cssi/SciSciGPT-SciSciNet huggingface dataset:
A review of studies on luxury hotels over the past two decades

The purpose of this study was to identify current research trends and clarify the changing direction of studies on luxury hotels. Scholarly studies published between 1994 and 2014 were examined through content analysis, using such keywords as “luxury hotels”, “deluxe hotels”, “upscale hotels”, “high-end hotels”, and “fouror five-star hotels”. The contributions were then screened to focus on luxury hotel-centered topics. The search revealed 70 qualified scholarly research articles. Conceptual studies were limited, with empirical studies representing a majority of the luxury hotel researches. The luxury hotel researches that were identified were categorized into nine groups by research themes: marketing, human resources (HR), finance, strategic management, technology, service quality, food science, tourism and others, with marketing, HR and technology being the most popular research themes. Analysis of methodological trends in luxury hotel research indicated that the majority of the researchers utilized quantitative methods employing various statistical analysis techniques. Overall, luxury hotel research is still limited in the number of publications and diversity of research topics. This study was the first comprehensive content analysis on luxury hotels conducted to date. The findings of this study may provide future researchers and academicians with new insights based on past study as well as ideas for future research. It is hoped this study will contribute to the development of a reliable knowledge base from which practitioners may inform plans and action regarding future luxury hotels.
Bioderived Acrylates from Alkyl Lactates via Pd-Catalyzed Hydroesterification

The conversion of methyl and ethyl lactate to their corresponding alkyl 2-(propionyloxy)propanoate esters was achieved by Pd catalyzed hydroesterificative coupling with carbon monoxide (CO) and ethylene (C2H4) at moderate temperatures and CO/C2H4 pressures. A screening of reaction conditions showed that the reaction could be carried out at low loadings of catalyst, which was generated in situ from inexpensive and commercially available reagents. High conversions and product yields were obtained in a variety of solvents and even under neat conditions. Product analysis identified transesterification to be the primary competing reaction, which could be mitigated by changing solvents, as well as minimizing the amount of excess acid present in solution. Pyrolysis of methyl and ethyl 2-(propionyloxy)propanoate transformed these esters into their respective acrylates suitable for subsequent polymerization, along with propionic acid as a valuable coproduct.
Predicting Prediabetes Through Facebook Postings: Protocol for a Mixed-Methods Study.

Background: The field of infodemiology uses health care trends found in public networks, such as social media, to track and quantify the spread of disease. Type 2 diabetes is on the rise worldwide, and social media may be useful in identifying prediabetes through behavior exhibited through social media platforms such as Facebook and thus in designing and administering early interventions and containing further progression of the disease. Objective: This pilot study is designed to investigate the social media behavior of individuals with prediabetes, before and after diagnosis. Pre- and postdiagnosis Facebook content (posts) of such individuals will be used to create a taxonomy of prediabetes indicators and to identify themes and factors associated with an actual diagnosis of prediabetes. Methods: This is a single-center exploratory retrospective study that examines 20 adults with prediabetes. The investigators will code Facebook posts 3 months before through 3 months after prediabetes diagnosis. Data will be analyzed using both qualitative content analysis methodology as well as quantitative methodology to characterize participants and compare their posts pre- and postdiagnosis. Results: The project was funded for 2015-2018, and enrollment will be completed by the end of 2018. Data coding is currently under way and the first results are expected to be submitted for publication in 2019. Results will include both quantitative and qualitative data about participants and the similarities and differences between coded social media posts. Conclusions: This pilot study is the first step in creating a taxonomy of social media indicators for prediabetes. Such a taxonomy would provide a tool for researchers and health care professionals to use social media postings for identifying those at greater risk of having prediabetes. International Registered Report Identifier (IRRID): DERR1-10.2196/10720
Factors linked with receiving a lymph node dissection during surgery for nonmetastatic renal cell carcinoma.

672Background: The benefit of a lymph node dissection (LND) in renal cell carcinoma (RCC) remains poorly defined. Despite this uncertainty, the American Urological Association (AUA) guideline on lo...
Visual Culture isn't Just Visual: Multiliteracy, Multimodality and Meaning

The central claim of this article is that contemporary cultural forms such as television and the Internet involve more than the perceptual system of sight and more than visual images as a communicative mode. Meaning is made through an interaction of music, the spoken voice, sound effects, language, and pictures. This means that even the recent shift to visual culture among art educators is insufficient to position art education within a reconceptualized, broad definition of communications. To be relevant to contemporary social practice, art education must embrace interaction between communicative modes. The recent concepts of multiliteracy and multimodality are suggested for this purpose. This article examines why these concepts have emerged, the challenge they make to art education's traditional interest in the visual, and what teachers can begin to do in the classroom.
Effects of handling and pair management on reproduction in Japanese quail (Coturnix coturnix ).

Abstract Three experiments were designed to study the effects of handling, pairing, and frequency of mating opportunities on reproduction in Japanese quail (Coturnixcoturnix) when the sexes were caged separately except during the 90 minute mating periods. In Experiments 1 and 2, 48 females and 48 males were allocated randomly to one of four treatments: 1) continuously paired, 2) paired daily with the same male, 3) paired daily with a different male, and 4) paired every third day with the same male. In Experiment 3, 44 males and 44 females used in Experiments 1 and 2 were again assigned randomly to one of four treatments: 1) continuously paired, 2) paired continuously but the females were handled at the beginning and end of a 90 minute period every third day to simulate the handling associated with moving birds between cages for mating, 3) paired every third day with the same male, and 4) paired every third day with a different male. In Experiments 1 and 3, the females were introduced into the males' cages, while in Experiment 2 males were introduced into the females' cages. In Experiment 1, the females paired every 1 or 3 days with the same males had fewer eggs with embryonic development than continously paired females. In Experiment 2, a reduced number of eggs with embryonic development was observed only in fermales paired every 3 days with the same male. In Experiment 1, more eggs hatched from continuously paired females than from females paired every third day with the same male. In Experiment 3, the females paired every third day with the same males had fewer settable, developing, or hatching eggs. In conclusion, it was found that when the sexes need to be caged separately, it is better to expose the females to different males.
Metastatic Merkel Cell Carcinoma Resulting in Complete Heart Block.

Merkel cell carcinoma (MCC) is an aggressive, rare cutaneous neuroendocrine carcinoma that can metastasize to the heart in exceedingly rare cases. The incidence of MCC in the United States is 0.7 per 100,000 person-years with a median age of 75 to 80 years at diagnosis and a male predominance ([1][1
Differential C-Q Analysis: A New Approach to Inferring Lateral Transport and Hydrologic Transients within Multiple Reaches of a Mountainous Headwater Catchment

Concentration-discharge (C-Q) relationships have been widely used as “hydrochemical tracers” to determine the variability in riverine solute exports across event, seasonal, annual, and decadal time scales. However, these C-Q relationships are limited to investigating solute transport dynamics at individual sampling stations, such that they create an incomplete understanding of the solute behavior upstream or downstream of the sampling station. Therefore, the objective of this study is to develop, apply and assess a differential C-Q approach that can characterize spatial variability in solute behavior across stations, as well as investigate their controls, by following a different spatial scheme and organizing the river into multiple sections. The differential C-Q approach captures the difference in concentration in a river segment over the difference in discharge, thereby accounting for gains, losses or fractional solute turnover between sampling stations. Using water quality data collected over four water years (2014-18) in a mountainous headwater catchment of the East River, Colorado, this study compares traditional and differential C-Q relationships in predicting solute behavior between three sampling stations distributed throughout the river. Results from the differential C-Q analysis demonstrate significant differences in solute behavior within upstream versus downstream reaches of the East River watershed. In particular, the meandering downstream section is marked by significant gains in both groundwater and solute concentrations as opposed to the dilution and the declining trends observed in the high-relief, steep terrain upstream reach. Shale mineralogy was determined to have a major influence on in-stream concentrations pertaining to Ca, DIC, DOC, Mg, Mo, NO3 and SO4. The analyses further revealed that total P concentration in the downstream reach exceeded the U.S. Environmental Protection Agency’s desired goal for control of eutrophication (110 ppb). Overall, differential C-Q metrics yield a better understanding of the lateral storage and interactions within catchments than traditional analyses, and holds potential for aiding water quality managers in the identification of critical stream reaches that assimilate harmful chemicals.
Influence of race/ethnicity and income on the link between adverse childhood experiences and child flourishing.

Background The impact of early adversity increases the risk of poor outcomes across the life course. Identifying factors that protect against or contribute to deleterious life outcomes represents an important step in resilience promotion among children exposed to adversity. Informed by resilience science, we hypothesized that family resilience mediates the relationship between adverse childhood experiences (ACEs) and child flourishing, and these pathways vary by race/ethnicity and income. Methods We conducted a secondary data analysis using the 2016-17 National Survey of Children's Health data reported by parents/guardians for 44,686 children age 6-17 years. A moderated-mediation model estimated direct, indirect, and total effects using a probit link function and stacked group approach with weighted least square parameter estimates. Results The main variables were related in expected directions. Family resilience partially mediated the ACEs-flourishing association. Although White and socioeconomically advantaged families were more likely to maintain family resilience, their children functioned more poorly at high-risk levels relative to Black and Hispanic children and across income groups. Conclusion Children suffer from cumulative adversity across race/ethnicity and income. Partial mediation of family resilience indicates that additional protective factors are needed to develop comprehensive strategies, while racial/ethnic differences underscore the importance of prevention and intervention programs that are culturally sensitive. Impact The key message of the article reinforces the notion that children suffer from cumulative adversity across race/ethnicity and income, and prevention of ACEs should be the number one charge of public policy, programs, and healthcare. This is the first study to examine family resilience in the National Survey Children's Health (NSCH) data set as mediating ACEs-flourishing by race/ethnicity and family poverty level. Examining an ACEs dose-response effect using population-based data within the context of risk and protective factors can inform a public health response resulting in a greater impact on prevention efforts.
Tuning topological phase and quantum anomalous Hall effect by interaction in quadratic band touching systems

Interaction-driven topological phases significantly enrich the class of topological materials and thus are of great importance. Here, we study the phase diagram of interacting spinless fermions filling the two-dimensional checkerboard lattice with a quadratic band touching (QBT) point. By developing new diagnosis based on the state-of-the-art density-matrix renormalization group and exact diagonalization, we determine accurate quantum phase diagram for such a system at half-filling with three distinct phases. For weak nearest-neighboring interactions, we demonstrate the instability of the QBT towards an interaction-driven spontaneous quantum anomalous Hall (QAH) effect. For strong interactions, the system breaks the rotational symmetry realizing a nematic charge-density-wave (CDW) phase. Interestingly, for intermediate interactions we discover a symmetry-broken bond-ordered critical phase sandwiched in between the QAH and CDW phases, which splits the QBT into two Dirac points driven by interaction. Instead of the direct transition between QAH and CDW phases, our identification of an intermediate phase sheds new light on the theoretical understanding of the interaction-driven phases in QBT systems. Topological materials are attracting a great deal of attention, and proposals suggesting that topologically trivial materials with a quadratic band touching point can be driven in a topological phase by electronic interactions that break time-reversal symmetry are very appealing. However, because of the very small energy gap protecting such topological phase, this effect remained so far elusive in microscopic calculations. Tian-Sheng Zeng, Wei Zhu and Donna Sheng developed a systematic and controlled scheme that allowed them to determine the accurate phase diagram of a 2D checkboard lattice with a quadratic band touching point, finding that for weak interactions a topological phase emerges. At stronger interactions an intermediate critical phase is observed before a nematic charge-density wave phase develops. This work opens the way to a deeper understanding of other topological systems driven by electronic interactions.
Neurophysiologic Characterization of Resting State Connectivity Abnormalities in Schizophrenia Patients.

Background: Patients with schizophrenia show abnormal spontaneous oscillatory activity in scalp-level electroencephalographic (EEG) responses across multiple frequency bands. While oscillations play an essential role in the transmission of information across neural networks, few studies have assessed the frequency-specific dynamics across cortical source networks at rest. Identification of the neural sources and their dynamic interactions may improve our understanding of core pathophysiologic abnormalities associated with the neuropsychiatric disorders. Methods: A novel multivector autoregressive modeling approach for assessing effective connectivity among cortical sources was developed and applied to resting-state EEG recordings obtained from n = 139 schizophrenia patients and n = 126 healthy comparison subjects. Results: Two primary abnormalities in resting-state networks were detected in schizophrenia patients. The first network involved the middle frontal and fusiform gyri and a region near the calcarine sulcus. The second network involved the cingulate gyrus and the Rolandic operculum (a region that includes the auditory cortex). Conclusions: Schizophrenia patients show widespread patterns of hyper-connectivity across a distributed network of the frontal, temporal, and occipital brain regions. Results highlight a novel approach for characterizing alterations in connectivity in the neuropsychiatric patient populations. Further mechanistic characterization of network functioning is needed to clarify the pathophysiology of neuropsychiatric and neurological diseases.
SU-E-T-571: Newly Emerging Integrated Transmission Detector Systems Provide Online Quality Assurance of External Beam Radiation Therapy

Purpose: Two newly emerging transmission detectors positioned upstream from the patient have been evaluated for online quality assurance of external beam radiotherapy. The prototype for the Integral Quality Monitor (IQM), developed by iRT Systems GmbH (Koblenz, Germany) is a large-area ion chamber mounted on the linac accessory tray to monitor photon fluence, energy, beam shape, and gantry position during treatment. The ion chamber utilizes a thickness gradient which records variable response dependent on beam position. The prototype of Delta4 Discover™, developed by ScandiDos (Uppsala, Sweden) is a linac accessory tray mounted 4040 diode array that measures photon fluence during patient treatment. Both systems are employable for patient specific QA prior to treatment delivery. Methods: Our institution evaluated the reproducibility of measurements using various beam types, including VMAT treatment plans with both the IQM ion chamber and the Delta4 Discover diode array. Additionally, the IQM’s effect on photon fluence, dose response, simulated beam error detection, and the accuracy of the integrated barometer, thermometer, and inclinometer were characterized. The evaluated photon beam errors are based on the annual tolerances specified in AAPM TG-142. Results: Repeated VMAT treatments were measured with 0.16% reproducibility by the IQM and 0.55% reproducibility by the Delta4 Discover.more » The IQM attenuated 6, 10, and 15 MV photon beams by 5.43±0.02%, 4.60±0.02%, and 4.21±0.03% respectively. Photon beam profiles were affected <1.5% in the non-penumbra regions. The IQM’s ion chamber’s dose response was linear and the thermometer, barometer, and inclinometer agreed with other calibrated devices. The device detected variations in monitor units delivered (1%), field position (3mm), single MLC leaf positions (13mm), and photon energy. Conclusion: We have characterized two new transmissions detector systems designed to provide in-vivo like measurements upstream from the patient. Both systems demonstrate substantial utility for online treatment verification and QA of photon external beam radiotherapy.« less
Preoperative Iris Angiography: a Prognostic Tool for Diabetic Patients

Iris neovascularization is one of the most severe ocular complications occuring after vitrectomy in diabetic patients. This complication can be predicted by performing preoperative iris fluorescein angiography.
Interventional Radiology Management of Unresectable Intrahepatic Cholangiocarcinoma

Inoperable intrahepatic cholangiocarcinoma (ICC) carries a dismal prognosis. Transarterial therapies have been shown by numerous small- and medium-sized series to prolong survival in these patients well beyond 1 year. Studies of drug-eluting bead transarterial chemoembolization (DEB-TACE) and yttrium-90 transarterial radioembolization (TARE) suggest longer survival may be achieved with these newer transarterial modalities. Research to date suggests that patient factors associated with prolonged survival after transarterial therapy include the absence of cirrhosis or the presence of at most Child A cirrhosis, normal or near normal performance status (Eastern Cooperative Oncology Group, ECOG, 0–1), peripheral tumor morphology, tumor hypervascularity, small tumor size, low tumor grade, low tumor burden, and the absence of portal thrombus. The presence of extrahepatic disease has not been found significantly to impact survival, confirming the high mortality from the primary disease. Several studies have directly compared different transarterial therapies. Several have found that transarterial chemoembolic (TACE) therapy is more effective than transarterial chemoinfusion (TACI); however, no study has been conducted to evaluate whether this difference between TACE and TACI persists in the subpopulation of hypovascular tumors. There is evidence that dual-agent conventional TACE with gemcitabine and cisplatin may be more effective than single-agent TACE. In addition to progress being made with transarterial therapies, early results of percutaneous thermal ablation for selected patients with small-to-moderate-sized unresectable ICC are promising. Three recent studies of patients receiving thermal ablation each reported median overall survival of over 30 months post-treatment. Prospective studies of transarterial and percutaneous ablative therapies are needed.
Modern American Capitalism

[T]he main sources of the resistance to change ... are to be found in the structure of privilege inherent in all societies. [R. Heilbroner, The Limits of American Capitalism, New York: Harper & Row, 1965, p. 70.]
Physical characteristics associated with weight misperception among overweight and obese men: NHANES 1999–2006

Objectives The purpose of this study was to (1) determine the prevalence of weight misperception among overweight and obese men with total body fat levels ≥ 25%, and (2) examine associations of weight misperception with anthropometric and body composition measures. Methods Data came from 4,200 overweight or obese men from the 1999 to 2006 National Health and Nutrition Examination Survey. Weight misperception was operationalized as having a dual-energy X-ray absorptiometry-derived total body fat percentage ≥25% and classifying oneself as either “underweight” or “about right weight.” Logistic regression was used to determine physical characteristics associated with weight misperception. Results Weight misperception was highest among Mexican American (35.9%) followed by Black (30.8%) and White men (22.9%). Physical characteristics (OR, 95% CI) associated with weight misperception were decreased arm fat (0.95, 0.91-0.98), being overweight (9.02, 5.34-15.24), and having a waist circumference ≤ 94 cm (2.31, 1.72-3.09). Conclusions Findings suggest that future research should include a measure of adiposity in the operationalization of weight misperception among male populations.
Placebo cessation in binge eating disorder: effect on anthropometric, cardiovascular, and metabolic variables.

Objective The aim of this study was to evaluate the effects of cessation of binge eating in response to placebo treatment in binge eating disorder (BED) on anthropometric, cardiovascular, and metabolic variables. Method We pooled participant-level data from 10 randomized, double-blind, placebo-controlled trials of medication for BED. We then compared patients who stopped binge eating with those who did not on changes in weight, body mass index (BMI), systolic and diastolic blood pressure, pulse, and fasting lipids and glucose. Result Of 234 participants receiving placebo, 60 (26%) attained cessation from binge eating. Patients attaining cessation showed modestly decreased diastolic blood pressure compared with patients who continued to binge eat. Weight and BMI remained stable in patients who stopped binge eating, but increased somewhat in those who continued to binge eat. Discussion Patients who stopped binge eating with placebo had greater reductions in diastolic blood pressure and gained less weight than patients who continued to binge eat. Self-report of eating pathology in BED may predict physiologic variables. Copyright © 2014 John Wiley & Sons, Ltd and Eating Disorders Association.
Matrix metalloproteinase-2 is an interstitial collagenase. Inhibitor-free enzyme catalyzes the cleavage of collagen fibrils and soluble native type I collagen generating the specific 3/4- and 1/4-length fragments.

The 72-kDa gelatinase/type IV collagenase (MMP-2) is a member of the matrix metalloproteinase (MMP) family of enzymes. This enzyme is known to cleave type IV collagen as well as degrade denatured collagens. However, native interstitial collagens are reportedly resistant to MMP-2 and are thought to be susceptible only to the interstitial collagenases MMP-1 and MMP-8. In this study we report that both human and chicken MMP-2, free of tissue inhibitors of metalloproteinases (TIMPs) are capable of cleaving soluble, triple helical type I collagen generating the ¾- and ¼-length collagen fragments characteristic of vertebrate interstitial collagenases. MMP-2 cleaves at the same Gly-Ile/Leu bond in the collagen α chains as interstitial collagenases with kcat and Km values similar to that of MMP-1. MMP-2 also is capable of degrading reconstituted type I collagen fibrils. The closely related 92-kDa gelatinase/type IV collagenase (MMP-9) is unable to cleave soluble or fibrillar collagen under identical conditions indicating that the specific collagenolytic activity of MMP-2 is not a general property of gelatinases. That MMP-2, a potent gelatinase, also can cleave fibrillar collagen provides an alternative to the proposal that two enzymes, an interstitial collagenase and a gelatinase, are required for the complete dissolution of stromal collagen during cellular invasion.
Conjunctival advancement versus nonincisional treatment for late-onset glaucoma filtering bleb leaks.

Abstract Objective To compare the outcomes of conjunctival advancement and nonincisional management of late-onset glaucoma filtering bleb leak. Design Retrospective, nonrandomized, comparative interventional trial. Participants Fifty-one eyes of 48 persons who underwent management of late-onset glaucoma filtering bleb leak from December 1986 through December 1999 were included. Thirty-seven eyes were included in the nonincisional treatment group (aqueous suppression with lubrication or patching, bandage contact lenses, cyanoacrylate glue, autologous blood injection, or a combination thereof) and 34 eyes were included in the surgical revision group (conjunctival advancement with preservation of the preexisting bleb). Twenty eyes underwent nonincisional treatment before surgical revision and were included in each treatment group. Methods Retrospective chart review of bleb leaks occurring at least 2 months after trabeculectomy. Successful treatment was defined as the resolution of the bleb leak, a final intraocular pressure (IOP) of 21 mmHg or less, and no significant complications such as blebitis, endophthalmitis, or bleb dysesthesia requiring a bleb revision. Main outcome measures Cumulative success of closure of the filtering bleb leak, complications resulting from the intervention, IOP before and after treatment, and number of glaucoma medications before and after treatment. Results The Kaplan-Meier cumulative probability of success at 12 and 24 months were 0.45 and 0.42, respectively, for the nonincisional treatment group and 0.80 and 0.80, respectively, for the surgical revision group. The overall difference between the cumulative success of surgical and nonincisional treatment was statistically significant ( P = 0.0001, log-rank test). In the nonincisional treatment group, only 20 of 37 eyes (54%) achieved initial sealing of the bleb leak after the treatment, and of those, almost half (8/20) eventually failed. Reasons for failure included persistent or recurrent leak (n = 21), blebitis or endophthalmitis (n = 6, including 4 with persistent leak), and bleb dysesthesia (n = 2). All eyes in the surgical group achieved closure of the leak, however 7 eventually failed because of leak recurrence (n = 2), elevated IOP (n = 3), or bleb dysesthesia (n = 2), and 11 required additional glaucoma medications. Conclusions Patients with late bleb leaks managed with conjunctival advancement were more likely to have successful outcomes and less likely to have serious intraocular infections than those managed more conservatively.
Terramechanics based terrain deformation for real-time off-road vehicle simulation

When ground vehicles navigate on soft terrains such as sand, snow and mud, they often leave distinctive tracks. The realistic simulation of such vehicle-terrain interaction is important for ground based visual simulations and many video games. However, the existing research in terrain deformation has not addressed this issue effectively. In this paper, we present a new terrain deformation algorithm for simulating vehicle-terrain interaction in real time. The algorithm is based on the classic terramechanics theories, and calculates terrain deformation according to the vehicle load, velocity, tire size, and soil concentration. As a result, this algorithm can simulate different vehicle tracks on different types of terrains with different vehicle properties. We demonstrate our algorithm by vehicle tracks on soft terrain.
High Pressure Transformation of La4Cu3MoO12 to a Layered Perovskite

Douglas A. Vander Griend, Sophie Boudin, andKenneth R. Poeppelmeier*Department of Chemistry and the Science and TechnologyCenter for SuperconductiVityNorthwestern UniVersity, 2145 Sheridan RoadEVanston, Illinois 60208-3113Masaki Azuma, Hiroki Toganoh, and Mikio TakanoInstitute for Chemical Research, Kyoto UniVersityUji, Kyoto-Fu 611, JapanReceiVed June 29, 1998High pressure (HP) can facilitate the synthesis of metastablesuperconductors because it stabilizes the perovskite structure. Inthis paper, we describe the HP synthesis of a new copper-richlayered perovskite, La
A beam-splitting reflection grating

A metallic grating made of triangular grooves filled with penetrable material is considered. A plane wave normally incident and polarized perpendicular to the grooves produces three plane waves, one backreflected and two obliquely reflected, for certain ratios between groove dimensions and wavelength. This geometrical optics solution is exact. In particular, if the material filling the grooves is isorefractive to the surrounding medium, then the backreflected field is zero.
Oxygen consumption in the rat during prolonged, acute starvation.

SummaryHypothyroid, hyperthyroid and euthyroid rats were subjected to acute starvation to extremis. Their oxygen consumption was measured daily. All groups showed an approximately equivalent early depression of oxygen consumption which is independent of the absolute level of the initial oxygen consumption.
SU-E-I-41: Non-Cartesian MR Image Reconstruction with Integrated Gradient Non-Linearity Correction

Purpose: Nonlinearities in the spatial encoding gradients of MRI systems cause geometric distortion in images. Typically, this is retrospectively corrected via image-domain interpolation (a.k.a., “gradwarp”) albeit with a loss of spatial resolution. For non-Cartesian MRI, the latter problem is exaggerated by noise and undersampling artifact. In this study, we describe a novel correction strategy that accounts for gradient nonlinearities during — rather than after — non-Cartesian MRI reconstruction, and demonstrate that this approach mitigates the resolution loss that can occur with standard methods. Methods: To test the proposed method, the American College of Radiology (ACR) quality control phantom was scanned on at 1.5 T (General Electric, v16.0, “zoom” gradient) using a 1.6x undersampled 3D non- Cartesian Shells trajectory (GRE, FOV=24 cm3, 120 shells, 16552 shots, 512 readout, matrix=2403). Image reconstruction was first performed via standard k-space density-compensated gridding and retrospectively corrected via cubic spline interpolation. Image reconstruction was then separately performed using a k-space and image-domain densitycompensated type-3 non-uniform fast Fourier transform (NUFFT), which provides a direct mapping between non-Cartesian k-space samples and warped image space voxel locations. Thus, no separate distortion correction procedure is needed for the proposed approach. The gradient distortion field was determined using vendor provided calibration data. Results: Phantom scan results show that both processing approaches successfully correct geometric distortion. However, visual inspection of the ACR phantom spatial resolution inserts shows that the proposed strategy preserves the resolution of the nominal (uncorrected) reconstruction while “gradwarp” imparts marked spatial blurring (especially for the 1.0 and 1.1 mm inserts) and thus resolution loss. Conclusion: We've presented a novel reconstruction strategy for non-Cartesian MRI that corrects for gradient nonlinearities during — rather than after — reconstruction, and thus better preserves image resolution than traditional interpolation-based methods. This approach is expected to be especially advantageous when imaging with non-standard magnet geometries. NIH RR018898; NIH EB10065
Mechanical analysis and optimization of a cup arthroplasty.

Abstract The surgeon performing cup arthroplasty is free to relocate the acetabulum and the greater trochanter within certain limits. A method was developed so that optimum relocation can be accomplished based on a mechanical analysis of the hip. Clinical observations indicated that acetabular pressure and abductor muscle force should be minimized. A force and pressure analysis was written based on information that can be obtained from an X-ray. The problem was then formulated as a constrained optimization problem from which optimum geometry can be obtained which minimizes either acetabular pressure or abductor force. A computer program was written using the sequential unconstrained minimization technique, and extensive numerical results were obtained. The results show that minimum abductor force is the best optimization criterion, that the acetabulum should be moved medially and inferiorly, and that the tip of the greater trochanter should be moved laterally to obtain the minimum abductor force. An example is given which shows that these modifications can lead to significant reductions in abductor force and acetabular pressure.
Identifying failure mechanisms of composite structures under compressive load

Abstract Various failure mechanisms involving both local and global deformation mechanisms of layered structures, consisting of differently oriented orthotropic laminae, are investigated with a large deformation finite element analysis. Under large compressive loads, fiber-reinforced composite structures can fail by buckling, kink band formation and/or delamination growth. Our aim is to identify the dominant mode which leads to the structural failure under a given boundary condition and geometrical shape. It is assumed that these structures contain initial interlaminar flaws represented by embedded delaminations. Such flaws can play a significant role in defining overall structural integrity and deformation mechanisms. Our study considers two structures with distinguished shapes, both consisting of four layer laminae. The first structure is a flat panel under compressive load and the second structure is a cylindrical shell subjected to external pressure. In both cases, the energy release rate and mixed-mode stress intensity factors are computed to quantify the crack driving force and used to measure likelihood of delamination growth. In the flat panel model, two buckling modes, a global and a local, are observed under quasi-static loading conditions. Depending upon the delamination length and laminate stacking orientations, the interaction of these two modes can produce an unstable post-buckling behavior. It is found that the energy release rate exceeds experimentally estimated fracture toughness values only after buckling occurs. In the cylindrical shell study, lower critical buckling loads are observed for models with longer interlaminar delamination as in the flat panel model. However, unlike the flat panel case, the energy release rate surpasses the critical toughness well before the applied pressure reaches the buckling load of the flawed cylindrical shell. This behavior implies that a shell containing an embedded defect along an interface can fail by delamination growth and therefore has a failure load lower than its critical buckling load. Also, for thicker cylindrical shells, the compressive internal stress exceeds the predicted stress required for kink band formation prior to structural buckling. The competition among these failure modes, buckling, delamination growth and compressive kinking in fiber-reinforced composite structures, is studied and a design diagram is introduced here. This diagram predicts a likely dominant failure mode for given structural dimensions and material properties. In addition, unstable delamination growth along the lamina interface under dynamic loading conditions is simulated using an iterative computational procedure. The results predict that the crack tip velocity can reach a fraction of the material wave speed leading to total structural failure in a very short time. For the cylindrical shell, the inertial effect on the pressure-deformation relation is investigated by comparing it with the static results.
Letting the gene out of the bottle: a comment on returning individual research results to participants.

Geneticists have become victims of their own success. Recent pressures to return individual research results to participants have arisen, in part, because genetic research now produces some useful ...
Structure and development of expanding western juniper woodlands as influenced by two topographic variables

Abstract Juniper and pinon woodlands have been expanding throughout the Intermountain West, USA since the late 1800s. Although causal factors attributed to woodland expansion have been documented, data are lacking that describe the influence of topographic features on rates of development and structural attributes of expanding woodlands. Our primary objective was to determine the relationship between stand-level developmental and structural attributes of four expanding western juniper (Juniperus occidentalis) woodlands with two topographic features commonly important to forest vegetation patterns, site exposure (an index of insolation exposure based on slope and aspect) and elevation. To accomplish this we measured tree density and age across four western juniper woodlands in Oregon and Idaho. Site exposure and elevation were consistently correlated with spatial and temporal components of woodland development and structure. Holding slope constant, a shift from a north to south aspect resulted in a 4.9 trees/ha/year decrease in tree establishment at a similar elevation. A 200 m rise in elevation was associated with a 1.8 trees/ha/year increase in tree establishment with similar exposure. A 100 m rise in elevation was associated with a 5-year decrease in the time required for a stand to reach dominance and a 22% increase in dominant tree density among stands with similar site exposure. Although significant, site exposure and elevation only explained a portion of the process of woodland dynamics. However, our data suggest exposure and elevation are contributing variables influencing woodland expansion across landscapes, resulting in spatial and temporal heterogeneity in stand structure and development. Models of woodland expansion incorporating landscape topographic features may be practical for identifying windows of opportunity for less costly restoration.
Multiple Dielectric Relaxation Times in an Irradiated Transmission Line

The theory of multiple dielectric relaxation times in an irradiated transmission line is developed in detail for strip lines and coaxial lines. The problem of deposition profiles, photo-Compton currents, and dielectric properties which vary arbitrarily is treated first; then the treatment is specialized to layered dielectrics. A numerical scheme is given for solving the resulting system of equations describing wave propagation on a line with layered dielectrics. The generalization to a shielded strip line (a three-conductor line) is also presented.
The problem of used nuclear fuel: lessons for interim solutions from a comparative cost analysis

Abstract An acceptable long-term solution for used (spent) fuel from nuclear power reactors has evaded all countries engaged in the civilian nuclear fuel cycle. Furthermore, many countries are trying to develop interim storage solutions that address the shortage of storage in the spent fuel cooling pools at reactors. The United States has a particularly acute problem due to its adherence to an open fuel cycle and its large number of reactors. Two main options are available to address the spent fuel problem: dry storage on-site at reactors and centralized storage at a facility away from reactors. Key to deciding which option makes better policy sense is the comparative economics of the two options. This paper provides one of the few comprehensive comparisons of costs for the two alternatives and discusses implications for other schemes and possible alternative solutions to the spent fuel problem for the United States.
Two dimensional eye movement recording using a photo-electric matrix method.

Abstract A photoelectric device is described for simultaneous recording of both horizontal and vertical eye movements in the range of ± 15 degrees. This small spectacle-mounted unit distinguishes itself by use of only a pair of photocells to transduce two dimensional eye movements —thereby facilitating simple adjustments and calibration.
Separation of double-stranded DNA fragments by capillary electrophoresis using polyvinylpyrrolidone and poly(N, N-dimethylacrylamide) transient interpenetrating network

A noncross-linked interpenetrating polymer network (IPN), consisting of poly(N,N-dimethylacrylamide) (PDMA) and polyvinylpyrrolidone (PVP, weight-average molecular weight M(w) = 1 x 10(6) g/mol) was synthesized by polymerizing N,N-dimethylacrylamide (DMA) monomers directly in PVP buffer solution and tested as a separation medium for double-stranded (ds)DNA analysis without further purification. Due to the incompatibility of PVP and PDMA, a simple solution mixture could incur a microphase separation and showed poor performance on dsDNA separation. However, a dramatic improvement was achieved by the formation of an IPN. We attributed the high sieving ability of IPN as due to an increase in the number of entanglements by the more extended polymer chains. Apparent viscosity studies showed that the IPN had a much higher viscosity than the simple mixture containing the same amount of PDMA and PVP. In 1 x Tris-borate-EDTA (TBE) buffer, the concentration ratio of PDMA and PVP had a great effect on the DNA separation. At optimal conditions, the 22 fragments in pBR322/HaeIII DNA were successfully separated within 15 min, with a resolution of better than 1.0 for 123/124 bp.
Modification of martian slope streaks by eolian processes

Recent images from the High Resolution Imaging Science Experiment (HiRISE) camera have shown that slope streaks have relief on the order of a meter or less. This study presents observations of transverse bedforms and infill deposits within slope streak beds that were not previously identified or were uncommon from earlier analyses of HiRISE images. Transverse bedforms are linear to slightly arcuate features oriented transverse to the slope streak bed which may be analogous to terrestrial splash or coarse-grained ripples based on their morphology, wavelength, and amplitude. In addition to the bedforms, there is also evidence that slope streak beds gradually shallow over time by infilling of material. The presence of ripples within slope streaks implies that saltation-capable material is available on the surface today and/or was available in the recent past. Although airfall dust is not a capable saltation source material, aggregates of electrostatically-bound dust that are possibly later cemented by salts may serve as a source. From the results of this study, we hypothesize a sequence of events in a slope streak formation and modification cycle where grains saltate to form ripples along the bed of a slope streak, airfall dust mantling causes gradual fading of the streak, and infill material buries the ripples, eventually reaching the pre-avalanche surface that removes all traces of relief.
Reproductive Senescence in Female C57BL/6J Mice: Ovarian Impairments and Neuroendocrine Impairments that Are Partially Reversible and Delayable by Ovariectomy*

Ovarian and neuroendocrine impairments were examined before and after the age-correlated loss of estrous cycles in C57BL/6J female mice. The role of ovarian secretions in inducing neuroendocrine impairments before and after the loss of estrous cycles was also examined by determining neuroendocrine impairments after prolonged ovariectomy. Young (6-month-old) cycling, middle-aged (12-, 14-, and 16-month-old) cycling or acyclic, and old (18-month-old) acyclic mice were used. Ovarian impairments were assessed by grafting old ovaries into young hosts. Neuroendocrine impairments were assessed by grafting young ovaries into middle-aged and old hosts, ovariectomized either at grafting or 2 months before, and by inducing a LH surge in mice that had been ovariectomized for 4 days, 1 month, or 2 months. One group of 16-month-old and one group of 18-month-old mice were also ovariectomized at 6 months of age; these groups were used to examine the steroid-induced LH surge. The LH surge was induced by inserting sc a single priming estradiol (E2) implant, followed by two more (surge-inducing) implants 6 days later; 33 h after the second implantation, mice were decapitated (1800 h). The number of estrous cycles supported by middle-aged and old ovaries grafted into young hosts was reduced by more than 90% compared with that in young ovaries. The number of estrous cycles supported by middle-aged and old hosts given young ovarian grafts was reduced by 60% and 90%, respectively, compared with that in young hosts. Middle-aged and old hosts also had progressively longer estrous cycles than young hosts. Levels of the E2-induced LH surge in middle-aged and old mice were also reduced by 60% and 90%, respectively, compared with levels in young mice. In old acyclic mice, ovariectomy for 2 months partially reversed impairments in the LH surge and partially restored the ability to support cycles with young grafts; these functions, normally 90% impaired in old mice, were only 60% impaired after prolonged ovariectomy. Moreover, ovariectomy 2 months before grafting in old hosts resulted in shorter estrous cycles and 60% fewer pituitary adenomas. In middle-aged cycling mice, ovariectomy for 2 months did not affect impairments in the LH surge or in the ability to support estrous cycles with young grafts; these functions remained 60% impaired in middle-aged mice ovariectomized for 2 months. If mice were ovariectomized when young, the age-correlated impairments of the E2-induced LH surge at 16 months were largely prevented.(ABSTRACT TRUNCATED AT 400 WORDS)
Psychosocial Resources and the SES‐Health Relationship

Psychosocial resources, which include optimism, coping style, a sense of mastery or personal control, and social support, influence the relationship between SES and health. To varying degrees, these resources appear to be differentially distributed by social class and related to health outcomes. Such resources may partially mediate the impact of SES on health. For example, environments that undermine personal control may have an impact on chronic arousal and the corresponding development of disease, such as CHD. Psychosocial resources may also moderate the impact of SES on health. For example, a large number of positive social relationships and a few conflictual ones may buffer individuals against the adverse effects of SES-related stress. These psychosocial resources are moderately intercorrelated, and so a research strategy that explores their coherence as a psychosocial profile that promotes resilience to stress is tenable and merits empirical examination. The erosion of these resources as one moves lower on the SES scale and specific factors that contribute to such erosion are discussed.