Miracle-dz/UniFAR-FTUs huggingface dataset:
Elastic velocity models for gas-hydrate-bearing sediments - a comparison

SUMMARY The presence of gas hydrate in oceanic sediments is mostly identified by bottom-simulating reflectors (BSRs), reflection events with reversed polarity following the trend of the seafloor. Attempts to quantify the amount of gas hydrate present in oceanic sediments have been based mainly on the presence or absence of a BSR and its relative amplitude. Recent studies have shown that a BSR is not a necessary criterion for the presence of gas hydrates, but rather its presence depends on the type of sediments and the in situ conditions. The influence of hydrate on the physical properties of sediments overlying the BSR is determined by the elastic properties of their constituents and on sediment microstructure. In this context several approaches have been developed to predict the physical properties of sediments, and thereby quantify the amount of gas/gas hydrate present from observed deviations of these properties from those predicted for sediments without gas hydrate. We tested four models: the empirical weighted equation (WE); the three-phase effectivemedium theory (TPEM); the three-phase Biot theory (TPB) and the differential effectivemedium theory (DEM). We compared these models for a range of variables (porosity and clay content) using standard values for physical parameters. The comparison shows that all the models predict sediment properties comparable to field values except for the WE model at lower porosities and the TPB model at higher porosities. The models differ in the variation of velocity with porosity and clay content. The variation of velocity with hydrate saturation is also different, although the range is similar. We have used these models to predict velocities for field data sets from sediment sections with and without gas hydrates. The first is from the Mallik 2L‐38 well, Mackenzie Delta, Canada, and the second is from Ocean Drilling Program (ODP) Leg 164 on Blake Ridge. Both data sets have Vp and Vs information along with the composition and porosity of the matrix. Models are considered successful if predictions from both Vp and Vs match hydrate saturations inferred from other data. Three of the models predict consistent hydrate saturations of 60‐80 per cent from both Vp and Vs from log and vertical seismic profiling data for the Mallik 2L-38 well data set, but the TPEM model predicts 20 per cent higher saturations, as does the DEM model with a clay‐water starting medium. For the clay-rich sediments of Blake Ridge, the DEM, TPEM and WE models predict 10‐ 20 per cent hydrate saturation from Vp data, comparable to that inferred from resistivity data. The hydrate saturation predicted by the TPB model from Vp is higher. Using Vs data, the DEM and TPEM models predict very low or zero hydrate saturation while the TPB and WE models predict hydrate saturation very much higher than those predicted from Vp data. Low hydrate saturations are observed to have little effect on Vs. The hydrate phase appears to be connected within the sediment microstructure even at low saturations.
Three-dimensional simulations of the orientation and structure of reconnection X-lines

This work employs Hall magnetohydrodynamic (MHD) simulations to study the X-lines formed during the reconnection of magnetic fields with differing strengths and orientations embedded in plasmas of differing densities. Although random initial perturbations trigger the growth of X-lines with many orientations, at late time a few robust X-lines sharing an orientation reasonably consistent with the direction that maximizes the outflow speed, as predicted by Swisdak and Drake [Geophys. Res. Lett. , 34, L11106, (2007)], dominate the system. The existence of reconnection in the geometry examined here contradicts the suggestion of Sonnerup [J. Geophys. Res., 79, 1546 (1974)] that reconnection occurs in a plane normal to the equilibrium current. At late time the growth of the X-lines stagnates, leaving them shorter than the simulation domain.
Quantitative Assessment of the Magnitude, Impact and Spatial Extent of Ultrasonic Clutter

Clutter is a noise artifact in ultrasound images that appears as diffuse echoes overlying signals of interest. It is most easily observed in anechoic or hypoechoic regions, such as in cysts, blood vessels, amniotic fluid, and urine-filled bladders. Clutter often obscures targets of interest and complicates anatomical measurements. An analytical expression that characterizes the extent to which clutter degrades lesion contrast was derived and compared to the measured contrast loss due to clutter in a bladder phantom. Simulation and phantom studies were performed to determine ideal and achievable signal-to-clutter ratios. In vivo clutter magnitudes were quantified in simultaneously-acquired fundamental and harmonic bladder images from five volunteers. Clutter magnitudes ranged from −30 dB to 0 dB, relative to the mean signal of the bladder wall. For this range of clutter magnitudes, the analytical expression predicts a contrast loss of 0–45 dB for lesions with clutter-free contrasts of 6–48 dB. A pixel-wise comparison of simultaneously-acquired fundamental and harmonic bladder images from each volunteer revealed an overall signal reduction in harmonic images, with average reductions ranging from 11–18 dB in the bladder interior and 9–11 dB in the tissue surrounding the bladder. Harmonic imaging did not reduce clutter in all volunteers.
Lack of interference between small bowel capsule endoscopy and implantable cardiac defibrillators: an ‘in vivo’ electrophysiological study

Background Capsule endoscopy is a widely performed procedure for small bowel investigation. Once swallowed by the patient, the capsule transmits images to an external recorder over a digital radiofrequency communication channel. Potential electromagnetic interferences with implantable cardiac devices have been postulated. Clinical studies on the safety of capsule endoscopy in patients with cardiac defibrillators are lacking. Objective The aim of this study was to assess potential mutual electromagnetic interferences between capsule and defibrillators. Methods This study used the Given M2A video capsule system. Ten different types of defibrillators were tested in a clinical setting. Before capsule ingestion, defibrillator electrical therapies were switched off. During capsule endoscopy patients were monitored with cardiac telemetry. At the end of capsule endoscopy the following defibrillator’s parameters were analysed: change in device settings; inappropriate shocks; inappropriate anti-tachycardia therapy; inappropriate sensing or pacing; noise detection; device reset; programming changes; permanent electrical damages. Any technical problem related to capsule image transmission was recorded. Results Neither defibrillator malfunction nor interference in sensing or pacing was recorded; conversely, no capsule malfunction potentially caused by defibrillators was registered. Conclusion Our results suggest that capsule endoscopy can be safely performed in patients with cardiac defibrillators.
Evaluation of the Treatment of Candiduria at an Academic Medical Center

To evaluate the epidemiology, management, and outcomes associated with candiduria in intensive care unit (ICU) and medical ward (MW) patients. This was a retrospective cohort study conducted in a tertiary care academic medical center. Adult patients aged between 18 and 75 years who were admitted for at least 5 days with a urinary culture that grew a Candida species between July 2010 and June 2011 were included. Medical records were retrospectively reviewed. Laboratory data, urinary symptoms, risk factors for urinary and invasive candidiasis, treatment, and patient outcomes were collected and evaluated. Sixty-seven ICU and 65 MW patients met the inclusion criteria. ICU patients were more likely to have risk factors for invasive candidiasis and candiduria. Candida albicans and Candida glabrata were the most frequently identified urinary isolates. Antifungal therapy was commonly initiated despite rapid replacement or removal of urinary drainage devices and a lack of patient reported symptoms. Fluconazole was the most commonly used antifungal agent, followed by micafungin. Hospital length of stay did not vary significantly between the ICU and MW groups (P = 0.0628). All-cause mortality was higher in the ICU patients compared with that of the MW patients (22.4% vs. 3.1%, P = 0.0012). Differences exist between ICU and MW patients that develop candiduria with respect to risk factors, and outcomes. Antifungals, including fluconazole and micafungin, were often used inappropriately (ie, asymptomatic patients) in this patient cohort. Efforts to improve healthcare provider awareness of the contemporary recommendations to manage candiduria are necessary to improve patient care and antifungal use.
Improved classifications of myocardial bull's-eye scintigrams with computer-based decision support system.

UNLABELLED In a recent study, artificial neural networks were trained to detect coronary artery disease using scintigraphic data as input. The performance of the networks was better than that of human experts using coronary angiography as a gold standard. In clinical practice, this type of neural networks will not take over the decision-making process from the physician but will assist by proposing an interpretation of the scintigram. The purpose of this study was to assess the influence of such decision support on the interpretations of the physicians. METHODS A population of 135 patients who had undergone both myocardial 99mTc-sestamibi rest/stress scintigraphy and coronary angiography within a 3-mo period was studied. An image set consisting of the bull's-eye rest, stress, difference and quote images was constructed for each patient. Three experienced physicians independently classified all image sets regarding the presence and/or absence of coronary artery disease in two vascular territories using a four-grade scale. The physicians classified the image sets twice with and twice without the advice of artificial neural networks. RESULTS The joint evaluation of the three physicians showed significantly improved performance with decision support, measured as increases in the areas under the receiver operating characteristic curves from 0.65 to 0.70 (P = 0.018) and from 0.79 to 0.82 (P = 0.006) for two vascular territories. Furthermore, the joint evaluation showed significantly less intraobserver and interobserver variability with decision support. CONCLUSION Physicians classifying myocardial bull's-eye images benefit from the advice of artificial neural networks. These results show the high potential for neural networks as clinical decision support systems.
Communicating age in Second Life: The contributions of textual and visual factors

Although considerable research has identified patterns in online communication and interaction related to a range of individual characteristics, analyses of age have been limited, especially those that compare age groups. Research that does examine online communication by age largely focuses on linguistic elements. However, social identity approaches to group communication emphasize the importance of non-linguistic factors such as appearance and non-verbal behaviors. These factors are especially important to explore in online settings where traditional physical markers of age are largely unseen. To examine ways that users communicate age identity through both visual and textual means, we use multiple linear regression and qualitative methods to explore the behavior of 201 players of a custom game in the virtual world Second Life. Analyses of chat, avatar movement, and appearance suggest that although residents primarily used youthful-looking avatars, age differences emerged more strongly in visual factors than in language use.
Defending against the Advanced Persistent Threat: An Optimal Control Approach

The new cyberattack pattern of advanced persistent threat (APT) has posed a serious threat to modern society. This paper addresses the APT defense problem, that is, the problem of how to effectively defend against an APT campaign. Based on a novel APT attack-defense model, the effectiveness of an APT defense strategy is quantified. Thereby, the APT defense problem is modeled as an optimal control problem, in which an optimal control stands for a most effective APT defense strategy. The existence of an optimal control is proved, and an optimality system is derived. Consequently, an optimal control can be figured out by solving the optimality system. Some examples of the optimal control are given. Finally, the influence of some factors on the effectiveness of an optimal control is examined through computer experiments. These findings help organizations to work out policies of defending against APTs.
Impact of tumor size on the clinical outcomes of patients with Robson Stage I renal cell carcinoma

In the TNM classification of renal cell carcinoma released in 1997, T1 tumors were defined as organ‐confined tumors 7.0 cm or less in size, and T2 as those larger than 7.0 cm. The consideration of tumor size should be predicated on its prognostic value in predicting survival, because the goal of clinical staging is to separate patients into similar classes of survival based on the extent of disease at presentation. The authors examined the impact of tumor size on the clinical outcomes of patients with Robson Stage I disease to determine a size cutoff that would maximize the predictive value of the TNM staging system.
Charges associated with pediatric head injuries: a five year retrospective review of 41 pediatric hospitals in the US

Abstract: Background: Brain injuries are a significant public health problem, particularly among the pediatric population. Brain injuries account for a significant portion of pediatric injury deaths, and are the highest contributor to morbidity and mortality in the pediatric and young adult populations. Several studies focus on particular mechanisms of brain injury and the cost of treating brain injuries, but few studies exist in the literature examining the highest contributing mechanisms to pediatric brain injury and the billed charges associated with them. Methods: Data were extracted from the Pediatric Health Information System (PHIS) from member hospitals on all patients admitted with diagnosed head injuries and comparisons were made between ICU and non-ICU admissions. Collected data included demographic information, injury information, total billed charges, and patient outcome. Results: Motor vehicle collisions, falls, and assaults/abuse are the three highest contributors to brain injury in terms of total numbers and total billed charges. These three mechanisms of injury account for almost $1 billion in total charges across the five-year period, and account for almost half of the total charges in this dataset over that time period. Conclusions: Research focusing on brain injury should be tailored to the areas of the most pressing need and the highest contributing factors. While this study is focused on a select number of pediatric hospitals located throughout the country, it identifies significant contributors to head injuries, and the costs associated with treating them.
Performance evaluation for multi-user MIMO IEEE 802.11ac wireless LAN system

In this paper, we evaluate the performance of the next generation standard IEEE 802.11ac wireless local area network (WLAN) system. IEEE 802.11 for the first time will employ downlink multi-user multi-input multi-output (MU-MIMO) technology. Precoding techniques greatly influences the performance of MU-MIMO transmission. We measure these improvements when realistic channel conditions are applied. We compare the performance of channel inversion (CI) and block diagonalization (BD) precoding methods paired with various MIMO detection techniques. From the simulation results, we show the effectiveness of BD precoding compared to CI precoding.
Molecular characterization and development of Sarcocystis speeri sarcocysts in gamma interferon gene knockout mice

SUMMARY The North American opossum (Didelphis virginiana) is the definitive host for at least three named species of Sarcocystis: Sarcocystis falcatula, Sarcocystis neurona and Sarcocystis speeri. The South American opossums (Didelphis albiventris, Didelphis marsupialis and Didelphis aurita) are definitive hosts for S. falcatula and S. lindsayi. The sporocysts of these Sarcocystis species are similar morphologically. They are also not easily distinguished genetically because of the difficulties of DNA extraction from sporocysts and availability of distinguishing genetic markers. Some of these species can be distinguished by bioassay; S. neurona and S. speeri are infective to gamma interferon gene knockout (KO) mice, but not to budgerigars (Melopsittacus undulatus); whereas S. falcatula and S. lindsayi are infective to budgerigars but not to KO mice. The natural intermediate host of S. speeri is unknown. In the present study, development of sarcocysts of S. speeri in the KO mice is described. Sarcocysts were first seen at 12 days post-inoculation (p.i.), and they became macroscopic (up to 4 mm long) by 25 days p.i. The structure of the sarcocyst wall did not change from the time bradyzoites had formed at 50–220 days p.i. Sarcocysts contained unique villar protrusions, ‘type 38’. The polymerase chain reaction amplifications and sequences analysis of three nuclear loci (18S rRNA, 28S rRNA and ITS1) and two mitochondrial loci (cox1 and cytb) of S. speeri isolate from an Argentinean opossum (D. albiventris) confirmed its membership among species of Sarcocystis and indicated an especially close relationship to another parasite in this genus that employs opossums as its definitive host, S. neurona. These results should be useful in finding natural intermediate host of S. speeri.
Molecular taxonomy and epidemiology of Blastomyces and Histoplasma species

Summary. Cladistic analysis of partial 26S rRNA sequences was used to estimate evolutionary distances among species and varieties of the dimorphic onygenalean genera Blastomyces, Coccidioides, Emmonsia, Histoplasma and Paracoccidioides. With the exception of Coccidioides, all genera were closely related, with about 5% base differences and even less (1–2%) between Blastomyces and Emmonsia. These data were supported by a teleomorph in the same genus Ajcllomyces. In a phylogenic study of a wide range of ascomycete orders and families, Coccidioides immitis was found to be closest to Aphanoascus fulvescens and Chrysosporium keratinophilum, and to have relative distances to the remaining dimorphic genera (family Onygenaceae) similar to those of the dermatophytes (family Arthrodermataceae). The sequencing data were confirmed by genomic comparisons. All dimorphic genera had a nuclear DNA base composition in the same range of 46.6–47.3% G + C. The DNA melting curves of Blastomyces and Histoplasma strains showed irregularities that were ascribed to the presence of AT‐rich stretches in satellite DNA rather than in mitochondrial DNA. Derivative profiles proved to be highly reproducible within regional populations and coincided with differences in clinical behaviour of each species. Blastomyces dermatitidis generated two kinds of curves, corresponding to the geographically distinct serotypes 1 and 2. The African type (serotype 2) was characterized by a classical sigmoidal melting curve similar to that for all strains of Coccidioides, Emmonsia and Paracoccidioides. In contrast, the American type (serotype 1) contained satellite DNA (27% G + C). A rRNA base difference of 1.5% was observed between geographical types, a value slightly higher than that noted between Histoblasma capsulatum and its variety farciminosum (0.9%). All three H. capsulatum varieties presented irregularities in their DNA melting curves. The molecular data support the recognition of two of them as agents of blastomycosis and the assignment of more than one species and two varieties to the genus Emmonsia.
Orientations of recrystallization nuclei developed in columnar-grained Ni at triple junctions

A high purity columnar grained nickel sample with a strong <001> fiber texture was cold rolled to 50% reduction in thickness, followed by annealing at different temperatures. Optical microscopy was used to depict the grain boundaries prior to annealing and to detect nuclei formed on grain boundaries after annealing. Electron backscatter diffraction was performed to characterize the orientations of the nuclei and the deformed grains. Hardness tests were conducted at deformed grains. The potentials of triple junctions as preferential nucleation sites, the influence of deformation differences between adjacent grains on nucleation and orientation relationships between nuclei and parent matrix are analyzed.
COP‐1, a member of the CCN family, is a heparin‐induced growth arrest specific gene in vascular smooth muscle cells

Vascular smooth muscle cell (VSMC) hyperplasia is responsible for the failure of 15–30% of vascular surgical procedures such as coronary artery bypass grafts and angioplasties. We and others have shown that heparin suppresses VSMC proliferation in vivo and in cell culture. We hypothesize that heparin inhibits VSMC proliferation by binding to cell surface receptors, resulting in selective modulation of mitogenic signal transduction pathways and altered transcription of a specific subset of growth regulatory genes. To test this idea, we used subtractive hybridization to identify differentially expressed mRNAs in heparin‐treated and untreated VSMC. We identified a heparin induced mRNA identical to Cop‐1, a member of the CCN family of proteins which are secreted, cysteine‐rich modular proteins involved in growth regulation and migration. Cop‐1 from smooth muscle cells appears to have a different expression pattern and possibly different functions than Cop‐1 from other cells. Cop‐1 mRNA is expressed at high levels in quiescent VSMC and at low levels in proliferating VSMC, an expression pattern highly characteristic of growth arrest specific genes. Cop‐1 mRNA is expressed at high levels in heparin treated VSMC and COP‐1 protein is secreted into culture medium. In tissues, Cop‐1 expression is observed in the uninjured rat aorta suggesting a possible role for Cop‐1 in vivo. We found PDGF, but not EGF, inhibits the expression of Cop‐1 in VSMC. Neither TGF‐β nor interferon‐β, two inhibitors of VSMC proliferation, were able to induce Cop‐1 expression. In addition, heparin does not induce Cop‐1 mRNA in endothelial cells and VSMC resistant to the antiproliferative effect of heparin. Conditioned medium from cells over‐expressing COP‐1 protein inhibits VSMC proliferation in culture. Together, our data indicate that COP‐1 may play a role in the antiproliferative mechanism of action of heparin. © 2001 Wiley‐Liss, Inc.
Treatment of type II gastric carcinoid tumors with somatostatin analogues.

Gastric carcinoid tumors are rare tumors that originate from gastric enterochromaffin-like cells in the oxyntic mucosa.1 There are three types of gastric carcinoid tumors: type I is associated with chronic atrophic gastritis, type II develops in patients with combined multiple endocrine neoplasia type 1 and the Zollinger–Ellison syndrome, and type III is sporadic.1 Although the pathogenesis of these tumors is not completely understood, hypergastrinemia has an important role in the development of types I and II.2 The multiple endocrine neoplasia type 1 gene locus may be involved in type II gastric carcinoid tumors.3,4 All three types are usually removed .