cssi/SciSciGPT-SciSciNet huggingface dataset:
Inhibition of proliferation without affecting the generation of cytotoxicity in the human mixed lymphocyte reaction

Abstract Phosphoramide mustard (PM) is considered to be the major tumoricidal metabolite of cyclophosphamide in vivo . The effects of this metabolite in vitro on several immune functions of human lymphocytes have been investigated. Very low concentrations (10 −7 to 10 −7 M ) of PM added to lymphocyte cultures inhibited proliferation of the lymphocytes in response to mitogens and alloantigens. At these concentrations, inhibition of proliferation appeared to be due to a direct action of PM on the proliferative cells. Thus, concanavalin A-stimulated lymphocytes still acquired IL-2 receptors (Tac antigen) normally in the presence of PM (10 −6 to 10 −9 M ). Only exceedingly high concentrations of PM (10 −5 M or greater) prevented the acquisition of Tac antigen. Similarly, the inhibition of proliferation was probably not related to endogenous IL-2 levels: addition of exogenous IL-2 to PM-containing cultures did not result in any restoration of proliferation. Further evidence that PM directly affected proliferative cells was that low concentrations of PM inhibited the proliferation of T cells continuously growing in IL-2. The exposure time to PM necessary for inhibition was essentially identical to those for lymphoproliferative responses to mitogens and alloantigens. Paradoxically, however, the generation of cytotoxic lymphocytes in mixed lymphocyte reactions (MLRs) and mixed lymphocyte tumor cell cultures (MLTCs) was very resistant to PM. In parallel MLRs and MLTCs the cytotoxic responses were resistant to approximately 1000-fold more PM than were the proliferative responses. Only at 10 −5 M PM were these inhibited. These data suggest that clonal expansion of cytotoxic lymphocytes or their precursors by proliferation is not an absolute requirement for the generation of cytolytic activity.
UV-LIGA and DRIE grating microfabrication and testing for sheet beam amplifiers at 220 GHz

Slow-wave sheet beam amplifiers are under development at NRL to demonstrate 50 watts CW at 220 GHz. We report on the microfabrication of amplifier gratings based on Ultraviolet Lithography (UV-LIGA) techniques using the SU-8 Photoresist for thick films. Deep Reactive Ion etching (DRIE) has also been investigated for grating circuits. An improved cold test fixture is being developed for the cold test process.
Mutational analysis of a mammalian reovirus mRNA capping enzyme.

Abstract The amino-terminal 42-kDa region of the 144-kDa mammalian reovirus λ2 protein is a guanylyltransferase. It catalyzes the transfer of GMP from GTP to the 5′ end of 5′-diphosphorylated mRNA via a phosphoamide with Lys-190. This amino acid is located at the base of a deep cleft. Based on sequence comparisons, the Kx[V/L/I]S motif is present in all known and proposed guanylyltransferases of the family Reoviridae. The requirement for this conserved sequence and other regions of the enzyme was analyzed by site-directed mutagenesis. Based on the enzymatic activity of the mutants, Lys-190 and Asp-191 are the only amino acids of the 190 KDLS sequence that are necessary for enzymatic activity. Since Asp-191 has its side chain oriented away from the cleft, most likely it plays an indirect role in forming a functional guanylyltransferase.
Disassembly Sequence Evaluation Using Graph Visualization and Immersive Computing Technologies

With the goal of making product recovery economically viable, disassembly sequence planning and evaluation can be used to influence product design features early in the product design process. Several researchers have investigated using optimization methods to determine disassembly sequences. One of the difficulties with using this approach is that because of the unique aspects of product disassembly at the end of life, input parameters for the optimization algorithms are commonly unavailable or estimated under high uncertainty. In practice, design engineers explore disassembly sequencing using either CAD software or manipulation of physical prototypes. These approaches produce solutions, but only intuitive solutions are explored and more optimal solutions may exist. To support decision making early in the design process, the research presented in this paper combines these two approaches within an immersive computing technology (ICT) application to aid in early product design with the goal of designing products with consideration of product recovery, reuse and recycle. The ICT application displays both 3D geometry of the product to be disassembled and an interactive graph visualization of the potential disassembly paths. The user can naturally interact with the geometric models and explore the potential paths indicated by the graph visualization. The optimal path can be indicated and the user can explore other potential paths. The result is an application that combines the strength of mathematical modeling with visualization and human interaction to provide an experience where the user can explore potential effects of design decisions. The initial application has been implemented in a 3 wall immersive projection environment and preliminary results show this approach proves to be an efficient method of evaluating and training potential disassembly sequences.
The consistency of relative incidence rates of nonviral sexually transmissible infections from health insurance claims and surveillance data, 2005-10.

Background Given the growing popularity of administrative data for health research, information on the differences and similarities between administrative data and customary data sources (e.g. surveillance) will help to inform the use of administrative data in the field of sexually transmissible infections (STIs). The objective of this study was to compare the incidence rates of three nonviral STIs from a large health insurance administrative database (MarketScan) with surveillance data. Methods: We computed and compared STI rates for 2005–10 from MarketScan and national surveillance data for three major nonviral STIs (i.e. chlamydia (Chlamydia trachomatis), gonorrhoea (Neisseria gonorrhoeae) and syphilis (Treponema pallidum)). For administrative data, we assessed the sensitivity of the rates to enrolee inclusion criteria: continuous (≥320 member-days) versus all enrolees. Relative rates were computed for 5-year age groups and by gender. Results: The administrative database rates were significantly lower (P < 0.01) than those in the national surveillance data, except for syphilis in females. Gonorrhoea and syphilis rates based on administrative data were significantly lower (P < 0.01) for all enrolees versus continuous enrolees only. The relative STI rates by age group from the administrative data were similar to those in the surveillance data. Conclusions: Although absolute STI rates in administrative data were lower than in the surveillance data, relative STI rates from administrative data were consistent with national surveillance data. For gonorrhoea and syphilis, the estimated rates from administrative data were sensitive to the enrolee inclusion criteria. Future studies should examine the potential for administrative data to complement surveillance data.
Computational simulation of biomechanics in e-PTFE and venous Miller's cuffs: implications for intimal hyperplasia.

A computational distal end-to-side Miller's cuff anastomotic model was used to analyse the possible difference in intimal hyperplasia (IH) formed between e-PTFE and venous cuffs. A large strain FEA model was used to compute the strain after physiological loading and the deformed geometries used as wall boundaries for CFD analysis. Regression analysis was performed to investigate relationships between mechanical factors and prior IH [15]. The results showed that the venous Miller's cuff anastomosis deformed twice as much as the e-PTFE cuff and that the expansion of both cuffs generated elevated strains in the artery floor while the fluid shear indices were qualitatively similar in each case. In the e-PTFE cuff, the strain and OSI correlated with IH in a proportional and equivalent manner; however, these regressions grossly over-estimated the predicted IH in the vein cuff. Thus, biomechanical effects may be important in synthetically cuffed anastomoses, but do not account for the reduced IH in venous cuffed...
The genetic basis of thermal reaction norm evolution in lab and natural phage populations.

Two major goals of laboratory evolution experiments are to integrate from genotype to phenotype to fitness, and to understand the genetic basis of adaptation in natural populations. Here we demonstrate that both goals are possible by re-examining the outcome of a previous laboratory evolution experiment in which the bacteriophage G4 was adapted to high temperatures. We quantified the evolutionary changes in the thermal reaction norms—the curves that describe the effect of temperature on the growth rate of the phages—and decomposed the changes into modes of biological interest. Our analysis indicated that changes in optimal temperature accounted for almost half of the evolutionary changes in thermal reaction norm shape, and made the largest contribution toward adaptation at high temperatures. Genome sequencing allowed us to associate reaction norm shape changes with particular nucleotide mutations, and several of the identified mutations were found to be polymorphic in natural populations. Growth rate measures of natural phage that differed at a site that contributed substantially to adaptation in the lab indicated that this mutation also underlies thermal reaction norm shape variation in nature. In combination, our results suggest that laboratory evolution experiments may successfully predict the genetic bases of evolutionary responses to temperature in nature. The implications of this work for viral evolution arise from the fact that shifts in the thermal optimum are characterized by tradeoffs in performance between high and low temperatures. Optimum shifts, if characteristic of viral adaptation to novel temperatures, would ensure the success of vaccine development strategies that adapt viruses to low temperatures in an attempt to reduce virulence at higher (body) temperatures.
Direct observation of a surface charge density wave

A CHARGE density wave (CDW) is a periodic symmetry-lowering redistribution of charge within a material, accompanied by a rearrangement of electronic bands (such that the total electronic energy is decreased) and usually a small periodic lattice distortion1,2. This phenomenon is most commonly observed in crystals of reduced symmetry, such as quasi-two-dimensional3 or quasi-one-dimensional4 materials. In principle, the reduction of symmetry associated with surfaces and interfaces might also facilitate the formation of CDWs; although there is some indirect evidence for surface charge density waves5–12,14, none has been observed directly. Here we report the observation and characterization of a reversible, temperature-induced CDW localized at the lead-coated (111) surface of a germanium crystal. The formation of this new phase is accompanied by significant periodic valence-charge redistribution, a pronounced lattice distortion and a metal–nonmetal transition. Theoretical calculations confirm that electron–phonon coupling drives the transition to the CDW, but it appears that some other factor—probably electron–electron correlations—is responsible for the ground-state stability of this phase.
ACTH receptor-mediated induction of leukocyte cyclic AMP.

Summary Studies were conducted to determine whether lymphocyte ACTH receptors behave as their structurally similar adrenal cell counterparts, in terms of adenylate cyclase activation and cyclic AMP (cAMP) production in the presence of ACTH. Treatment of mouse mononuclear splenocytes with ACTH (10 −5 to 10 −10 M) induced a consistent rise in cAMP. ACTH treatment of more homogenous cell populations, represented by Molt 4 T lymphoblast and S49A T cell lymphoma lines, yielded a dramatic, dose-related increase in cAMP levels for S49A cells but not for Molt 4 cells. Immunofluorescence assays, employing an antiserum to the adrenal cell ACTH receptor, indicated that 45% of splenocytes, 69% of S49A cells, and
Teens' consumer interaction styles: the impact of assertive and aggressive behaviour on attitudes towards marketing practices

Over half-billion global teens between the ages of 13 and 18 years represent a dynamic opportunity for marketers who wish to grow their businesses and build consumer loyalty. Consumer interaction styles are the consistent behaviour patterns that individuals employ in transactions or exchanges in the marketplace. Assertiveness and aggressiveness represent two distinct interaction styles that enable individuals to achieve a desired outcome. Because teen consumers are an important consumer segment and subscribe to the notion that their voices must be heard, understanding their interaction styles is necessary for businesses and marketers. The purpose of this study was to examine teens' consumer interaction styles according to specific demographic and lifestyle characteristics and investigate the impact of assertive and aggressive interaction styles on attitudes towards marketing practices (i.e. product, retailing, advertising, and pricing). Data were collected from a US teen sample (n = 467) at both rural and urban high schools. Independent t-tests compared the propensity of teens' assertive and aggressive consumer interaction styles according to specific demographic and lifestyle characteristics. Structural Equation Modeling using AMOS 6.0 program was performed to test the hypothesized relationships. Results indicated that an assertive interaction style was pervasive among US teen consumers, while the aggressive interaction style had disparities according to unique demographic and lifestyle characteristics. Assertive and aggressive interaction styles demonstrated negative influences on teen consumers' attitudes towards products and retailing practices. By interpreting the negative impact of teens' assertive and aggressive consumer interaction styles, marketers can develop effective strategies that appeal to this demanding consumer.
Molecular dynamics simulations of compressed liquid hydrogen

Abstract Molecular dynamics simulations have been performed for highly compressed fluid hydrogen in the density and temperature regime of recent shock-compression experiments. Both density functional and tight-binding electronic structure techniques have been used to describe interatomic forces. A new tight-binding model of hydrogen has been developed with a single s orbital on each atom that reproduces properties of the dimer, of various crystalline structures, and of the fluid. The simulations give pressures and electrical conductivities in general agreement with the measured values. The pressures are also compared with recent quantum Monte Carlo results. This analysis provides a firm foundation for exploring the origins of the rapid change in electrical conductivity with temperature and density observed in the experiments. The simulations indicate that the conductivity in fluid hydrogen in this regime arises both from: (1) closing of the band gap due to thermal effects and compression; (2) electron hopping facilitated by the dissociated atoms (monomers) with the latter process the most important. Finally, we find that the internal structure of cool, dense hydrogen has a pronounced time-dependent nature with molecules (dimers) constantly dissociating and atoms (monomers) constantly associating all of the time.
Induced pluripotent stem cells for conserving endangered species

Induced pluripotent stem cells have been derived from two endangered wildlife species. There are exciting possibilities, yet formidable challenges, for these cells to contribute to real-life species preservation.
Observer performance using monitors with different phosphors: an ROC study

The goal of the study was to compare observer performance using a P104 vs P45 CRT monitor for display of radiographic images. Different types of phosphor in a CRT monitor can affect the SNR, which in turn could affect the visibility of certain structures of lesions in an image. A series of portable CR chest images with subtle pulmonary nodules were presented to radiologists. They were instructed to search the images while their eye position was recorded. They reported on the presence or absence of a nodule, rate their confidence and reported on image quality. Physical measurements were also taken for both monitors (e.g., dynamic range, MTF, veiling glare). Observer performance was slightly better with the P45 than with the P104 monitor, although the difference was not statistically significant. Physical characterization of the two monitors also revealed advantages for the P45 monitor. P104 monitors are typically used in Asia while P45 monitors are typically used in the US. This study shows that choice of monitor phosphor may influence diagnostic and/or visual search performance and thus should be taken into account when selecting a monitor for clinical use.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Computational study of a nonhierarchical decomposition algorithm

Optimizing the design of complex ground and flight vehicles involves multiple disciplines and multilayered computer codes stitched together from mostly incompativle disciplinary codes. The application of established, large-scale, optimization algorithms to the complete model is nearly impossible. Hierarchical decompositions are inappropriate for these types of problems and do not parallelize well. Sobieszczanski-Sobieski has proposed a nonhierarchical decomposition strategyfor nonlinear constrained optimization that is naturally parallel. Despite some successes on engineering problems, the algorithm as originally proposed fails on simple two-dimensional quadratic programs. This paper demonstrates the failure of the algorithm for quadratic programs and suggests a number of possible modifications.
Assistive devices for gait in Parkinson's disease

While medications have improved the function of patients with Parkinson's disease (PD), over time most patients experience progressive problems with gait and balance. There have been important recent advances in the development of mechanical assistive devices that have the potential of improving mobility, but there are possible risks and the optimal role for such devices in PD has not been carefully studied. We review the available literature and provide practical information about available mobility assistive devices for patients with PD.
Artificial Turf Incubators for Raising Muskellunge to Swim-Up Fry

Abstract Muskellunge Esox masquinongy eggs were incubated in artificial turf incubators in five lakes in Michigan and Wisconsin in 1985. Mean survival of swim-up fry from green eggs was 12% and from eyed eggs was 39%. This technique provides the manager with an economical and rapid method for raising muskellunge in lakes with inadequate spawning habitat.
Crime, Punishment, and Social Structures of Accumulation Toward a New and Much Needed Political-Economy of Justice

The political-economic processes subsumed under the term globalization are remaking nearly every facet of social life, including patterns of crime and justice. Nevertheless, most criminological theory focuses on the etiology of individual crime causation or on failures in local-level institutions, giving little attention to the role of larger-scale sociological forces. The authors propose that there is a need to develop theoretical and methodological strategies that can capture the impact of structural change on patterns of crime and justice. The authors suggest that social structure of accumulation theory offers a useful model for incorporating current macro-social changes into theory and research in criminology. To substantiate this argument, the authors offer a detailed exploration of how changes in labor regimes and related shifts in the balance of placative versus repressive control strategies played key roles in shaping crime problems and patterns of justice in the 20th century.
Photosynthesis in Rhodospirillum rubrum. I. Autotrophic carbon dioxide fixation.

The incorporation and distribution of activity from 14CO2 was investigated under autotrophic conditions in the facultative photoautotroph, Rhodospirillum rubrum, with cells cultured on hydrogen, carbon dioxide, and ammonium sulfate. In 1 second 14CO2 fixation experiments essentially all of the activity was found in 3-phosphoglyceric acid: plotted against time percent incorporation into phosphate esters has a strikingly negative slope. These results suggest that under autotrophic conditions the reductive pentose phosphate cycle or the key reactions of the cycle play a major role in carbon metabolism in this photosynthetic bacterium. Incorporation into amino acids and into intermediates of the tricarboxylic acid cycle was quite low.
Family structure and mental health: the mediating effects of socioeconomic status, family process, and social stress.

Although numerous studies reveal differences in mental health by the structure of one's family of origin, there remains debate regarding the processes generating these patterns. Using a sample of y...
Nitrous oxide analgesia: partial antagonism by naloxone and total reversal after periaqueductal gray lesions in the rat

Abstract Analgesia induced by nitrous oxide was examined using radiant heat tail flick and electrical evoked foot flick tests in rats. Rats exposed to 80 and 60% nitrous oxide expressed statistically significant elevations of percent analgesia (% MPE) compared to air exposed rats. Rats exposed to 30% nitrous oxide showed no significant difference in percent analgesia. Pretreatment with naloxone (10 mg/kg s.c.) produced a significant decrease in % MPE and an increase in variance of response after exposures to 80% nitrous oxide in a double blind study. Kainic acid lesions of the ventral and caudal periaqueductal grey (PAG) reversed analgesia produced by 80% nitrous oxide in a crossover blink study compared to saline lesions. In conclusion, this evidence suggests that the caudal-PAG-raphe mangus-dorsal horn pain inhibition pathway is in part involved in the analgesia induced by nitrous oxide.
Selective and effective killing of angiogenic vascular endothelial cells and cancer cells by targeting tissue factor using a factor VII-targeted photodynamic therapy for breast cancer

The cell surface receptor tissue factor (TF) is regarded as a common but specific target on angiogenic tumor vascular endothelial cells (VECs) and tumor cells in many types of cancer including breast cancer. The purpose of this study is to develop a selective and effective TF-targeting photodynamic therapy (PDT) by using its natural ligand factor VII (fVII)-conjugated Sn(IV) chlorin e6 (SnCe6) for the treatment of breast cancer. A cross linker EDC was used to covalently conjugate fVII protein to SnCe6, and the binding activity and phototoxicity was confirmed by ELISA and in vitro PDT. The efficacy of fVII-tPDT was assessed in vitro by crystal violet staining assay and in vivo by measuring tumor size in mice carrying murine or human breast cancer xenografts. We show that active site-mutated (K341A) fVII protein can be internalized into breast cancer cells and vascular endothelial growth factor (VEGF)-stimulated human umbilical vein endothelial cells (HUVECs) as angiogenic VECs. fVII-tPDT not only enhances 12-fold the in vitro efficacy but also selectively and effectively kills angiogenic HUVECs and breast cancer cells via specifically binding of fVII to TF and inducing apoptosis and necrosis as the underlying mechanism. Furthermore, fVII-tPDT can significantly inhibit the tumor growth of murine and human breast cancer without obvious toxicities in mice. We conclude that fVII-tPDT using fVII–SnCe6 conjugate can selectively and effectively kill angiogenic VECs and breast cancer cells in vitro and significantly inhibit the tumor growth of murine and human breast cancer in mice.
The evidence for middle-Wisconsin peopling of Beringia: An evaluation

Broken large mammal fossil bones in eastern Beringia have been used to argue for a middle-Wisconsin, or earlier, time of human entry into North America, It has been inferred that these controversial Pleistocene bones are artifacts because (1) they are similar to those found in archaeological sites and (2) they can be reproduced in the laboratory by replication. However, fractured, flaked, polished, faceted, cut, and scratched bones similar to the purportedly human artifacts described from Beringia are known to be produced by natural processes. New experimental data demonstrate that identifications of Pleistocene bone artifacts on the basis of differential staining and fresh breakage are suspect. Physical processes, such as the violent forces of river ice breakups in the north, and bone crushing by mammalian scavengers produce similar pseudo-artifacts. Additionally, the middle-Wisconsin dates associated with some of the finished tools, and human and dog bones from Beringia are open to question. The lack of credible dates on these artifacts raises doubt about the model of human colonization of Beringia, developed in the 1960s, which proposed an interstadial colonization of the New World.
Bacteriologic examination of tissues surgically removed as an aid in the diagnosis of diseases of the chest.

Obviously, it should be our cherished goal to try to establish a positive clinical diagnosis in every case of pulmonary disease. Careful and diligent use must be made of the many useful tests and examinations that are available for this purpose. The close co-operation of the roentgenologist, bronchoscopist, bacteriologist and other specialists is highly important. Despite all this, there will remain a goodly number of patients suffering from pulmonary disease in whom a positive diagnosis cannot be arrived at. It is often unwise, in a case of this type, to procrastinate too long with periods of observation or with tests that require many weeks for completion, because of the danger that the lesion may be malignant in nature, thereby requiring prompt treatment if it is to be eradicated successfully. In properly selected cases of this type, exploratory thoracotomy is often indicated; the pathologist can often furnish a prompt explanation of the underlying cause of the pulmonary lesion. In cases in which the cause is uncertain, bacteriologic studies of the tissue should be employed, as often useful information which might otherwise escape detection may be obtained by this method.
Spondylometaphyseal dysplasia with cone‐rod dystrophy

The co-occurrence of ophthalmologic abnormality and intrinsic skeletal dysplasia is uncommon. We describe eight instances of a unique form of spondylometaphyseal dysplasia (SMD) associated with cone-rod dystrophy (although documentation is insufficient to be certain of that diagnosis in some). This is a new, syndromic form of SMD for which there is evidence for autosomal recessive transmission. Recognition of the specific bony features described here should precipitate comprehensive ophthalmologic assessment, since vision impairment becomes significantly disabling with age.
The Legacy and Logic of Research on the Identification of Gifted Persons.

Are we identifying the "truly gifted" student? How should we test the efficacy of our procedures? The authors assess research on the topics of defining and identifying exceptional potential. They propose three alternative criteria to intelligence test scores as the key criterion for identification.
The effects of therapeutic vs. high‐intensity ultrasound on the rabbit growth plate

Six of 6-week-old NZ rabbits underwent ultrasound treatment using a therapeutic dose (0.5 W/cm(2)) and other six were treated with a higher dose (2.2 W/cm(2)) to the lateral aspect of the left knee joint for 20 min per day and a total of six weeks. The right knee joint served as a control. The goal of this study is to see if the therapeutic dose and high dose (approximately 45-fold therapeutic dose) will have toxic effects on the physis. Histological review appeared normal growth plate in the therapeutic group. In the high dosage group three of six cases displayed flattening of the distal femoral epiphysis and wedging of the proximal tibial plateau and indistinct growth plate lines. It is of interest to note that there are opening radiolucent area in the lateral aspect on the femoral metaphysis in five of six cases, where bone resorption has taken place. Histological results showed that there are disordered arrays of the cartilaginous cells in the proliferative zone. The height of the lateral physis in the high dose group is not only greater than that in the therapeutic dose (1083.8 vs. 500.3 micro m), but also greater than that in their contralateral control (530.7 micro m) (P<0.05). This short-term study demonstrates that high dose ultrasound has profound pathologic effects in growing bone. Therapeutic doses of ultrasound do not have an adverse effect on bone growth in the short-term follow-up.
Local staging of prostate cancer by tumor volume, prostate-specific antigen, and transrectal ultrasound.

Abstract Conventional methods of staging prostate tumors are highly inaccurate. To improve clinical staging, prostate-specific antigen (PSA) levels (> 10 ng/mL), sonographic tumor volume (> 3 cc), maximum tumor diameter, length of capsular tumor abutment, and overall impression of capsular irregularity suggesting periprostatic tumor spread were assessed in 29 men prior to undergoing radical prostatectomy for clinically localized tumor. After surgery, 18 men had tumor confined to the prostate, while 11 men had histologic evidence of extracapsular disease. Analysis of the parameters measured showed these were the most helpful factors in predicting the presence of extracapsular disease. However, the positive and negative predictive values were only 70 to 90 percent. Therefore, the clinical usefulness of any one measurement alone in determining treatment for the individual patient is limited. However, combining these parameters yields an improved prediction of extracapsular disease. All 6 patients with PSA
PRACTICAL SAFETY CONSIDERATIONS FOR SHORT HEADWAY AUTOMATED TRANSIT SYSTEMS

Continued interest in Personal Rapid Transit (PRT) systems as one solution to urban traffic congestion emphasizes the need for careful consideration of the safety of short headway automated transit systems. Current approaches to the determination of safe headways are reviewed. The reduction in headway which could be achieved by improved braking and signaling hardware is outlined. Improved design of emergency brakes is the most important single factor in the reduction of safe headways. Very short headway systems are reviewed from a safety standpoint. Such systems might be safely operated if operation at intermediate headways (separations on the order of the stopping distance) can be avoided.
Comparative feeding ecology and habitats use of Crenicichla species (Perciformes: Cichlidae) in a Venezuelan floodplain river

Feeding behavior and habitat use of two species of pike cichlids, or mataguaros, (Crenicichla lugubris and C. aff. wallacii) were studied in the rio Cinaruco, a floodplain river in the Venezuelan llanos. We examined 309 individuals of C. lugubris and 270 individuals of C. aff. wallacii from both the main channel and lagoons throughout the falling-water phase of the annual hydrological cycle. Crenicichla lugubris was common within habitats that contained rocks or woody debris, whereas C. aff. wallacii was more abundant in lagoons than the main channel, especially within shallow areas containing leaf litter. Although we did not capture C. aff. wallacii in rocky shoals, they sometimes were observed in these habitats. Crenicichla lugubris was larger than C. aff. wallacii (198.4 mm and 44.6 mm, respectively). Analysis of stomach contents showed that larger specimens (> 100 mm SL) C. lugubris fed mostly on small fishes (e.g. characids, cichlids), but juveniles ( 100 mm CP) se alimentaram principalmente de peixes pequenos (e.g. caracideos e ciclideos), e os menores (< 100 mm CP) consumiram principalmente larvas aquaticas de insetos, escamas de peixes e camaroes. Crenicichla aff. wallacii se alimentou de insetos aquaticos e outros invertebrados associados ao folhico.
Analysis and finite element approximation of a coupled, continuum pipe-flow/Darcy model for flow in porous media with embedded conduits

We consider the continuum Darcy/pipe flow model for flows in a porous matrix containing embedded conduits; such coupled flows are present in, e.g., karst aquifers. The mathematical well-posedness of the coupled problem as well as convergence rates of finite element approximation are established in the two-dimensional case. Computational results are also provided.
Prospects for Development of an Index of Biotic Integrity for Evaluating Habitat Degradation in Coastal Systems

Abstract A multivariate index for assessment of habitat quality and its degradation, the Index of Biotic Integrity (IBI), has been developed for stream fish communities. the extension of the IBI concept to coastal waters is proposed by the development of an estuarine IBI based on macrobenthos and submerged aquatic vegetation. Eleven variables are proposed for inclusion in this index, although further consideration of the appropriateness of several variables is required. It is concluded that development of an IBI for coastal systems is feasible.
Correlations Destroy Acoustic Plasmons in Superlattices

It is demonstrated that interlayer correlations bring about important qualitative changes in the collective mode structure of superlattices, as compared to the random-phase-approximation predictions. The RPA acoustic plasmon is converted into an optic-like mode where the k = 0 long-wavelength frequency is a sensitive function of the strength of the interlayer correlations and of q, the wave number along the direction perpendicular to the layers. The result should motivate Raman measurements on GaAs/AlGaAs samples in parameter domains where the d/a ratio (d is the separation distance between adjacent layers, a the interparticle spacing within a layer) is of order unity and where rs > 2. On demontre que dans une structure formee de couches d'electrons a deux dimensions, le caractere des modes collectifs est profondement modifie par les correlations Coulombiennes entre les couches. En effet, a cause de ces correlations, le plasmon RPA acoustique se transforme dans un plasmon optique dont la frequence est une fonction sensible (i) de la force de correlations entre les couches et (ii) de q, le vecteur d'onde lelong de la direction perpendiculaire aux couches. Ce resultat doit motiver des experiences sur le systeme GaAs/AlGaAs cn domaines de parametres ou le rapport d/a (d est la distance de separation entre les couches voisines, a est le rayon Wigner-Seitz a I'interieure d'une couche) est de I'ordre de I'unite et ou rs > 2.
Significance of Glutathione in Lung Disease and Implications for Therapy

Glutathione is a tripeptide that contains an important thiol (sulfhydryl) group within the central cysteine amino acid. Glutathione is involved in numerous vital processes where the reducing potential of the thiol is used. Several lung disorders are believed to be characterized by an increase in alveolar oxidant burden, potentially depleting alveolar and lung glutathione. Low glutathione has been linked to abnormalities in the lung surfactant system and the interaction between glutathione and antiproteases in the epithelial lining fluid of patients. Normal levels of intracellular glutathione may exert a critical negative control on the elaboration of proinflammatory cytokines. The increase of intracellular reactive oxygen species is believed to correlate with the activation of NF-kappa B, a transcription activator linked to the elaboration of several cytokines. There is now sufficient data to strongly implicate free radical injury in the genesis and maintenance of several lung disorders in humans. This information is substantial and will help the development of clinical studies examining a variety of inflammatory lung disorders.
Complex Modulation of Cell Type-Specific Signaling in Response to Type I Interferons

The type I interferons (IFNs) are pleiotropic cytokines that regulate many different cellular functions. The major signaling pathway activated by type I IFNs involves sequential phosphorylation of the tyrosine residues of the Janus kinase (JAK) and signal transducers and activators of transcription (STAT) proteins, providing the primary mechanism through which gene expression is induced. Recent work has shown that the responses are quite complex, as shown by different responses to specific subtypes of type I IFN, activation of kinases in addition to JAKs, patterns of activation of all seven STATs in different cells, and activation of transcription factors other than STATs. The type I IFNs use this complexity to regulate many different biological functions in different types of cells, by activating different specific signals and patterns of gene expression.
Reproducibility of physiologic parameters obtained using functional computed tomography in mice

High-speed X-ray computed tomography (CT) has the potential to observe the transport of iodinated radio-opaque contrast agent (CA) through tissue enabling the quantification of tissue physiology in organs and tumors. The concentration of Iodine in the tissue and in the left ventricle is extracted as a function of time and is fit to a compartmental model for physiologic parameter estimation. The reproducibility of the physiologic parameters depend on the (1) The image-sampling rate. According to our simulations 5-second sampling is required for CA injection rates of 1.0ml/min (2) the compartmental model should reflect the real tissue function to give meaning results. In order to verify these limits a functional CT study was carried out in a group of 3 mice. Dynamic CT scans were performed on all the mice with 0.5ml/min, 1ml/min and 2ml/min CA injection rates. The physiologic parameters were extracted using 4 parameter and 6 parameter two compartmental models (2CM). Single factor ANOVA did not indicate a significant difference in the perfusion, in the kidneys for the different injection rates. The physiologic parameter obtained using the 6-parameter 2CM model was in line with literature values and the 6-parameter significantly improves chi-square goodness of fits for two cases.
An ephemeral sex pheromone in the urine of female house mice (Mus domesticus)

From previous research, the ultrasonic vocalizations of male mice (Mus domesticus) to female mouse urine were hypothesized to be learned as a result of classical conditioning during adult heterosexual encounters. According to this interpretation, a previously neutral conditioned stimulus in female urine comes to elicit vocalizations as a result of its association with some other unknown unconditioned stimulus associated with adult females. However, the research from which this hypothesis was derived utilized urine collected from females housed in metabolic cages. Three experiments further examined the classical conditioning hypothesis using two types of female urine: (i) metabolic-cage-collected urine and (ii) freshly voided urine. Experiment 1 demonstrated that, in contrast to vocalizations to metabolic-cage-collected urine, adult heterosexual experience was not necessary for males to vocalize to freshly voided female urine. In addition, unlike metabolic-cage-collected urine (Experiment 3), freshly voided urine remained a potent stimulus for eliciting vocalizations during repeated testing (Experiments 2 and 3). Finally, freshly voided urine appeared to cause a previously neutral stimulus (cotton swab) to acquire ultrasound eliciting properties (Experiment 2). We suggest from these findings that two chemosignals that elicit vocalizations from males may exist in female mouse urine: (i) a potent, but volatile or easily degraded, unconditioned stimulus to which males vocalize without sexual experience and (ii) a nonvolatile, chemically stable conditioned stimulus.
Interpenetrating polymer network of poly(vinyl chloride) and polymethacrylates

A curable polymeric composite was prepared using equal weights of poly(vinyl chloride) (PVC), reactive polyfunctional methacrylate monomers, and inorganic fillers. Peroxide initiated in situ polymerization of the polyfunctional methacrylate monomers in the PVC matrix produced an interpenetrating polymer network (IPN) structure. The polymerization kinetics and the degree of polymerization were investigated using differential scanning calorimetry (DSC), carbon-13 nuclear magnetic resonance (13C NMR), and solvent extraction. All measurements indicated that during polymerization, the PVC is either crosslinked by or grafted onto the methacrylate three-dimensional network structure. The rheological properties of the composite were measured before curing using a Rheometrics mechanical spectrometer and found to exhibit mainly viscous behavior and diminished elasticity. The PVC and the methacrylate monomers form a two-phase system when mixed at room temperature. However, when heated to 100°C the PVC dissolves in the monomers and forms a one-phase optically clear blend with a single glass transition temperature. In the presence of peroxide, the one-phase blend is stable and does not separate out upon cooling and storing at room temperature.
Arthroscopic Decompression for Impingement Syndrome Secondary to an Unstable Os Acromiale

Abstract Purpose: The purpose of this study was to examine cases of patients with impingement syndrome secondary to an unfused, unstable, os acromiale. Type of Study: Retrospective case series. Materials and Methods: Twelve consecutive patients (13 shoulders) presented with impingement symptoms in the presence of an os acromiale. The os acromiale, at the meso-acromion level, was seen on standard radiographs. The patients were all treated conservatively with rotator cuff strengthening, stretching, anti-inflammatory medications, and steroid injections. All patients underwent an impingement test with lidocaine, resulting in complete relief of their pain. After failure of the conservative management, the 12 patients (13 shoulders) underwent an extended arthroscopic subacromial decompression. The goal of the modified arthroscopic acromioplasty was resection of adequate bone to remove the mobile anterior acromial tip. In general, this consisted of more bony resection than the typical arthroscopic acromioplasty. Postoperatively, the patients began a rehabilitation program emphasizing early range of motion followed by isolated free-weight rotator cuff strengthening exercises. Five shoulders had a partial-thickness tear of the rotator cuff. Four involved less than 50% of the thickness of the rotator cuff. These 4 partial-thickness tears underwent arthroscopic rotator cuff debridement. One partial-thickness tear was greater than 50% and repair was performed with a mini-open deltoid-splitting technique. Results: Results were evaluated using UCLA shoulder scoring. Preoperatively, the score averaged 17. The 3-month postoperative score was 27, and at 6 and 12 months, averaged 28. The final follow-up score averaged 31. There were 11 satisfactory results with UCLA scores ≥28. Two unsatisfactory results showed UCLA scores in the fair category. Full strength of the anterior deltoid and rotator cuff muscles was achieved in all patients by 6 months postoperatively as evaluated by manual muscle testing. Twelve of the 13 shoulders were rated by the patients as having a satisfactory result. All of the patients rated their cosmetic results as acceptable. There was no evidence of postoperative deltoid detachment. No patient developed pain at the pseudarthrosis point. Conclusions: Given the previously reported poor results with attempts at fusion of an unstable os acromiale and open complete excision of meso-acromial fragments, the authors conclude that an extended arthroscopic subacromial decompression results in a reasonable outcome for patients with impingement syndromes secondary to an unstable os acromiale. Arthroscopy: The Journal of Arthroscopic and Related surgery, Vol 16, No 6 (September), 2000: pp 595–599
Brownian motion in cones

We study the asymptotic behavior of Brownian motion and its conditioned process in cones using an infinite series representation of its transition density. A concise probabilistic interpretation of this series in terms of the skew product decomposition of Brownian motion is derived and used to show properties of the transition density.
Change in Submission Procedure

HE TRANSACTIONS has finally discovered the World Wide Web. We knew it was there all along, but we politely tolerated its presence sort of the way an adult tolerates a cute but unruly child. Now, the child is grown, and our staid journal, in keeping with its proud tradition of nurturing innovation, welcomes the new kid into the enterprise. This is our way of saying, by means of simile, that the digital age has arrived at the TRANSACTIONS. Beginning on April 5 of this year, prospective authors will begin submitting their manuscripts via ScholarOne, which is formerly known as Manuscript Central. ScholarOne Manuscripts is a web-based submission and peer review workflow that offers authors, editors, and reviewers with Internet access an easy streamlined means for developing, submitting, reviewing, and revising manuscripts. The potential benefits of a web-based system I think are obvious. For authors, it offers a shorter “sub-to-pub” time. For editors and staff, it reduces administrative overhead. For the Editor-in-Chief, it provides for easier tracking of manuscripts through the editorial process and a tool for gathering and analyzing pertinent trends and statistics. For reviewers, it
Forecaster Workstation Design: Concepts and Issues

Abstract Some basic ideas about designing a meteorological workstation for operational weather forecasting are presented, in part as a complement to the recently published discussion of workstation design by R. R. Hoffman. Scientific weather forecasting is defined and used as a basis for developing a set of necessary structural capabilities in a workstation. These capabilities include: built-in excess capacity for flexibility, user-defined product menus, interactivity at the level of being able to change the data as well as analyzed fields, and a software suite of operators by which virtually any product can be custom built through concatenation of mathematically defined operations on any of the data resident within the workstation. The need for user involvement is stressed by showing an example of a real forecaster “workstation” that successfully provided most of these capabilities and, in contrast, by pointing out the flaws in the current National Weather Service operational workstation's development. I...
Preconditioned descent algorithm for rapid calculations of magnetohydrodynamic equilibria

Abstract Conjugate gradient descent algorithms have been used in several magnetohydrodynamic (MHD) equilibrium codes to find numerical minima of the MHD energy and thus to locate local stable equilibria. Numerical convergence studies with the spectral equilibrium code VMEC (variational moments equilibrium code) have shown that the number of descent iterations required to obtain a fixed level of convergence grows linearly with the number of radial mesh points. This undesirable mesh dependence is due to the quadratic dependence on the radial mesh spacing of the condition number for the linearized discrete MHD equations. By use of a preconditioning matrix to coalesce the eigenvalues of the linearized MHD forces around unity, it is possible to reduce the condition number substantially and thereby nearly eliminate the mesh size dependence of the convergence rate of the descent algorithm. An invertible, positive-definite tridiagonal preconditioning matrix is derived from the force equations used in VMEC, and the improvement in temporal convergence is demonstrated for several three-dimensional equilibria.