PRI analyzes development process artifacts (e.g., designs pertaining to reliability or safety analysis reports) to quantify process risks that may lead to higher system risk. We applied PRI to the hazard analysis processes of a network-centric, Department of Defense system-of-systems and two NASA spaceflight projects to assess the risk of not achieving one such emergent property, software safety, during the early stages of the development lifecycle. The PRI methodology was used to create measurement baselines for process indicators of software safety risk, to identify risks in the hazard analysis process, and to provide feedback to projects for reducing these risks.

Analysis, optimization and verification of Illumina-generated 16S rRNA gene amplicon surveys.

The exploration of microbial communities by sequencing 16S rRNA genes has expanded with low-cost, high-throughput sequencing instruments. Illumina-based 16S rRNA gene sequencing has recently gained popularity over 454 pyrosequencing due to its lower costs, higher accuracy and greater throughput. Although recent reports suggest that Illumina and 454 pyrosequencing provide similar beta diversity measures, it remains to be demonstrated that pre-existing 454 pyrosequencing workflows can transfer directly from 454 to Illumina MiSeq sequencing by simply changing the sequencing adapters of the primers. In this study, we modified 454 pyrosequencing primers targeting the V4-V5 hyper-variable regions of the 16S rRNA gene to be compatible with Illumina sequencers. Microbial communities from cows, humans, leeches, mice, sewage, and termites and a mock community were analyzed by 454 and MiSeq sequencing of the V4-V5 region and MiSeq sequencing of the V4 region. Our analysis revealed that reference-based OTU clustering alone introduced biases compared to de novo clustering, preventing certain taxa from being observed in some samples. Based on this we devised and recommend an analysis pipeline that includes read merging, contaminant filtering, and reference-based clustering followed by de novo OTU clustering, which produces diversity measures consistent with de novo OTU clustering analysis. Low levels of dataset contamination with Illumina sequencing were discovered that could affect analyses that require highly sensitive approaches. While moving to Illumina-based sequencing platforms promises to provide deeper insights into the breadth and function of microbial diversity, our results show that care must be taken to ensure that sequencing and processing artifacts do not obscure true microbial diversity.

Enhanced sound absorption of aluminum foam by the diffuse addition of elastomeric rubbers

The sound absorption properties of open cell aluminum foams are understood to be significant (Ashby et al. Metal Foams: A Design Guide, 2000) with theoretical models presented in the literature [J. Acoust. Soc. Am. 108, 1697–1709 (2000)]. The pores that exist in metal foams, as artifacts of the manufacturing process, are left unfilled in the vast majority of cases. Work done by the US Navy (US patent 5895726 A) involved filling the voids with phthalonitrile prepolymer, resulting in a marked increase in sound absorption and vibration damping. The work presented here involves adding small amounts of elastomeric rubbers to the metal foam, thereby coating the ligaments of the foam with a thin layer of rubber. The goal is to achieve an increase in sound absorption without the addition of cost and weight. The work involves testing aluminum foam samples of various thicknesses and pore sizes in an impedance tube, with and without the added rubber. A design of experiment model was employed to gauge the effect of the various manufacturing parameters on the sound absorption and to set the stage for a physics-based predictive model.

On the verification of UML/OCL class diagrams using constraint programming

Assessment of the correctness of software models is a key issue to ensure the quality of the final application. To this end, this paper presents an automatic method for the verification of UML class diagrams extended with OCL constraints. Our method checks compliance of the diagram with respect to several correctness properties including weak and strong satisfiability or absence of constraint redundancies among others. The method works by translating the UML/OCL model into a Constraint Satisfaction Problem (CSP) that is evaluated using state-of-the-art constraint solvers to determine the correctness of the initial model. Our approach is particularly relevant to current MDA and MDD methods where software models are the primary artifacts of the development process and the basis for the (semi-)automatic code-generation of the final application.

Identification of Esophagitis Dissecans Superficialis by Endoscopy

An 88-year-old woman with multiple medical issues including atrial fibrillation, left ventricular systolic dysfunction, chronic congestive heart failure, mitral regurgitation, cardiac arrest, syncope, hypertension, and severe diverticulosis was referred to endoscopy for melena. At endoscopy, white, linear, desquamating plaques were identified in the distal esophagus (Figure A). The oral mucosa was normal, and the only other finding was mild gastric mucosal erythema. There was no history of cutaneous bullous disorders. Medications included allopurinol, amlodipine, furosemide, lisinopril, metoprolol, rivaroxaban, tramadol, and acetaminophen. Distal esophageal biopsies revealed a “two-toned” appearance in intact squamous mucosa fragments (Figure B). The basal layer remained basophilic, whereas the superficial layer was markedly eosinophilic with crowded, pyknotic nuclei, with pockets of edema separating the morphologically distinct areas. In other foci the superficial layer, marked by extensive parakeratosis, was sloughed from the basal layer, correlating to the desquamating plaques identified at endoscopy (Figure C). These endoscopic and histologic features are those of esophagitis dissecans superficialis (EDS) (aka sloughing esophagitis). This is a rare benign condition in which vertical strips of sloughing squamous mucosa create the endoscopic appearance described as “gift-wrap ribbons.” Cases of patients coughing up or vomiting the sloughed mucosa have been reported. Presenting symptoms include dysphagia, odynophagia, and heartburn, although many patients are asymptomatic and undergo endoscopy for unrelated reasons. Although no one specific etiology has been identified, a recent study found that patients with EDS were older and were more likely to be chronically debilitated, to have died since biopsy, and to be taking 5 or more medications when compared with the control population. They were more likely to have hypertension and heart conditions such as valvular disease, arrhythmia, and congestive heart failure. Furthermore, central nervous system suppressants and medications associated with esophageal injury (iron, Kcl, aspirin) were specifically found to be associated with EDS. Cutaneous bullous disorders, particularly pemphigus vulgaris (PV), can cause features identical to EDS. Esophageal involvement in PV may be more prevalent than previously recognized. Absence of cutaneous or oral pharyngeal lesions and immunofluorescence can assist in ruling out PV. Diagnostic considerations to exclude include candidiasis, pill esophagitis, mucosal trauma (hot beverages, chemical irritants), celiac disease, processing artifact, and rigid endoscopy with esophageal dilation. No specific therapy is recommended for treating EDS, and the clinical course is driven by the patient’s underlying disease (possibly self-limited). There are no published data to guide follow-up. Our patient’s advanced age, polypharmacy, and debilitating chronic medical conditions fit well with EDS, although definitive cause remains unknown. Melena was attributed to rivaroxaban, which resolved after discontinuation. Omeprazole was prescribed for gastritis

Comparison of Life-Stage-Dependent Internal Dosimetry for Bisphenol A, Ethinyl Estradiol, a Reference Estrogen, and Endogenous Estradiol to Test an Estrogenic Mode of Action in Sprague Dawley Rats

Bisphenol A (BPA) was administered by gavage (2.5-300,000 μg/kg body weight (bw)/day) to pregnant Sprague Dawley dams, newborn pups, and continuing into adulthood. Aglycone (i.e., unconjugated and active) and conjugated (i.e., inactive) BPA were evaluated by liquid chromatography electrospray tandem mass spectrometry (LC-ES/MS/MS) in serum to better interpret toxicological endpoints measured in the study. Ethinyl estradiol (EE2, 0.5 and 5 μg/kg bw/day) and the endogenous hormones, 17β-estradiol (E2) and testosterone, were similarly evaluated. Mean BPA aglycone levels in vehicle and naïve control rat serum (0.02-0.5 ng/ml) indicated sample processing artifact, consistent with literature reports of a propensity for postexposure blood contamination by BPA. Direct measurements of BPA-glucuronide in vehicle and naïve control serum (2-10nM) indicated unintentional exposure and metabolism at levels similar to those produced by 2.5 μg/kg bw/day BPA (7-10nM), despite careful attention to potential BPA inputs (diet, drinking water, vehicle, cages, bedding, and dust) and rigorous dosing solution certification and delivery. The source of this exposure could not be identified, but interpretation of the toxicological effects, observed only at the highest BPA doses, was not compromised. Internal exposures to BPA and EE2 aglycones were highest in young rats. When maximal serum concentrations from the two highest BPA doses and both EE2 doses were compared with concurrent levels of endogenous E2, the ERα binding equivalents were similar to or above those of endogenous E2 in male and female rats of all ages tested. Such evaluations of estrogenic internal dosimetry and comprehensive evaluation of contamination impact should aid in extrapolating risks from human BPA exposures.

Acoustic nonlinear full-waveform inversion on an outcrop-based detailed geological and petrophysical model (Book Cliffs, Utah)

Analog outcrops are commonly used to develop predictive reservoir models and provide quantitative parameters that describe the architecture and facies distribution of sedimentary deposits at a subseismic scale, all of which aids exploration and production strategies. The focus of this study is to create a detailed geological model that contains realistic reservoir parameters and to apply nonlinear acoustic full-waveform prestack seismic inversion to this model to investigate whether this information can be recovered and to examine which geological features can be resolved by this process.Outcrop data from the fluviodeltaic sequence of the Book Cliffs (Utah) are used for the geological and petrophysical two-dimensional model. Eight depositional environments are populated with average petrophysical reservoir properties adopted from a North Sea field. These units are termed lithotypes here. Synthetic acoustic prestack seismic data are then generated with the help of an algorithm that includes all internal multiples and transmission effects. A nonlinear acoustic full-waveform inversion is then applied to the synthetic data, and two media parameters, compressibility (inversely related to the square of the compressional wave velocity vP) and bulk density, ρ, are recovered at a resolution higher than the shortest wavelength in the data. This is possible because the inversion exploits the nonlinear nature of the relationship between the recorded data and the medium contrast properties. In conventional linear inversion, these details remain masked by the noise caused by the nonlinear effects in the data. Random noise added to the data is rejected by the nonlinear inversion, contributing to improved spatial resolution. The results show that the eight lithotypes can be successfully recovered at a subseismic scale and with a low degree of processing artifacts. This technique can provide a useful basis for more accurate reservoir modeling and field development planning, allowing targeting of smaller reservoir units such as distributary channels and lower shoreface sands.

Business process artefact adaptability approach based on artificial immune systems

Changes in business conditions have forced enterprises to continuously be dynamic and flexible. Recent research has focused on developing adaptive business process management systems. However, those approaches do not take in consideration the business process context execution. On the other hand, modularity concern is a common strategy to a lower application complexity: it results in modules that are easy to maintain, to adapt, and to replace. In this work, each activity of a business process is encapsulated in an entity named artefact. These artefacts have an interface, a function and manual instruction described with very expressive formal languages that manage high level concepts. This study aims to apply artificial immune systems AIS to business process applications making their business process artefacts capable to be adaptive to changes that their environments are faced. We explore how in some ways, stimulus or change in business process execution environment can be considered as an antigen and the business process fragment artefact considered as antibody react to this stimulus.

A Critical Review of the Classic Metaphyseal Lesion: Traumatic or Metabolic?

The purpose of this study was to review the hypothesis that classic metaphyseal lesions represent traumatic changes in abused infants and compare these lesions with healing rickets. Using a PubMed search, a multidisciplinary team reviewed studies that reported the histopathologic correlation of classic metaphyseal lesions. Selective studies of growth plate injury and rickets were cross-referenced. Nine identified classic metaphyseal lesion studies were performed by the same principal investigator. Control subjects were inadequate. Details of abuse determination and metabolic bone disease exclusion were lacking. The presence of only a single radiology reviewer prevented establishment of interobserver variability. Microscopy was performed by two researchers who were not pathologists. Classic metaphyseal lesions have not been experimentally reproduced and are unrecognized in the accidental trauma literature. The proposed primary spongiosa location is inconsistent with the variable radiographic appearances. Classic metaphyseal lesions were not differentiated from tissue processing artifacts. Bleeding and callus were uncommon in spite of the vascular nature of the metaphysis. The conclusion that excessive hypertrophic chondrocytes secondary to vascular disruption were indicative of fracture healing contradicts the paucity of bleeding, callus, and periosteal reaction. Several similarities exist between classic metaphyseal lesions and healing rickets, including excessive hypertrophic chondrocytes. "Bucket-handle" and "corner fracture" classic metaphyseal lesions resemble healing rickets within the growth plate and the perichondrial ring, respectively. The age of presentation was more typical of bone fragility disorders, including rickets, than reported in prior child abuse series. The hypothesis that classic metaphyseal lesions are secondary to child abuse is poorly supported. Their histologic and radiographic features are similar to healing infantile rickets. Until classic metaphyseal lesions are experimentally replicated and independently validated, their traumatic origin remains unsubstantiated.

7.0 Managing virological failure

7.0 Managing virological failure

In randomization we trust? There are overlooked problems in experimenting with people in behavioral intervention trials

ObjectivesBehavioral intervention trials may be susceptible to poorly understood forms of bias stemming from research participation. This article considers how assessment and other prerandomization research activities may introduce bias that is not fully prevented by randomization. Study Design and SettingThis is a hypothesis-generating discussion article. ResultsAn additivity assumption underlying conventional thinking in trial design and analysis is problematic in behavioral intervention trials. Postrandomization sources of bias are somewhat better known within the clinical epidemiological and trials literatures. Neglect of attention to possible research participation effects means that unintended participant behavior change stemming from artifacts of the research process has unknown potential to bias estimates of behavioral intervention effects. ConclusionStudies are needed to evaluate how research participation effects are introduced, and we make suggestions for how research in this area may be taken forward, including how these issues may be addressed in the design and conduct of trials. It is proposed that attention to possible research participation effects can improve the design of trials evaluating behavioral and other interventions and inform the interpretation of existing evidence.

THE PLATEAU DE BURE + 30 m ARCSECOND WHIRLPOOL SURVEY REVEALS A THICK DISK OF DIFFUSE MOLECULAR GAS IN THE M51 GALAXY

We present the data of the Plateau de Bure Arcsecond Whirlpool Survey (PAWS), a high spatial and spectral resolution 12CO(1-0) line survey of the inner 10 x 6 kpc of the M51 system, and the first wide-field imaging of molecular gas in a star-forming spiral galaxy with resolution matched to the typical size of Giant Molecular Clouds (40 pc). We describe the observation, reduction, and combination of the Plateau de Bure Interferometer (PdBI) and IRAM-30m "short spacing" data. The final data cube attains 1.1"-resolution over the 270" x 170" field of view, with sensitivity to all spatial scales from the combination of PdBI and IRAM-30m data, and brightness sensitivity of 0.4 K (1 sigma) in each 5 km/s-wide channel map. We find a CO-luminosity of 9.10^8 K km/s pc^2, corresponding to a molecular gas mass of 4.10^9 Msol for a standard CO-to-H2 conversion factor. Unexpectedly, we find that a large fraction, (50 +/- 10)%, of this emission arises mostly from spatial scales larger than 36" or about 1.3 kpc. Through a series of tests, we demonstrate that this extended emission does not result from a processing artifact. We discuss its origin in light of the stellar component, the 12CO/13CO ratio, and the difference between the kinematics and structure of the PdBI-only and hybrid synthesis (PdBI + IRAM-30m) images. The extended emission is consistent with a thick, diffuse disk of molecular gas with a typical scale height of about 200 pc, substructured in unresolved filaments which fills about 0.1% of the volume.

Geochemistry and nano-mineralogy of two medium-sulfur northeast Indian coals

The petrology, mineralogy, and inorganic geochemistry of two contrasting high-sulfur, vitrinite-rich subbituminous to bituminous coals from the North Eastern Region (NER) of India have been studied using a combination of optical microscopy, quantitative X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM/SAED), and chemical analysis techniques. The study reveals that the Fe nano-particles are present in Indian high-sulfur Tertiary coals including nano-pyrite, Fe-oxyhydroxides and a small amount of sphalerite. The pyrite is present as framboids and unsymmetrical cubic crystals (rhombohedral). They contain potentially hazardous elements viz. As, Pb, and Se measured by EDS techniques. Mineral-matter residues isolated from the coals by low-temperature oxygen-plasma ashing are dominated by carbonate minerals (calcite, dolomite, ankerite), pyrite and pyrite oxidation products (jarosite and coquimbite), kaolinite, illite, and quartz. Sulfate-bearing phases such as tschermigite, bassanite and gypsum are also present, probably as artifacts of the plasma-ashing process.