cssi/SciSciGPT-SciSciNet huggingface dataset:
Induction of an epithelial-mesenchymal transition by an in vivo adheron-like complex

The embryonic vertebrate heart consists of two epithelia: the myocardium and endothelium, separated by the myocardial basement membrane (MBM). The myocardium has been shown to induce endothelial transformation into prevalvular mesenchyme in a temporally and site restricted manner. Previously, we hypothesized that the myocardial-endothelial interaction is mediated in vivo by aggregates of 30-nm particles in the MBM which can be removed by EDTA extraction. These MBM extracts contain fibronectin and other lower Mr proteins and can initiate an epithelial-mesenchymal transition in the AV (atrioventricular canal) endothelium of embryonic chick heart in collagen gel culture. These and other data suggested that the 30-nm multicomponent particles are similar, structurally and compositionally, to multimolecular complexes, termed adherons, secreted by L6 muscle cells in culture. The purpose of this study was to (1) test whether the removal of the 30-nm particles from MBM extracts of embryonic chick hearts would remove the in vitro biological activity and (2) determine if the fractionated MBM extracts can cause AV endothelial cells to follow the same differentiation pathway observed in vivo by monitoring immunohistochemically the cell surface expression of N-CAM. Results showed that centrifugation of extract at 100,000g for 1 hr produced a supernatant fraction that was unable to initiate mesenchyme formation from AV endothelium. However, the resuspended pellet fraction did initiate differentiation of endothelium into mesenchyme. Conditioned medium from L6 skeletal muscle cultures could not substitute for the EDTA extract of embryonic heart. Endothelial cells undergoing the transition to form mesenchyme, both in vivo and in vitro, showed a concomitant decrease in N-CAM staining. This suggested that the pellet-induced formation of migrating cells in the collagen gels is not the result a novel in vitro phenomenon.
The association between forms of aggression, leadership, and social status among urban youth

While much prior research has documented the negative associations between aggression, peer relationships, and social skills, other research has begun to examine whether forms of aggression also may be associated with prosocial skills and increased social status. However, few studies have examined these associations within diverse samples of elementary aged youth. The current study examined the associations between aggression, popularity, social preference, and leadership among 227 urban, ethnic minority (74 % African American, 9 % bi-racial including African American, 12 % other ethnic minorities, and 5 % European American) elementary school youth (average age 9.5 years, 48.5 % female). Results indicated that in an urban, high risk environment, displaying aggressive behaviors was associated with increased perceived popularity, decreased social preference, and, in some cases, increased perceived leadership. The results also suggested gender differences in the association between the forms of aggression (i.e. relational and overt) and popularity. The current study underscores the importance of examining youth leadership along with forms of aggression and social status among urban minority youth. Implications for future research and aggression prevention programming are highlighted.
Identification of small peptides and their antibodies in the prevention of toxic shock syndrome

Abstract Previous studies in this laboratory have shown that a synthetic peptide (38 aa) was able to both neutralize all superantigens known in an “in vitro” blastogenesis assay as well as to protect animals in vivo. Similar results were achieved with a 12-aa peptide. To determine which amino acids were crucial for this inhibition, we prepared a series of single-alanine substitute peptides spanning the 12 amino acids. These studies indicated that the first 3 amino acids of the 12-mer peptide CMY were crucial for inhibition of the superantigen effects in vitro. Furthermore, CMY or YMC in both the D and L forms were equally effective in inhibiting the superantigen properties. These results indicate that both a 12-aa peptide as well as trimers of that peptide can protect against superantigen-induced lethal shock.
Detailed Potentiometric Study of Al3+ and Cr3+ with Malic Acid in Aqueous Solutions

It appeared that malic acid solubilized both Al 3+ and Cr 3+ in aqueous solutions at all pH-values in 0.1 M NaNO 3 at 25 o C. The detailed potentiometric measurements indicated that these free tri-valent metal ions released a net of three protons (3H + â€™s) into the solution. Free malic acid released a net of (2H + â€™s) into the solution from the two carboxylates. However, in the presence of metal ions malic acid effectively releases a net of three protons (3H + â€™s) into the solution; two from the two carboxylates and the third from the alcoholic group. The reaction mixture of Al 3+ :malic acid indicated the formation of a dimeric species. The proposed structure of this dimeric species is in good agreement with what has been shown in the literature. We are presenting a dimeric species that may play an important role in malate transportation across cell membrane. Formation of the Al 3+ -malic acid complexes cover the span of a total of 400 mV; from +250 mV to - 150 mV. The Cr 3+ -malic acid reaction mixture indicated the formation of a dimeric species as well.
Feasibility of real-time graphical simulation for active monitoring of visibility-constrained construction processes

The lack of clear visibility and spatial awareness frequently results in construction accidents such as workers being struck by heavy equipment; and collisions between equipment and workers or between two pieces of equipment. In addition, certain processes such as excavation and drilling inherently pose constraints on equipment operators' abilities to clearly perceive and analyze their working environment. In this paper, the authors investigate the types of spatial interactions on construction sites and the need for graphical real-time monitoring. A computing framework is presented for monitoring interactions between mobile construction equipment and static job-site entities, workers, and other equipment. The framework is based on the use of sensor-based tracking, georeferenced models, and a resulting concurrent, evolving 3D graphical database. The developed framework enables a real-time 3D visualization scheme that provides equipment operators with graphical job-site views that are not possible through conventional on-site cameras. The two key parameters affecting a proximity monitoring framework's effectiveness are measurement error and latency. Measurement error refers to the error in proximity computation--with respect to ground truth or theoretically expected values. Latency is a difference in the time between when an event occurs in the real world and when a proximity monitoring framework provides output to warning systems that end users depend upon. Results from validation experiments conducted to analyze the achievable measurement error and latency of the monitoring framework using indoor GPS tracking as a ground truth system are also presented and discussed.
A TV Horizontal I/C

The design of new integrated circuits must be oriented to the cost and flexibility demanded by the function. This paper describes a new I/C which houses the horizontal APC system in only 8 pins while retaining excellent flexibility. Simple, yet sufficient circuits for the RC oscillator and balanced phase detector have all important parameters available externally. A special predriver circuit uses one pin to adjust the output for any type of horizontal driver. By modifying the external circuitry, the TV designer can tailor the I/C to meet a wide range of performance requirements in monochrome and color TV.
On the Mechanism of Cathodic Protection

Abstract Changes in the distribution of anodic sites on steel and aluminum surfaces have been monitored by applying a pH-indicating dye and observing how the color pattern on the surface changes as cathodic protection is applied. In addition, cathodic polarization curves for steel in seawater have been correlated with 120-day weight loss measurements and surface morphological observations for specimens receiving various levels of cathodic protection. The results are discussed in terms of the Mears and Brown, Hoar, and LaQue theories of cathodic protection and their implications as to the criteria for cathodic protection and the consequences of underprotection.
First-Name Stereotypes and Essay Grading

Summary This research studied whether grades given to elementary school students' essays are affected by stereotyped perceptions of their first names. American women (N = 180) in undergraduate teacher education courses each graded one essay identified by a purported first name. High, medium, and low desirability names were stratified by sex and randomly placed on the essays. No evidence was found that the grades assigned to the essays were influenced by the first names. This result is discussed in terms of the effects of (a) raters' failure to perceive the first names on the essays, (b) using names based on a desirability stereotype rather than a scholastic achievement stereotype demension, and (c) the detailed grading instructions which apparently minimized irrelevant factors in the grading process.
Hydroforming of sheet metal using a viscous pressure medium

Abstract Conventional sheet hydroforming uses water with additives as pressure medium. However, viscous pressure forming (VPF), using a viscous material can also be used in the hydroforming process and offers the advantages of improved sealing to reduce leakage and easier handling in prototype production of a small number of parts. This paper describes the application of VPF to the forming of a non-symmetric part from steel, aluminum and a nickel alloy. FEA simulation and blank holder force control are utilized to optimize the process conditions. The effect of process variables upon the achievable part geometry is discussed. Comparison of FEA predictions with experiments illustrated that metal flow and thinning can be estimated with good accuracy.
Plasmonic interference and coherence in metallic nanostructures

A general discussion of radiative interference processes in plasmonic nanostructures is presented. It will be shown that the interference between subradiant and superradiant plasmon modes can induce pronounced Fano resonances it the optical spectra.
Retinol‐binding protein in equine endometrium

Summary In Exp. 1, endometrial biopsies were collected from normally cycling, unmated mares at Days 0, 4, 8, 10, 12, 14 and 16 and from pregnant mares at Days 10, 12, 14 and 15 after ovulation (2 mares/day) and immediately frozen on solid CO2. In Exp. 2, biopsies were obtained from acyclic intact mares treated with steroids in regimens designed to simulate an oestrous cycle (oestrogen, low progesterone or high progesterone). Duplicate endometrial samples from each mare were frozen for RNA analysis or pooled within day and incubated in vitro for analysis of proteins secreted into the medium by 2-D PAGE and fluorography. Fluorograms from all 3 groups revealed proteins with electrophoretic mobility consistent with RBP (Mr 21, 000–22, 000, pI 5–6.5) Identification of these proteins as immunoreactive RBP was confirmed by western blot analysis. Endometrium which had been frozen at the time of collection was pooled within day (Exp. 1) or within group (Exp. 2), and total RNA was extracted. Northern blot analysis revealed positive hybridisation for RBP at ˜0.9 kb in all samples. These results demonstrate the presence of mRNA for RBP in equine endometrium during the oestrous cycle and early pregnancy, that equine endometrium synthesises and secretes RBP, and that RBPmRNA and protein concentration may be influenced by the steroid environment. Endometrial RBP probably plays a critical role in successful development of the equine embryo and establishment of pregnancy.
On the causes of landslides: Human activities, perception, and natural processes

Conceptual equations are presented for the net benefits, total risk, and total vulnerability associated with hazard zone occupation. It is shown that, as they are polycausal phenomena, landslides require a more sophisticated approach to this form of analysis than that employed for most other forms of hazard.
Galactic mass loss - A mild evolutionary correction to the angular size test

Galactic mass loss due to gas production by an evolving stellar population and removal due to supernovae or some other energy source can alter the size of a galaxy over a long time through the adiabatic invariants of the orbits. Numerical and analytic results show that if the mass profile changes homologously, the scale size of the galaxy does also. Under conventional assumptions about galaxy age and initial mass function, this bloating is smaller than the differences between open and flat cosmologies at z = 0.5. If, however, some elliptical galaxies maintain star formation until recent epochs and then lose a (correspondingly) larger fraction of their mass, the effect may be important. It may also be important in decreasing the size of cD galaxies as a result of gas accretion.
Myasthenia gravis induced by monoclonal antibodies to acetylcholine receptors

Autoantibodies to nicotinic acetylcholine receptors (AChRs) are demonstrable in sera of approximately 90% of patients with myasthenia gravis (MG), a disease of neuromuscular transmission1. The consistent abnormality in MG is a low amplitude of miniature endplate potentials (m.e.p.ps) due to decreased sensitivity of the postsynaptic membrane to the neurotransmitter, acetylcholine (ACh). This reflects a decrease in numbers of AChRs in the membrane (for review see ref. 2). The pathogenicity of anti- AChR antibodies has been documented in vivo by passive transfer of MG from human to mouse3 and from rat to rat4 and in vitro on cultured muscle cells5–8. However, titres of anti-AChR antibodies in serum do not correlate closely with severity of muscle weakness in MG patients1. This lack of correlation very probably reflects the heterogeneity of specificities of anti-AChR antibodies which is known to exist in MG2. For example, antibodies directed to determinants of AChRs which are inaccessible in vivo may be generated in the course of the disease without being relevant to disease pathogenesis. Identification of antigenic determinants of AChRs which are the primary target(s) of antibody attack in MG is a logical prerequisite to designing antigen-specific immunotherapy for this disease. We report here the production by hybridoma cells of monoclonal rat antibodies reactive with muscle AChR, both adult and fetal, in all of six mammalian species studied. Antibodies produced by two of these hybridoma lines bound to one or more antigenic determinant(s) exposed extracellularly, but remote from the binding site for cholinergic ligands, in the postsynaptic membrane of muscle, and caused a defect of neuromuscular transmission in mice, rats and guinea pigs. These findings establish conclusively that neuromuscular transmission can be impaired by monospecific anti–AChR antibodies which do not inhibit the binding of neurotransmitter to its receptor site.
Applying wavelets to predict solar PV output power using generalized regression neural network

This paper presents a hybrid intelligent approach to forecast short-term output power of a PV system. The proposed hybrid method is composed of a data filtering technique based on wavelet transform (WT) and generalized regression neural network (GRNN). In order to validate the prediction capability of the proposed WT+GRNN model, test results are compared with other soft computing models (SCMs). This paper uses a PV system data derived from Ashland, Oregon. Simulation results demonstrate the greater ability of GRNN model to handle nonlinear solar PV time-series data, and when it is combined with the WT, the forecasting accuracy is greatly enhanced.
Changes in Soil Fungal Communities, Extracellular Enzyme Activities, and Litter Decomposition Across a Fire Chronosequence in Alaskan Boreal Forests

Wildfires are a pervasive disturbance in boreal forests, and the frequency and intensity of boreal wildfires is expected to increase with climate warming. Boreal forests store a large fraction of global soil organic carbon (C), but relatively few studies have documented how wildfires affect soil microbial communities and soil C dynamics. We used a fire chronosequence in upland boreal forests of interior Alaska with sites that were 1, 7, 12, 24, 55, ~90, and ~100 years post-fire to examine the short- and long-term responses of fungal community composition, fungal abundance, extracellular enzyme activity, and litter decomposition to wildfires. We hypothesized that post-fire changes in fungal abundance and community composition would constrain decomposition following fires. We found that wildfires altered the composition of soil fungal communities. The relative abundance of ascomycetes significantly increased following fire whereas basidiomycetes decreased. Post-fire decreases in basidiomycete fungi were likely attributable to declines in ectomycorrhizal fungi. Fungal hyphal lengths in the organic horizon significantly declined in response to wildfire, and they required at least 24 years to return to pre-fire levels. Post-fire reductions in fungal hyphal length were associated with decreased activities of hydrolytic extracellular enzymes. In support of our hypothesis, the decomposition rate of aspen and black spruce litter significantly increased as forests recovered from fire. Our results indicate that post-fire reductions in soil fungal abundance and activity likely inhibit litter decomposition following boreal wildfires. Slower rates of litter decay may lead to decreased heterotrophic respiration from soil following fires and contribute to a negative feedback to climate warming.
Observations on the association of auroral luminosity with auroral X-rays and cosmic noise absorption

Abstract Simultaneous observations of auroral luminosity and bremsstrahlung X-rays from the same balloon payload are reported here. Comparison of the balloon measurements with riometer records has shown the same variety of associations that appear in other studies of auroral phenomena. Because the photometer and scintillation counter geometries are fixed relative to each other and view equivalent regions of the sky at the production layer, it has been possible to investigate behavioral differences in the low and high energy portions of the precipitated electron spectrum with more certainty than when comparing balloon and ground-based observations. Certain aspects of the present observations suggest that temporal variations in these two energy ranges are rather independent, on occasion. These observations support the suggestion that two mechanisms having characteristically different energy spectra control the acceleration and/or precipitation of energetic electrons. Correlations of auroral luminosity with X-rays then depend upon the degree of coupling between the mechanisms.
Flowering, capsule and seed characteristics in Cuphea

We modeled the flowering and capsule set dynamics, quantified the level of variation in seed characteristics, elucidated the inter-relationships between seed and capsule physical dimensions, and quantified their impact on single seed weight in the cuphea germplasm line PSR23. Temporal patterns of flowering and capsule set were largely time-dependent and highly auto-correlated, with significant autoregressive parameters of number of flowers (0.76) and number of capsules (0.74). Large numbers of seeds per capsule were associated with large coefficient of variation in single seed weight. Seed number and seed weight per capsule, when log-transformed, exhibited a slope of −0.65 indicating that cuphea plants have only a limited capacity to maintain seed weight by adjusting seed number if resources vary. Capsule tissue/seed weight ratio and number of seeds per capsule have the largest potential impact on single seed weight. Sensitivity analyses indicated that capsule perimeter (>76 mm), capsule major (>23 mm) and minor axes (>7.0 mm), capsule circularity (between 0.350 and 0.375), capsule area (<85 mm2), capsule tissue/seed weight ratio (<0.40), and number of seeds per capsule (∼9.0) would optimize single seed weight. This information would help plant breeders exploit genotypic variability in seed and capsule characteristics and agronomists identify optimum trait combinations to produce high yields of this potential oilseed crop.
Use of gene expression, biochemical and metabolite profiles to enhance exposure and effects assessment of the model androgen 17β‐trenbolone in fish

The impact of exposure by water to a model androgen, 17β-trenbolone (TRB), was assessed in fathead minnows using an integrated molecular approach. This included classical measures of endocrine exposure such as impacts on testosterone (T), 17β-estradiol (E2), and vitellogenin (VTG) concentrations in plasma, as well as determination of effects on the hepatic metabolome using proton nuclear magnetic resonance spectroscopy. In addition, the rates of production of T and E2 in ovary explants were measured, as were changes in a number of ovarian gene transcripts hypothesized to be relevant to androgen exposure. A temporally intensive 16-d test design was used to assess responses both during and after the TRB exposure (i.e., depuration/recovery). This strategy revealed time-dependent responses in females (little impact was seen in the males), in which changes in T and E2 production in the ovary, as well as levels in plasma, declined rapidly (within 1 d), followed shortly by a return to control levels. Gene expression measurements revealed dynamic control of transcript levels in the ovary and suggested potential mechanisms for compensation during the exposure phase of the test. Proton nuclear magnetic resonance spectroscopy revealed a number of hepatic metabolite changes that exhibited strong time and dose dependence. Furthermore, TRB appeared to induce the hepatic metabolome of females to become more like that of males at both high test concentrations of TRB (472 ng/L) and more environmentally relevant levels (33 ng/L).
An empirical investigation of the process of knowledge transfer in international strategic alliances

This research proposes and tests a basic model of organizational learning that captures the process of knowledge transfer in international strategic alliances. Based on a cross-sectional sample of 147 multinationals and a structural equation methodology, this study empirically investigates the simultaneous effects of learning intent, learning capacity (LC), knowledge ambiguity, and its two key antecedents – tacitness and partner protectiveness – on technological knowledge transfer. In the interest of expanding our understanding of the organizational mechanisms that both hinder and facilitate learning, the concept of LC is refined into three distinct components: resource-, incentive-, and cognitive-based LC. Further, the strength of the relationships between these theoretical constructs and knowledge transfer is examined in light of the possible moderating effects of organizational culture, firm size, and the form and competitive regime of the alliance. Consistently, learning intent (as a driver) and knowledge ambiguity (as an impediment) emerge as the most significant determinants of knowledge transfer. Moreover, the effects of partner protectiveness and LC on the learning outcome are moderated by the firm's own culture towards learning, the size of the firm, the structural form of the alliance, and the fact that partners may or may not be competitors.
Identification and estimation of bounds on school performance measures: a nonparametric analysis of a mixture model with verification

This paper identifies and nonparametrically estimates sharp bounds on school performance measures based on test scores that may not be valid for all students. A mixture model with verification is developed to handle this problem. This is a mixture model for data that can be partitioned into two sets, one of which (the so-called verified set) is more likely to be from the distribution of interest than the other. An administrative classification of each student as English proficient or limited English proficient determines these sets. An analysis of performance measures for some California public schools reveals how verification information and plausible monotonicity restrictions can bound the range of disagreement about school performance based on observed scores. Copyright © 2006 John Wiley & Sons, Ltd.
Design Evolution Using the Artisan-Patron Model: The Case of Automobile Evolution

This paper uses the descriptive Artisan-Patron (AP) model to create a transparent framework to analyze how environmental variables such as fuel price, price of steel, and CAFE legislation affected the evolution of the automobile (namely horsepower and weight). The analysis and results demonstrate the utility of the AP model as a frame for complex multi-epoch adaptive design problems.Copyright © 2005 by ASME
Osteochondroma of the convexity: pathologic-neuroimaging correlates of a lesion that mimics high-grade meningioma

Intracranial chondromas are uncommon benign lesions usually attached to dura and located over the convexity of the skull. Osteochondromas are even rarer and additionally contain a benign bony component. Both lesions are reportedly difficult to distinguish from meningiomas on pre-operative neuroimaging studies, although few detailed pathologic-neuroimaging correlation studies have appeared in the literature, particularly for intracranial osteochondromas. A 33-year-old woman with a 4-year history of headaches presented with recent onset of left-sided muscle spasms and weakness. Two days prior to admission to our hospital, neuroimaging studies had shown a large right convexity mass with unusual multifocal bright signal intensities throughout an otherwise isointense mass. The bright signals were interpreted as showing multifocal hemorrhage and the mass was felt to be a convexity meningioma. However, subsequent catheter angiography characterized the lesion as being avascular. The mass was resected en bloc. Extensive histological sectioning revealed a benign osteochondroma predominantly composed of lobules of hypocellular cartilage. Microdissection of the different components revealed that the multifocal, spicule-like bright foci interpreted as hemorrhage on neuroimaging studies were instead foci of benign bone containing metaplastic bone marrow with trilineage hematopoietic cell populations and adipose tissue. Centrally, the hilum of the lesion contained avascular loose connective tissue. No recent or remote hemorrhage was identified anywhere in the lesion. Rare convexity osteochondromas may be mistaken for high-grade meningiomas on neuroimaging studies; their avascular nature, coupled with their complex signal pattern can serve as clues to the correct pre-operative diagnosis.
Single-phase membrane ozonation of hazardous organic compounds in aqueous streams

Abstract The use of ozone to treat hazardous organic wastes in water is limited by the low solubility of ozone in water. The use of semipermeable nonporous silicone capillary membranes to transfer ozone nondispersively into an aqueous phase and ozonate organic species has been studied for the single pollutants phenol, nitrobenzene and acrylonitrile. Preliminary experimental results are presented here to demonstrate the efficacy of such a process using silicone capillary membranes. The substantially larger a (surface area per unit volume of device) (15.3 cm 2 /cm 3 in the case of module 2) that this membrane ozonator provides leads to a significantly larger value of mass transfer parameter compared to those in conventional equipments. For iodometric consumption of ozone, the value of k l a in presence of reaction was found to be 5.8 × 10 −3 s −1 in module 2 compared to calculated values of 1.058 × 10 −3 s −1 for a packed column containing Raschig rings 1.3 cm in size and 3.22 × 10 −4 s −1 for a bubble column operating under comparable superficial gas and liquid velocities.
Parties and Procedural Choice in the House Rules Committee

Party-based theories argue that leaders of the majority party use restrictive rules to increase that majority's influence over policy. However, informational theorists suggest that restrictive rules reduce information costs and encourage committee specialization. Using data on every bill on which the House Rules Committee placed a rule from the 94th through 109th Congresses, I test these explanations. Considering the use of restrictive rules, the evidence verifies some of the predictions of partisan theories, but unveils mixed support for informational theories. In addition, we learn that Democratic and Republican majorities differ with respect to the use of restrictive rules. The results indicate that Republican majorities behaved as more of a procedural cartel than their Democratic predecessors.
Segmenting Corporate Exporting Activities: Sporadic versus Regular Exporters

The primary focus of this study is an examination of differences between characteristics and activities ofsporadic andregular exporters. This mode of classifying exporting firms, which has not previously been studied in a rigorous fashion is shown to be valid and has important policy implications. This classification is robust, with a high degree of convergent and internal validity. The two groups are shown to be similar along several key dimensions of exporting behavior such as size, age, and size of export orders. However, there are distinct differences with regard to such factors as initial market entry influences, export profit margins, export distribution channels, and information use. These critical differences relate to dynamism and level of exportmarketing activities undertaken. Conceptual, practical, and policy implications are discussed.
"Phase diagram" of the vortex-solid phase in Y-Ba-Cu-O crystals: A crossover from single-vortex (1D) to collective (3D) pinning regimes.

We construct a phase diagram'' of the vortex-solid phase of Y-Ba-Cu-O single crystals by making a first overall connection of the shape of the magnetic hysteresis {ital M}({ital H},{ital T}) with the single-vortex (1D) and collective (3D) pinning regimes. The crossovers between different regimes are visualized by drawing contours of constant critical current density {ital J}{sub {ital c}} in the {ital H}-{ital T} plane. We identify the transition from 1D to 3D pinning, and from the nonlocal into a local behavior of vortex bundles in the collective pinning regime. A direct correlation between the shape of {ital M}({ital H}) and the field-dependent thermal relaxation rate is demonstrated. We also identify a signature of the thermal softening boundary at which thermal fluctuations on the scale of the coherence length {xi} are relevant.
Computer simulation of engulfment and other movements of embryonic tissues.

Abstract Using a model proposed earlier by Goel et al. and a set of plausible motility rules, a computer simulation of engulfment of two or more intact embryonic tissues is successfully carried out. The same motility rules are used to simulate the rounding up of a tissue, centralization of one tissue within another tissue (a phenomenon not yet observed), and phase inversion, a process which may have relevance to differentiation. The finnal structures bear a good resemblance to those observed experimentally. The software, in conjunction with an appropriate hardware configuration, allows a visual display of the dynamics of cellular movement. These simulations indicate that the range of inter-cellular interactions controlling these tissue rearrangements extends only one or two cell diameters.
In utero losartan withdrawal and subsequent development of fetal inferior vena cava thrombosis.

BACKGROUND: Angiotensin receptor blockers are antihypertensive medications prescribed by a wide variety of physicians, especially for patients with coexistent diabetes mellitus. Angiotensin receptor blockers, as well as angiotensin-converting enzyme inhibitors, are contraindicated in pregnancy. CASE: We describe the reversal of losartan-induced oligohydramnios at 27 weeks of gestation with subsequent development of fetal thrombosis and possible mechanism of action for this extremely rare in utero complication. CONCLUSION: This theory may help explain the fetal stillbirths in women taking this class of medications during the second and third trimester of pregnancy.
Nonlinear feature extraction for perceptually-based low-bit-rate image coding

A novel feature extraction technique based on a new class of nonlinear filters is presented for perceptually based, low bit rate image compression. In addition to having remarkable computational efficiency, the filters adaptively extract perceptually relevant edge and texture information with less amplification of noise than conventional linear filters. A two-band nonlinear decomposition based on the filters is constructed so that this feature information can be separated from the image. Separate coding strategies are examined that effectively quantize these features and the more stationary, low frequency residual information. The resulting compression scheme is compared with traditional methods of image compression and is shown to exhibit clear advantages in perceptual reconstruction quality.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Gene mapping studies with the syndrome of autism.

The UCLA Registry for Genetic Studies of Autism had collected data on 308 families by February 1, 1983. A subsample of 46 families withat least two affected children was analyzed for evidence of a Mendelian mode of inheritance. The data were consistent with an autosomal recessive mode of inheritance (Ritvo, E. R., Spence, M. A., Freeman, B. J. Mason-Brothers, A., Mo. A., and Marazita, M. L., 1985, American Journal of Psychiatry, in press). Thirty-four of these families were subjected to gene linkage analyses with 30 standard phenotypic gene markers. There is no evidence of linkage between the purported autism locus and HLA, either from analysis of HLA haplotype sharing or fromlod scores. In addition, close linkage with autism, i.e., ≤5% recombination, could be excluded for 19 of the other autosomal genetic markers. The largest positivelod score, 1.04, was with haptoglobin (HP), at recombination frequencies of 10% in males and 50% in females. Normal C-and Q-banded chromosome polymorphisms were evaluated for association with autism and as additional linkage markers.
NF-Y cooperates with USF1/2 to induce the hematopoietic expression of HOXB4.

Abstract The transcription factor homeobox B4 (HOXB4) is preferentially expressed in immature hematopoietic cells and implicated in the transition from primitive hematopoiesis to definitive hematopoiesis as well as in immature hematopoietic cell proliferation and differentiation. We previously identified Hox response element 1 (HxRE-1) and HxRE-2/E-box as 2 critical DNA-binding sites of the HOXB4 promoter active in hematopoietic cells and demonstrated that upstream stimulating factor 1 and 2 (USF1/2) activate HOXB4 transcription through their binding to the E-box site. Here we report that the trimeric regulatory complex nuclear factor Y (NF-Y) is the factor that recognizes HxRE-1 and activates the HOXB4 promoter in hematopoietic cells. We further show that NF-Y interacts biochemically with USF1/2 on the HOXB4 promoter, and that the formation of this NF-Y/USF1/2 complex is required for the full activity of the HOXB4 promoter. Most important, NF-Ya subunit protein levels are found to be lower in c-Kit-Gr-1+ granulocytic bone marrow (BM) cells than in c-Kit+ immature BM cells, in parallel with a reduction of NF-Y occupancy on the HOXB4 promoter as shown by chromatin immunoprecipitation (ChIP) assay. These results suggest that NF-Y is a developmentally regulated inducer of the HOXB4 gene in hematopoietic cells. (Blood. 2003;102:2420-2427)
Susceptibility to NK cell lysis is abolished in tumor cells by a factor which restores their contact inhibited growth

It is well recognized that physical contact between natural killer (NK) cells and tumor targets is necessary for cell lysis. Therefore, any modulation of the tumor cell surface that alters intercellular contact could affect NK cell cytotoxicity. To examine this hypothesis, a contact inhibitory factor (CIF), which had been shown to restore contact inhibition of growth to several malignant cell lines was tested for its ability to render such cells immune to recognition by NK cells. When three NK-sensitive melanoma and two NK-sensitive colon carcinoma targets were cultured with CIF, they did not only change morphologically, but also showed a 70% to 95% reduction in their sensitivity to lysis by NK cells. In addition, K562 cells, which grow in suspension and do not permit a morphologic evaluation of the CIF effect, also became resistant to lysis by NK cells after culture with CIF. CIF did not reduce the viability nor the cytotoxicity of NK cells. CIF did not contain interferon nor did the CIF-treated targets induce the production of interferon during the cytotoxicity assay. It is concluded that restoration of contact inhibition of growth and resistance to NK cell lysis are cell surface phenomena that may run in parallel.
Evaluation and comparison of spatial interpolators II

The performance of several variations on ordinary kriging and inverse distance estimators is evaluated. Mean squared errors (MSE) were calculated for estimates made on multiple resamplings from five exhaustive data bases representing two distinctly different types of estimation problem. Ordinary kriging, when performed with variograms estimated from the sample data, was more robust than inverse-distance methods to the type of estimation problem, and to the choice of estimation parameters such as number of neighbors.
Intensive medical therapy for asymptomatic carotid artery stenosis.

The majority of carotid revascularization procedures are done in patients without recent symptoms of cerebral ischemia (asymptomatic carotid stenosis). In previous studies from the past two decades, the stroke risk associated with asymptomatic carotid stenosis has been estimated to be 2–2.5% per year. Given the relatively benign nature of asymptomatic carotid stenosis, it has been proposed that confining revascularization to a limited, higher-risk subgroup is a sensible strategy. Evidence is accumulating that improved medical therapy has led to a lower risk of stroke in medically treated patients and that ultrasound methods can identify higher-risk patients. These developments are highlighted in this article.
Abstract 4456: Biochemical and structural characteristics of crizotinib-resistant ALK mutants.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Anaplastic lymphoma kinase (ALK), when aberrantly regulated through gene translocations or mutations, has been implicated as an oncogenic driver in a variety of cancers. XALKORI (crizotinib) is an FDA-approved therapy for locally advanced or metastatic (ALK)-positive non-small cell lung cancer (NSCLC). Mutations of certain residues within the ALK kinase domain have been associated with crizotinib resistance. To understand the molecular basis of mutational resistance, we have kinetically and structurally characterized several clinical mutations of ALK kinase domain. In the basal-state (nonphosphorylated) proteins, mutations C1156Y, F1174L, L1152R and L1196M resulted in 14 to 52-fold increase in catalytic efficiency of phosphorylation of an activation loop peptide. Accordingly, these mutants were more rapidly autophosphorylated, compared to wild-type enzyme. In addition, F1174L, C1156Y and L1156Y had 2 to 6-fold higher catalytic efficiencies when fully activated by autophosphorylation. Conversely, catalytic efficiencies of nonphosphorylated and phosphorylated G1269A variant decreased by 1.2 and 1.6-fold, respectively. Inhibition of L1152R, L1196M and G1269A by crizotinib was reduced by 3-28-fold, compared to wild-type enzyme, from Ki determinations. From direct binding studies of the L1196M “gatekeeper” mutation, the loss of crizotinib binding occurred 6 and 13-fold for phosphorylated and nonphosphorylated proteins, respectively. By crystallographic studies apoenzyme and crizotinib complexes of ALK kinase domain displayed an inactive kinase conformation that is stabilized by an extended hydrophobic network of residues. F1174 and L1196 are part of this hydrophobic core, and mutations of these residues are predicted to destabilize the inactive ALK conformation. Taken together, these results suggest that most of the resistant mutations (e.g. L1196M, F1174L, C1156Y, L1152R) result in a more dynamic protein that increases substrate turnover. In addition, the reduction of crizotinib binding for the mutations in the vicinity of the inhibitor binding site (L1196M, G1269A) is likely a contributing factor for the resistance. This structural and kinetic analysis of mutational resistance may be useful for design of new inhibitors targeting multiple clinical mutations of ALK. Citation Format: Sergei Timofeevski, Wei Liu, Ya-Li Deng, Alexei Brooun, Simon Bergqvist, Shannon Karlicek, Brion Murray, Ben Bolanos, Michele McTigue. Biochemical and structural characteristics of crizotinib-resistant ALK mutants. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4456. doi:10.1158/1538-7445.AM2013-4456
Alan McLeod Sargeson FAA. 13 October 1930 — 29 December 2008

Alan Sargeson was an extraordinarily gifted inorganic chemist who consistently made important and lasting contributions to his discipline. His lifelong interests were in the area of coordination chemistry, especially in the stereochemistry and reactivity of complexes involving the transition element cobalt. Notable discoveries included the elucidation of the mechanisms of substitution reactions of cobalt complexes, the demonstration that amino acid amides and their esters and phosphate esters incorporated in properly designed metal complexes could achieve the high rates of hydrolysis displayed by enzyme reactions, and perhaps most notably the discovery of the ready formation of cage complexes in which the metal is fully encapsulated. His impact on his field was far reaching, his achievements were at the highest level and for more than 30 years he was among the few who dominated the field.
Enhanced Conversion of Racemic α-Arylalanines to (R)-β-Arylalanines by Coupled Racemase/Aminomutase Catalysis

The Taxus phenylalanine aminomutase (PAM) enzyme converts several (S)-α-arylalanines to their corresponding (R)-β-arylalanines. After incubating various racemic substrates with 100 μg of PAM for 20 h at 31 °C, each (S)-α-arylalanine was enantioselectively isomerized to its corresponding (R)-β-product. With racemic starting materials, the ratio of (R)-β-arylalanine product to the (S)-α-substrate ranged between 0.4 and 1.8, and the remaining nonproductive (R)-α-arylalanine became enriched. To utilize the (R)-α-isomer, the catalysis of a promiscuous alanine racemase from Pseudomonas putida (KT2440) was coupled with that of PAM to increase the production of enantiopure (R)-β-arylalanines from racemic α-arylalanine substrates. The inclusion of a biocatalytic racemization along with the PAM-catalyzed reaction moderately increased the overall reaction yield of enantiopure β-arylalanines between 4% and 19% (depending on the arylalanine), which corresponded to as much as a 63% increase compared to the turnover wit...
Expression screening reveals an orphan receptor chick ovalbumin upstream promoter transcription factor I as a regulator of neurite/substrate-cell contacts and cell aggregation.

A rat homologue of chick ovalbumin upstream promoter transcription factor I (COUP-TF I) was isolated using an expression cloning method developed to iso-late neurite outgrowth inhibitors. Overexpression of COUP-TF I in 3T3 fibroblasts resulted in reduction of stable contact formation between neurites and transfected cells. Additionally, COUP-TF I enhanced retinoic acid response element-dependent reporter gene expression in 3T3 fibroblasts, indicating that COUP-TF I can modulate transcriptional activation in these cells. Our data suggest that COUP-TF transcription factors are involved in the regulation of cell surface molecules during neurogenesis.
Teacher salaries in Latin America: A review

Abstract In this paper we use data from household surveys of 12 Latin American countries to assess how teacher salaries compare to workers in other occupations. The results show great variability from one country to another, ranging from an apparent underpayment of teachers in Bolivia by 35% relative to the control group, and a respective overpayment of 65% in Colombia. However, when statistical controls are introduced for the differential education, hours worked and gender composition between teachers and the comparison group, much of the earnings differential between the two groups disappears. On the basis of this finding, we cannot support the position that teachers are either overpaid or underpaid.
A review of chlorhexidine and its use in special populations

The purpose of this paper is to review the mechanism of the action, safety, and side-effects of chlorhexidine, and to provide guidelines for its use in special populations. Chlorhexidine has been used orally since 1959, primarily for the control of dental plaque. Chlorhexidine is a safe material, with low toxicity potential when used correctly. The most conspicuous side-effects are the development of yellow-brown stains on the teeth, tongue, and at the margins of anterior restorations, and an alteration in taste sensation. The use of chlorhexidine is indicated in developmentally disabled, medically compromised patients, and in dependent elderly populations, since these groups are often physically unable to remove plaque by mechanical means. Clinicians should not prescribe chlorhexidine indiscriminately for all patients, however, until analyzing its efficacy, safety, and side-effects.
Novel porcine repetitive elements.

Background: Repetitive elements comprise ~45% of mammalian genomes and are increasingly known to impact genomic function by contributing to the genomic architecture, by direct regulation of gene expression and by affecting genomic size, diversity and evolution. The ubiquity and increasingly understood importance of repetitive elements contribute to the need to identify and annotate them. We set out to identify previously uncharacterized repetitive DNA in the porcine genome. Once found, we characterized the prevalence of these repeats in other mammals. Results: We discovered 27 repetitive elements in 220 BACs covering 1% of the porcine genome (Comparative Vertebrate Sequencing Initiative; CVSI). These repeats varied in length from 55 to 1059 nucleotides. To estimate copy numbers, we went to an independent source of data, the BACend sequences (Wellcome Trust Sanger Institute), covering approximately 15% of the porcine genome. Copy numbers in BAC-ends were less than one hundred for 6 repeat elements, between 100 and 1000 for 16 and between 1,000 and 10,000 for 5. Several of the repeat elements were found in the bovine genome and we have identified two with orthologous sites, indicating that these elements were present in their common ancestor. None of the repeat elements were found in primate, rodent or dog genomes. We were unable to identify any of the replication machinery common to active transposable elements in these newly identified repeats. Conclusion: The presence of both orthologous and non-orthologous sites indicates that some sites existed prior to speciation and some were generated later. The identification of low to moderate copy number repetitive DNA that is specific to artiodactyls will be critical in the assembly of livestock genomes and studies of comparative genomics.