cssi/SciSciGPT-SciSciNet huggingface dataset:
Impact of Medicaid Expansion on Healthcare Access Among Individuals Living With Chronic Diseases.

Introduction The Affordable Care Act's Medicaid expansion has been found to increase healthcare access among low-income individuals in the general population. Fewer studies have explored the impact of Medicaid expansion on healthcare access among those living with chronic diseases. It is also unclear whether the impact of Medicaid expansion varies across levels of educational attainment or poverty among this subgroup. This study investigates the impact of Medicaid expansion on healthcare access among adults aged 18–64 years living with chronic diseases, as well as its variations across educational attainment and federal poverty levels. Methods The 2011–2017 Behavioral Risk Factor Surveillance System data were used. Difference-in-difference analyses explored the impact of Medicaid expansion on healthcare access (health insurance coverage, routine checkup, having a personal doctor, and cost-related delayed care within the past 1 year) among individuals living with chronic diseases. Analyses were also stratified by levels of educational attainment and quartiles of the federal poverty level. Data were analyzed between February and November 2019. Results Medicaid expansion was associated with increased health insurance coverage (β=0.27, 95% CI=0.16, 0.38), increased likelihood of having a routine checkup (β=0.12, 95% CI=0.04, 0.22) within the past 1 year, increased likelihood of having a personal doctor (β=0.08, 95% CI=0.01, 0.12), and decreased likelihood of reporting cost-related delayed care (β=−0.10, 95% CI=−0.19, −0.02). Medicaid expansion was associated with increased health insurance coverage across all levels of educational attainment and federal poverty level quartiles. Conclusions Medicaid expansion increased healthcare access for low-income individuals living with chronic diseases.
The distinction between the terms sex and gender

Abstract Terminological distinction between “sex” and “gender”: while sex is a biological term distinguishing females and males by their biological and chromosomal characteristics, gender is a term related to societal and socioeconomic differences between positions and roles usually ascribed to female and male behavior.
Application of dielectrophoresis towards characterization of rare earth elements biosorption by Cupriavidus necator.

Abstract This work presents the dielectric characterization of rare earth elements (REEs) biosorption by Cupriavidus necator using dielectrophoretic crossover frequency measurements. Traditional means of characterizing biomass for biosorption is limited and time consuming. In this research we are presenting, for the first time, an electrokinetic method termed as dielectrophoresis (DEP) for the characterization of biosorption (uptake) of rare earth elements (REEs) by gram negative bacteria - Cupriavidus necator. To characterize, a 3mm-diameter point and planar microwell device platform is used to measure the DEP crossover frequency that yields the dielectric properties of the targeted biosorbents. Quantified dielectric properties of native Cupriavidus necator (REE−) and those exposed to rare earth elements (REE+): europium, neodymium, and samarium revealed a substantial change in the surface characteristics of the Cupriavidus necator after exposure to the REE solution. The response of C. necator to changes in REE exposure is substantially different for europium but similar between neodymium and samarium. Statistically both the REE+ and REE− groups dielectric signatures were significantly different proving that the REEs were absorbed by the bacteria. This research will revolutionize and impact the researchers and industrialists in the field of biosorption seeking for economical, greener, and sustainable means to recover REEs.
Anger as a Mechanism of Injustice Appraisals in Pediatric Chronic Pain.

Abstract Mechanisms explaining the relationship between pain-related injustice appraisals and functional outcomes in youth with chronic pain have yet to be examined. In studies of adults, greater pain-related injustice is associated with worse depressive symptoms and greater pain through greater anger. No study to date has examined anger expression as a mediator in the relationships between pain-related injustice appraisals and physical and psychosocial functioning in youth with chronic pain. The current sample consisted of 385 youth with varied pain conditions (75% female, 88% White, Mage=14.4 years) presenting to a university-affiliated pain clinic. Patients completed self-report measures assessing anger expression (anger-out and anger-in), pain-related injustice, pain intensity, functional disability, and emotional, social, and school functioning. Bootstrapped mediation analyses indicated that only anger-out (indirect effect= -.12, 95% CI: -.21, -.05) mediated the relationship between pain-related injustice and emotional functioning, whereas both anger-out (indirect effect= -.17, 95% CI: -.27, -.09) and anger-in (indirect effect= -.13, 95% CI: -.09, -.001) mediated the relationship between pain-related injustice and social functioning. Neither mode of anger expression mediated the relationship between pain-related injustice and pain intensity, functional disability, or school functioning. Collectively, these findings implicate anger as one mechanism by which pain-related injustice impacts psychosocial outcomes for youth with chronic pain. Perspective: Anger expression plays a mediating role in the relationship between pain-related injustice appraisals and psychosocial outcomes for youth with chronic pain. Anger represents one target for clinical care to decrease the deleterious impact of pain-related injustice on emotional and social functioning.
Biases in air quality models capturing ozone trends at the urban, regional and national scales: Impacts on Relative Response Factors (RRFs)

Abstract Chemical transport models (CTMs) are widely used in scientific studies and air quality management. A particular application is to assess how pollutant concentrations, particularly ozone and PM, respond to emission controls. As part of a dynamic evaluation, two widely used CTMs, CMAQ and CAMx, were evaluated for how well they captured trends in observed surface ozone, as well as the changes in associated concentrations, between 2001 to 2011 and 2011 to 2016. Those periods were chosen as additional effort was used to improve emissions estimates for all three years. Prior studies found that both emissions inventories and observations indicate reductions in both ozone and NO2 during these periods, but studies have found that NO2 observations have not agreed as well with estimated emissions. In general, given the efforts to harmonize model inputs, the two models performed very similarly and captured the ozone declines for both the 2001–2011 and 2011–2016 periods at the national level, though moderate biases were found in some locations. At the national scale, ozone trends for the 2011–2016 period were better captured by the models than those for the 2001–2011 period. Both models overestimated the observed decrease in ground level NO2 at the higher end of the concentration spectrum. This is linked to, and can cause, the detected tendency of the models to have larger than observed increases in ozone at the lower end over time. At the metropolitan statistical area (MSA) level, the performance of capturing the ozone trends varied. For some MSA's, the models estimated the wrong direction in the trends; e.g., in Denver, where maximum 8-hr average ozone levels increased from 2001 to 2011, the models predicted a decrease. The US EPA recommends location specific Relative Response Factors (RRFs) to adjust results when applying the models for air quality management purposes. At the regional level, the simulated ozone RRFs were up to 8% larger than the observed RRFs for the 2001–2011 period, suggesting that the models underestimated the ozone decrease. For the 2011–2016 period, with a couple of exceptions, the simulated RRFs were up to 9% smaller than observed RRFs, indicating a negative bias in the simulated trend. For individual MSAs, the ratio of the simulated to observed RRFs ranged between 0.86 (Knoxville for 2001–2011) and 1.40 (Los Angeles for 2001–2011). This is possibly linked to potential biases in the estimated emissions trends. Such high biases could lead to similar biases in the estimated emissions controls required for an area to attain the air quality standards. The results indicate that there are both spatial and temporal biases in how well the two models have captured the observed ozone and NO2 trends. Air quality planning agencies should aim to diagnose and reduce such biases before using model results for air quality management.
Dysregulated Transferrin Receptor Disrupts T Cell Iron Homeostasis to Drive Inflammation in Systemic Lupus Erythematosus

T cells in systemic lupus erythematosus (SLE) exhibit mitochondrial abnormalities including elevated oxidative stress. Because excess iron can promote these phenotypes, we tested iron regulation of SLE T cells. A CRISPR screen identified Transferrin Receptor (CD71) as important for Th1 cells but detrimental for induced regulatory T cells (iTreg). Activated T cells induce CD71 to increase iron uptake, but this was exaggerated in T cells from SLE-prone mice which accumulated iron. Treatment of T cells from SLE-prone mice with CD71 blocking antibody reduced intracellular iron and mTORC1 signaling and restored mitochondrial physiology. While Th1 cells were inhibited, CD71 blockade enhanced iTreg. In vivo this treatment reduced pathology and increased IL-10 in SLE-prone mice. Importantly, disease severity correlated with CD71 expression on SLE patient T cells and blocking CD71 enhanced IL-10 secretion. Excess T cell iron uptake thus contributes to T cell dysfunction and can be targeted to correct SLE-associated pathology.
Overcoming a Hurricane and Maintaining Wellness in College Student Physical Education

Background: With instructional time lost due to natural disasters, it is essential to examine the effect of a physical education course (PED 101) on college student well-being and motivation. Aim: This research examines the effect of physical education classes with a wellness component on wellness and motivation during a disruptive hurricane. Methods: A pre and posttest survey methodology was utilized to measure well-being and motivation, including by gender and exercise frequency, using the Wellness Inventory on college students enrolled in PED 101 who experienced Hurricane Florence. Results: All 12 dimensions of participants' wellness and their motivation to make changes in those wellness dimensions increased by the end of the hurricane semester. The results found significant changes between the pre- and post-assessment scores for all dimensions of wellness and motivation for male and female participants, as well as for all levels of exercise frequency. Conclusions: Including a well-being and motivation component in a college level physical education curriculum may enhance students' overall well-being and motivation during a disruptive hurricane.
No Changing the Conversation? Immigrant Integration Efforts in Metropolitan Phoenix

We examine attempts by public officials and advocates in the Phoenix, Arizona, metropolitan area to help integrate and empower Latino immigrants – socially, economically, and politically – in the face of an anti-immigrant political climate. We find that despite the emergence of a growing number of increasingly sophisticated advocacy organizations, service-providing nonprofits, and Latino elected officials, the participation of immigrants is severely constrained and efforts at broader integration are hamstrung. Four factors appear to be at work: an overwhelming focus in the current political dialogue on undocumented immigration and enforcement; meager resources due in part to a racialized social construction of “immigrants” in Arizona; a generational divide among Latino advocates; and certain institutional features of governance in the Phoenix region. Our empirical evidence draws upon extensive semi-structured interviews with advocates, service providers, and public officials and a review of media coverage and government documents.
The Influence of the Amorphous Phase on Boron Atom Distributions in Ion Implanted Silicon

The nuclear reaction, 10B(n, 4He)7, has been used to investigate the B depth distribution obtained by ion implantation into crystalline Si in a “random” direction and into amorphous Si produced by Si ion bombardment. The presence of the amorphous phase before B ion implantation has a pronounced effect on the B depth distribution (i.e. implantation into misaligned crystalline Si is not equivalent to implantation into amorphous Si). The presence of an amorphous phase has a marked effect on the amount of diffusional broadening of the B distribution during annealing at 900°C.
The Effects of Linguistic Qualifiers and Intensifiers on Group Interaction and Performance in Computer-Supported Collaborative Argumentation.

This study tested the effects of linguistic qualifiers and intensifiers on the number and types of replies elicited per argument and per challenge posted in online debates. To facilitate collaborative argumentation, thirty-two students (22 females, 10 males) enrolled in a graduatelevel online course classified and labeled their messages as arguments, challenges, supporting evidence, or explanations prior to posting each message. The findings showed that qualified arguments elicited 41 percent fewer replies (effect size = -.64), and the reduction in replies was greatest when qualified arguments were presented by females than males. Challenges without qualifiers, however, did not elicit more replies than challenges with qualifiers. These findings suggest that qualifiers were used to hedge arguments, and such behaviors should be discouraged during initial stages of identifying arguments (more so in all-female than in all-male groups) in order to elicit more diverse and more opposing viewpoints needed to thoroughly and critically analyze arguments.
Threshold choice and the analysis of protein marking data in long-distance dispersal studies

Summary 1. A valuable technique in the study of insect movement is protein marking, a quantitative method where individuals are categorized as marked or unmarked based on the amount of foreign protein detected by an enzyme-linked immunosorbent assay (ELISA). 2. Whether individuals are considered marked or not is dependent on a threshold value chosen by the experimenter. The traditional method of choosing the threshold accepts some risk of false positives, wherein unmarked individuals are misclassified as marked. The error rate associated with this method, adopted from the rubidium marking literature, relies on assumptions violated by most ELISA data. 3. We critically examined the effect of violating these assumptions on the false positive rate. In long-distance dispersal studies where the ratio of unmarked to marked insects is high, false positives can seriously bias estimates of insect movement abilities. 4. Simulations demonstrated that the conventional method for choosing a threshold (i) masks the presence of false positives, (ii) results in a 10-fold higher than expected false positive rate, and (iii) relies on assumptions of normality that are rarely satisfied; non-normality produces further increases in false positive rates. 5. We provide some solutions by introducing a new procedure for choosing a threshold that decreases the incidence of false positives and allows data to be corrected for anticipated rates of false positives. This methodology should enhance researcher confidence in the data generated from dispersal studies using protein marking techniques.
Characterizing disease states from topological properties of transcriptional regulatory networks

High throughput gene expression experiments yield large amounts of data that can augment our understanding of disease processes, in addition to classifying samples. Here we present new paradigms of data Separation based on construction of transcriptional regulatory networks for normal and abnormal cells using sequence predictions, literature based data and gene expression studies. We analyzed expression datasets from a number of diseased and normal cells, including different types of acute leukemia, and breast cancer with variable clinical outcome. We constructed sample-specific regulatory networks to identify links between transcription factors (TFs) and regulated genes that differentiate between healthy and diseased states. This approach carries the advantage of identifying key transcription factor-gene pairs with differential activity between healthy and diseased states rather than merely using gene expression profiles, thus alluding to processes that may be involved in gene deregulation. We then generalized this approach by studying simultaneous changes in functionality of multiple regulatory links pointing to a regulated gene or emanating from one TF (or changes in gene centrality defined by its in-degree or out-degree measures, respectively). We found that samples can often be separated based on these measures of gene centrality more robustly than using individual links. We examined distributions of distances (the number of links needed to traverse the path between each pair of genes) in the transcriptional networks for gene subsets whose collective expression profiles could best separate each dataset into predefined groups. We found that genes that optimally classify samples are concentrated in neighborhoods in the gene regulatory networks. This suggests that genes that are deregulated in diseased states exhibit a remarkable degree of connectivity. Transcription factor-regulated gene links and centrality of genes on transcriptional networks can be used to differentiate between cell types. Transcriptional network blueprints can be used as a basis for further research into gene deregulation in diseased states.
Stimulation of choline acetyltransferase activity by ethanol in in vitro preparations of rat cerebrum

Abstract Choline acetyltransferase activity in homogenates, or in partially purified extracts of rat brain cerebra, was increased by 11–37% in the presence of ethanol when incubated at 38°C with [ 14 C] acetyl-CoA, choline chloride and alcohol concentrations of 0.17M to 1.02M. In preincubation experiments with enzyme preparations and ethanol, inactivation of the enzyme by the alcohol, which occurs at incubation times longer than 20 minutes, could be at least partially prevented by the addition of certain components of the incubation mixture to the preincubation mixture.
Activities of tryptophan-metabolizing enzymes in liver and brain of rats treated with aflatoxins

Abstract Male Sprague-Dawley rats were treated ip twice daily for 10 days with mixed aflatoxins (10 μg/kg body weight) and then the activities of liver tryptophan 2,3-dioxygenase and brainstem tryptophan 5-hydroxylase were determined in vitro . Total tryptophan 2,3-dioxygenase activity was reduced by aflatoxin treatment while holoenzyme activity was not. Induction of tryptophan 2,3-dioxygenase activity by l -tryptophan was not altered by the treatment though induction by hydrocortisone was blocked. It is suggested that aflatoxin may alter the tryptophan 2,3-dioxygenase-haem bond in vivo rather than affect enzyme or cofactor synthesis. Kinetics studies performed in vitro on brain tryptophan 5-hydroxylase showed that aflatoxin treatment in vivo increased the K m of the hydroxylase when l -trytophan and synthetic 6,7-dimethyl-5,6,7,8-tetrahydrobiopterin were used as the substrate and cofactor, respectively. However, aflatoxin treatment did not alter the V max of tryptophan-5-hydroxylase.
An agent-based stochastic ruler approach for a stochastic knapsack problem with sequential competition

We examine a situation in which a decision-maker executes a sequence of resource allocation decisions over time, but the availability of the indivisible resources at future epochs is uncertain due to actions of competitors. We cast this problem as a specialized type of stochastic knapsack problem in which the uncertainty of item (resource) availability is induced by competitors concurrently filling their own respective knapsacks. Utilizing a multi-period bounded multiple-choice knapsack framework, we introduce a general discrete stochastic optimization model that allows a nonlinear objective function, cardinality constraints, and a knapsack capacity constraint. Utilizing a set of greedy selection rules and agent-based modeling to simulate the competitors' actions, we solve the problem with a stochastic ruler approach that incorporates beam search to determine item selection of the types specified by the solution representation. We illustrate the computational effectiveness of our approach on instances motivated by a sports league draft as well as generic problem instances based on the knapsack literature.
Novel Copolymers of Styrene. 2. Some Ring-substituted Ethyl 2-Cyano-3-phenyl-2-propenoates

Electrophilic trisubstituted ethylenes, ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates, RPhCH˭C(CN)CO2C2H5 (where R is 2-Cl, 3-Cl, 4-Cl, 2-Br, 3-Br, 4-Br, 2-F, 3-F, 4-F, 2-Cl-4-F, 2-Cl-6-F, 3-Cl-4-F) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and ethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 4-Br (7.74) > 2-Br (1.62) > 3-Cl (1.56) > 3-Br (1.39) > 4-F (0.97) > 3-F (0.86) = 4-Cl (0.86) > 2-Cl-6-F (0.57) > 3-Cl-4-F (0.51) > 2-Cl (0.49) > 2-F (0.42) > 2-Cl-4-F (0.37). Relatively high Tg of the copolymers in comparison with that of polystyrene indicates a decrease i...
VLF wave generation by amplitude‐modulated HF heater waves at Gakona, Alaska

[1] Experiments conducted at Gakona, Alaska, using the intensity-modulated HF heating waves to interact with electrojet currents for the generation of VLF waves, are reported. An unexpected large increasing rate from 4 to 8 kHz in the frequency dependency of the VLF radiation intensity was observed. The peak value at 8 kHz was intense (about 7.5 dB above that of the 2 kHz signal used as a marker) and the wave intensity from 5 to 17 kHz appeared to be abnormally high (i.e., stronger than that at 2 kHz). In the experiments, we also observed the enhancement of spread-E irregularities at electrojet current altitudes due to the amplitude-modulated heater wave. These results and theoretical analyses suggest that temporally modulated electrojet currents mix with heater wave-excited density irregularities to form whistler mode currents, which generate VLF whistler waves directly with much larger intensities and better directivity than a Hertzian dipole can.
Usefulness of tumor volumetry by magnetic resonance imaging in assessing response to radiation therapy in carcinoma of the uterine cervix.

Abstract Purpose: Clinical evaluation of tumor size in cervical cancer is often difficult, and clinical signs of radiation therapy failure may not be present until well after completion of treatment. The purpose of this study is to investigate early indicators of treatment response using magnetic resonance (MR) imaging for quantitative assessment of tumor volume and tumor regression rate before, during, and after radiation therapy. Methods and Materials: Thirty-four patients with cervical cancer Stages IB [5], IIB [8], IIIA [1], IIIB [14], IVA [3], IVB [1], and recurrent [2] were studied prospectively with four serial MR examinations obtained at the start of radiation therapy, at 2-2.5 weeks (20–24 Gy), at 4–5 weeks (40–50 Gy), and 1–2 months after treatment completion. Tumor volume was assessed by three-dimensional volumetric measurements using T 2 -weighted images of each MR examination. The volume regression rate was generated based on the four sequential MR studies. These findings were correlated with local control, metastasis rate, and disease-free survival. Median follow-up was 18 months (range: 9–43 months). Results: The tumor regression rate after a dose of 40–50 Gy correlated significantly with treatment outcome. The actuarial 2-year disease-free survival was 88.4% in patients with tumors regressing to p = 0.007). The incidence of local recurrence was 9.5% (2 out of 21) and 76.9% (10 out of 13), respectively ( p initial tumor volume showed that this observation was valid in patients with initial volumes between 40 and 100 cm 3 . Analysis by FIGO stage confirmed this observation in all patients except those with Stage IB. Conclusion: Sequential tumor volumetry using MR imaging appears to be a sensitive measure of the responsiveness of cervical cancer to irradiation. Treatment response can be assessed as early as during the course of radiation therapy by measurement of initial tumor volume and regression rate at 40–50 Gy. In patients with large (>40 cm 3 ) and advanced (Stage ≥ IIIA) tumors, this technique may be helpful in supplementing the clinical examination for response assessment. The identification of patients at high risk for treatment failure may ultimately lead to improved clinical outcome.
Transcriptional regulation of an unusual trypsin-related protein expressed during insect metamorphosis

The full-length cDNA for a trypsin-related protein expressed during larval-pupal metamorphosis was obtained. The encoded N-terminal half of the protein possessed similarity to trypsin proteases, including the correctly positioned histidine and aspartic acid members of the catalytic triad. However, the remainder of the encoded protein bore little resemblance to trypsin, and was altogether missing the canonical sequence containing the catalytic serine residue. The product of in vitro transcription/translation of the cDNA was a 28 kDa protein. Under normal conditions of a declining juvenile hormone titer, transcription of the mRNA as a proportion of total genomic transcription steadily increased for the first 3 days of the final stadium, but this increase was delayed and suppressed by maintenance of a high juvenile hormone titer. During the normal increase in transcription on day 3 of the final stadium, a sharp decline was observed in the steady-state abundance of the transcript, measured relative to abundance of the remaining mRNAs, suggesting that the stability of the message decreases after tissue commitment for a pupal molt.
Measurement and calculation of arc power and heat transfer efficiency in pulsed gas metal arc welding

AbstractThis study investigates the heat transfer efficiency of the pulsed gas metal arc welding (GMAW-P) process. The arc power and heat input were calculated from arc current and voltage measurements and the heat input was also measured with a liquid nitrogen calorimeter. The measured heat transfer efficiency for GMAW-P varied slightly over a wide range of pulse parameters, with an average value of 70%, a maximum of 72% and a minimum of 68%. Welding heat transfer efficiency based on arc power calculated as the product of average current and voltage was too high (averaging 82%), while that calculated using the product of the root mean square (RMS) of the average current and voltage was too low (averaging 61%). Both also varied significantly with pulsing parameters. Mathematical analysis shows that average instantaneous power values must be used when current and voltage vary significantly with time. The experimental differences between the average instantaneous power and the other calculated values are ex...
Pain and activity limitations in children with Duchenne or Becker muscular dystrophy

The purpose of this study was to examine the prevalence and characteristics of pain in children with Duchenne (DMD) or Becker (BMD) muscular dystrophy, including the nature of disagreements concerning pain symptoms among children, parents, and physicians, and limitations in daily activities. Male children (age 8-18 y, n=53) and parents (n=53) completed questionnaires assessing pain intensity (visual analogue scale), pain frequency (Likert scale [LS]), pain duration (LS), emotional distress due to pain (LS), and pain location (body outline markings). The Child Activity Limitations Interview was also completed by both raters to assess daily activities that are limited by recurrent pain. Physicians completed a form indicating medical history and pain symptoms. The majority of children with DMD (mean age 13 y 11 mo [SD 3.38]; range 8-18 y) or BMD (mean 14 y 10 mo [SD 1.48]; range 12-17 y) were non-ambulatory (79 and 50% respectively) and experienced pain according to self (54-80%) and parent reports (70-90%). Pain typically occurred at least once per week and was of mild to moderate intensity. Most children experienced pain for less than a few hours and little to moderate levels of emotional distress due to pain. Pain occurred in the lower back, spine, and legs, and was described as 'aching'. Children and parents indicated significantly more intense pain than the physician. Actual agreement between parent and child report on pain symptoms was poor to fair. Pain is a common occurrence in children with DMD or BMD, yet may be under-recognized. Pain assessment needs to be a standard part of care and may identify difficulties faced by these children to be targeted by interventions.
Radiowave Receiving System Intercept Probability Model

A model is presented for estimating the intercept probabilities of radiowave-acquisition receiving systems. The specific architecture of each of the receiving systems is not important, but there must be two or more of them and they must operate in such a manner that for each trial (event) they alarm independently from a statistical point of view. The data giving the number of alarms for each receiver and the number of receivers alarming for each trial is all that is required. These data are used to form estimates of the conditional probabilities of intercept and simultaneous alarm. A least mean square estimator is then used to find the unconditional intercept probabilities.
Studying the effects of matrix stiffness on cellular function using acrylamide-based hydrogels.

Tissue stiffness is an important determinant of cellular function, and changes in tissue stiffness are commonly associated with fibrosis, cancer and cardiovascular disease. Traditional cell biological approaches to studying cellular function involve culturing cells on a rigid substratum (plastic dishes or glass coverslips) which cannot account for the effect of an elastic ECM or the variations in ECM stiffness between tissues. To model in vivo tissue compliance conditions in vitro, we and others use ECM-coated hydrogels. In our laboratory, the hydrogels are based on polyacrylamide which can mimic the range of tissue compliances seen biologically. "Reactive" cover slips are generated by incubation with NaOH followed by addition of 3-APTMS. Glutaraldehyde is used to cross-link the 3-APTMS and the polyacrylamide gel. A solution of acrylamide (AC), bis-acrylamide (Bis-AC) and ammonium persulfate is used for the polymerization of the hydrogel. N-hydroxysuccinimide (NHS) is incorporated into the AC solution to crosslink ECM protein to the hydrogel. Following polymerization of the hydrogel, the gel surface is coated with an ECM protein of choice such as fibronectin, vitronectin, collagen, etc. The stiffness of a hydrogel can be determined by rheology or atomic force microscopy (AFM) and adjusted by varying the percentage of AC and/or bis-AC in the solution. In this manner, substratum stiffness can be matched to the stiffness of biological tissues which can also be quantified using rheology or AFM. Cells can then be seeded on these hydrogels and cultured based upon the experimental conditions required. Imaging of the cells and their recovery for molecular analysis is straightforward. For this article, we define soft substrata as those having elastic moduli (E) 20,000 Pascal.
Current mode oscillators using a voltage to current transducer in CMOS technology

Abstract Realization of oscillators using a voltage to current transducer (VCT) in CMOS technology is addressed. The VCT can be configured to produce resistances and inductors. Analogues of LC- and RC-based oscillators can then be implemented using the VCTs. The output is available as current signals. This will be useful in current mode signal processing using VLSI technology.
Reverse transcription and polymerase chain reaction technique for quantification of mRNA in primary astrocyte cultures.

The reverse transcription and polymerase chain reaction technique (RT-PCR) was assessed for the quantification of changes in mRNA levels from primary astrocyte cultures. The effects of dibutyryl cyclic AMP (dBcAMP) on glial fibrillary acidic protein (GFAP) mRNA and the effects of tumor necrosis factor-alpha (TNF-α), interlekin-1 beta (IL-1β), and lipopolysaccharide (LPS) on interleukin-6 (IL-6) mRNA were examined. Two quantitative PCR methods were used: one involved carrying out the reaction in the exponential phase and the other involved the coamplification of a competitive target sequence. Increased GFAP mRNA in response to chronic dBcAMP treatment and increased IL-6 mRNA in response to TNF-α/IL-1β were readily detected. Both RT-PCR techniques were found to be suitable for the detection of large as well as smaller (twofold) changes in mRNA levels. The advantages and limitations of RT-PCR for mRNA quantification are discussed. © 1993 Wiley-Liss, Inc.
Aerodynamics of airfoils with vortex trapped by two spanwise fences

An airfoil configuration is presented whose lift is enhanced by a trapped-vortex flow field. Based on the research to date, it is recommended that two spanwise fences be used to enclose the trapped vortex and that the fence heights be adjusted so that the equilibrium condition can be achieved with little or no mass removal from the core region of the vortex. It is also shown that the vortex bubble can be located fore and aft on the airfoil to control aerodynamic parameters, such as the pitching moment. Applications of the high-lift concept presented here are briefly discussed.
Conceptual distinctions amongst generics.

Generic sentences (e.g., bare plural sentences such as ‘‘dogs have four legs’’ and ‘‘mosquitoes carry malaria’’) are used to talk about kinds of things. Three experiments investigated the conceptual foundations of generics as well as claims within the formal semantic approaches to generics concerning the roles of prevalence, cue validity and normalcy in licensing generics. Two classes of generic sentences that pose challenges to both the conceptually based and formal semantic approaches to generics were investigated. Striking property generics (e.g. ‘‘sharks bite swimmers’’) are true even though only a tiny minority of instances have the property and thus pose obvious problems for quantificational approaches, and they also do not seem to characterize kinds in terms of the principled or statistical connections investigated in previous research (Prasada & Dillingham, 2006,
Spectral Studies of tert-Butyl Isothiocyanate-Inactivated P450 2E1†

Inactivation of cytochrome P450 2E1 by tert-butyl isothiocyanate (tBITC) resulted in a loss in the spectrally detectable P450−reduced CO complex. The heme prosthetic group does not appear to become modified, since little loss of the heme was observed in the absolute spectra or the pyridine hemochrome spectra, or in the amount of heme recovered from HPLC analysis of the tBITC-inactivated samples. Prolonged incubations of the inactivated P450 2E1 with dithionite and CO resulted in a recovery of both the CO complex and the enzymatic activity. Inactivated samples that were first reduced with dithionite for 1 h prior to CO exposure recovered their CO spectrum to the same extent as samples not pretreated with dithionite, suggesting that the major defect was an inability of the inactivated sample to bind CO. Spectral binding studies with 4-methylpyrazole indicated that the inactivated P450 2E1 had an impaired ability to bind the substrate. Enzymatic activity could not be restored with iodosobenzene as the altern...
Case report 696

A case of chondroblastoma involving the right acetabulum and superior pubic ramus in a 60-year-old man has been presented. Tissue was obtained by open biopsy. The clinical and radiographic characteristics of chondroblastoma in general, and this tumor in particular, were discussed. The histopathology and differential diagnosis were also considered. The relatively uncommon site of the tumor and its occurrence in an older patient made the radiographic diagnosis difficult, and other possibilities were discussed.
Stimulation by lipoxygenase products of superoxide anion production in FMLP-treated neutrophils.

Our recent observation that leukotriene B4 (10−9M) is a potent enhancer of FMLP-initiated neutrophil superoxide anion formation prompted an evaluation of the ability of other lipoxygenase products and related compounds to modulate this response. The results indicate that FMLP-evoked O 2 − may be enhanced by 10−8–10−7 M levels of a number of lipids, in addition to LTB4, including 5-HPETE, 5-HETE, 5,15-DiHPETE and by higher levels of other 15-series lipoxygenase products and arachidonic acid. It is of interest that the relative potency of these agents in potentiating the superoxide response to FMLP approximately parallels their reported ability to induce chemotactic activity in leukocytes.
Contagious yawning and laughing: Everyday imitation- and mirror-like behavior

Infectious yawning and laughing offer a convenient, noninvasive approach to the evolution, development, production, and control of imitation-like and mirror-like phenomena in normal, behaving humans.
A micro-scale model for predicting contact resistance between bipolar plate and gas diffusion layer in PEM fuel cells

Contact resistance between the bipolar plate (BPP) and the gas diffusion layer (GDL) in a proton exchange membrane (PEM) fuel cell constitutes a significant portion of the overall fuel cell electrical resistance under the normal operation conditions. Most current methods for contact resistance estimation are experimental and there is a lack of well developed theoretical methods. A micro-scale numerical model is developed to predict the electrical contact resistance between BPP and GDL by simulating the BPP surface topology and GDL structure and numerically determining the status for each contact spot. The total resistance and pressure are obtained by considering all contact spots as resistances in parallel and summing the results together. This model shows good agreements with experimental results. Influences of BPP surface roughness parameters on contact resistance are also studied. This model is beneficial in understanding the contact behavior between BPP and GDL and can be integrated with other fuel cell simulations to predict the overall performance of PEM fuel cells.
Linear Diffusion and Internal Voltages in Conducting Enclosures Subjected to a Direct Lightning Strike

ABSTRACT Wall voltages interior to a conducting enclosure subjected to lightning currents are estimated. The results are applied to the specific problem of a cylindrical can with end caps subjected to symmetric axial lightning current. The voltage on the side wall of the can is approximated by the solution of a planar conducting slab excited by a plane magnetic field. The end caps are treated by solving the problem of a current filament terminating normally in an infinite planar slab. The integral transform solution of both these problems is given and reduced to a convergent series expansion which is summed numerically. Both early and late time approximations are given. The end cap problem is shown to be well approximated by the much simpler planar solution when applied incrementally from the effective static radius of the filament to the end cap radius. A simple circuit model is also presented, which very closely models the planar diffusion problem. Thus the complete cylindrical enclosure problem is appr...
The Invisible Interface: MS Word in the Writing Center

Abstract Writing centers have developed best practices in order to help student writers, most popularly, non-directive tutoring pedagogies, based on the use of paper drafts. These same tutoring protocols have been extended to computer-based face-to-face sessions under the assumption that they will have similar outcomes, which subscribes to the myth of technology as a transparent tool that does not affect the writing that emerges from it. A lack of attention to computers in the writing center extends to the use of word processing programs like MS Word. This article discusses these issues in the context of a case study of one tutor in computer-based tutoring sessions in a writing center. Throughout these sessions, situations arose involving the use of the MS Word interface that affected the nature of the session itself. This case study suggests that computers, and particularly the MS Word program, need to be examined critically to consider how their use corresponds with the mission of the writing center itself. There are a number of strategies that can also help tutors use MS Word in ways that will best serve students’ individual needs.
Thermal injury and sepsis modulates β-adrenergic receptors and cAMP reponses in monocyte-committed bone marrow cells

Abstract We have previously reported that adrenergic stimulation enhances monocytopoiesis following experimental burn injury and sepsis (BI/S). In the present work we measured β-adrenergic receptor number and affinity in bone marrow committed monocyte progenitor cells (CD59 + ) following BI/S. We find that BI/S treatment significantly decreased monocyte progenitor cell β-adrenergic receptors but significantly increased receptor binding affinity and isoproterenol-stimulated cAMP production. CD14 expression in macrophages derived in vitro from CD59 + cells following BI/S was significantly increased by epinephrine and this change was blocked by β 2 -adrenergic receptor antagonist. PCR analysis suggests the presence of β 2 - but not β 1 -adrenergic receptors. Enhanced adrenergic receptor signaling in CD59 + bone marrow cells following BI/S may be important in macrophage development.
Evaluation of Slower-Growing Broiler Genotypes Grown with and Without Outdoor Access: Sensory Attributes

Consumer interest in organic and natural poultry production is growing. An experiment was conducted to assess the impact of genotype and outdoor access on sensory attributes of broiler meat. One slow-growing genotype (S), 2 medium-growing genotypes (M1 and M2), and a commercial fast-growing genotype (F) were raised (straight-run) for 81, 67, or 53 d, respectively. The placement dates were staggered to achieve a similar final BW, and each genotype was processed on the same day. Each genotype was assigned to 3 pens of 24 birds each, and all birds were raised in indoor floor pens in a naturally ventilated facility. The S and F genotypes were also assigned to 2 floor pens with outdoor access (during daylight hours) containing 36 birds each. All birds were provided with the same starter, grower, and finisher feeds, and birds were commercially processed. Breast and thigh meat were evaluated for sensory attributes and acceptability by a consumer panel. The M1 and M2 breasts were more tender than other indoor genotypes (P < 0.05); however, all treatments scored "slightly to moderately tender." The thigh meat of the M2 birds was more flavorful than that of S birds (P < 0.05), and the flavor of the S thigh meat was less liked than other indoor genotypes (P < 0.05). Outdoor access did not impact flavor. These data indicate that differences in sensory attributes may exist among genotypes with different growth rates and reared with or without outdoor access.
Meningiomas Involving the Clivus: A Six-Year Experience with 41 Patients

A series of 41 meningiomas involving the clivus operated on from July 1983 to January 1990 is reported. The presenting symptoms and signs of these patients were similar to those reported previously. All the patients were evaluated by pre- and postoperative thin-section, high-resolution computed tomography using soft tissue and bone algorithms. Most of the patients also underwent magnetic resonance imaging. The regions of the clivus involved by tumor were divided into upper, middle, or lower regions on the basis of anatomical landmarks. The diameter of the tumor was measured in three axes, and a tumor volume and a tumor equivalent diameter were computed to categorize tumors as small, medium, large, or giant types. There were 9 medium, 27 large, and 5 giant tumors in this series. Some simple and some complex operative approaches were employed to effect tumor removal. Large and giant tumors often required more than one operative approach to remove the tumor. Intraoperative technical difficulties included tumor consistency, vascularity, dissection from the brain stem, and vascular and cranial nerve encasement. Postoperative computed tomographic scans documented total excision in 32 patients (78%). Residual tumor remained in the clival or cavernous sinus areas. These patients were either being observed, or were treated with gamma knife radiosurgery. There was one operative death due to pneumonia (2%), and three patients (7%) suffered permanent major neurological changes, presumably due to vascular occlusions in the posterior circulation. In the follow-up period, which ranged from 3 to 76 months, 2 patients (6%) with tumors that had appeared to be totally excised experienced recurrence. These patients were treated by a second operation, alone or in combination with radiation therapy. Two patients who had subtotal excisions (25%) had evidence of regrowth. In 2 patients, tumor growth continued despite gamma knife radiosurgery or external beam radiotherapy.
A screen for over-secretion of proteins by yeast based on a dual component cellular phosphatase and immuno-chromogenic stain for exported bacterial alkaline phosphatase reporter

To isolate over-secretors, we subjected to saturation mutagenesis, a strain of P.pastoris exporting E. coli alkaline phosphatase (EAP) fused to the secretory domain of the yeast α factor pheromone through cellular PHO1/KEX2 secretory processing signals as the α-sec-EAP reporter protein. Direct chromogenic staining for α-sec-EAP activity is non-specific as its NBT/BCIP substrate cross-reacts with cellular phosphatases which can be inhibited with Levulinic acid. However, the parental E(P) strain only exports detectable levels of α-sec-EAP at 69 hours and not within the 36 hour period post-seeding required for effective screening with the consequent absence of a reference for secretion. We substituted the endogenous cellular phosphatase activity as a comparative reference for secretion rate and levels as well as for colony alignment while elevating specificity and sensitivity of detection of the exported protein with other innovative modifications of the immuno-chromogenic staining application for screening protein export mutants. Raising the specificity and utility of staining for α-sec-EAP activity required 5 modifications including some to published methods. These included, exploitation of endogenous phosphatase activity, reduction of the cell/protein burden, establishment of the direct relation between concentrations of transcriptional inducer and exported membrane immobilized protein and concentrations of protein exported into growth media, amplification of immuno-specificity and sensitivity of detection of α-sec-EAP reporter enzyme signal and restriction of staining to optimal concentrations of antisera and time periods. The resultant immuno-chromogenic screen allows for the detection of early secretion and as little as 1.3 fold over-secretion of α-sec-EAP reporter protein by E(M) mutants in the presence of 10 fold -216 fold higher concentrations of HSA. The modified immuno-chromogenic screen is sensitive, specific and has led to the isolation of mutants E(M) over-secreting the α-sec-EAP reporter protein by a minimum of 50 fold higher levels than that exported by non-mutagenized E(P) parental strains. Unselected proteins were also over-secreted.