cssi/SciSciGPT-SciSciNet huggingface dataset:
Biology of intervertebral disc aging and degeneration: involvement of the extracellular matrix.

Study design A review of current knowledge and opinions concerning the biologic changes that take place during development, maturation and degeneration of the intervertebral disc. Objective To provide an overview of the changes that occur in structure and composition of the extracellular matrix of the intervertebral disc and to explain the origin of such changes and their functional consequences. Summary of background data The structure of the intervertebral disc, and, in particular, the composition of its extracellular matrix, changes throughout life, ultimately resulting in tissue degeneration in the adult. Methods A review of the published scientific literature. Results In the young disc, the outer anulus fibrosus and inner nucleus pulposus have clear physical and molecular properties, although these differences become less distinct in the adult. The age changes are due to variations in both the abundance and structure of the macromolecules, particularly aggrecan, and the structural variations may be due to changes in both synthesis and degradation. It is not clear how many of the changes are by design to adapt to the altered environment of the growing spine. However, it is commonly thought that the degradative changes are detrimental to disc function, a property that is exacerbated by the inability of the mature avascular disc to remove and replace accumulated degradation products. The rate at which these detrimental changes occur may vary between individuals because of genetic, biomechanical, and nutritional differences. Such changes are thought to form the basis of tissue loss associated with disc degeneration. Conclusion Changes in intervertebral disc structure throughout life ultimately result in tissue degeneration and the need for medical intervention. Current research is aimed at trying to restore the integrity of the degenerate disc matrix by biologic means, although at present it is not clear what the structure of the most appropriate repair tissue should be or how it can be achieved.
THE MARKET SHARE IMPACT OF SERVICE FAILURES

This paper develops a simple but powerful model that relates service satisfaction/dissatisfaction to market share. The model is based on an intuitive service satisfaction framework that relates three service system parameters (service success rate, complaint rate, and service recovery rate) to the percent of satisfied customers. A dynamic model is then posited that relates the defection rate and the addition rate to market share changes. The service satisfaction/market share model yields useful insights into how market share is influenced by these service system parameters. The surprisingly simple model predicts changes in market share due to changes in customer satisfaction.
Circulating endothelial progenitor cells correlate to stage in patients with invasive breast cancer

Tumor growth and metastasis is dependent on the formation and assembly of new blood vessels, a process known as neo-angiogenesis. Both pre-existing and circulating vascular cells have been shown to contribute to the assembly of tumor neo-vessels in specific tumors. Mobilization of endothelial progenitor cells (EPCs) from the bone marrow constitutes a crucial step in the formation of de novo blood vessels, and levels of peripheral blood EPCs have been shown to be increased in certain malignant states. However, the role of circulating EPCs in breast cancer is largely unknown. We recruited twenty-five patients with biopsy-proven invasive breast cancer at Weill Cornell Breast Center to participate in a pilot study investigating the correlation of circulating EPCs to extent of disease and initiation of chemotherapy. For each patient, a baseline sample was drawn before systemic treatment, and for seventeen of those patients, a second sample was taken after the first round of chemotherapy. Levels of peripheral blood EPCs, as defined by co-expression of CD133 and VEGFR2, were quantified by flow cytometry. Breast cancer patients with stage III & IV disease had statistically higher levels of circulating EPCs than did patients with stage I & II disease (median = 165,000 EPCs/5 x 10(6)MNCs vs. median = 6,920 EPCs/5 x 10(6)MNCs, respectively, P < 0.0001). In addition, in late-stage patients, levels of EPCs demonstrated a statistically significant drop after initiation of chemotherapy (median = 162,500 EPCs/5 x 10(6)MNCs [pre] vs. median = 117,500 EPCs/5 x 10(6)MNCs [post], P = 0.01). These results suggest that circulating EPCs may serve as a potential tumor biomarker in breast cancer and that EPCs may represent a plausible target for future therapeutic intervention.
The Existence of a Bottom-Living Calanoid Copepod Fauna in Deep Water With Descriptions of Five New Species 1)

Speziell entwickelte Schliessnetze wurden (mit Hilfe des Forschungsunterseebootes "Alvin") zum Fang von plankto-benthischen Copepoden im Tiefenwasser uber dem Kontinentalabhang sudlich von Woods Hole verwendet. Auf zwei Stationen (1500 und 1000 m Tiefe) wurden je zwei Proben gesammelt, eine 20 cm uber dem Boden, die andere mehr als 100 m uber dem Boden. In den zwei dicht am Boden gesammelten Proben wurden vierzehn planktobenthische calanoide Copepoden identifiziert einschliesslich funf neuer Arten. Keine dieser Arten wurde in den zwei Proben gefunden, die 120 und 260 m uber dem Boden gesammelt wurden. Die benthische calanoide Fauna wurde mit derjenigen in ahnlicher Tiefe bei Neuseeland verglichen. Die taxonomische Zusammensetzung der beiden calanoiden Faunen war verschieden; aber es wurde der Schluss gezogen dass die abweichende Methode, die zum Sammeln bei Neuseeland verwendet worden war, keinen gultigen Vergleich zulasst.
OLD WINE IN A NEW BOTTLE

Author's summary.— Similarity of a recent American story to a well-known Grimm Marchen. Investigation reveals the antiquity of the tale and its widespread dissemination in the literature of the world.
A computerized analysis of supersonic nonuniform flows over sharp and spherically blunted cones at angle of attack

Abstract A system of computer programs has been developed to predict supersonic inviscid and viscous nonuniform flow fields over sharp and spherically blunted cones at angle of attack. For blunt cones the flow fields considered were axisymmetric wake flows positioned such that the flow in the subsonic nose region remained axisymmetric. For sharp cones, both axisymmetric wake flows and two-dimensional shear flows were considered. The programs used in solving inviscid flow fields incorporate a modified inverse method for solving subsonic flow regions and modified axiymmetric and three-dimensional method of characteristics procedures for solving the supersonic flow regions. Body properties predicted by the inviscid solutions were used as edge data for solution of the corresponding laminar boundary-layers over the bodies. The viscous flow solutions were obtained using axisymmetric and full three-dimensional boundary-layer programs. Typical results from inviscid calculations have shown the development of strong adverse pressure gradients over both sharp and blunt cones in wake flows. In addition a thin entropy layer was found near the surface of both bodies; however, the normal pressure gradient was found to be negligible for the nonuniform flows considered. For the sharp cone in shear flow, property variation along the body was found to be almost linear. In all cases the aerodynamic coefficients were found to be significantly affected by the free-stream nonuniformity. Typical viscous flow field results have shown that relative to uniform flow values the skin friction and heat transfer increase along the windward streamline of both blunt and sharp cones in the nonuniform flows considered. Decreasing the width of the wake in wake flow increases the heat transfer and skin friction.
NLOS-communication between shadowed vehicles using by-standing relay vehicles

We consider a dual-hop vehicle to vehicle (V2V) relay channel, where a source vehicle communicates with a destination vehicle using a third vehicle as a relay node. The inter-vehicle relay channel is the product of two independent fading processes generated by two independent groups of scatterers. A novel MMSE estimator is proposed for the aforementioned dual-hop relay channel. The fading process at each hop is modeled as Rayleigh fading as well as Nakagami-m fading. The latter is widely used for modeling severe fading in V2V channels.
Normalized BMD as a predictor of bone strength.

Rationale and Objectives. In the noninvasive evaluation of bone quality, bone mineral density (BMD) has been shown to be the single most important predictor of bone strength and osteoporosis-related fracture. Among the methods of measuring BMD, dual x-ray absorptiometry (DXA) has widespread acceptance due to its low radiation, low cost, and high precision. However, DXA measures area BMD instead of true volumetric density; thus, a larger bone will tend to have a high BMD than will a smaller bone. Therefore, the comparison of BMDs of bones of different sizes can be misleading. In this study, the authors tried to compensate for the size effect by normalizing the area BMD with bone size as measured from a standard pelvic radiograph. Materials and Methods. The overall method for calculation of normalized BMD included conventional areabased BMD from DXA and the extraction of geometric measures from pelvic radiographs. The database for analysis included 34 femoral neck specimens. Regression analysis was performed between the normalized volumetric BMD, measured from femoral neck region, and the mechanical properties obtained from trabecular bone cubes machined from the same region. Results. After normalization of the area BMD, the coefficient of determination increased from 0.30 to 0.43 for the Young modulus and from 0.27 to 0.37 for bone compressive strength. Conclusion. A noninvasive method of normalizing BMD can improve the prediction of bone mechanical properties and has potential in monitoring changes in growing skeletons and in the clinical evaluation of bone quality.
Teratogenic effects of lithium in mice

The question of the teratogenicity of lithium carbonate was tested in two inbred strains of mice that are susceptible to teratogens. Strains 129 and A/J mice were treated with varying dosages of lithium carbonate on day 8, 9, or 10, and strain A/J mice were sequentially treated on days 11, 12, and 13 of gestation. Another group of mice of strain 129 were given lithium carbonate in drinking water throughout pregnancy. Levels of lithium were determined in mouse serum (and in brain) of mothers and their offspring with the purpose of comparing equivalent values in mice and in man. A baseline dosage of 0.8 mg of lithium carbonate was chosen, since this dose produced a serum lithium level of 0.8 meq/L, which is comparable to values of patients treated for manic-depressive illness. This baseline dosage or 2 and 4 times this amount did not prove teratogenic in strain 129 mice. However, 5.0 mg (200 mg/kg), which is one-half the LD50 value, caused 41% malformations. The baseline dosage did not cause malformations in strain A/J when given on day 11, 12, or 13 of gestation. Lithium carbonate given in the drinking water to strain 129 mice throughout pregnancy at a concentration that produces serum levels in mice consistent with human values was deleterious. The data suggest that whole or part of total litters were eliminated. The few survivors were apparently normal. Our results suggest that 6 times the therapeutic serum lithium level in humans is teratogenic in mice, as tested by acute experiments. Chronic treatment with a quantity of lithium that produces a serum level equivalent to that of human values is toxic to whole or part of the litters of mice.
The Effect of Tissue Expansion on Previously Irradiated Skin

• Opinion remains divided over the advisability of tissue expansion in previously irradiated skin. We examined the properties of, and complications associated with, tissue expansion in previously irradiated rabbit scalps. Irradiation injury was produced using fractionated roentgen rays, with a total dose of 5000 cGy over a 5-week interval. Following a 20-week convalescence interval, expansion was incrementally conducted over 4 weeks. Monitored parameters included cutaneous perfusion as indicated by fiberoptic dermofluorometry, intraluminal pressure, linear surface gain, and area of surface necrosis. The incidence and severity of complications, including surface necrosis, were significantly higher among irradiated animals. Furthermore, the overlying skin of irradiated animals demonstrated a significantly decreased compliance and measurable area gain. Given the inferior expandability and higher tendency toward complications with contemporary expansion techniques in previously irradiated skin, alternate reconstructive options are preferable in this setting. ( Arch Otolaryngol Head Neck Surg. 1992;118:419-426)
Numerical algorithm based on transmutation for solving inverse wave equation

This paper develops algorithms for solving an undetermined coefficient problem for a wave equation. The algorithms are based on an integral representation for the solution to the wave equation obtained by using transmutation. The convergence of the algorithm is studied and numerical experiments are performed.
Surgical management of urethral strictures based on etiology. Where do urethral stents fit in

Recent studies in the urologic literature indicate a renewed interest in the management of urethral stricture disease. Specifically, urologists are now treating all types of urethral strictures regardless of location, etiology, or extent with methods other than primary urethroplasty or direct vision internal urethrotomy (DVIU), i.e., balloon dilation or urethral stenting. To see which patients might best be managed by these new modalities, we reviewed our experience with urethral strictures at LAC-USC Medical Center.
Classical Statements on Geopolitics and the Aftermath of War

The relationship among geopolitical position, political legitimacy, and internal conflict has been rejuvenated as a topic of theoretical interest. This revival of interest has, to a degree, borrowed from earlier theories, but the implications of these earlier theories have not been fully explored. In this article the classical geopolitical statements of Herbert Spencer and Max Weber are modeled to highlight their continued relevance to sociological theories that address the relationship between geopolitics and internal societal processes.
Behavioral Observations of Parents With ADHD During Parent Training.

Objective: Several studies suggest that parental ADHD impedes behavioral parent training (BPT) outcomes. Parental ADHD symptoms exhibited during BPT may interfere with the acquisition of new skills...
Extended trench-gate power UMOSFET structure with ultralow specific on-resistance

An ultralow specific on-resistance power UMOSFET structure with the trench-gate extending down to the N+ substrate is presented. Specific on-resistances in the range 100–200 μΩ cm2 have been experimentally demonstrated for devices capable of supporting up to 25 V. Comparison of theoretical and experimental results is provided.
Leaching with Subsurface Drip Irrigation under Saline, Shallow Groundwater Conditions

One option for coping with the high soil salinity levels caused by saline, shallow groundwater conditions along the west side of the San Joaquin Valley is to convert from sprinkler or surface irrigation methods to drip irrigation. Experiments in commercial fields revealed that subsurface drip irrigation of processing tomato ( Lycopersicon esculentum Mill. var. esculentum ) is highly profitable under these conditions compared with other irrigation methods. The experiments also showed that little or no field-wide leaching occurred, based on the conventional or water balance approach to estimating the leaching fraction (LF), yet soil salinity measurements showed considerable leaching around the drip lines. Actual LFs could not be calculated because LF, soil salinity, soil water content, and root density all varied with distance and depth around the drip lines. Therefore, we conducted a numerical modeling study using the HYDRUS-2D computer simulation model to evaluate leaching with drip irrigation under saline, shallow groundwater conditions for different amounts of applied water, water table depths, and irrigation water salinity, described by the electrical conductivity of the irrigation water (EC iw ). Results showed that LF values ranged from 7.7 to 30.9% as applied water amounts increased from 60 to 115% of the potential evapotranspiration (ET pot ) for the EC iw = 0.3 dS m −1 irrigation water, even though the water balance method showed no leaching for applied water amounts equal to or smaller than ET pot . The spatially varying soil wetting patterns that occur under drip irrigation caused the localized leaching, which was concentrated near the drip line.
The dynamics of the vaginal microbiome during infertility therapy with in vitro fertilization-embryo transfer

Purpose To determine the vaginal microbiome in women undergoing IVF-ET and investigate correlations with clinical outcomes.
The Whole in Every Part: Steiner and Waldorf Schooling

(1990). The Whole in Every Part: Steiner and Waldorf Schooling. The Educational Forum: Vol. 54, No. 1, pp. 79-91.
Development of a three-phase bus impedance matrix in the complex frequency domain for transient analysis in unbalanced distribution systems

Abstract Untransposed feeders, a combination of single-phase, two-phase and unequal three-phase loads impose imbalance in distribution systems. This paper presents a generalized computer technique to develop the three-phase bus impedance matrix Z bus3 (s) in the complex frequency domain. The method utilizes the phase-frame representation of the network elements. Consequently, the transient response due to line removals or additions, asymmetrical shunt faults, series faults, and capacitor switching can be simulated by modifying Z bus3 (s) . Thus, the proposed method makes it possible to analyze a power system network considering imbalance and the frequency dependence of the feeder parameters, and to obtain the transient response due to fault or capacitor switching conditions in the presence of harmonic distortion.
Proximal Impact of Two First-Grade Preventive Interventions on the Early Risk Behaviors for Later Substance Abuse, Depression, and Antisocial Behavior

We assessed the immediate effects of two universal, first-grade preventive interventions on the proximal targets of poor achievement, concentration problems, aggression, and shy behaviors, known early risk behaviors for later substance use/abuse, affective disorder, and conduct disorder. The classroom-centered (CC) intervention was designed to reduce these early risk behaviors by enhancing teachers' behavior management and instructional skills, whereas the family-school partnership (FSP) intervention was aimed at improving parent-teacher communication and parental teaching and child behavior management strategies. Over the course of first and second grades, the CC intervention yielded the greatest degree of impact on its proximal targets, whereas the FSP's impact was somewhat less. The effects were influenced by gender and by preintervention levels of risk. Analyses of implementation measures demonstrated that greater fidelity to the intervention protocols was associated with greater impact on behavior ratings and on achievement scores, thus providing some evidence of specificity in the effect of the interventions.
Selection on Somatic Cell Score to Improve Resistance to Mastitis in the United States

Increased genetic susceptibility to mastitis has accompanied the rapid genetic increase in milk yield, and genetic selection for mastitis resistance should be considered. Somatic cell score is recommended as an indicator trait to achieve genetic improvement for mastitis resistance. Heritability of somatic cell score is around 10%, and genetic correlation between somatic cell score and clinical mastitis is around .6 to .8. Selection for lower somatic cell score is consistent with the goal of maximizing genetic improvement for total economic merit and should be included in breeding programs. National genetic evaluations for somatic cells scores will use the same animal models and methods as are currently used for milk yield traits. Reliabilities of PTA for somatic cell scores will be smaller than for yield traits because of lower heritability and availability of records from fewer cows. Several forms are proposed for reporting genetic evaluations of somatic cells to producers, and advantages and disadvantages are discussed. Using somatic cell scores for breeding decisions would marginally decrease genetic gain for milk yield and increase total economic merit. Optimal selection indexes would slow the rate of increase in mastitis, rather than decrease its incidence.
ITER Relevant Reflectometry Developments on DIII-D

A number of reflectometer systems are under development on the DIII-D tokamak which are directly relevant to ITER needs and requirements. These include density profile measurement systems, a divertor reflectometer system, an inside launch reflectometer system for core access, and RF wave and edge density profile measurements at an ICRF antenna. For density profile measurements a new solid-state fast sweep FM reflectometer system has been installed on DIII-D. The faster sweep rates, combined with improved/optimal data processing routines developed over several years1,2 have resulted in more accurate profiles with improved time resolution, as required for routine operation on ITER. Also on DIII-D is an AM reflectometer system developed by ORNL which is being contrasted with the FM technique. A new reflectometer system is now operating in the lower divertor floor and is intended for peak density, density profile, and turbulence measurements. An inside launch reflectometer system has been upgraded for first tests of core profile measurements using the left hand X-mode cutoff. Use of the left hand cutoff and inside launch is necessary for core access for reflectometry on ITER.3 RF heating is also an option for ITER, and RF coupling/directionality depend on the position and details of the edge density profile. On DIII-D, reflectometry has provided detailed edge density profile measurements at the ICRF antenna. Also, a novel application of reflectometry on DIII-D has been the determination of the internal RF electric field profile in the plasma, which is related to the RF power deposition profile. Design and operational considerations as well as first data from the above systems are presented.
Simplicity versus accuracy in a model of cache coherency overhead

The important factors building a model of coherency overhead for a single-bus, shared memory multiprocessor are analyzed. Three architectural features are examined: the size of the coherency block, the cache size, and the type of bus operation used to carry out a particular coherency function. The experiments judge the effect of each architectural parameter on model accuracy by selectively including it in a base model and then comparing the model's predictions of coherency overhead to the results of detailed multiprocessor simulations. The results indicate that coherency block size is critical to include in a model of coherency overhead. This improves the accuracy of the base model by a factor of approximately 5-50, depending on the application. Cache size and the type of coherency-related bus operation are less important, contributing a 1.5% (for 128 kbyte caches) and 6% improvement, respectively, averaged over all traces. >
Learning Theories in Computer Science Education

College instruction may be primarily concerned in most cases with the content of their academic lessons, and not very much with their instructional delivery. However, the effective application of learning theories in higher education has an impact on student performance. This paper surveys the applicability of constructivism, cognitive information processing and behaviorism in computer science education. However, student success in learning computer science theory is not limited to only those three learning theories. In general, research findings suggest that effective computer science instruction involves the design of cognitive models that facilitate retrieval, and a consistent application of positive reinforcement.
Cysteine‐free rop: A four‐helix bundle core mutant has wild‐type stability and structure but dramatically different unfolding kinetics

Cysteine residues can complicate the folding and storage of proteins due to improper formation of disulfide bonds or oxidation of residues that are natively reduced. Wild-type Rop is a homodimeric four-helix bundle protein and an important model for protein design in the understanding of protein stability, structure and folding kinetics. In the native state, Rop has two buried, reduced cysteine residues in its core, but these are prone to oxidation in destabilized variants, particularly upon extended storage. To circumvent this problem, we designed and characterized a Cys-free variant of Rop, including solving the 2.3 A X-ray crystal structure. We show that the C38A C52V variant has similar structure, stability and in vivo activity to wild-type Rop, but that it has dramatically faster unfolding kinetics like virtually every other mutant of Rop that has been characterized. This cysteine-free Rop has already proven useful for studies on solution topology and on the relationship of core mutations to stability. It also suggests a general strategy for removal of pairs of Cys residues in proteins, both to make them more experimentally tractable and to improve their storage properties for therapeutic or industrial purposes.
SOME IMPLICATIONS OF DIRECT POSITIVE INTERACTIONS FOR COMMUNITY SPECIES DIVERSITY

Direct positive interactions (mutualisms and commensalisms) are generally accepted as important processes in communities. They appear to be most common in environments with relatively high physical disturbance, stress, or predation, where associated species can increase the growth and survival of other species unable to survive in isolation. Although ecologists have documented direct positive interactions among species for decades, there is less known about how these interactions affect community species diversity patterns. In this paper, we present a qualitative theoretical model that considers how direct positive interactions affect community species diversity. The model uses, as its basis, familiar unimodel species diversity models (i.e., “compensatory mortality” and “intermediate disturbance” hypothesis) to understand where direct positive interactions are likely to be important. Initially, it predicts that direct positive interactions increase species diversity by facilitating species that might not normally survive under very high physical disturbance, stress, or predation. In addition, it suggests that, under intermediate physical disturbance, stress, or predation, facilitator species that might normally be competitively excluded are released from competition. We suggest that facilitator species may then create new interaction webs that would not be possible in their absence. To illustrate these ideas, we describe a case study taken from a New England salt marsh community where a gradient in physical conditions occurs. In this community, direct positive interactions, and their indirect effects, are predicted to increase the species diversity by at least 35%. This empirical case study and model show that by incorporating direct positive interactions into ecological experiments and theory, it is possible to expand our understanding of the mechanisms responsible for community species diversity patterns.
A semantic framework for heterogeneous database environments

Describes a semantic framework for the analysis of global view update operations in a heterogeneous database environment. A semantic data model is used to form global conceptual schemas and to represent the meta data of global schemas using a self-describing approach. The semantic model is also used to represent the meta data of local schemas and the mapping between local and global schemas. Set-oriented views of objects are then formed over the global conceptual schema using an object algebra. An approach known as constraint analysis is applied to the analysis of view update operations, identifying side effects and alternative update translations. The constraint analysis process helps to refine the scope of a global view based on the constraints of the underlying local schemas and the types of update operations to be performed. The constraint analysis process also supports semantic query optimization. The approach described in this paper provides a uniform interface for defining global object-oriented views, together with analysis tools. >
Changes in spinning anatomy and thread stickiness associated with the origin of orb-weaving spiders☆

The cribellum is an oval spinning field whose spigots produce silk fibrils that form the outer surfaces of the primitive prey capture threads found in aerial spider webs. A comparison of the cribella and cribellar capture threads of 13 species of spiders representing seven families (Amaurobiidae, Desidae, Dictynidae, Filistatidae, Neolanidae, Oecobiidae, and Uloboridae) confirms that the stickness of a cribellar thread is directly related to the number of spigots on a spider's cribellum. This comparison also demonstrates that the origin of orb-weaving spiders from ancestors that constructed less highly organized webs was associated with increases in both the weight-specific number of cribellum spigots and the weight-specific stickiness of cribellar prey capture threads. In contrast to other cribellate spiders, the number of cribellum spigots of orb-weaving species of the family Uloboridae scales to spider mass. Thus, the origin of orb-weaving spiders involved not only behavioural changes that stylized and restricted the placement of cribellar threads, but also included morphological changes that increased the stickiness of these capture threads by endowing them with more cribellar fibrils.
Shifting Contexts: Transformations in Anthropological Knowledge

Shifting Contexts: Transformations in Anthropological Knowledge. MARILYN STRATHERN, ed. London and New York: Routledge, 1995. xii + 193 pp., figures, contributors, notes, references, name index, subject index.
Ionization Balance, Chemical Abundances, and the Metagalactic Radiation Field at High Redshift

We have carried out a series of model calculations of the photoionized intergalactic medium (IGM) to determine the eUects on the predicted ionic column densities due to uncertainties in the published di- electronic recombination (DR) rate coefficients. Based on our previous experimental work and a com- parison of published theoretical DR rates, we estimate there is in general a factor of 2 uncertainty in existing DR rates used for modeling the IGM. We demonstrate that this uncertainty results in factors of D1.9 uncertainty in the predicted N V and Si IV column densities, D2.0 for O VI, and D1.7 for C IV .W e show that these systematic uncertainties translate into a systematic uncertainty of up to a factor of D3.1 in the Si/C abundance ratio inferred from observations. The inferred IGM abundance ratio could thus be less than or greater than If the latter is true, then it suggests the metagalactic radi- (Si/C) _ 3(Si/C) _ . ation —eld is not due purely to quasars but includes a signi—cant stellar component. Lastly, column density ratios of Si IV to C IV versus C II to C IV are often used to constrain the decrement in the metagalactic radiation —eld at the He II absorption edge. We show that the variation in the predicted Si IV to C IV ratio due to a factor of 2 uncertainty in the DR rates is almost as large as that due to a factor of 10 change in the decrement. Laboratory measurements of the relevant DR resonance strengths and energies are the only unambiguous method of removing the eUects of these atomic physics uncertainties from models of the IGM. Subject headings: atomic processescosmology: miscellaneousdiUuse radiation ¨ intergalactic mediumquasars: absorption lines
Chaos in the swing dynamics

The swing equations model the interactions of generators (or subsystems of generators) in an electric power system. They are used to study "transient stability", or stability of the system right after a large disturbance (e.g. a fault). For a system of n generators, the two swing equations are given. The equations take into account the mechanical rotor angle of each generator, and its rotor angular velocity, as well as the inertia constant, the damping constant and the (constant) mechanical power input at each machine. The equations are coupled only through the terms that represent the electrical power output at each machine demanded by the network. Integral equations are developed assuming that there is no damping and no resistence in the transmission lines, and that resistive loads are located only at generator busses. These equations can be used to reduce the system by one degree of freedom (two dimensions). The equations are broadened to cover the case of 3-generator system (2 degrees of freedom).
Patch antenna with switchable slots (PASS): reconfigurable design for wireless communications

Reconfigurable antennas are becoming popular in antenna engineering because of their capability in frequency agility, bandwidth enhancement, and polarization diversity. Reconfigurable designs have been applied to dipole antennas, slot antennas, and microstrip antennas. Compared to normal designs, they exhibit attractive features of compact structure, similar radiation performance and little co-site interference. This paper presents a novel reconfigurable design: patch antenna with switchable slots (PASS). The PASS concept, various PASS designs, and its applications are discussed.
Polymer NMR spectroscopy. VII. The stereochemical configuration of polytrifluorochloroethylene

The NMR spectrum of polytrifluorochloroethylene in 3,3′-bistrifluoromethylbiphenyl solution at 150°C. consists of two doublets having unequal components. Those at lower field correspond to CF2 chain units, while those at higher field correspond to CFCL units. In the CF2 doublet, the weaker component (at lower field) is found to have half the area of the stronger (at higher field), for polymers prepared over a 120°C. range of polymerization temperatures. By comparison to the spectra of the model compounds meso- and dl-CF2ClCFClCF2CFClCF2Cl, the peaks of which closely coincide with those of the polymer when both are compared at 150°C., it is concluded that of the two CF2 peaks in the polymer spectrum, the weaker one represents CF2 groups which are between monomer units in isotactic dyads whereas the stronger one represents CF2 groups which are between monomer units in syndiotactic dyads. It follows that in trifluorochloroethylene propagation, syndiotactic dyad formation is twice as probable as isotactic dyad formation. This preference for syndiotactic placement corresponds to an activation entropy for isotactic propagation 1.38 e.u. more negative than that for syndiotactic propagation; there is no difference in the activation enthalpies. This behavior is in contrast to that previously found for methyl methacrylate propagation; here, preference for syndiotactic placement is entirely dictated by a greater activation enthalpy for isotactic placement.
Dark state vibronic coupling in the Ã(2Π) ← ͠X(2Σ+) band of ethynyl radical via high resolution infrared absorption spectroscopy.

The high resolution infrared spectrum for the A (2Π) ← (2Σ+) origin band of jet-cooled ethynyl radical (C2H) in the gas phase is reported, which exhibits a strong, parity-specific local perturbation in the upper 2Π1/2 state. Based on revised parity assignments of the levels, the perturbing state is unambiguously determined to be 2Σ+ symmetry, and thus coupled to the A (2Π) state by ΔK = ±1 Coriolis interactions. By incorporating Σ-Π Coriolis coupling into the unperturbed Hamiltonian (containing only rotational, spin-rotational, spin-orbit, and lambda-doubling contributions), we are now able to fit the observed 2Π-2Σ+ origin band to a sub Doppler experimental uncertainty of 15 MHz (0.0005 cm−1). In addition, the observation of pairs of transitions to mixed states permits determination of the band origin (νpert) and rotational constant (Bpert) for the “dark” 2Σ+ state, which prove to be in remarkably quantitative agreement with full vibronic predictions of Tarroni and Carter as well as UV dispersed fluorescence studies of Hsu et al. This represents an important benchmark in mapping out non-Born–Oppenheimer vibronic interactions and energy level structure in a polyatomic combustion radical system, an understanding of which will be key to modeling chemical reactions in both terrestrial and astronomical environments.
Tocopherol induced angiogenesis in placental vascular network in late pregnant ewes

Background: Tocopherols have biphasic, proangiogenic and antiangiogenic therapeutic effects. The objective of this clinical trial was to clarify tocopherol’s placental angiogenic potential in late pregnant ewes following oral supplementation. Methods: Eighteen pregnant ewes during late gestation were selected for this study. Ewes were given oral supplementation of 500 mg of alpha-tocopherol (aT; N = 6) or 1000 mg of gamma-tocopherol (gT; N = 7) or placebo (CON; N = 5) once daily from 107 to 137 days post breeding. Serum was obtained at weekly intervals and tissue samples were obtained at the end of supplementation to: 1) evaluate tocopherol concentrations in serum, uterus and placentome; 2) evaluate relative mRNA expressions of Vascular Endothelial Growth Factor (VEGF), Placental Growth Factor (PlGF), endothelial Nitric Oxide Synthase (eNOS) and Hypoxia Inducible Factors (HIF) in uterus, caruncle and cotyledon; 3) analyze the morphometry of the placental vascular network. Results: Supplementation of aT or gT resulted in increased concentrations in serum, placentome and uterus compared to control (P < 0.05). In aT group, mRNA expressions of PlGF, eNOS and HIF-1a in cotyledon were greater than the CON group. In gT group, mRNA expressions of VEGF, eNOS, HIF-1 alpha and HIF-2 alpha in caruncle and uterus, and HIF-1a in cotyledon, were greater than the CON group. Morphometry analysis revealed increased angiogenesis in the supplemented groups. Conclusion: Daily oral supplementation of aT or gT increased angiogenesis in the placental vascular network in pregnant ewes during late gestation. Increase in placental angiogenesis may provide nutrients required for the development and growth of fetus during late pregnancy.
Maternal Diagnosis of Obesity and Risk of Cerebral Palsy in the Child

Objective To examine the association between maternal hospital diagnoses of obesity and risk of cerebral palsy (CP) in the child. Study design For all California hospital births from 1991-2001, we linked infant and maternal hospitalization discharge abstracts to California Department of Developmental Services records of children receiving services for CP. We identified maternal hospital discharge diagnoses of obesity ( International Classification of Diseases, 9th edition 646.1, 278.00, or 278.01) and morbid obesity ( International Classification of Diseases, 9th edition 278.01), and performed logistic regression to explore the relationship between maternal obesity diagnoses and CP. Results Among 6.2 million births, 67 200 (1.1%) mothers were diagnosed with obesity, and 7878 (0.1%) with morbid obesity; 8798 (0.14%) children had CP. A maternal diagnosis of obesity (relative risk [RR] 1.30, 95% CI 1.09-1.55) or morbid obesity (RR 2.70, 95% CI 1.89-3.86) was associated with increased risk of CP. In multivariable analysis adjusting for maternal race, age, education, prenatal care, insurance status, and infant sex, both obesity (OR 1.27, 95% CI 1.06-1.52) and morbid obesity (OR 2.56, 95% CI 1.79-3.66) remained independently associated with CP. On stratified analyses, the association of obesity (RR 1.72, 95% CI 1.25-2.35) or morbid obesity (RR 3.79, 95% CI 2.35-6.10) with CP was only significant among women who were hospitalized prior to the birth admission. Adjusting for potential comorbidities and complications of obesity did not eliminate this association. Conclusions Maternal obesity may confer an increased risk of CP in some cases. Further studies are needed to confirm this finding.
CONSERVATION GENETICS OF TWO ENDANGERED UNIONID BIVALVE SPECIES, EPIOBLASMA FLORENTINA WALKERI AND E. CAPSAEFORMIS (UNIONIDAE: LAMPSILINI)

The genus Epioblasma consists of 20 species and eight subspecies, of which 15 species and four subspecies are presumed or probably extinct. Remaining taxa are considered endangered or threatened largely due to habitat destruction or modification. We conducted a molecular genetic study on all known extant populations of two federally endangered freshwater Epioblasma species: the tan riffle-shell, E.florentina walkeri (Wilson & Clark, 1914), and oyster mussel, E. capsaeformis (Lea, 1834), to determine the extent of genetic variation within and among populations of the two species. Mitochondrial DNA sequence data from two protein-coding genes (COI and ND1) failed to differentiate E. capsaeformis from E. f. walkeri. Molecular variation within and between the two species does not exceed limits observed within Epioblasma brevidens, although substantial genetic differences are observed among E. brevidens, E. triquetra and E. capsaeformis + E. florentina walkeri. Although data do not support the recognition of the two taxa as separate phylogenetic species, they still warrant endangered status due to the fact that few reproducing populations are known. Life history and population biology studies have already been conducted on the single known extant reproducing population of nominal E. f walkeri. However, similar comparative studies should be conducted on the different mantle-pad morphs of nominal E. capsaeformis populations to provide valuable data for more effective management of the recovery of the phylogenetic species and to further test our hypothesis.
A derivative of the plasma protease inhibitor α2‐macroglobulin regulates the response to peripheral nerve injury

Peripheral nerve injury induces endoneural inflammation, controlled by diverse cytokines and extracellular mediators. Although inflammation is coupled to axonal regeneration, fulminant inflammation may increase nerve damage and neuropathic pain. alpha(2)-Macroglobulin (alpha2M) is a plasma protease inhibitor, cytokine carrier, and ligand for cell-signaling receptors, which exists in two well-characterized conformations and in less well-characterized intermediate states. Previously, we generated an alpha2M derivative (alpha(2)-macroglobulin activated for cytokine binding; MAC) similar in structure to alpha(2)M conformational intermediates, which binds tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), and inhibits endotoxin toxicity. In this study, we report that the continuum of cytokines that bind to MAC includes IL-6 and IL-18. MAC inhibited TNF-alpha-induced p38 mitogen-activated protein kinase activation and cell death in cultured Schwann cells. When administered by i.p. injection to mice with sciatic nerve crush injury, MAC decreased inflammation and preserved axons. Macrophage infiltration and TNF-alpha expression also are decreased. MAC inhibited TNF-alpha expression in the chronic constriction injury model of nerve injury. When MAC was prepared using a mutated recombinant alpha2M, which does not bind to the alpha2M receptor, low-density lipoprotein receptor-related protein-1, activity in the chronic constriction injury model was blocked. These studies demonstrate that an alpha2M derivative is capable of regulating the response to peripheral nerve injury by a mechanism that requires low-density lipoprotein receptor-related protein-1.
Host Range of Puccinia psidii, a Potential Biological Control Agent of Melaleuca quinquenervia in Florida

Abstract The rust fungus Puccinia psidii infects the foliage and causes dieback of actively growing tips on several myrtaceous plants in South and Central America. It has recently been discovered in south Florida causing a similar disease on Melaleuca quinquenervia. We therefore evaluated P. psidii as a potential biological control agent of this invasive tree. Typical disease symptoms on M. quinquenervia included distortion and abscission of young foliage and dieback of severely infected tips. Young stems with living bark developed lesions and localized swellings. The stems became brittle and prone to breakage at the point of these swellings. Often, flowers and young seed capsules also developed eruptive pustules. Host range tests were performed on 18 species in 11 genera of Myrtaceae by inoculating expanding leaves with uredospores of two P. psidii isolates: MISOL, obtained from M. quinquenervia, and PISOL, obtained from Pimenta dioica. Results showed Callistemon viminalis, Eugenia reinwardtiana, M. decora, M. quinquenervia, Myrcianthes fragrans, Myrciaria cauliflora, P. dioica, and Psidium guajava to be susceptible to both isolates. Eucalyptus grandis, Eugenia paniculatum, and Syzygium cumini manifested chlorotic halos that developed into brown leaf spots but had no sporulation and were therefore considered resistant. The remaining seven species ( Calyptranthes pallens, Eugenia confusa, Eugenia foetida, Eugenia uniflora, Feijoa sellowiana, Psidium cattleianum, and S. jambos ) exhibited no symptoms and were considered immune to both isolates. The ability of these isolates to initiate pustules on susceptible hosts differed significantly. Overall, both isolates induced more pustules on M. quinquenervia, E. reinwardtiana, and P. dioica than on other susceptible species. Based on host range, both Florida isolates of P. psidii appear similar to one that infects Pimenta spp. in Jamaica. Our studies included a limited number of plant species grown under optimal conditions for disease expression. Field tests will be needed to ascertain their susceptibility under more natural conditions. The P. psidii and M. quinquenervia pathosystem probably represents a “new association,” because of the disparate origins of the two species involved and their adventive status in Florida.
Radioembolization (Yttrium-90 Microspheres) for Metastatic Hepatic Malignancies

Radioembolization is the process of permanently implanting radioactive microspheres into hepatic malignant tumors using the hepatic arterial system for delivery. The most common therapeutic radioisotope used in this form of brachytherapy (placing radioactive sources into or next to a tumor) is yttrium-90 (90Y). Since the earliest attempts to implant liver tumors, the technique has been surprisingly similar—a catheter is situated into a branch of the hepatic artery, and microspheres (25–35 micron diameter) containing 90Y preferentially flow to tumors as opposed to normal liver. The microspheres are small enough to penetrate into the tumors but too large to pass out of the hepatic capillary beds, and so they permanently reside in the tumor. The most common cancers treated with 90Y microspheres are primary hepatocellular carcinoma, and metastatic tumors from primary colorectal, neuroendocrine, pancreas, and breast carcinomas. The toxicity profile is highly favorable for this outpatient procedure with fewer than 2% serious adverse events (gastric ulceration 1–2%, radiation-induced liver failure 0.8%). Overall response rates are 30–75% (RECIST) based on tumor type, and in colorectal cancers, there is a proven survival improvement with 90Y in patients whose chemotherapy agents are no longer inducing a response. The use of radioembolization continues to rapidly grow for a variety of patient subgroups which now include first line therapy in neuroendocrine and colorectal tumor types.