cssi/SciSciGPT-SciSciNet huggingface dataset:
Characteristics and Outcomes of Patients with Anti-Glomerular Basement Membrane Antibody Disease and Anti-Neutrophil Cytoplasmic Antibodies.

BACKGROUND It is unclear whether patients with Anti-Glomerular Basement Membrane (GBM) disease and Anti-Neutrophil Cytoplasmic Antibodies (ANCA), so called "Double-Positive" (DP), have a different clinical presentation and outcome compared to patients with anti-GBM antibody disease alone. This study describes the clinical and histologic characteristics as well as the patient and renal outcomes of DP patients at the University of Washington compared to patients with anti-GBM antibody disease alone. METHODS Adults admitted to the University of Washington and Harborview Medical Centers from 2000 to 2016 who had a kidney biopsy showing anti-GBM disease characterized by crescentic glomerulonephritis with strong linear staining of glomerular basement membranes for IgG by immunofluorescence were included. Subjects were classified into anti-GBM or DP based on serologic testing. Information on demographics, clinical presentation, biopsy findings, initial treatment, and rates of relapse and patient and renal survival were collected. Continuous and categorical variables were analyzed using the Mann-Whitney U and Fisher's exact tests, respectively. RESULTS There were 6 anti-GBM and 7 DP patients. Two patients were lost to follow-up after one year. There was no significant difference in clinical presentation or outcomes between the two groups. Two DP patients had greater than 50% global glomerulosclerosis. All the subjects developed ESRD. Two DP patients had a relapse while off immunosuppression. Two patients in each group died within 5 years of diagnosis. CONCLUSION Two DP patients in our cohort had a relapse within 5 years of diagnosis. Multicenter studies are needed to determine whether DP patients have a higher relapse rate and need prolonged immunosuppression.
Extravillous Trophoblast, Trophoblastic Invasion, and Fibrinoid

The nonvillous parts of the placenta include the chorionic plate, cell islands, cell columns, placental septa, basal plate, marginal zone, and fibrinoid deposits (Fig. 8.1). These structures do not participate in maternofetal exchange, but have mechanical and metabolic functions.
Recognizing the CT Manifestations of Gynecologic Conditions Encountered in the Emergency Department.

Abstract Women commonly present to the emergency room with subacute or acute symptoms of gynecologic origin. Although a pelvic exam and ultrasound (US) are the preferred initial diagnostic tools for gynecologic entities, a CT is often the first line imaging modality in the emergency department. We will provide a review of normal uterine enhancement and normal pregnancy related findings, and then familiarize radiologists with the CT appearances of gynecologic entities classically described on ultrasound that may present to the emergency department.
Association between VTE and MGMT status in patients with high grade glioma.

e14055Background: Patients with high grade gliomas (HGG), WHO grades III and IV, are at increased risk of venous thromboembolism (VTE) compared to patients with other malignancies. This suggests a ...
SiC MOSFET Based Modular Universal Power Electronics Regulator

A modular and scalable SiC MOSFET based universal power electronics regulator (UPER) allows coordinated integration of energy resources and loads, elimination of extra power conversion stages, and allowance of more sources or loads added with a simple plug and play feature. A comprehensive investigation has been conducted in term of the typical distributed generations and loads employed in buildings, in order to outline a detailed specification for UPER. Thus, a common DC bus voltage of 500 V and power rating of 3 kW are dedicatedly selected. The UPER hardware design and implementation are completely illustrated, including the static and dynamic characterization of the employed SiC MOSFET. The dedicated universal power cell and Plug-and-Play gate driver performs reliable continuous operation even exposed to an extreme fast switching speed (> 100 V/ns). The continuous operation of buck mode verified the UPER hardware development at 50 kHz with an overall efficiency of 98.19%. A new voltage polarity reversal phenomenon was also discovered in the verification of the isolated DAB stage with planar transformers.
The Tax Advantage of Corporate Debt after Tax Reform: A Direct Test of the Effect of Anticipated Tax Rate Changes on Corporate Leverage

The Tax Reform Act of 1986 (TRA86) provided a natural experiment for analyzing the influence of taxes on corporate leverage decisions. A centerpiece of TRA86 was the lowering of the maximum statutory corporate marginal tax rate facing corporations from 46 percent to 34 percent accompanied by broad changes in the tax base, and the curtailment or elimination of numerous tax shields. This paper uses direct estimates of the effects of the tax changes on corporate marginal tax rates, focusing on the tax savings from increased leverage, and provides an estimate of the extent anticipated changes in marginal tax rates influenced corporate leverage decisions. The results show TRA86 was expected to decrease average marginal tax rates approximately 5 percentage points and decrease the dispersion of tax rates across industries. The second half of the paper tests whether the anticipated marginal tax rate changes had an effect on corporate leverage. The estimates provide support for the role of corporate taxation in firms' leverage decisions, and quantify the leverage changes in response to TRA86. In addition, since the effects of the tax change are measured directly, rather than through a proxy, an estimate of the magnitude of such changes can be made. Corporate debt in 1988 is estimated to have been $312 billion lower than it would have been in the absence of TRA86.
Application of the Hydro (solvento) thermal Technique to the Synthesis of Metal Carbonyl Chalcogenide Clusters. 2. Synthesis and X-ray Structures of [{Fe4Te4(CO)10}2(Te2)]2− and [{Fe2Se(CO)6}2(Se2)]2−

The hydrothermal reaction of Fe(CO)[sub 5] with Na[sub 2]Te[sub 2] in the presence of Ph[sub 4]PCl at 110[degrees]C forms (Ph[sub 4]P)[sub 2][[l brace]Fe[sub 4]Te[sub 4](CO)[sub 10][r brace][sub 2](Te[sub 2])] (I) while the reaction of Fe(CO)[sub 5] with Na[sub 2]Se[sub 2] in superheated methanol at 80[degrees]C results in (Ph[sub 4]P)[sub 2][[l brace]Fe[sub 2]Se(CO)[sub 6][r brace][sub 2](Se[sub 2])] (II). The structures of (I) and (II) were determined by X-ray single-crystal analysis. (I) crystallizes in the space group P[bar 1], and (II) in the space group P2[sub 1]/n. The [[l brace]Fe[sub 4]Te[sub 4](CO)[sub 10][r brace][sub 2](Te[sub 2])][sup 2[minus]] anion in (I) forms a ditelluride, Te[sub 2][sup 2[minus]], bridged double cubane-like structure with eight iron atoms in two Fe[sub 4]Te[sub 4] cubes being octahedrally-coordinated by briding tellurium ligands and terminal CO groups. The [[l brace]Fe[sub 2]Se(CO)[sub 6][r brace][sub 2](Se[sub 2])][sup 2[minus]] molecule in (II) adopts a double butterfly' conformation caused by an intramolecular Se-Se linkage between two Fe[sub 2]Se[sub 2](CO)[sub 6] units. All iron atoms in this structure have a distorted octahedral geometry achieved by selenium ligands, CO groups, and a Fe-Fe single bond. The average Fe-Te bond distance is 2.619(4) [Angstrom], and Fe-Se = 2.386(17) [Angstrom]. 30 refs., 4 figs., 5 tabs.
Effect of Aging on the Fatigue Life and Shear Strength of SAC305 Solder Joints in Actual Setting Conditions

Solder alloy materials are utilized to form mechanical and electrical connections between printed circuit boards and the electronic components. Enhancing the reliability of the electronic components is mainly dependent on the reliability of the interconnected solder joints. Therefore, estimating the reliability and fatigue behavior of the solder joints under realistic operating conditions is crucial. Aging is one of the major factors that may reduce the fatigue and mechanical properties of solder joints. The objective of this study is to assess the fatigue life and the shear strength of SAC305 solder joints under several levels of cycling stress amplitudes and different aging conditions at actual setting conditions. Instron Micromechanical Tester is used to perform accelerated shear fatigue tests on individual SAC305 solder joints. The fatigue lives of SAC305 solder joints are examined at cycling loads of 16 MPa, 20 MPa, and 24 MPa, aging times of 0, 10 hrs and 100 hrs and aging temperatures of 100°C and 150°C. The total number of combinations tested is eighteen where each has seven solder joint samples. Two-parameter Weibull distribution was constructed for each combination to assess the reliability. The hysteresis loop for each cycle was developed, and the plastic strain and the inelastic work per cycle were measured. The effects of different aging conditions on the inelastic work per cycle and the plastic strain at different stress amplitudes are demonstrated. A power equation is used to express the correlation between the fatigue life and stress amplitude and the results indicated a significant reduction in the fatigue life when the stress amplitude is increased. The results also showed that increasing the aging time and the aging temperature leads to a reduction in the fatigue life. Finally, reliability prediction models as a function of time (cycles) and stress amplitude at different aging conditions are constructed. The effect of aging on the shear strength is investigated as well.
Neoliberalism in a Time of Crisis: A Critical Assessment of the Defining Policies of the Obama Administration

This paper considers three key areas of the Obama administration's domestic policy-its handling of the 2008 economic crisis and its aftermath, energy policy and health care in answering the question, "Was it neoliberal?"
Nourishment Recommendation Framework for Children Using Machine Learning and Matching Algorithm

Food plays an important role in daily life and is related to our core existence. The food that we eat supplies nutriments to the body. A balanced diet full of essential vitamins and minerals in adequate amount will help an individual reach their full growth potential especially children because a proper diet results in an increase in the learning ability, stamina and strength. It even has a positive impact on their behavior. To offer an efficient method regarding food intake, in this paper, we proposed a Nourishment Recommendation Framework (NRF) where we take user input from children, analyze the data and finally an output is generated that presents an improved diet plan. It aims to provide children from 8–13 years with healthy meals according to their age, growth, gender and health records.
Two-Mode Threshold Graph Dynamical Systems for Modeling Evacuation Decision-Making During Disaster Events

Recent results from social science have indicated that neighborhood effects have an important role in an evacuation decision by a family. Neighbors evacuating can motivate a family to evacuate. On the other hand, if a lot of neighbors evacuate, then the likelihood of an individual or family deciding to evacuate decreases, for fear of looting. Such behavior cannot be captured using standard models of contagion spread on networks, e.g., threshold models. Here, we propose a new graph dynamical system model, 2mode-threshold, which captures such behaviors. We study the dynamical properties of 2mode-threshold in different networks, and find significant differences from a standard threshold model. We demonstrate the utility of our model through agent based simulations on small world networks of Virginia Beach, VA. We use it to understand evacuation rates in this region, and to evaluate the effects of the model and of different initial conditions on evacuation decision dynamics.
Abstract PHB05: Mechanism-based computational models to study interplay between EGFR inhibitors and KRAS mutants

An early genotype-to-phenotype relationship in cancer personalized medicine was that KRAS mutations confer resistance to EGFR inhibitors in colorectal cancer. Confusingly, phase 3 clinical trials found that patients with the KRAS G13D mutation were an exception to this rule. That constitutively active KRAS mutants would cause resistance to EGFR inhibitors seemed intuitive, and it appeared inconsistent with known mechanisms of RAS biology for any constitutively active KRAS mutant to behave differently. We have developed a computational model that describes the biochemical mechanisms of RAS signal regulation. Simulations of this mass-action model reproduce known patterns of RAS pathway activation. The incorporation of the specific biochemical parameters for different KRAS mutants has allowed us to uncover novel, non-obvious insights into the response of KRAS G13D and KRAS G12C colorectal cancers to EGFR inhibition. For KRAS G13D, the model revealed EGFR inhibition leads to reduced wild-type HRAS and NRAS signaling in KRAS G13D cancers, but not KRAS G12D or KRAS G12V cancers. The model also revealed a critical dependence upon tumor suppressor NF1, and that the impaired binding of KRAS G13D to NF1 frees NF1 to act on wild-type RAS. Importantly, our computational predictions have been prospectively validated experimentally. Our computational model has also revealed that cotreatment of KRAS G12C colorectal cancer with EGFR and KRAS G12C inhibitors results in a depletion of the active forms of both wild-type and mutant RAS proteins, which we have also confirmed experimentally. For both KRAS G13D and KRAS G12C colorectal cancers, our work demonstrates how computational models can identify behaviors that logically follow from what is known, but which the complexity of the RAS signaling network has prevented from previously being uncovered despite extensive, empirical, experimental efforts. This abstract is also being presented as Poster B51. Citation Format: Edward C. Stites. Mechanism-based computational models to study interplay between EGFR inhibitors and KRAS mutants [abstract]. In: Proceedings of the AACR Special Conference on the Evolving Landscape of Cancer Modeling; 2020 Mar 2-5; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2020;80(11 Suppl):Abstract nr PHB05.
Decentralized Control Synthesis for Air Traffic Management in Urban Air Mobility

Urban air mobility (UAM) refers to air transportation services within an urban area, often in an on-demand fashion. We study air traffic management (ATM) for vehicles in a UAM fleet, while guaranteeing system safety requirements such as traffic separation. Existing ATM methods for unmanned aerial systems, such as UAS traffic management, utilize alternative approaches which do not provide strict safety guarantees. No established infrastructure exists for providing ATM at scale for UAM. We provide a decentralized, hierarchical approach for UAM ATM that allows for scalability to high traffic densities as well as providing theoretical guarantees of correctness with respect to user-provided safety specifications. Our main contributions are two-fold. First, we propose a novel UAM ATM architecture that divides the control authority between vertihubs that are each in charge of all UAM vehicles in their local airspace. Each vertihub also contains a number of vertiports that are in charge of UAM vehicle takeoffs and landings. The resulting architecture is decentralized and hierarchical, which not only enables scalability, but also robustness in the event of any individual vertihub or vertiport no longer being operational. Second, we provide a contract-based correct-by-construction reactive synthesis approach that provably guarantees safety properties with respect to user-provided specifications in linear temporal logic. We demonstrate the approach on large-volume UAM air traffic data.
Accelerating Iterated Persistent Homology Computations with Warm Starts.

Persistent homology is a topological feature used in a variety of applications such as generating features for data analysis and penalizing optimization problems. We develop an approach to accelerate persistent homology computations performed on many similar filtered topological spaces which is based on updating associated matrix factorizations. Our approach improves the update scheme of Cohen-Steiner, Edelsbrunner, and Morozov for permutations by additionally handling addition and deletion of cells in a filtered topological space and by processing changes in a single batch. We show that the complexity of our scheme scales with the number of elementary changes to the filtration which as a result is often less expensive than the full persistent homology computation. Finally, we perform computational experiments demonstrating practical speedups in several situations including feature generation and optimization guided by persistent homology.
The engulfment of a precipitated particle in a saturated melt during solidification

Abstract A rigorous, finite-element model is employed to study the engulfment of a precipitated solid particle during solidification in a saturated melt, in which solute segregation, compositional effects on melting temperature, and reaction of the solute with the particle occur. The case of a silicon carbide (SiC) particle approaching a solid-liquid interface in a silicon melt supersaturated with carbon is specifically considered. Critical engulfment velocities are computed for particles with different surface reaction rates, as characterized by the Damkohler number, a dimensionless ratio of reaction to diffusion. Consistent with prior studies, an inert particle is predicted to be less likely to be engulfed when solute effects are present. However, a particle with fast surface reaction is more likely to be engulfed than in a system without solute effects, which is likely relevant for SiC particles during silicon crystal growth. Most interestingly, a particle for which the surface reaction is characterized by a Damkohler number of order unity is predicted to never be engulfed.
Acculturation, Bilateral Hostility, and Psychological Wellbeing of U.S.-dwelling Chinese during the COVID-19 Pandemic.

The COVID-19 pandemic has sparked hostility against Chinese immigrants and sojourners in the U.S. and other countries. Making the situation worse, strong resentment against this group has also emerged in China due to the fear of returnees spreading the disease. Integrating research on acculturation and hostile media perception, we examined how such bilateral hostility along with different acculturation components (i.e., cultural identification, COVID-19-related media use, and individualistic-collectivistic value) influenced U.S.-dwelling Chinese's psychological well-being during the COVID-19 pandemic. Based on the results from a two-wave survey assessing the cultural identity and value, COVID-19-related media use, and psychological distress of a group of relatively young and highly educated U.S.-dwelling Chinese (N = 1,256) between March and April 2020, we found that identification with both U.S. and Chinese cultures alleviated immigrants and sojourners' psychological distress. Further, COVID-19-related media use served as a stressor during the pandemic, and perceived hostility from China led to stronger psychological distress among U.S.-dwelling Chinese.
Homogeneously Staining Regions and Double Minute Chromosomes, Prevalent Cytogenetic Abnormalities of Human Neuroblastoma Cells

Publisher Summary This chapter focuses on in vitro cultivation of human neuroblastoma cells and presents several morphological and biochemical characteristics of human neuroblastoma cells in culture. Both the human and mouse neuroblastoma cell lines have morphological, biochemical, and electrophysiological attributes of neuronal cells. The chapter describes an earlier study in which large double-minute chromosomes (DMs) and ring forms, such as observed in methotrexate-resistant cells with amplified dihydrofolate reductase genes and in several human neuroblastoma cell lines, were observed in a small number of cases. Although a large number of human tumors with DMs have been described in the literature, the relative proportion of tumors or tumor cell lines characterized by DM-containing cells is low. Various studies of antifolate-resistant rodent cell lines have demonstrated that both homogeneously staining regions and DMs in those cells are cytological indicators of amplified dihydrofolate reductase genes.
Development and validation of a new transgenic hairless albino mouse as a mutational model for potential assessment of photocarcinogenicity

Short-term phototoxicity testing is useful in selecting test agents for the longer and more expensive photocarcinogenesis safety tests; however, no validated short-term tests have been proven reliable in predicting the outcome of a photocarcinogenesis safety test. A transgenic, hairless, albino (THA) mouse model was developed that carries the gpt and red/gam [Spi(-)] genes from the gpt delta mouse background and the phenotypes from the SKH-1 mouse background to use as a short-term test in lieu of photocarcinogenesis safety tests. Validation of the THA mouse model was confirmed by exposing groups of male mice to sub-erythemal doses of ultraviolet B (UVB) irradiation for three consecutive days emitted from calibrated overhead, Kodacel-filtered fluorescent lamps and measuring the mutant frequencies (MFs) in the gpt and red/gam (Spi(-)) genes and types of mutations in the gpt gene. The doses or irradiation were monitored with broad-spectrum dosimeters that were calibrated to a NIST-traceable standard and cumulative CIE-weighted doses were 20.55 and 41.0mJ/cm(2) (effective). Mice were sacrificed 14 days after the final UVB exposure and MFs in both the gpt and red/gam genes were evaluated in the epidermis. The exposure of mice to UVB induced significant ten- to twelve-fold increases in the gpt MF and three- to five-fold increases in the Spi(-) MF over their respective background MF, 26±3×10(-6) and 9±1×10(-6). The gpt mutation spectra were significantly different between that of the UVB-irradiated and that of non-irradiated mice although the mutation spectra of both groups were dominated by C→T transitions (84% and 66%). In mice exposed to UVB, the C→T transitions occurred almost exclusively at dipyrimidine sites (92%), whereas in non-irradiated control mice, the C→T transitions occurred at CpG sites (86%). These results suggest that the newly developed THA mice are a useful and reliable model for testing UVB-induced mutagenicity in skin tissue. The application of this model for short-term prediction of solar-induced skin carcinogenicity is presently under investigation.
Keepers of the Flame

They don't know how, in an A-security ward, he finagled himself a matchbook. But he did; he set his hair on fire?again?and here he is now, thrashing violently over the rec room floor, a nightmare's nightmare come to wakeful life. I wish I could write about him. Even here, amidst the veteran excrement eaters, lesion-pickers and zero-eyed starers, he's known as The Legend. And when he's doused and forcibly sedated, and a fidgety calm returns, we see the rec room television bears the image of a holocaustal fire in some riot-torn downtown; I could swear it's an infant that the jumpy 'copter camcorder footage catches being pitched off a roof. Somebody bearing witness to this, in an essay. Someone adequately finding an interior heat that's equal to this contagion of madness and rage. I've done that essay, I've written that poem, before. But now, today, the subject is the sifted-down ash of a mild regret that grabs me by the jacket lapels and shakes me with a wiry strength, imploring me to tell its story?and, to be honest, I need to hearken to this. When I look carefully, I see that the jacket it grabs me by is a baggy vinyl windbreaker that I wore all through the autumn of 1956. I'm eight. The air is . . . listen: "I asked many people what scent first came to mind at the mention of autumn. To most, I think, it was the smell of burning leaves" (E. W. Teale, Autumn Across America, 1956). The air is signifiers, is something stirring chthonically in the memory hookup. Everything else?the overpowering sweep of human drama with its winged awards and its ambulance wail?is sacrificed now, to be this smoke that rises from an oildrum like a pillar, one of hundreds of thousands of pillars that bear up the sky of that year.
Permeability to nonelectrolytes as an indicator of change in membrane lipid structure in Hordeum vulgare cells infected by Erysiphe graminis f. sp. hordei

The passive permeability to water and nonelectrolytes of epidermal cells from partially dissected coleoptiles of Hordeum vulagare was investigated in uninfected tissue and in tissue infected with a compatible race of the powdery mildew fungus, Erysiphe graminis f. sp. hordei . Permeability constants were determined plasmometrically for water and for the increasingly nonpolar electrolytes: urea, methyl urea, and ethyl urea. Measurements were taken 48 h after inoculation, usually in heavily infected tissues which exhibited concave plasmolysis. Permeability of cells to water or urea was unchanged by infection. Permeability to methyl urea was reduced significantly in the cultivar Montcalm, but not consistently in Atlas or AlgS. Permeability to ethyl urea in AlgS was reduced by half by infection. The reduced permeability occurred not only in haustoriumcontaining cells. but throughout heavily infected tissue. If tissues were left overnight on plasmolyzing solution of α-methyl glucose, uninfected tissues deplasmolyzed and regained turgor whereas infected tissue did not, suggesting that the α-methyl glucose entered healthy, but not infected cells. The results indicate that infection altered the plasmalemma of host cells, reducing passive permeability to α-methyl glucose and the more lipophilic of the nonelectrolytes tested.
Radio Telemetry Applied to Tire Vibrations

This paper discusses the industrial radio telemetry system for use in typical automotive engineering measurements. Considerations of transducer type and measurement class (static or dynamic) are discussed in terms of selection of a telemetry system. Telemetry specifications and their interpretations are discussed along with characteristics and limitations of direct/FM and AM/FM systems. As an example application the measurement of inservice tire vibrations with radio telemetry is presented. The example includes selection and calibration of the telemetry system and presentation of typical telemetry tire vibration data.
Teachers' Work, Food Policies, and Gender in Argentina

Few studies explore teachers' involvement in school feeding, questioning gendered implications within a feminine and feminized profession. Ethnographic data from one public high school in Metropolitan Buenos Aires suggest that teachers' efforts to address student hunger added new work roles: food advocates/activists, food managers, and service providers/caregivers. The data illustrate the collision of gendered roles (feeding and teaching) as well as how the gendered nature of policy shapes teachers' work.
Strategies for Teaching the Differential Use of Alcoholism Treatment Approaches

Abstract Differential approaches to alcoholism treatment have the potential for more effectiveness than the use of one particular model. Teaching differential use of alcoholism treatment approaches is difficult, but it can be facilitated by focusing on students' resistances to learning, conflicting resource priorities in schools of social work, and instructors' frames of reference related to alcohol. These issues serve as the foundation for creative teaching strategies that encourage the use of more diverse approaches to alcohol treatment.
Molecular and functional analysis of pollen-active genes

Pollen development has been studied for many years, but only recently at the molecular level. Two objectives of recent molecular analyses of pollen development are to understand the regulatory circuits that control differential gene expression in pollen and to determine the functions of pollen-expressed proteins during pollen development, germination and pollen-pistil interactions. Another focus is the isolation of anther-specific promoters, in order to manipulate reproductive development via chimeric gene constructs in transgenic plants.
Miniaturized Packaged (Embedded) Antennas for Portable Wireless Devices

Packaged (embedded) antennas are becoming more and more in need with the rapid proliferation of wireless communication devices and systems. This include mobile phones, pagers, wireless PDAs, phones with enhanced GPS services, terminals with Bluetooth/WLAN functionalities, and RFID tags for inventory tracking and identification. In this article an overview of miniaturized packaged (embedded) antennas is presented. This includes multiband embedded antennas for mobile phone applications in the 900/1900-MHz bands, Bluetooth/WLAN in 2.4- and 5–6-GHz bands. Miniaturized planar inverted-F antennas (PIFAs) are discussed along with wideband monopoles for possible triple-band applications. Surface-mount PIFAs, integrated inverted-F antennas (IFAs), and packaged monopole type radiators are discussed for Bluetooth and WLAN applications. Finally, some future trends in this research area are also discussed. Keywords: miniaturized; wireless; packaged; embedded; antenna; PIFA; patch; internal; small; electrically small antennas
DIRECTIONALITY AND NONRECIPROCALITY OF CHI-STIMULATED RECOMBINATION IN PHAGE Λ

Chi's are genetic elements that stimulate generalized recombination in their locale in phage λ. All Chi's, wherever located on λ's chromosome, act asymmetrically in crosses blocked in DNA replication: (1) They stimulate exchange primarily to their left on the conventional λ map, and (2) the stimulated exchange is frequently nonreciprocal, the recombinant carrying the Chi element being produced less often than the complementary product.
The effect of gum chewing on sensitivity associated with in-office whitening procedures

Objectives Tooth sensitivity is the most common side effect of in-office tooth-whitening procedures. The purpose of this study was to determine whether chewing gum containing 0.6% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) before tooth whitening would reduce tooth sensitivity during an in-office whitening procedure. Methods Thirty participants were enrolled and randomized into three groups as follows: group 1 was instructed to not chew gum during the study period; group 2 chewed five pieces of gum (with 0.6% CPP-ACP) for 10 min each day 1 week before whitening; and group 3 chewed five pieces of gum (without CPP-ACP) for 10 min each day 1 week before whitening. All participants had their teeth whitened with a 30% hydrogen peroxide in-office whitening procedure. The participants' shades of teeth were evaluated with a spectrophotometer four times during the study: at the initial screening visit, immediately before whitening, immediately after whitening and 1 week after whitening. Participants' sensitivity levels were evaluated each time the shades were evaluated and additionally at 24 h after whitening using a 100-mm visual analogue scale. Results Thirty participants were enrolled in the study. The average shade change was −2.27 (±2.07). The average sensitivity for all groups at visit 1 was 5.12 (±13.94). The average sensitivity for all groups after whitening was 19.81 (±13.95). There were significant differences in sensitivity between groups 2 and 3 (P = 0.02), but neither group was significantly different from the control group (P = 0.86, P = 0.07). Conclusions Chewing gum before whitening, including gum with CPP-ACP, did not reduce sensitivity during in-office whitening procedures.
Climate of opportunity

With the shift of power in the US Congress comes an chance to re-engage in the debate over climate change. But the process will not be simple, says our new columnist David Goldston.
Disorder effects in dynamic fragmentation of brittle materials

While fragmentation of brittle materials is a phenomenon that occurs commonly, a consistent theoretical description of this process is not yet available. In this paper, we introduce a one-dimensional micromechanics-based statistical model for fragmentation in a brittle material and analyze the model using two different approaches, namely, an exact numerical method based on the method of characteristics and a dynamic mean-field theory. The mean-field theory is derived by averaging the equations that govern the dynamics of flaws in a self-consistent manner and explicitly accounts for both the statistical nature of flaw distributions and the stress-wave-mediated communication between flaws. It is shown that the mean-field theory provides an accurate description of the damage evolution process that takes place during fragmentation and predicts fragment sizes that are in close quantitative agreement with the numerical calculations.
Neurocognitive testing and functioning in adults sickle cell disease.

The impact of cerebrovascular events (CVE) on cognitive functioning in adults with sickle cell disease is not well understood. Sequelae of CVEs can adversely impact their quality of life. We reviewed neurocognitive presentation and testing in adults with sickle cell disease. We evaluated the frequency of complaints of memory disturbance using survey methodology in a sample of 109 adult patients with sickle cell disease (48 males, 61 females). A subsample of 24 patients also received a memory questionnaire where specific cognitive functions were assessed.Overall, we found that males and females did not differ in the frequency of experienced memory disturbance during painful crises. However, the frequency of men reporting that their ability to remember where they place common objects such as keys (p = 0.017) and remembering the item they intended to buy in a grocery store or pharmacy (p = 0.048) was worse now compared to when they were in high school and was greater when compared to women. The frequency of ...
Self-aligned AlGaAs/InGaAs/GaAs collector-up heterojunction bipolar transistors for microwave applications

Summary form only given. The authors discuss the recent development of high-performance AlGaAs/InGaAs/GaAs collector-up HBTs (heterojunction bipolar transistors) fabricated by using a novel self-aligned base/collector process. Transistors with collector widths down to 2.6 mu m and base doping up to 1*10/sup 20//cm/sup 3/ have been fabricated and tested. Based on s-parameters measured up to 26 GHz, an extrapolated current gain bandwidth, f/sub t/, of 65 GHz and a maximum frequency of oscillation, f/sub max/, of 102 GHz have been obtained. To the authors' knowledge, these are the first C-up HBTs demonstrated to operate at or above microwave frequencies. >
Haplotype Block Structure and Its Applications to Association Studies: Power and Study Designs

Recent studies have shown that the human genome has a haplotype block structure, such that it can be divided into discrete blocks of limited haplotype diversity. In each block, a small fraction of single-nucleotide polymorphisms (SNPs), referred to as “tag SNPs,” can be used to distinguish a large fraction of the haplotypes. These tag SNPs can potentially be extremely useful for association studies, in that it may not be necessary to genotype all SNPs; however, this depends on how much power is lost. Here we develop a simulation study to quantitatively assess the power loss for a variety of study designs, including case-control designs and case-parental control designs. First, a number of data sets containing case-parental or case-control samples are generated on the basis of a disease model. Second, a small fraction of case and control individuals in each data set are genotyped at all the loci, and a dynamic programming algorithm is used to determine the haplotype blocks and the tag SNPs based on the genotypes of the sampled individuals. Third, the statistical power of tests was evaluated on the basis of three kinds of data: (1) all of the SNPs and the corresponding haplotypes, (2) the tag SNPs and the corresponding haplotypes, and (3) the same number of randomly chosen SNPs as the number of tag SNPs and the corresponding haplotypes. We study the power of different association tests with a variety of disease models and block-partitioning criteria. Our study indicates that the genotyping efforts can be significantly reduced by the tag SNPs, without much loss of power. Depending on the specific haplotype block–partitioning algorithm and the disease model, when the identified tag SNPs are only 25% of all the SNPs, the power is reduced by only 4%, on average, compared with a power loss of ∼12% when the same number of randomly chosen SNPs is used in a two-locus haplotype analysis. When the identified tag SNPs are ∼14% of all the SNPs, the power is reduced by ∼9%, compared with a power loss of ∼21% when the same number of randomly chosen SNPs is used in a two-locus haplotype analysis. Our study also indicates that haplotype-based analysis can be much more powerful than marker-by-marker analysis.
Unilateral 6-hydroxydopamine lesion of dopamine neurons and subchronic L-DOPA administration in the adult rat alters the expression of the vesicular GABA transporter in different subsets of striatal neurons and in the substantia nigra, pars reticulata.

Abstract The loss of dopamine neurons combined or not with the subsequent administration of l -DOPA in patients with Parkinson’s disease or in experimental models of the disease results in altered GABAergic signaling throughout the basal ganglia, including the striatum and the substantia nigra, pars reticulata. However, the molecular mechanisms involved in altered GABA neurotransmission remain poorly understood. In order to be released from synaptic vesicles, newly synthesized GABA is transported from the cytosol into synaptic vesicles by a vesicular GABA transporter. The objective of this study was to examine the hypothesis that expression of the vesicular GABA transporter (vGAT) is altered in the unilateral 6-hydroxydopamine model of Parkinson’s disease. Our results provide evidence that a unilateral 6-hydroxydopamine lesion results in increased and decreased vGAT mRNA levels in striatopallidal and striatonigral neurons, respectively. These two subsets of neurons were identified by the co-expression or lack of co-expression of preproenkephalin, a marker of striatopallidal neurons, using double-labeling in situ hybridization histochemistry. Such changes occurred in the striatum ipsilateral to the 6-hydroxydopamine lesion and were paralleled by decreased vGAT protein levels in the substantia nigra, pars reticulate (SNr). On the other hand, the subchronic systemic administration of l -DOPA increased vGAT mRNA levels in preproenkephalin-negative neurons on the side ipsilateral and, to a lesser extent, the side contralateral to the 6-hydroxydopamine lesion. Systemic l -DOPA also increased vGAT protein levels in the ipsi- and contralateral SNr. As a whole, the results provide original evidence that vGAT expression is altered in the 6-hydroxydopamine model of Parkinson’s disease. They also suggest that the behavioral effects induced by a subchronic administration of l -DOPA to 6-hydroxydopamine-lesioned rats involve an increase in the vesicular release of GABA by striatonigral neurons.
329 CHONDROGENIC POTENTIAL OF PORCINE ADIPOSE-DERIVED STEM CELLS, CHONDROCYTES, PERIOSTEAL CELLS, AND FIBROBLASTS IN A PELLET CULTURE SYSTEM

Regenerative medicine has long sought to develop therapies for articular cartilage repair and for enhancing endochondral ossification to address complications of long bone healing. The objective of this study was to determine the chondrogenic potential of porcine primary cell cultures for possible utility in orthopedic tissue engineering applications. Adipose-derived mesenchymal stem cell (ASC), chondrocyte (positive control), periosteal cell, and fibroblast (negative control) primary cell cultures from 8- to 12-month-old Yorkshire pigs were plated at 5000 to 10 000 cells cm–2 in 75-cm2 cell culture flasks using high-glucose Dulbecco's Modified Eagle's Medium (DMEM) supplemented with NaHCO3, 10% fetal bovine serum (FBS), and antimicrobials (penicillin-streptomycin, gentamicin sulfate, and amphotericin B), then incubated at 37°C, 5% CO2, and 18% O2. Cells were trypsinized at ~80% confluency and transferred into 15-mL conical tubes at 500 000 cells tube–1. Suspensions were washed twice by centrifugation in DPBS then condensed via a final centrifugation in 1.0 mL of negative control media (DMEM + 10% FBS) or chondrogenic base media consisting of high-glucose DMEM with 40 µg mL–1 of proline, 50 µM ascorbic acid-2-phosphate, 100 nM dexamethasone, antimicrobials, and 1× insulin-transferrin-selenium solution added. Chondrogenic additives tested were 2% FBS, Kartogenin (200 nM, 400 nM, or 4 µM), 10 ng mL–1 of BMP-4, or a combination of 10 ng mL–1 of BMP-6 + 10 ng mL–1 of TGFβ-3. Pellets were incubated with media changed every 2 to 3 days for a period of 2 to 4 weeks, fixed with 4% paraformaldehyde in DPBS, and then frozen at –80°C in Neg 50 Frozen Section Medium. Eight-micrometer sections were cut using a cryostat onto charged slides. Histochemical staining was performed using hematoxylin and eosin (H&E) for cell morphology and Safranin O and Alcian Blue for cartilage matrix markers. Immunofluorescent staining was done to detect collagen II and aggrecan with the nuclear marker lamin-C used to assess cell viability. Chondrocyte pellets grown in chondrogenic media, regardless of additive, exhibited cartilage matrix formation with H&E and stained strongly positive with Safranin O, Alcian Blue, and collagen II. The ASC pellets grown in chondrogenic media showed mixed cell morphology and areas of early cartilage matrix formation with H&E and stained faintly positive with Safranin O, Alcian Blue, and collagen II at 3 weeks in culture. Periosteal cell pellets had similar morphology in all conditions and did not stain positive for cartilage matrix markers. Fibroblast pellets did not survive any condition for processing. In conclusion, porcine chondrocytes and ASC were able to form cartilage matrix in a pellet culture system with chondrogenic media regardless of additive, while porcine fibroblasts and periosteal cells showed limited to no chondrogenic potential in the conditions tested.
A numerical approach to space-time finite elements for the wave equation

We study a space-time finite element approach for the nonhomogeneous wave equation using a continuous time Galerkin method. We present fully implicit examples in 1+1, 2+1, and 3+1 dimensions using linear quadrilateral, hexahedral, and tesseractic elements. Krylov solvers with additive Schwarz preconditioning are used for solving the linear system. We introduce a time decomposition strategy in preconditioning which significantly improves performance when compared with unpreconditioned cases.
Strata of vector spaces of forms in R = k[x, y], and of rational curves in ℙ k

Consider the polynomial ring R = k[x, y] over an infinite field k and the subspace R j of degree- j homogeneous polynomials. The Grassmanian G = Grass(R j , d) parametrizes the vector spaces V ⊂ R j having dimension d. The strata Grass H (R j , d) ⊂ G determined by the Hilbert functions H = H(R/(V)) or, equivalently, by the Betti numbers of the algebras R/(V), are locally closed and irreducible of known dimension. They satisfy a frontier property that the closure of a stratum is its union with lower strata [I1, I2]. The strata are determined also by the decomposition of the restricted tangent bundle $$\mathcal{T}_V = \varphi _V^* (\mathcal{T})$$ where $$\mathcal{T}$$ is the tangent bundle on ℙ d −1 and ϕ V is the rational curve determined by V. Each stratum corresponds to a partition, and the the poset of strata under closure is isomorphic to the poset of corresponding partitions in the Bruhat order. They are coarser than the strata defined by D. Cox, A. Kustin, C. Polini, and B. Ulrich [CKPU] and studied further in [KPU], that are determined in part by singularities of ϕ V . We explain these results and give examples to make them more accessible. We also generalize a result of D. Cox, T. Sederberg, and F. Chen and another of C. D’Andrea concerning the dimension and closure of μ families of parametrized rational curves from planar [CSC, D] to higher dimensional embeddings (Theorem 1.11).
Drug discovery: How melanomas bypass new therapy

The promise of an exciting new drug that inhibits the mutant B-RAF protein in skin cancer is marred by the fact that most patients relapse within a year. Fresh data hint at how such resistance emerges. See Letters p.968 & p.973 Clinical trials in melanoma patients carrying B-RAF gene mutations have shown promising results with the B-RAF kinase inhibitor PLX4032, but many patients go on to become resistant. Two papers now uncover possible mechanisms for this resistance. Nazarian et al. report that melanomas can acquire resistance due to mutations of N-RAS or increased expression of PDGFRβ, and Johannessen et al. report resistance due to upregulation of MAP3K8/COT. Each of these mechanisms seems to apply to some patients in the recent PLX4032 trial, yet surprisingly, no secondary B-RAF mutations were observed.
Changes in leucyl-tRNA species during ageing of detached soybean cotyledons

Abstract During ageing of detached soybean cotyledons quantitative changes in certain species of leucyl- t RNA occur. Of the six leucyl- t RNAs obtained by Freon column fractionation there is an increase in the relative amount of leucyl- t RNA 5,6 and a decrease in the amount of leucyl- t RNA 1 with age. The amount of leucyl- t RNA 5,6 increases from 6% of the total in dry seeds to 20% in 8-day-old cotyledons. Our results suggest that the relative amounts of leucyl- t RNA 5,6 probably arise either by, (a) modification of some preexisting t RNA, a process unaffected by partial inhibition of RNA synthesis, protein synthesis, or methylation of RNA, or (b) a preferential destruction of leucyl- t RNA 1–4 .
Effect of exogenous progesterone on prostaglandin F2α release and the interestrous interval in the bovine

Abstract The present study was developed to determine if administration of progesterone, early in the estrous cycle of the cow, stimulated an advanced pulsatile release of PGF2α from the uterine endometrium resulting in a decreased interestrous interval. Twenty-three cyclic beef cows were randomly assigned to receive either sesame oil or progesterone (100 mg) on Day 1, 2, 3 and 4 of the estrous cycle. Peripheral plasma concentrations of progesterone and the metabolite of prostaglandin F2α, 15-keto-13, 14-dihydro-prostaglandin F2α (PGFM) were measured by radioimmunoassay. Administration of exogenous progesterone increased peripheral plasma concentration of progesterone in treated (3.67 ng/ml) compared to control (1.28 ng/ml) cows from Day 2 through 5 of the estrous cycle. Progesterone administration shortened the interestrous interval (16.7 d) compared to controls (21.6 d). The shortened interestrous intervals in treated cows resulted from an earlier decline in peripheral plasma progesterone. Decline of peripheral plasma progesterone concentrations is coincident with an increased pulsatile release of PGFM in both progesterone treated and control cows. Results indicate that administration of exogenous progesterone stimulates an earlier maturation of endometrial development, causing an advanced release of PGF2α which shortens the interestrous interval of the cow.
Correction of Hyperinsulinemia by Glyburide Treatment in Nondiabetic Patients with Thalassemia Major

Correction of Hyperinsulinemia by Glyburide Treatment in Nondiabetic Patients with Thalassemia Major