cssi/SciSciGPT-SciSciNet huggingface dataset:
Integrating wearable data into circadian models

Abstract The emergence of wearable health sensors in the last decade has the potential to revolutionize the study of sleep and circadian rhythms. In particular, recent progress has been made in the use of mathematical models in the prediction of a patient's internal circadian state using data measured by wearable devices. This is a vital step in our ability to identify optimal circadian timing for health interventions. We review the available data for fitting circadian phase models with a focus on wearable data sets. Finally, we review the current modeling paradigms and explore avenues for developing personalized parameter sets in limit cycle oscillator models to further improve prediction accuracy.
Protocolized Based Management of Cerebrospinal Fluid Drains in Thoracic Endovascular Aortic Aneurysm Repair Procedures.

Background Spinal cord ischemia (SCI) resulting in paraplegia is a devastating complication associated with thoracic endovascular aortic aneurysm repair (TEVAR) whose incidence has significantly declined over time. In this review, we present our experience with a multidisciplinary clinical protocol for cerebrospinal fluid (CSF) drain management in patients undergoing TEVAR. Furthermore, we aimed to characterize complications of CSF drain placement in a large, single center experience of patients who underwent TEVAR. Methods This retrospective review is of patients undergoing TEVAR with and without CSF drain placement between January 2014 and December 2019 at a single institution. Patient demographics, hospital course, and drain-related complications were analyzed to assess the incidence of CSF drain-related complications. Results A total of 235 patients were included in this study, of which 85 received CSF drains. Eighty patients (94.1%) were placed by anesthesiologists, while 5 (5.9%) were placed under fluoroscopic guidance by interventional neurosurgery. The most common level of placement was L3-L4 in 38 (44.7%) cases followed by L4-L5 in 36 (42.4%) cases. The mean duration of CSF drain was 1.9 ± 1.4 days. Complications due to CSF drainage occurred in 5 (5.9%) patients and included partial retainment of catheter, subdural edema, epidural hematoma, headache, and bleeding near the drain site. The overall 30-day mortality rate was 5.5% and did not differ between those who received a CSF drain and those who did not (P = 0.856). The overall incidence of SCI resulting in paraplegia was 1.7% in the studied patients. Conclusions A protocol-based CSF drainage program for spinal cord protection involves a multifaceted approach in identification and selection of patients meeting criteria for prophylactic drain placement, direct closed loop communication, and perioperative management by an experienced team. Despite the inherent advantages of CSF drain placement, it is not without complications, thus risk and benefit need to be weighed in context of the procedure and the patient with close communication and team approach.
Contracting Costs and Reputational Contracts

Reputational capital is a frequently cited attribute of private equity transactions. In this paper we construct a simple model to illustrate the relationship between reputational capital, covenants and loan spreads in the leveraged loan market. Our model predicts that reliance on reputational capital varies inversely with a sponsor’s past loan performance and the efficiency of the enforcement formal contracts terms. Our model also predicts that for sponsored deals, spreads will be lower on Cov-Lite loans than loans with maintenance covenants. Using a large sample of leveraged loans originated between 2005 and 2018, we find evidence consistent with these predictions.
Osteoporosis and fractures in rheumatoid arthritis.

Purpose of review Rheumatoid arthritis (RA) is associated with increased risk for osteoporotic fracture. We highlight RA-specific risk factors for bone mineral density (BMD) loss and fractures and considerations regarding the diagnosis and treatment of osteoporosis in patients with RA. Recent findings Anticitrullinated protein antibody (ACPA) positivity, although associated with low BMD in early RA, is not associated with accelerated BMD loss over time when compared to ACPA negative individuals. Studies have found reduced BMD in individuals on low doses of glucocorticoids (GCs). Poor functional status and frailty are additional important risk factors for low BMD and fractures. Heightened fracture risk in RA may be mitigated by tight disease control, and biologic therapies are associated with more stable BMD compared to nonbiologic therapies. Evidence-based guidelines specific for treating osteoporosis in patients with RA do not exist. Thus, treatment decisions are based on general osteoporosis guidelines, taking into account additional RA-specific risk factors. Summary Recent studies have advanced knowledge of RA-specific risk factors for BMD loss and fractures. Future studies applying these findings to modify established fracture risk algorithms as well as evaluating osteoporosis treatments in RA cohorts are needed to reduce the risk of disabling fractures in these patients.
Volunteering and health: The role of social network change.

Abstract Objectives Levels of volunteering may differentially influence multiple dimensions of health among older adults. Further, increasing evidence indicates social networks represent critical bridging and bonding contexts for the volunteering-health link. This study examines two research questions: 1) does volunteering level (low, moderate, high) influence physical and mental health in the same ways? And 2) does social network change moderate this link? Methods Data come from Waves 1 and 2 of the longitudinal Social Relations Study (n = 556) collected in 1992 and 2005 and the sub-sample of adults age 50 and older at Wave 2. Regression analyses predicting self-rated health and depressive symptoms were conducted to examine main effects of volunteering and moderating effects of social network change. Results Volunteering at a moderate level (101–300 hours per year) was associated with fewer depressive symptoms compared to those not volunteering. Social network change moderated the association between volunteering and self-rated health. Among those reporting a decrease in the proportion of non-family in their network (decrease in bridging), a moderate level of volunteering was associated with better self-rated health. Conclusion While moderate levels of volunteering are associated with better mental health, the link to physical health is only present in the context of decreasing network bridging. Identifying specific circumstances under which volunteering is beneficial is critical for developing interventions to promote health for all, including those in mid and later life.
Lower respiratory tract infection hospitalizations among American Indian/Alaska Native adults, Indian Health Service and Alaska Region, 1998-2014.

OBJECTIVES This study describes the changes in lower respiratory tract infection (LRTI) rates from 1998 to 2014 among hospitalized American Indian/Alaska Native (AI/AN) adults residing in Alaska and other Indian Health Service (IHS) regions. METHODS Age-adjusted hospital discharge rates and rate ratios were calculated from the IHS Direct and Contract Health Services Inpatient Dataset, IHS National Patient Information Reporting System for AI/AN adults ≥18 years, hospitalized at an IHS-operated, tribally operated, or contract hospital with an LRTI-associated diagnosis during 1998-2014. RESULTS Overall, there were 13 733 LRTI-associated hospitalizations in Alaska (1998-2014), with an age-adjusted rate of 13.7/1000 adults. Among non-Alaska (non-AK) AI/AN, there were a total of 79 170 hospitalizations, with a rate of 8.6/1000 adults. In the pre-PCV7 and pre-PCV13 periods, LRTI rates were higher in Alaska (AK) AI/AN (12.4 and 14.1, respectively) when compared to non-AK AI/AN (10.1 and 9.1, respectively) (P < 0.0001). In the post-PCV7 and post-PCV13 periods, LRTI rates were also higher in AK (13.5 and 15.0, respectively) compared to non-AK (9.2 and 7.3, respectively) (P < 0.0001). CONCLUSIONS Over the study period, a 26% increase in rates of LRTI among adult AI/AN residing in AK compared with a 38% decrease in rates among AI/AN residing in non-AK were observed. This disparity is likely due to a variety of factors such as tobacco use, crowding, etc. Strategies to reduce LRTI in AI/AN adults are needed.
161 Incidence of pneumothorax from chest wall blocks for ambulatory breast cancer surgery in a high-volume practice

Background and Aims There is growing interest in regional anesthesia for breast surgery however many clinicians avoid paravertebral blocks (PVB) for fear of causing pneumothorax due to proximity to the pleura. Fascial plane blocks have been proposed as alternative approaches that may be safer for patients. We describe the rate of pneumothorax from PVB and serratus blocks in our high-volume practice. Methods This IRB-approved retrospective study assessed 2,793 patients who received a regional block for mastectomy from January 5, 2016 – April 22, 2020 subdivided by laterality and block type (Table 1). We calculated risk of pneumothorax (including 95% C.I.) for patients who received: at least one PVB; at least one serratus block; unilateral blocks; and bilateral blocks. All blocks were placed preoperatively with ultrasound-guidance by an experienced anesthesiologist or supervised trainee. Results PVB: 2251 patients, one pneumothorax. Complication rate 0.04%; 95% C.I. Serratus: 520 patients, one pneumothorax. Complication rate 0.2%; 95% C.I. Unilateral: 1081 patients, no pneumothorax. Complication rate 0%; 95% C.I. 0%, 0.3% Bilateral: 1712 patients, two pneumothoraces. Complication rate 0.1%; 95% C.I. Conclusions Pneumothorax is a rare complication of ultrasound-guided PVB and serratus blocks in a high-volume practice. This aligns with the prior findings of Pace1 in a retrospective study of 856 patients who received ultrasound-guided PVB, none of whom had suspected pneumothorax. We report a slightly higher rate of pneumothorax with serratus blocks, suggesting that fascial plane blocks are not necessarily ‘safer.’
Theory and Management of the Downer Cow

Sick animals of all quadruped species often become recumbent, but the recumbency of the downer cow seems to have some unique features. While a well accepted definition of the downer cow is not available, commonly recognized downer syndromes do not occur in other species.
SU-E-T-322: Dosimetric Evaluation of Rib Dose in Peripheral Lung Tumors Treated with X-Ray Voxel Monte Carlo (XVMC) Based Lung Stereotactic Body Radiotherapy (SBRT) Following RTOG 0915 Guidelines

Purpose: To evaluate XVMC computed rib doses for peripherally located non-small-cell-lung tumors treated with SBRT following RTOG-0915 guidelines. Methods: Twenty patients with solitary peripherally located non-small-cell-lung tumors were treated using XVMC-based SBRT to 50–54Gy in 5−3 fractions, respectively, for PTV(V100%)=95%. Based on 4D-CT, ITV was delineated on MaximumIP images and organs-at-risk(OARs) including ribs were contoured on MeanIP images. Mean PTV(ITV+5mm uniform margin) was 46.1±38.7cc (range, 11.1–163.0cc). XVMC SBRT treatment plans were generated with a combination of non-coplanar 3D-conformal arcs/beams, and were delivered by Novalis-TX consisting of HD-MLCs and a 6MV-SRS(1000MU/min) beam, following RTOG-0915 criteria. XVMC rib maximum dose and dose to <1cc, <5cc, <10cc were evaluated as a function of PTV, prescription dose and 3D-distance from tumor isocenter to the most proximal rib contour. Plans were re-computed using heterogeneity-corrected pencil-beam (PB-hete) algorithm utilizing identical beam geometry/MLC positions and MUs and subsequently compared to XVMC. Results: XVMC average maximum rib dose was 50.9±6.4Gy (range, 35.1–59.3Gy). XVMC mean rib dose to <1cc was 41.6±5.6Gy (range, 27.9–47.9Gy), <5cc was 31.2±7.3Gy (range, 10.6–43.1Gy), and <10cc was 21.2±8.7Gy (range, 1.1–36Gy), respectively. For the given prescription, correlation between PTV and rib doses to <5cc (p=0.005) and <10cc (p=0.018) was observed. 3D-distance from the tumor isocenter to the proximal rib contour strongly correlated with maximum rib dose (p=0.0001). PB-hete algorithm overestimated maximum rib dose and dose to <1cc, <5cc, and <10cc of ribs by 5%, 3%, 3%, and 3%, respectively. Conclusion: PB-hete overestimates ribs dose relative to XVMC. Since all the clinical XVMC plans were generated without compromising the target coverage (per RTOG-0915), almost all patient’s ribs doses were higher than the protocol guidelines. As expected, larger tumor size and proximity to ribs received higher absolute dose to ribs. Prospective observation is needed to determine if XVMC delivered rib doses correlates with patient symptoms including chest wall pain and/or rib fractures.
Heterologous expression of the cloned guinea pig α2A, α2B, and α2C adrenoceptor subtypes : radioligand binding and functional coupling to a cAMP-responsive reporter gene

Abstract Functional studies have shown that 6-chloro-9-[(3-methyl-2-butenyl)oxy]-3-methyl-1H-2,3,4, 5-tetrahydro-3-benzazepine (SKF 104078) has very low affinity for prejunctional α2-adrenoceptors (α2-AR) in the guinea pig atrium. In this study, we have cloned guinea pig homologues of the human α2-C10, α2-C2 and α2-C4 AR subtypes and have studied them in isolation by heterologous expression in cultured mammalian cells. Oligonucleotide primers, designed from conserved areas of the human α2-ARs were used in a polymerase chain reaction (PCR) with template cDNA synthesized from guinea pig atrial mRNA. Three PCR products were obtained that shared identity with the three human α2-AR subtypes. A guinea pig (gp) genomic library was screened with a cDNA clone encoding a portion of the gp-α2A, and genes containing the complete coding sequences of the guinea pig α2A, α2B, and α2C AR subtypes were obtained. These guinea pig genes were subcloned into a eukaryotic expression plasmid and were expressed transiently in COS-7 cells. The binding of the α2-selective antagonist [3H]MK-912 to membranes prepared from these cells was specific and of high affinity with Kd values of 810 pM for gp-α2A, 2700 pM for gp-α2B and 110 pM for gp-α2C. Competition for the binding of [3H]MK-912 by SKF 104078 indicated that it was of moderately high affinity (~ 100 nM) but that it was not selective for any of the guinea pig α2-AR subtypes. Co-expression of guinea pig α2-AR subtypes with a cyclicAMP-responsive chloramphenicol acetyltransferase (CAT) reporter gene resulted in agonist-dependent modulation of CAT activity. For the gp-α2A, a biphasic response was obtained with low concentrations of noradrenaline (NE) decreasing forskolin-stimulated CAT activity and high concentrations causing a reversal. For the gp-α2B, NE produced mostly potentiation of forskolin-stimulated activity, and for the gp-α2C, NE caused mainly inhibition. Overall, the pharmacology of the cloned guinea pig α2-AR subtypes was in agreement with data obtained for the native guinea pig receptors and was functionally similar to that of the cloned human α2-AR subtypes.
Quasi-one-dimensional scattering with general transverse two-dimensional confinement

Confinement-induced resonances (CIR) in quasi-one-dimensional (quasi-1D) systems have been theoretically predicted and observed in various ultracold atomic gases. Here a regularized local frame transformation method is developed to treat CIR in a quasi-1D system that has an arbitrary transverse trap shape in general. The method is applied to predict the CIR position in a system having a square transverse geometry with hard walls.
Disruption of mutually negative regulatory feedback loop between interferon-inducible p202 protein and the E2F family of transcription factors in lupus-prone mice

Studies have identified IFN-inducible Ifi202 gene as a lupus susceptibility gene (encoding p202 protein) in mouse models of lupus disease. However, signaling pathways that regulate the Ifi202 expression in cells remain to be elucidated. We found that steady-state levels of Ifi202 mRNA and protein were high in mouse embryonic fibroblasts (MEFs) from E2F1 knockout (E2F1−/−) and E2F1 and E2F2 double knockout (E2F1−/−E2F2−/−) mice than isogenic wild-type MEFs. Moreover, overexpression of E2F1 in mouse fibroblasts decreased expression of p202. Furthermore, expression of E2F1, but not E2F4, transcription factor in mouse fibroblasts repressed the activity of 202-luc-reporter in promoter-reporter assays. Interestingly, the E2F1-mediated transcriptional repression of the 202-luc-reporter was independent of p53 and pRb expression. However, the repression was dependent on the ability of E2F1 to bind DNA. We have identified a potential E2F DNA-binding site in the 5′-regulatory region of the Ifi202 gene, and mutations in this E2F DNA-binding site reduced the E2F1-mediated transcriptional repression of 202-luc-reporter. Because p202 inhibits the E2F1-mediated transcriptional activation of genes, we compared the expression of E2F1 and its target genes in splenic cells from lupus-prone B6.Nba2 congenic mice, which express increased levels of p202, with age-matched C57BL/6 mice. We found that increased expression of Ifi202 in the congenic mice was associated with inhibition of E2F1-mediated transcription and decreased expression of E2F1 and its target genes that encode proapoptotic proteins. Our observations support the idea that increased Ifi202 expression in certain strains of mice contributes to lupus susceptibility in part by inhibiting E2F1-mediated functions.
Esophageal cryptococcosis in a patient with the hyperimmunoglobulin E-recurrent infection (Job's) syndrome

Patients with the hyperimmunoglobulin E-recurrent infection (Job's) syndrome, which is characterized by an elevated immunoglobulin E level, recurrent staphylococcal infections, and an abnormality of neutrophil chemotaxis, have been reported to have visceral Candida infections in addition to their more frequent pyogenic infections. We report a patient with Job's syndrome who presented with massive hematemesis secondary to esophageal cryptococcosis. A thorough evaluation for an occult neoplasm or extraesophageal cryptococcosis was negative. The patient received a 6-wk course of amphotericin B (970 mg) and 5-fluorocytosine with complete radiographic and endoscopic resolution of the lesion. He is doing well 18 mo after therapy. The patient was not anergic, and his response to T-cell mitogens, helper-to-suppressor T-cell ratio, total number of T cells, and immunoglobulin-producing capability were all normal. This case is unusual in that it is the first documentation of a cryptococcoma of the esophagus and underscores the importance of culturing abnormal specimens for unsuspected pathogens in unusual clinical circumstances.
Investigation of DOTA-Metal Chelation Effects on the Chemical Shift of 129Xe

Recent work has shown that xenon chemical shifts in cryptophane-cage sensors are affected when tethered chelators bind to metals. Here, we explore the xenon shifts in response to a wide range of metal ions binding to diastereomeric forms of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) linked to cryptophane-A. The shifts induced by the binding of Ca(2+) , Cu(2+) , Ce(3+) , Zn(2+) , Cd(2+) , Ni(2+) , Co(2+) , Cr(2+) , Fe(3+) , and Hg(2+) are distinct. In addition, the different responses of the diastereomers for the same metal ion indicate that shifts are affected by partial folding with a correlation between the expected coordination number of the metal in the DOTA complex and the chemical shift of (129) Xe. These sensors may be used to detect and quantify many important metal ions, and a better understanding of the basis for the induced shifts could enhance future designs.
Tumor cell dispersal: A little movement goes a long way

Human tumors display a surprising paucity of mutations when compared with an equivalent mass of normal cells. Remarkably, even within large tumors, the majority of mutations, especially driver mutations, are contained within most neoplastic cells, and genetic heterogeneity is limited. This
Seasonal yield distribution of cool-season grasses following winter defoliation.

Graziers in southeastern USA often stockpile forage in late summer to extend the grazing season and reduce feeding costs. The effect of winter grazing on the following growing seasons production in the upper Midwest has not been reported. This study was conducted to determine the consequential forage yield and persistence of several cool-season grasses following various winter defoliation and N fertilization treatments in the upper Midwest. Grass cultivars included early and late-maturing orchardgrass (Dactylis glomerata L.), quackgrass [Elytrigia repens (L.) Nevski], reed canarygrass (Phalaris arundinacea L.), smooth bromegrass (Bromus inermis Leyss.), tall fescue (Festuca arundinacea Schreb.), and timothy (Phleum pratense L.). October, December, or March defoliation generally did not affect seasonal forage yield except when early spring growth preceded March defoliation, reducing first-cut forage yields. Without N, timothy, reed canarygrass, and orchardgrass had the highest seasonal forage yields. Both orchardgrass varieties, tall fescue, and reed canarygrass had the greatest response to N whereas timothy had the lowest response. While both spring-applied N treatments (single and split application of 101 kg ha -1 ) had carryover effects into the midsummer cuttings, the single N application resulted in higher seasonal forage yield than the split-N application. Tall fescue had the greatest carryover response to N in both years. Orchardgrass and reed canarygrass provided the highest forage yields throughout the season. Tall fescue and both orchardgrass varieties were most persistent and timothy, smooth bromegrass, and quackgrass were least persistent.
Evaluation of Liquefaction Potential Using Neural Networks Based on Adaptive Resonance Theory

The incomprehensible loss of lives and extensive damages to transportation facilities caused by earthquakes emphasize the need for robust and reliable methods for evaluating the liquefaction potential of sites. Traditional methods for evaluating liquefaction potential are based on correlating data from the standard penetration test (blow count, N), cone penetration test (cone resistance, qc), or the shear wave velocity (Vs) with the cyclic stress ratio. These methods are unable to incorporate the complex influence of various soil and in situ state parameters. This problem encouraged the development of numerous nontraditional methods such as artificial neural networks that try to learn and account for the influence of various soil and in situ state properties. The possibility of using neural networks based on adaptive resonance theory (ART) for the prediction of liquefaction potential was explored. These networks have been shown to be far more efficient and reliable than the commonly used backpropagation a...
Atomistic lattice-gas modeling of CO oxidation on Pd(100): Temperature-programed spectroscopy and steady-state behavior

We have developed an atomistic lattice-gas model for the catalytic oxidation of CO on single-crystal Pd(100) surfaces under ultrahigh vacuum conditions. This model necessarily incorporates an detailed description of adlayer ordering and adsorption-desorption kinetics both for CO on Pd(100), and for oxygen on Pd(100). Relevant energetic parameters are determined by comparing model predictions with experiment, together with some guidance from density functional theory calculations. The latter also facilitates description of the interaction and reaction of adsorbed CO and oxygen. Kinetic Monte Carlo simulations of this reaction model are performed to predict temperature-programed reaction spectra, as well as steady-state bifurcation behavior.
Absorption and emission line shapes in the O(2) atmospheric bands: Theoretical model and limb viewing simulations.

A multiple scattering radiative transfer model has been developed to carry out a line-by-line calculation of the absorption and emission limb measurements that will be made by the High Resolution Doppler Imager to be flown on the Upper Atmosphere Research Satellite. The multiple scattering model uses the doubling and adding methods to solve the radiative transfer equation, modified to take into account a spherical inhomogeneous atmosphere. Representative absorption and emission line shapes in the O2 1Sigma(+)g - 3Sigma(-)g atmospheric bands (A,B, and gamma) and their variation with altitude are presented. The effects of solar zenith angle, aerosol loading, surface albedo, and cloud height on the line shapes are also discussed.
International water management in the Aral Sea basin

ABSTRACT The collapse of the Soviet Union in late 1991 has created five new states in the Aral Sea basin in Central Asia. In addition to the turmoil resulting from this political change, this section of the Aral Sea basin suffers from serious environmental degradation, including the desiccation of the Aral Sea itself This situation has arisen from the Soviet government's decision to develop the region as a center for cotton production from the early 1960s onward, a policy requiring heavy applications of agricultural chemicals and enormous irrigation diversions from the basin's two main rivers. the Amu and Syr Darya. Consequently the jive new states in the region have inherited a complex environmental and water management problem from a time when this part of the basin was managed by a singlegovernment. Any attempts to ameliorate the serious environmental degradation found in some parts of the basin now requires cooperation between the new states. This article reports on the measures taken by the new state...
Cytomegalovirus Infection of Rats Increases the Neointimal Response to Vascular Injury Without Consistent Evidence of Direct Infection of the Vascular Wall

Background—Previous studies suggest that infection may play a role in restenosis and atherogenesis; cytomegalovirus (CMV) is one of the implicated pathogens. To determine a potential causal role of CMV in these disease processes, we assessed whether CMV infection increases the neointimal response to injury of the rat carotid artery. Methods and Results—Carotid injury was performed on 60 rats; immediately thereafter, 30 rats were infected with rat CMV, and the other 30 were mock-infected. Six weeks later, rats were euthanized, and the salivary glands, spleen, and carotid arteries were harvested. CMV infection was associated with significant exacerbation of the neointimal response to injury (neointimal to medial ratio 0.81±0.59 versus 0.31±0.38 in CMV-infected versus control rats; P<0.0001). This occurred despite absence of infectious virus from vascular tissues and detection of CMV DNA by polymerase chain reaction in the injured artery only at day 3 after infection. Persistent distant infection, associated...
The influence of carbon on melt processing Ag sheathed Bi2Sr2CaCu2O8 tape

Abstract We have investigated the influence of carbon on the melt processing of Ag sheathed Bi 2 Sr 2 CaCu 2 O 8 (2212) tapes. With increasing carbon content the melting and freezing temperatures of the 2212 phase decrease, varying from ∼865 to 850°C for carbon contents ranging from 0.02 to 0.16 wt.%, respectively, in the 2212 powder. The carbon content affects the phase assemblage in the melt and fully-processed tape. With increasing carbon content, the amount of Bi 2 (Sr,Ca) 4 O x in the melt decreases, and the amount of (Sr,Ca) 2 CuO 3 increases. SrCO 3 forms at high carbon contents. Methods to reduce the carbon content in 2212 powder have been studied. It can be removed by heating in flowing O 2 at 800°C or in vacuum at 600°C. The critical current density in tape with high carbon content is low (1 to 1.5 kA/cm 2 ) due to large nonsuperconducting phases and porosity in the microstructure.
Effect of venting on cast gold full crowns

I t would be highly desirable if the marginal opening of a crown could be reduced significantly by venting the crown before cementation without making any other alteration of the casting. Both electrochemical milling and etching require a long time. Also, the equipment that is necessary to do the electrochemical milling is not generally available to the practitioner. Although stripping can be done with aqua regia, the amount of gold removed by the process is at best an estimate and the process is time-consuming. Therefore, a procedure that can be accomplished at the chair, with a minimum of time and equipment, would help dentists to improve the marginal adaptation of full-crown castings. In 1966, a study’ was made to determine the type of margin of a cast gold restoration that would be acceptable to experienced dentists. The results showed that interproximal margins from 34 microns up to 119 microns were acceptable. This study underlines the difficulties involved in using an explorer and radiographs to evaluate a subgingival margin after cementation of a cast restoration. One of the most common causes of failure of any cast restoration is the solubility of the luting agent used to cement the restoration.’ Because the rate of marginal washout is related to the amount of exposed cement at the margin, anything that can be done to reduce the amount of marginal opening will increase the restoration’s chance for success. Several factors can influence the marginal opening of a crown after cementation. Of these factors, the consistency of the mixed cement and the contour of the preparation are important considerations, but the failure of the cemented crown to go completely to place on the prepared tooth is also a common source of error. One result of incomplete seating is an increased amount of exposed cement at the margins.
Correlation of neural cell adhesion molecules with perineural spread of squamous cell carcinoma of the head and neck

Perineural spread (PNS) is a poor prognostic factor associated with increased risk of local recurrence and nodal metastasis and reduced survival of patients with squamous cell carcinoma of the head and neck (SCCHN). There is some evidence to indicate that neural cell adhesion molecules (NCAMs) may play a role in PNS of a variety of tumor types. We performed this study to investigate whether NCAM expression can be used as a predictor of PNS in SCCHN. The surgical specimens of 66 patients with SCCHN were evaluated with monoclonal IgG antibody immunoperoxidase staining for NCAM. Of the 41 specimens with PNS, 38 (93%) showed evidence of NCAM expression. In contrast, only 9 specimens (36%) without PNS expressed NCAMs. The difference in NCAM expression between the study and control groups was statistically significant (P < 0.01).
Going the Distance for Protein Function Prediction: A New Distance Metric for Protein Interaction Networks

In protein-protein interaction (PPI) networks, functional similarity is often inferred based on the function of directly interacting proteins, or more generally, some notion of interaction network proximity among proteins in a local neighborhood. Prior methods typically measure proximity as the shortest-path distance in the network, but this has only a limited ability to capture fine-grained neighborhood distinctions, because most proteins are close to each other, and there are many ties in proximity. We introduce diffusion state distance (DSD), a new metric based on a graph diffusion property, designed to capture finer-grained distinctions in proximity for transfer of functional annotation in PPI networks. We present a tool that, when input a PPI network, will output the DSD distances between every pair of proteins. We show that replacing the shortest-path metric by DSD improves the performance of classical function prediction methods across the board.
Rapid modeling of diffuse reflectance of light in turbid slabs

An efficient and accurate hybrid model of the Monte Carlo technique and the diffusion theory was developed to simulate the diffuse reflectance of light in a turbid slab due to an infinitely narrow light beam. The narrow beam was normally incident on the top surface of the slab. The hybrid model was accurate in modeling the diffuse reflectance near the light source, where the diffusion theory was most inaccurate. The hybrid model was much faster than a pure Monte Carlo method by a factor as great as several hundred, depending on the optical properties, the thickness of the slab, and the settings of the hybrid and the Monte Carlo computations. The computation speed of the hybrid model was insensitive to the optical properties of the medium, in contrast to the pure Monte Carlo technique. The diffusion theory was accurate in modeling both the diffuse reflectance far from the source and the diffuse transmittance. The hybrid model and the diffusion theory should be used in conjunction for efficient and accurate computation of diffuse reflectance and diffuse transmittance.
Molecular structure, mechanical behavior and failure mechanism of the C-terminal cross-link domain in type I collagen

Collagen is a key constituent in structural materials found in biology, including bone, tendon, skin and blood vessels. Here we report a first molecular level model of an entire overlap region of a C-terminal cross-linked type I collagen assembly and carry out a nanomechanical characterization based on large-scale molecular dynamics simulation in explicit water solvent. Our results show that the deformation mechanism and strength of the structure are greatly affected by the presence of the cross-link, and by the specific loading condition of how the stretching is applied. We find that the presence of a cross-link results in greater strength during deformation as complete intermolecular slip is prevented, and thereby particularly affects larger deformation levels. Conversely, the lack of a cross-link results in the onset of intermolecular sliding during deformation and as a result an overall weaker structure is obtained. Through a detailed analysis of the distribution of deformation by calculating the molecular strain we show that the location of largest strains does not occur around the covalent bonding region, but is found in regions further away from this location. The insight developed from understanding collagenous materials from a fundamental molecular level upwards could play a role in advancing our understanding of physiological and disease states of connective tissues, and also enable the development of new scaffolding material for applications in regenerative medicine and biologically inspired materials.
Light pressure on chiral sculptured thin films and the circular Bragg phenomenon

For a circularly polarized plane wave incident normally on a chiral sculptured thin film (STF), we determined that light pressure per unit thickness on the film is high when the incident plane wave and the chiral STF are co-handed, the loss factor in the chiral STF is as low as possible, the wavelength is either the center-wavelength of the Bragg regime or close to it, and the ratio of the film thickness normalized by the period is moderately high.
REACTIVITY OF R2ALH (R = ME, BUI) AND ME3M (M AL, GA, IN) TOWARD THE SILYLPHOSPHINES P(SIME3)3 AND HP(SIME3)2

The reactivities of Me2AlH with P(SiMe3)3 and of Me3M (M = Al, Ga, In) and Bui2AlH with P(SiMe3)3 and HP(SiMe3)2 were monitored with multinuclear NMR to determine the trend for adduct formation and...
Physiological, morphological and growth responses to rhizosphere hypoxia by seedlings of North American bottomland oaks

Certaines especes de chenes du sud des Etats-Unis sont distribuees le long de gradients topographiques dans les plaines inondables. Du fait des differences dans l'aeration des sols associees a ces gradients, nous avons teste l'hypothese que ces especes presentent des resistances differentes a l'hypoxie rhizospherique. Quatre especes occupant differents sites des plaines inondables (Quercus lyrata, Q laurifolia, Q phellos, et Q nigra) ont ete soumises a deux experimentations pour evaluer les reponses des plantes au debut et a la fin de la premiere saison. Dans les deux etudes, la tolerance a l'hypoxie a ete estimee par la mesure d'echanges gazeux, l'accumulation de biomasse, et la croissance de la pousse et de la racine. Des differences de resistance a l'hypoxie de la rhizosphere ont ete mises en evidence et les consequences sur la distribution des especes dans les plaines inondables ont ete discutees.
Analyses of Activity for Factor Xa Inhibitors Based on Monte Carlo Simulations

Monte Carlo/Extended Linear Response (MC/ELR) simulations have been conducted on 60 inhibitors of human factor Xa to determine the important interactions associated with their activity. A variety of physicochemical descriptors were configurationally averaged during the course of the simulations of each inhibitor bound to factor Xa and free in water. A regression equation was then derived; it reproduces the experimental inhibition data with a correlation coefficient, r2, of 0.74, an rms error of 0.67 kcal/mol, and an average unsigned error of 0.60 kcal/mol using only two physically reasonable descriptors. The two factors that emerged as important in determining inhibitory potential are (1) favorable van der Waals interactions between protein and ligand and (2) direct hydrogen bonding between the inhibitor and protein. The conclusions were supported with structural analyses and results of MC/free energy perturbation (FEP) calculations.
Modeling a novel ion exchange process for arsenic and nitrate removal

Arsenate and nitrate can be removed quantitatively from drinking water by anion exchange. However, if the raw water contains substantial concentrations of sulfate or nitrate, the resin becomes exhausted quickly, and the requirements for regenerant (brine) can make the process unattractive. Previously, we described a modified ion exchange operating procedure for arsenic removal from solutions containing sulfate that could overcome this problem. This paper extends that work to solutions containing nitrate, and presents a mathematical model for the process. The selectivity coefficient for sulfate over nitrate of a strong base anion exchange resin increased dramatically with increasing ionic strength, partially counteracting the decrease in SO(4)/NO(3) separation factor predicted from mass action considerations. The value of this selectivity coefficient in different solutions can be used in conjunction with mass balances and solid/liquid equilibrium considerations to explore the brine requirement when the modified treatment process is applied to influent waters with various compositions. The modeling results indicate that, for relatively low influent nitrate concentrations, the volume of water treated per unit volume of brine used can be increased greatly by using the modified ion exchange process. At higher influent nitrate concentrations, the modified process remains advantageous, but is less so. The use of separate brine solutions to regenerate the upstream and downstream columns magnifies the benefits of the modified process significantly. If the sulfate in the brine is precipitated as CaSO(4)(s) rather than BaSO(4)(s), the brine usage rate increases by only 30-40%, even though the former solid is orders of magnitude more soluble than the latter.
The Inhibited Power Motive, Type A Behavior, and Patterns of Cardiovascular Response During the Structured Interview and Thematic Apperception Test

The Type A behavior pattern and the inhibited power motive have been implicated in the development of coronary heart disease (CHD). Since it is widely believed that enhanced cardiovascular responsivity may be one mechanism by which individuals develop CHD, the present study examined the relationship of Type A behavior and the inhibited power motive to different patterns of cardiovascular response during two behavioral tasks. Forty-one (24 Type A's, 17 Type B's) male undergraduates underwent the Type A structured interview (SI) and the Thematic Apperception Test (TAT) while a broad range of cardiovascular functions were simultaneously recorded. Different patterns of cardiovascular response were observed during the SI and TAT, and Type A's showed a greater tendency than Type B's to exhibit increased heart rate (HR), systolic blood pressure (SBP), and forearm blood flow (FBF) during the SI and the preparatory phase (but not the story-telling phase) of the TAT. The inhibited power motive was not related to enhanced cardiovascular responsivity during the SI or TAT. The implications of these findings for the development of CHD are discussed.
Flow across structured fiber bundles: a dimensionless correlation

Abstract We present a computational analysis of viscous flow across unidirectional arrays of fiber bundles using the boundary element method (BEM). We consider hexagonal arrays of fiber bundles in which the individual filaments are packed in hexagonal or square arrangements. Up to 300 individual filaments are included in each simulation. These are simple but not trivial models for dual porosity fibrous media (such as the preforms used in composites manufacturing or fiber bundles used in hollow membrane oxygenators) characterized by different inter- and intra-tow porosities. The way these porosities interact to determine the hydraulic permeability of such media is not well understood. Numerical solution of the flow problem yields the flowrate through the unit cell, from which the hydraulic permeability (Kp) of the dual porosity medium is computed. Through a large number of simulations we determine Kp for a range of inter- and intra-tow porosities and for a range of fiber sizes. A semi-empirical correlation is proposed which collapses all the numerical data (a total of 380 data points) on a single curve, for both, hexagonal and square intra-tow fiber arrangements. This correlation allows prediction of the permeability of hexagonal arrays of fiber bundles from a knowledge of their inter- and intra-tow porosities, the type of intra-tow packing and the size (or number) of the intra-tow filaments.
Studies on the Accuracy Stability and Efficiency of a New Time Integration Scheme for Ballast Modeling Using the Discrete Element Method

This paper presents the development of a semi-implicit time integration scheme, originally developed for structural dynamics in the 1970’s, and its implementation for use in Discrete Element Methods (DEM) for rigid particle interaction, and interaction of elastic bodies that are modeled as a cluster of rigid interconnected particles. The method is developed in view of ballast modeling that accounts for the flexibility of aggregates and the arbitrary shape and size of granules. The proposed scheme does not require any matrix inversions and is expressed in an incremental form making it appropriate for non-linear problems. The proposed method focuses on improving the efficiency, stability and accuracy of the solutions, as compared to current practice. A critical discussion of the findings of the studies is presented. Extended verification and assessment studies demonstrate that the proposed algorithm is unconditionally stable and accurate even for large time step sizes. It is demonstrated that the proposed method is at least as computationally efficient as the Central Difference Method. Guidelines for the implementation of the method to ballast modeling are discussed.Copyright © 2014 by ASME
Cultural Mechanisms in Neighborhood Effects Research in the United States

This paper discusses the current state of the U.S. literature on cultural mechanisms in neighborhood effects research. We first define what we mean by neighborhood effects and by cultural mechanisms. We then review and critique two theoretical perspectives on the cultural context of disadvantaged neighborhoods that are explicitly integrated into recent neighborhood effects literature in the U.S.: "deviant subculture" and "cultural heterogeneity." We then draw on other related U.S. literatures from urban studies, cultural sociology, and culture and inequality to suggest some other conceptualizations that may be useful in advancing our understanding of the role of culture in neighborhood effects. We discuss the conceptual and methodological issues that will have to be grappled with in order to move this literature forward and conclude by offering concrete suggestions, both short-term and long-term, for a research agenda.
Quantitative behavior of surfactants at the liquid/vacuum interface by secondary ion mass spectrometry

Abstract The behavior of a multicomponent solution of similar surfactants at the glycerol-vacuum interface as a function of bulk concentration has been studied using secondary ion mass spectrometry. Results obtained are consistent with a model which assumes simultaneous ion production, both from the surface monolayer and from the underlying bulk solution. Substantial differences in ionization efficiency among the surfactants studied were not observed. Sensitivity differences were attributable solely to differences in surface activity.
MECHANISM OF COBALT CLUSTER SIZE CONTROL IN CO-MCM-41 DURING SINGLE-WALL CARBON NANOTUBES SYNTHESIS BY CO DISPROPORTIONATION

The mechanisms controlling the reduction of cobalt and the growth of metallic cobalt clusters in Co-MCM-41 catalysts at different stages in the process of single-wall carbon nanotubes (SWNT) synthesis were investigated both by in-situ and ex-situ X-ray absorption spectroscopy. We have found that prereduction of the catalyst in hydrogen at temperatures below 700 °C does not reduce the cobalt ions to metallic cobalt, but removes hydroxyl groups and oxygen ions creating oxygen vacancies and/or a partially reduced cobalt species. The prereduction treatment, however, does increase the density of electrons at the Fermi level weakening the interaction of Co2+ with the silica framework. Subsequent exposure of the catalyst to CO at 750 °C causes CO to strongly interact with the cobalt clusters most likely by the transfer of electrons into the d orbitals of Co. This strong interaction makes the cobalt more mobile at the surface and allows it to nucleate into clusters capable of dissociating CO and initiating the gr...
Regulation of p53 expression by thymidylate synthase

Previous studies showed that thymidylate synthase (TS), as an RNA binding protein, regulates its own synthesis by impairing the translation of TS mRNA. In this report, we present evidence that p53 expression is affected in a similar manner by TS. For these studies, we used a TS-depleted human colon cancer HCT-C cell that had been transfected with either the human TS cDNA or the Escherichia coli TS gene. The level of p53 protein in transfected cells overexpressing human TS was significantly reduced when compared with its corresponding parent HCT-C cells. This suppression of p53 expression was the direct result of decreased translational efficiency of p53 mRNA. Similar results were obtained upon transfection of HCT-C cells with pcDNA 3.1 (+) containing the E. coli TS gene. These findings provide evidence that TS, from diverse species, specifically regulates p53 expression at the translational level. In addition, TS-overexpressing cells with suppressed levels of p53 are significantly impaired in their ability to arrest in G1 phase in response to exposure to a DNA-damaging agent such as γ-irradiation. These studies provide support for the in vivo biological relevance of the interaction between TS and p53 mRNA and identify a molecular pathway for controlling p53 expression.