cssi/SciSciGPT-SciSciNet huggingface dataset:
Concepts and hypotheses: inflammatory hypothesis in the pathogenesis of cerebral cavernous malformations.

Objective Cerebral cavernous malformations (CCMs) affect more than one million Americans, predisposing them to a lifetime risk of hemorrhagic stroke and epilepsy. A potential role of the immune response in this disease has not been postulated previously but is compelling given the unique antigenic milieu of CCM lesions with sequestered thrombi and a leaky blood-brain barrier and the numerous examples of immune modulation of angiogenesis in other disease states. The objective of this article is to reveal novel observations about apparent immune responses in CCM lesions excised from human patients and to outline the potential pathobiological significance of these observations, specific hypotheses for future research, and potential clinical implications. Methods We reviewed data from differential gene expression revealing several immunoglobulin and other related genes markedly upregulated within human CCM lesions. Other observations are presented revealing infiltration of antibody-producing B lymphocytes and plasma cells in CCM lesions. We also present recent data demonstrating fivefold enrichment of gamma globulin to albumin ratio in a human lesion compared with serum from the same patient and oligoclonality of IgG in four of five CCM lesions, but not in paired sera from the same patients or in control specimens. Results We describe ongoing research aiming to characterize cellular and humoral components of the immune response in CCMs and initiating investigation into its clonality by isoelectric focusing on the predominant immunoglobulin isotypes isolated from the lesion, in comparison to the patient's serum, and by the distribution of lengths of complementary-determining region 3 of the immunoglobulin heavy chain genes in messenger ribonucleic acid isolated from lesions and from pooled plasma cells and B cells laser captured from CCMs in comparison to peripheral lymphocytes from the blood of the same patients. Conclusion Immune response could play a role in or represent a potential marker of CCM lesion proliferation and hemorrhage or could otherwise contribute to lesion phenotype. The ongoing studies will generate preliminary data for future research aimed at comparing the immune response in quiescent versus clinically aggressive CCM lesions. An oligoclonal immune response shown in this research would stimulate future experiments to identify autoimmune or extrinsic antigenic triggers involved in CCM disease.
Changes in lipid composition during spore germination of Rhizopus arrhizus

Changes in lipid components were determined during germination of spores of Rhizopus arrhizus Fischer. During the first 2 h of germination the total lipids decreased then the concentration of total lipids increased during the later periods. The content of neutral lipids decreased during germination, whereas the content of polar lipids increased. The free fatty-acid content decreased during the 8 h germination period, whereas the mono-, di- and triglyceride concentrations varied during the germination process. The predominant fatty acids in the ungerminated spores were palmitic, oleic and linoleic, whereas in the germinated spore they were stearic and oleic.
The photobiology of microbial pathogenesis.

1Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, United States of America, 2Department ofBiochemistry and Molecular Biology, and The Committee on Microbiology, The University of Chicago, Chicago, Illinois, United States of America
Overview: the current role of the vascular diagnostic laboratory.

T HE TESTING METHODS used in the noninvasive vascular diagnostic laboratory have evolved over the last 40 years to bridge the gap between the subjective clinical assessment of vascular disorders and invasive contrast studies of the arteries and veins. Many of the early noninvasive tests utilized continuous wave Doppler ultrasound to detect blood flow. These tests were referred to as indirect methods because they relied on detection of major changes in pressure or flow produced by arterial or venous disease. Therefore, only hemodynamically significant lesions could be identified reliably. The indirect tests included the periorbital Doppler examination for extracranial carotid artery disease, the continuous wave Doppler evaluation for deep vein thrombosis, and segmental arterial blood pressure measurement in the extremities. Some of these tests, such as measurement of ankle systolic blood pressure, still are useful in the clinical setting, but most have given way to the direct approach of duplex scanning. 1 The principal advantage of duplex scanning is that it obtains both anatomic and physiologic information directly from sites of vascular disease. Since duplex scanning emerged in the 1980s as the preferred noninvasive test for extracranial carotid artery disease, advances in ultrasound technology have extended its applications to the vessels of the abdomen and extremities. This combination of B-mode imaging and spectral analysis of pulsed Doppler signals provided the first opportunity to accurately characterize vascular disease without resorting to invasive procedures. The duplex approach is based on the concept that arterial lesions produce localized disturbances in blood flow patterns that can be characterized by analysis of Doppler flow signals. Accordingly, the B-mode image is used to place a pulsed Doppler sample volume within the vessel of interest, and the local flow pattern is assessed by spectral waveform analysis. Although the B-mode image may be valuable for identifying anatomic variants, arterial wall thickening or calcification, and thrombi in the venous system, it has not been possible to determine accurately the degree of arterial narrowing from the B-mode image alone. Therefore, the classification of arterial disease severity mainly is based on interpretation of pulsed Doppler spectral waveforms. Color-flow imaging is an alternative to spectral waveform analysis for displaying Doppler information. Within certain technical limitations, the color-flow image permits visualization of moving blood in the plane of the B-mode image; it can be helpful for identifying vessels, particularly when they are small, deeply located, or anatomically complex. However, it is difficult to assess disease severity based on the color-flow image alone, and spectral waveforms still are necessary for accurate disease classification. While the noninvasive vascular diagnostic laboratory initially was of interest only to vascular
Thin film rheology and lubricity of hyaluronic acid solutions at a normal physiological concentration

Using a surface forces apparatus to measure forces, and optical (multiple beam) interferometry to mea- sure surface shapes and separations (to ±1 A), the normal, viscous, and shear (lubrication) forces between smooth mica surfaces in aqueous hyaluronic acid (HA) solutions were measured. The experimental conditions of loading pres- sures, pH, and HA concentration were set to closely corre- spond to physiological human knee-joint conditions. From the force and optical (refractive index) measurements, it was concluded that, like other negatively charged polyelectro- lytes, HA does not naturally adsorb on the mica surface which is hydrophilic and weakly negatively charged at physiological conditions: the polymer solution exhibits the bulk viscosity (22.5 ± 1.5 cP) for films thicker than about 0.4 mm of the polymer, whereas for thinner films, the viscosity decreases monotonically toward the value of the pure elec- trolyte solution (1 cP) as HA is extruded from between the surfaces. This is indicative of a repulsive "depletion" inter- action of HA with each mica surface and to a weakly attrac- tive polymer-mediated force between the two surfaces. Thus, free HA in synovial fluid is not expected to act as a good "boundary lubricant." Relaxation measurements on approaching and receding surfaces in HA solutions were also performed, and it is shown that the presence of HA in the bulk solution can improve "hydrodynamic" modes of lubrication, for example, by assuaging the compression stroke. The study includes information that is beneficial to researchers working with biomaterials viscosupplementa- tion devices. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 514-523, 2002
Molecular diagnosis of hereditary inclusion body myopathy by linkage analysis and identification of a novel splice site mutation in GNE

Many myopathies share clinical features in common, and diagnosis often requires genetic testing. We ascertained a family in which five siblings presented with distal muscle weakness of unknown etiology. We performed high-density genomewide linkage analysis and mutation screening of candidate genes to identify the genetic defect in the family. Preserved clinical biopsy material was reviewed to confirm the diagnosis, and reverse transcriptase PCR was used to determine the molecular effect of a splice site mutation. The linkage scan excluded the majority of known myopathy genes, but one linkage peak included the gene GNE, in which mutations cause autosomal recessive hereditary inclusion body myopathy type 2 (HIBM2). Muscle biopsy tissue from a patient showed myopathic features, including small basophilic fibers with vacuoles. Sequence analysis of GNE revealed affected individuals were compound heterozygous for a novel mutation in the 5' splice donor site of intron 10 (c.1816+5G>A) and a previously reported missense mutation (c.2086G>A, p.V696M), confirming the diagnosis as HIBM2. The splice site mutation correlated with exclusion of exon 10 from the transcript, which is predicted to produce an in-frame deletion (p.G545_D605del) of 61 amino acids in the kinase domain of the GNE protein. The father of the proband was heterozygous for the splice site mutation and exhibited mild distal weakness late in life. Our study expands on the extensive allelic heterogeneity of HIBM2 and demonstrates the value of linkage analysis in resolving ambiguous clinical findings to achieve a molecular diagnosis.
Endogenous convolutional sparse representations for translation invariant image subspace models

Subspace models for image data sets, constructed by computing sparse representations of each image with respect to other images in the set, have been found to perform very well in a variety of applications, including clustering and classification problems. One of the limitations of these methods, however, is that the subspace representation is unable to directly model the effects of non-linear transformations such as translation, rotation, and dilation that frequently occur in practice. In this paper it is shown that the properties of convolutional sparse representations can be exploited to make these methods translation invariant, thereby simplifying or eliminating the alignment pre-processing task. The potential of the proposed approach is demonstrated in two diverse applications: image clustering and video background modeling.
Therapeutic Implications of Behavior Change Theory in Post-Divorce Counseling and Education Programs

Abstract The psychological, social and environmental elements of divorce consist of change for everyone in the family. A child's adjustment to divorce depends not on the event itself, but how it's lived afterward. Behavior modeled by the parents will have an impact on the children's adjustment. There have been parenting-after-divorce training programs in the United States for nearly three decades. The content of the programs differs significantly. Some programs concentrate on education of the parents, counseling, bibliotherapy, and others utilize a model of both education and counseling. Regardless of the type of program or whether it's required or voluntary, behavior change theory should also be included in the counseling and educational curriculum. This concept gives parents the tools to continually self-evaluate their knowledge, desires and direction in their post-divorce relations with their ex-spouse. As well as having a positive effect on the children from the parental involvement, it may also have ...
What's growing on your keyboards?

Thousands of users touch the keyboards and mice of public computers at the University of Rochester ever day. In conjunction with the University of Rochester Medical Center we set out to discover what the users leave behind. Samples were taken from the busiest computers on campus and tested for the presence of bacteria and viruses. A variety of cleaning products was also tested to measure the efficacy of cleaning methods.
Five types of basket cell in the hippocampal dentate gyrus: a combined Golgi and electron microscopic study.

Five types of basket cell in the hippocampal denate gyrus of rats were analysed with a combined Golgi and electron microscopic method. Light microscopic observations show that the large somata of these different cell types are located either in the granule cell layer or within 30–50 μm of this layer. The somata of basket cells are pyramidal, horizontal, fusiform or multipolar. Dendrites of basket cells are aspinous or sparsely spinous and are found in all layers of the dentate gyrus. Their axons form an extensive plexus in the granule cell and lower molecular layers.
Cellular and C-type viral factors in infections by polyoma virus hr-t mutants.

Abstract The effects of endogenous cellular factors and of murine leukemia virus (MLV) infections on the growth and transforming properties of polyoma virus hr-t mutants have been examined. Moloney MLV confers a permissive state on 3T3 cells, enhancing the growth of hr-t mutant NG-18. However, MLV infection of normal rat kidney (NRK) cells does not enable NG-18 to transform these cells. Fv-1 restriction, pretreatment of cells with mitomycin C, or serum starvation after MLV infection, all prevent MLV from inducing the permissive state in 3T3 cells. Primary mouse embryo cells, which are constitutively permissive for hr-t mutant growth, and primary rat or hamster embryo cells, are not able to be transformed by hr-t mutants, hr-t mutants are unable to induce either lectin agglutinability or transformation in a variety of mouse cells that are permissive for hr-t mutant growth. It thus appears that endogenous cellular factors or exogenous MLV infections in mouse cells induce a permissive state, thereby enhancing the growth of hr-t mutants which are presumedto have lost the ability to induce that state. These factors act only to bypass the need for the hr-t function in polyoma virus growth, and do not restore hr-t viral gene activity in inducing transformation and related cellular properties. The results are discussed in terms of a model proposed earlier for pleiotropic regulation of cellular factors by the hr-t viral gene (Staneloni et al. , 1977 , Virology 77 , 598–609).
High-dose erythropoietin during cardiac resuscitation lessens postresuscitation myocardial stunning in swine

We investigated the metabolic and functional myocardial effects of erythropoietin (EPO) administered during resuscitation from cardiac arrest using an open-chest pig model of ventricular fibrillation and resuscitation by extracorporeal circulation, after having reported in rats a reversal of postresuscitation myocardial dysfunction associated with activation of mitochondrial protective pathways. Ventricular fibrillation was induced in 16 male domestic pigs and left untreated for 8 minutes, after which extracorporeal circulation was started and maintained for 10 additional minutes, adjusting the extracorporeal flow to provide a coronary perfusion pressure of 10 mmHg. Defibrillation was accomplished and the extracorporeal flow was adjusted to secure a mean aortic pressure of 40 mmHg or greater during spontaneous circulation for up to 120 minutes. Pigs were randomized 1:1 to receive EPO (1200 U/kg) or 0.9% NaCl before starting extracorporeal circulation. Severe postresuscitation myocardial dysfunction developed in both groups. However, recovery of myocardial function—comparing baseline with 120 minutes postresuscitation—was better in pigs treated with EPO than NaCl, as shown for left ventricular ejection fraction (from 45 ± 8% to 36 ± 9% in EPO, not significant; and from 46 ± 8% to 26 ± 8% in NaCl, P P 2 consumption (12 ± 6 mL/min/unit of tissue vs 6 ± 2 mL/min/unit of tissue, P
Quantum fluctuations and the c-axis optical conductivity of high-T c superconductors

A theory of the frequency dependence of the interplane conductivity of a strongly anisotropic superconductor is presented. The form of the conductivity is shown to be a sensitive probe of the strength of quantum and thermal fluctuations of the phase of the superconducting order parameter. The temperature dependence of the superfluid stiffness and of the form of the absorbtion at frequencies of the order of twice the superconducting gap is shown to depend on the interplay between superconducting pairing, phase coherence, and the mechanism by which electrons are scattered. Measurements of the c-axis conductivity of high-${T}_{c}$ superconductors are interpreted in terms of the theory.
Distribution and number of transferrin receptors in Parkinson's disease and in MPTP-treated mice.

Abstract Transferrin is a glycoprotein that functions primarily to deliver iron to the cell. Recent studies suggest that the transferrin receptor mediates the intracellular delivery and transport of iron bound to transferrin in the CNS. Iron-catalyzed free radical generation has been proposed as a possible cause of nigral cell death in Parkinson's disease. Our hypothesis is that abnormal iron handling by the transferrin receptor may contribute to the formation of free radical species which catalyze the lipid peroxidation of nigral cell membranes. We have assessed the number of transferrin receptors on membrane fractions prepared from the human striatum from control subjects and patients with Parkinson's disease. Equilibrium-binding studies demonstrated a reversible, saturable, and high-affinity transferrin binding site (KD = 3 nM) in human brain membranes. Regional binding assays indicate that the number of transferrin receptors in the putamen was reduced significantly in Parkinson's disease. The density of transferrin receptors was unaltered in membranes prepared from the caudate nuclei and the globus pallidus. To address the possibility that transferrin receptors are located on dopaminergic terminals, we have examined the distribution and number of transferrin receptors in the striatum of MPTP-treated mice using in vitro autoradiographic methods. In these experiments, the loss of dopaminergic terminals in the striatum was visualized by differential [3H]mazindol uptake site autoradiography. A marked reduction in the density of both transferrin receptors and [3H]mazindol binding sites was observed in the mouse striatum 7 days post-MPTP treatment. Quantitative densitometric analysis demonstrated a recovery in [125I]ferrotransferrin binding in the striata of mice sacrificed at later survival times. The time-course for the recovery of striatal transferrin receptors preceded the rise in [3H]mazindol binding sites. Taken together, these observations suggest that transferrin receptors may be located, in part, on dopaminergic terminals. The recovery of [125I]ferrotransferrin binding in the striatum may reflect early sprouting of dopaminergic fibers. Alternatively, transferrin receptors may be up-regulated in surviving dopaminergic terminals as a cellular adaptation to increased metabolic activity.
Symmetry Lowering in Extreme-Electron-Density Perovskite Quantum Wells

We report on structural distortions in extreme-electron density (6x1014 cm-2) confined quantum wells of SrTiO3 embedded in GdTiO3. Sr-column displacements are measured using high-angle annular dark-field imaging in scanning transmission electron microscopy. Using thick SrTiO3 layers as a reference, orthorhombic-like Sr-site displacements are observed when SrTiO3 quantum wells are thinner than 4 SrO layers, in precise agreement with an experimentally observed metal-to-insulator transition. It is shown that the structural displacements are absent in thicker quantum wells, even in the immediate proximity to the orthorhombic GdTiO3. The results are discussed in the context of strong electron correlations in this system.
Short course high fractional dose irradiation in advanced and recurrent head and neck cancer

Abstract Thirty patients with advanced head and neck cancer were treated with 400 rad daily to a total of 4400 to 5200 rad. Twenty-three patients had previously untreated stage III and IV cancer and 7 patients had recurrent head and neck cancer. As a pilot study, 9 of 30 patients also had received metronidazole (6 Mg/M 2 ) every other day during radiotherapy. The previously untreated patients (stage III (2), stage IV (21) ) had a local control rate of 61 % (14/23) with a 45% two year actuarial survival. Three of 9 patients who were treated with high fractional dose irradiation plus metronidazole developed confluent mucositis of more than three weeks duration. Only 3 of the remaining 21 patients experienced similar mucositis. In all cases mucositis subsided without sequelae. One patient who received radiation and metronidazole and another who received radiation only developed laryngeal edema which required tracheotomy. Seven of 9 metronidazole treated patients remain disease free at this time. The 7 patients with recurrent disease achieved some degree of palliation but none survived.
The Foxc2 Transcription Factor Regulates Angiogenesis via Induction of Integrin β3 Expression

Forkhead transcription factor Foxc2 is an essential regulator of the cardiovascular system in development and disease. However, the cellular and molecular functions of Foxc2 in vascular endothelial cells are still not fully understood. Here, through gene expression profiling in endothelial cells, we identified molecules associated with cell-extracellular matrix interactions, integrin β3 (Itgb3), integrin β5 (Itgb5), and fibronectin, as downstream targets of Foxc2. We found that Itgb3 expression is directly regulated by Foxc2 through multiple Forkhead-binding elements within two high homology regions in the Itgb3 promoter. Because Itgb3 is known to regulate angiogenesis, we further tested whether Foxc2 is directly involved in angiogenesis by regulating Itgb3 expression by in vitro experiments. Overexpression of Foxc2 significantly enhanced endothelial cell migration and adhesion, whereas this effect was strongly inhibited by Itgb3 neutralization antibody. In accordance with these results, pulmonary microvascular endothelial cells isolated from Foxc2 heterozygous mutant mice showed a marked reduction in Itgb3 expression and cell migration. Finally, ex vivo aortic ring assay to test the sprouting and microvessel formation revealed enhanced microvessel outgrowth by Foxc2 overexpression. Conversely, microvessel outgrowth from aortas of Foxc2 heterozygous mutant mice was reduced. Taken together, these results suggest that Foxc2 directly induces Itgb3 expression and regulates angiogenesis by Itgb3-mediated endothelial cell adhesion and migration.
ATP, Activation, and the Heat of Shortening of Muscle

Prof. A. V. Hill has challenged biochemists to find whether the heat of shortening of muscle has any equivalent in the chemistry of muscle. It is shown that the heat of shortening, which is reabsorbed as tension disappears, is not degraded free energy from the splitting of ATP. It must be reversibly transformed entropy from a repeated cyclic reaction such as coil-helix transitions in part of the myosin–actin cross bridges.
Individualized care for the treatment of alcoholism

Abstract Through a discussion of several case vignettes, the author emphasizes the utilization of an individually tailored treatment approach when working with people experiencing problem related to alcohol consumption. Patients may achieve abstinence without believing in the disease concept of alcoholism, and attending Alcoholics anonymous meetings need not always be a part of the treatment. Furthermore, for some patients, controlled drinking may be as desirable an outcome as abstinence. The importance of entertaining a multiplicity of perspectives when conducting clinical work with such patients is discussed.
Polarization-state mixing in multiple-beam diffraction and its application to solving the phase problem

Interference among Bragg beams and effects of polarization state mixing in a multibeam diffraction process leads to a new method of determining noncentrosymmetric phases when an elliptically polarized x-ray beam is used. This idea is demonstrated by an experiment on a GaAs single crystal. With a structurally known noncentrosymmetric crystal the same method can be used to measure the degree of a circular polarization.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Richard Lionheart: bad king, bad crusader?

This paper analyzes the impact of King Richard Lionheart of England during his tenure as leader of the Third Crusade. It examines crusade policy and the significance of Richard's decisions to deviate from it. The lack of control which both the Church and normative crusading precedents had over him becomes apparent. Richard's failure to take Jerusalem leads to the conclusion that his self-centred, puerile interests in personal adventures destroyed the chance for success of the Third Crusade, and thus prolonged warfare. Most wars have some sort of peace as the ultimate goal. The Third Crusade is no exception, but Richard subverted the goal of peace by turning away from a siege of Jerusalem and toward various other adventures, for example, attacks on Egyptian holdings, border skirmishes, the conquest of Cyprus from the Byzantines. Still, the Lionheart's legend persists from his day to our own to extol chivalrous virtues and courageous action. This paper presents the other side of the coin in the hope of approaching a more balanced, accurate portrayal of Richard's crusade leadership and of the ends of crusade ideology which he undermined.
The phenomenon of fluid creep in acute burn resuscitation

Several reports have documented that modern burn patients receive far more resuscitation fluid than predicted by the Parkland formula-a phenomenon termed "fluid creep." This article reviews the incidence, consequences, and possible etiologies of fluid creep in modern practice and uses this information to propose some therapeutic strategies to reduce or eliminate excessive fluid resuscitation in burn care. A literature review was performed of historical references that form the foundation of modern fluid resuscitation, as well as reports of fluid creep and its consequences. The original Parkland formula required a 24-hour volume of 4 ml/kg/%TBSA lactated Ringer's solution followed by an infusion of 0.3-0.5 ml/kg/ %TBSA plasma. Modern iterations of this formula have omitted the colloid bolus. Numerous exceptions to the formula have been noted, most consistently patients with inhalation injuries. In contrast, recent reports document greatly increased fluid requirements in unselected patients, which seems to consist largely of progressive edema formation in unburned areas, increasing after the first 8 hours post-burn. This has been linked to occurrence of the abdominal compartment syndrome and other serious complications. Strategies to reduce fluid creep include the avoidance of early overresuscitation, use of colloid as a routine component of resuscitation or for "rescue," and adherence to protocols for fluid resuscitation. Fluid creep is a significant problem in modern burn care. Review of original investigations of burn shock, coupled with modern reports of fluid creep, suggests several mechanisms by which this problem can be controlled. Prospective trials of these therapies are needed to confirm their effectiveness.
Thresholds for cavitation produced in water by pulsed ultrasound

The threshold for transient cavitation produced in water by pulsed ultrasound was measured as a function of pulse duration and pulse repetition frequency at both 0.98 and 2.30 MHz. The cavitation events were detected with a passive acoustic technique which relies upon the scattering of the irradiation field by the bubble clouds associated with the events. The results indicate that the threshold is independent of pulse duration and acoustic frequency for pulses longer than approximately 10 acoustic cycles. The threshold increases for shorter pulses. The cavitation events are likely to be associated with bubble clouds rather than single bubbles.
True or false? Order is not uniquely defined in symmetry adapted perturbation theory

It is often stated in reviews of the theory of intermolecular interactions that one of the weaknesses of symmetry adapted perturbation theory is that order in the perturbation is not uniquely defined. The statement is false. It is based on a misinterpretation of a commutator relationship which intertwines the antisymmetrizer, the unperturbed Hamiltonian and the perturbation. Correctly interpreted, the commutator relation can be combined with the perturbed eigenproblem to eliminate from the perturbation expansion terms which contribute zero in infinite order when the perturbation is turned on fully and to sum selected terms to infinite order in the expansion parameter. A surprising consequence of including exchange symmetry by means of the commutator relation is that order in the expansion parameter is not the same as order in the perturbing potential.
Theoretical analysis of how pressure buildup and CO2 migration can both constrain storage capacity in deep saline aquifers

Abstract Estimating the carbon dioxide (CO 2 ) storage capacity of deep saline aquifers is important for identifying those most suitable for sequestration, and for planning the future development of CO 2 storage projects. Currently, capacity estimates are highly uncertain due in part to uncertainty in the dominant constraint on capacity: both the pressure buildup from injection and the space available to trap CO 2 have been identified as constraints, but have not been rigorously compared to determine the conditions under which each is more limiting. In this study, we evaluate their relative importance in an idealized aquifer using simple, but dynamic models of how pressure rises during injection and how CO 2 becomes trapped in the pore space. We show that there exists a crossover injection duration, T c , below which pressure constraints dominate, but above which the CO 2 migration becomes the more limiting constraint. We illustrate this behavior by applying the models to the Fox Hills Sandstone.
The rate of convergence of a generalized stable population.

In an age-structured population that grows exponentially, each age groupPi(t) at periodt is asymptotically equivalent tox0t for some positive number x0. In this paper we show that the speed at which the ith age group reaches its exponential state of equilibrium can be measured by the rate at which the ratio vi(t)=Pi(t)/pi(t−1) converges tox0. The age specific rate of convergence is determined by considering a quantityr satisfyingvi(t)-x0¦⩽ rt whent is large;Ri=Infr (over all initial populations,r satisfying the above inequality) is the R-factor used in numerical analysis to measure the rate at which the sequencevi(t) converges tox0;Si=- In Ri is then defined as the rate of convergence to stability of the ith age group. The case of constant net maternity rates is studied in detail; in this contextS0 is compared to the population entropyH, which was proposed by Tuljapurkar (1982) as a measure of the rate of convergence to stability.
SOME RAMSEY THEORY IN BOOLEAN ALGEBRA FOR COMPLEXITY CLASSES

It is known that for two given countable sets of unary relations A and B on ω there exists an infinite set H ⫅ ω on which A and B are the same. This result can be used to generate counterexamples in expressibility theory. We examine the sharpness of this result.
Better breast cancer survival for postmenopausal women who are less overweight and eat less fat. The Iowa Women's Health Study.

Background. The authors sought to determine whether prediagnosis obesity, body-fat distribution, and dietary intake of fats, antioxidants, and fiber may be related to survival after the diagnosis of breast cancer. Methods. The mortality rates of 698 postmenopausal patients with unilateral breast cancer in a large cohort study were analyzed. Body-mass index, waist-to-hip ratio, and food-frequency data were collected by questionnaire within 6 years before breast cancer was diagnosed. Results. Adjusted for age, women in the highest tertile of body mass index had a 1.9-fold higher risk (95% confidence interval = 1.0-3.7) of dying after breast cancer than those in the lowest tertile; adjusted for other prognostic variables (age, smoking, education level, extent of breast cancer, and tumor size), this relative risk was 1.5 (95% CI = 0.7 to 2.9). Waist-to-hip ratio was not related to risk of dying nor was intake of fiber or several dietary antioxidants. Independent of other prognostic variables, risk of death after breast cancer was statistically significantly elevated, with a relative risk greater than 2.0 for the highest tertiles of total fat, saturated fat, and monounsaturated fat intake, expressed as grams per day. An adjustment for energy intake, which also was associated positively with fatality, weakened these associations somewhat. Conclusions. Although clinical trials are required, these findings support the hypothesis that a high fat intake is associated with reduced survival of postmenopausal women with breast cancer and suggest that women with breast cancer should consider limiting their intake of fat. Cancer 1995; 76:275–83.
Comparison of motor reflex and vocalization thresholds following systematically administered morphine, fentanyl, and diazepam in the rat: Assessment of sensory and performance variables

Abstract The relative influence of systematically administered morphine, fentanyl, and diazepam on the thresholds of spinal motor reflexes (SMRs), vocalizations elicited during stimulation (VDSs), and vocalization afterdischarges (VADs) was assessed. Responses were elicited by applying graded electric current to the tail. Performance (latency and amplitude) of all three responses was monitored to determine whether elevations in threshold were confounded by performance decrements. All three drugs were found to elevate VAD thresholds more readily than VDS and SMR thresholds. VADs were also most susceptible to the deleterious effects of these drugs on motor performance. Nevertheless, across the dose range of morphine and fentanyl that elevated thresholds of all three responses without disrupting the performance of any response, the order of susceptibility to threshold increases remained VAD, VDS, and SMR. Diazepam also elevated VAD thresholds more readily than VDS thresholds across a dose range that failed to disrupt performance of either response. SMR thresholds were only elevated by diazepam when administered in doses that significantly disrupted performance. Results are discussed in terms of supporting the validity of VADs as a model of the affective-motivational dimension of pain.
Models Clarified: Responding to Langdon Gilkey

We respond to concerns raised by Langdon Gilkey. The discussion addresses the nature of theological thinking today, the question of truth within the situation of pluralism, the identity and difference between theological models and scientific models, and the proposed methods for testing theological models.
Solution Structure of the HIV-1 Exon Splicing Silencer 3.

Abstract Alternative splicing of the human immunodeficiency virus type 1 (HIV-1) genomic RNA is necessary to produce the complete viral protein complement, and aberrations in the splicing pattern impair HIV-1 replication. Genome splicing in HIV-1 is tightly regulated by the dynamic assembly/disassembly of trans host factors with cis RNA control elements. The host protein, heterogeneous nuclear ribonucleoprotein (hnRNP) A1, regulates splicing at several highly conserved HIV-1 3′ splice sites by binding 5′-UAG-3′ elements embedded within regions containing RNA structure. The physical determinants of hnRNP A1 splice site recognition remain poorly defined in HIV-1, thus precluding a detailed understanding of the molecular basis of the splicing pattern. Here, the three-dimensional structure of the exon splicing silencer 3 (ESS3) from HIV-1 has been determined using NMR spectroscopy. ESS3 adopts a 27-nucleotide hairpin with a 10-bp A-form stem that contains a pH-sensitive A+C wobble pair. The seven-nucleotide hairpin loop contains the high-affinity hnRNP-A1-responsive 5′- UAG U-3′ element and a proximal 5′-GAU-3′ motif. The NMR structure shows that the heptaloop adopts a well-organized conformation stabilized primarily by base stacking interactions reminiscent of a U-turn. The apex of the loop is quasi-symmetric with UA dinucleotide steps from the 5′-GAU-3′ and 5′- UA G U-3′ motifs stacking on opposite sides of the hairpin. As a step towards understanding the binding mechanism, we performed calorimetric and NMR titrations of several hnRNP A1 subdomains into ESS3. The data show that the UP1 domain forms a high-affinity (Kd = 37.8 ± 1.1 nM) complex with ESS3 via site-specific interactions with the loop.
Promoting Foreign Culture Acquisition via the Internet in a Sociocultural Context

The integration of technology in education is generally assumed to aid learning. The primary purpose of this study was to capture the complexity of the process of incorporating the use of new technologies in an advanced foreign language (FL) course. The study provides a detailed description of the activity in which the participants engaged to acquire cultural knowledge through the use of the Internet. It also examines how the instructional context advanced learning. Findings of this study seem to suggest that learning can indeed be assisted by computers when the use of these tools is supported by appropriate theories of learning and careful orchestration of the curriculum.
Two Woman Saw

Artist Kaucyila Brooke recalls a moment in the feminist movement through fragmented glimpses into her relationships on and with the land. This article is a photo and text narrative of life in lesbian intentional communities in 1970s Oregon and Minnesota.
Sensitivity simulation of compressed sensing based EW receiver using orthogonal matching pursuit algorithm

The wideband coverage of the traditional FFT-based electronic warfare (EW) receiver is limited by the sampling frequency of the analog-to-digital converter (ADC). Compressed sensing (CS) based wideband EW digital receiver has been proposed and under development to process wideband sparse signals with reduced sampling rate. In this study, we calculate the sensitivity of a CS based EW receiver. Two modulation schemes of CS are used. One is pseudorandom chip (PRC) and the other is non-uniform sampling (NUS) modulation. The orthogonal matching pursuit (OMP) algorithm is used to process CS data. The insufficient nature of the sparcity of the signal adversely affects the signal detection probability for both PRC and NUS modulation schemes. Methods to remedy this problem in both modulation schemes are proposed. The improvement in the signal detection and thus the sensitivity performance of the CS based receiver are presented.
Photon number divergence in the quantum theory of n -photon down conversion

The process of n-photon down conversion is considered both with a quantized pump and in the parametric approximation. In the parametric approximation it is formally found that the photon number diverges at a finite time for ng2. This divergence limits the times for which the parametric approximation is useful. The divergence does not occur if the pump is quantized. Furthermore, it is shown that the Hamiltonian with a quantized pump is essentially self-adjoint. This means that the questions that have been raised about the existence of the time-development operator in the parametric approximation do not arise when the pump is quantized.
New estimates of overall properties of heterogeneous solids

Abstract A complete formal similarity of the standard techniques for estimating overall elastic properties and phase averages of local mechanical and transformation stress and strain fields in heterogeneous materials is established for the self-consistent and Mori–Tanaka methods, and for Walpoles formulation of the Hashin–Shtrikman variational bounds. Regardless of the dissimilar and often heuristic assumptions that had motivated the original formulations, the only essential difference between these techniques had been the choice of the comparison medium where each phase was assumed to be embedded in the solution of the inclusion problem. Therefore, any number of related averaging methods can be developed from other choices made such that the resulting moduli predictions do not violate the bounds. Several new types of admissible comparison media are proposed and evaluated for composites reinforced by spherical particles or aligned fibers and also for porous media with spherical cavities. Many new estimates of overall moduli and local mechanical and transformation field averages can be obtained in this manner, for modeling and/or interpretation of a variety of experimental data in two or multiphase heterogeneous aggregates. A close agreement with the self-consistent results is found for one of the proposed choices.
Toward Developing New Occupational Science Measures: An Example from Dementia Care Research

The Activity in Context and Time (ACT) was developed as a quantitative, direct observational measure of environmental correlates of time-use and quality of life of people with dementia living in nursing homes or other long term care institutions. A variety of experiences and considerations influenced the decision to develop the ACT including: commitments honed through clinical practice in occupational therapy; research experiences with nonhuman primates; moral challenges of research with persons with dementia; and relevant scholarship in environmental psychology, gerontology, occupational therapy and science. To develop and refine the ACT such that it could meet modest criteria of validity and reliability, numerous theoretical and practical challenges also had to be addressed. Critique of the ACT suggests limitations and strengths of direct observational measures, as well as specific ways in which the ACT does and does not contribute to an integral holistic science of occupation. By describing the ongoing methodological journey of the ACT including its early influences, developmental challenges, strengths and limitations, and anticipated future refinements, it is hoped that this article might be of value to other researchers who are interested in developing new methodologies that embody and advance an occupational science perspective.
Quantification of Natural Vapor Fluxes of Trichloroethene in the Unsaturated Zone at Picatinny Arsenal, New Jersey

The upward flux of trichloroethene (TCE) vapor through the unsaturated zone above a contaminated, water-table aquifer at Picatinny Arsenal, New Jersey, has been studied under natural conditions over a 12-month period. Vertical gas-phase diffusion fluxes were estimated indirectly by measuring the TCE vapor concentration gradient in the unsaturated zone and using Fick's law to calculate the flux. The total gas-phase flux (e.g., the sum of diffusion and advection fluxes) was measured directly with a vertical flux chamber (VFC). In many cases, the upward TCE vapor flux was several orders of magnitude greater than the upward TCE diffusion flux, suggesting that mechanisms other than steady-state vapor diffusion are contributing to the vertical transport of TCE vapors through the unsaturated zone. The measured total flux of TCE vapor from the subsurface to the atmosphere is approximately 50 kg/yr and is comparable in magnitude to the removal rate of TCE from the aquifer by an existing pump-and-treat system and b...
Mechanisms of impact head injury

Summary A review of research on brain trauma mechanisms operative during head impact is presented from a clinically relevant biomechanical perspective. Emphasis is placed on microscopic mechanisms, gleaned from isolated neural tissue and cellular biomechanisms research, and their relation to macro sale mechanisms observed in head injury victims and in experimental physical model experiments. Experimental and clinico-pathologic research, past and ongoing, substantiating the centripetal theory for concussive brain injury is also reviewed in the context of recent advancements in computations biomechanics of head injury brought about by the expanding availability of high speed super computers and brain imaging. A synopsis of our current computational research activities in head impact simulation is presented and some preliminary results are cited.
Electrical and Mechanical Properties of Chick Embryo Heart Chambers

Electrical and mechanical events of the atrium, ventricle and conus of the 72-hour chick embryo heart were recorded by a specially designed instrument. The electrical-mechanical delay and the time of muscular contraction differed among the chambers, the atrium being the most rapid and the conus, the slowest. Muscular relaxation times of the atrium and ventricle were approximately one-half that of the conus. Mechanical performance, gaged by the approximations of work and power, was greatest for the ventricle, but based on the muscle mass (protein), values for the ventricle and conus were similar. Electrical activation of the ventricle followed a consistent pathway, suggesting the existence of a preferential conduction system prior to the development of the His bundle.
Extracellular matrix regenerated : tissue engineering via electrospun biomimetic nanofibers

While electrospinning had seen intermittent use in the textile industry from the early twentieth century, it took the explosion of the field of tissue engineering, and its pursuit of biomimetic extracellular matrix (ECM) structures, to create an electrospinning renaissance. Over the past decade, a growing number of researchers in the tissue engineering community have embraced electrospinning as a polymer processing technique that effectively and routinely produces non-woven structures of nanoscale fibers (sizes of 80 nm to 1.5 µm). These nanofibers are of physiological significance as they closely resemble the structure and size scale of the native ECM (fiber diameters of 50 to 500 nm). Attempts to replicate the many roles of native ECM have led to the electrospinning of a wide array of polymers, both synthetic (poly(glycolic acid), poly(lactic acid), polydioxanone, polycaprolactone, etc.) and natural (collagen, fibrinogen, elastin, etc.) in origin, for a multitude of different tissue applications. With various compositions, fiber dimensions and fiber orientations, the biological, chemical and mechanical properties of the electrospun materials can be tailored. In this review we highlight the role of electrospinning in the engineering of different tissues and applications (skin/wound healing, cartilage, bone, vascular tissue, urological tissues, nerve, and ligament), and discuss its potential role in future work. Copyright © 2007 Society of Chemical Industry
Photonic components for short range optical interconnects

Optical interconnect technology will play an increasingly important role in servers and supercomputers as a means to keep pace with the increasing intra-system bandwidth requirements. Low-cost and high density optical packaging concepts are required.