cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermal tolerance affects mutualist attendance in an ant-plant protection mutualism.

Mutualism is an often complex interaction among multiple species, each of which may respond differently to abiotic conditions. The effects of temperature on the formation, dissolution, and success of these and other species interactions remain poorly understood. We studied the thermal ecology of the mutualism between the cactus Ferocactus wislizeni and its ant defenders (Forelius pruinosus, Crematogaster opuntiae, Solenopsis aurea, and Solenopsis xyloni) in the Sonoran Desert, USA. The ants are attracted to extrafloral nectar produced by the plants and, in exchange, protect the plants from herbivores; there is a hierarchy of mutualist effectiveness based on aggression toward herbivores. We determined the relationship between temperature and ant activity on plants, the thermal tolerance of each ant species, and ant activity in relation to the thermal environment of plants. Temperature played a role in determining which species interact as mutualists. Three of the four ant species abandoned the plants during the hottest part of the day (up to 40 °C), returning when surface temperature began to decrease in the afternoon. The least effective ant mutualist, F. pruinosus, had a significantly higher critical thermal maximum than the other three species, was active across the entire range of plant surface temperatures observed (13.8–57.0 °C), and visited plants that reached the highest temperatures. F. pruinosus occupied some plants full-time and invaded plants occupied by more dominant species when those species were thermally excluded. Combining data on thermal tolerance and mutualist effectiveness provides a potentially powerful tool for predicting the effects of temperature on mutualisms and mutualistic species.
Early Thrombotic Stenosis of Aortic Bioprosthetic Valves: Report of Two Cases

Thrombotic stenosis of a Carpentier-Edwards porcine bioprosthesis occurred in two patients within 3 months after aortic valve replacement. Both patients underwent successful replacement of the aortic prosthesis. Although previously reported, this complication of aortic porcine bioprostheses is uncommon.
Low resolution meets high: towards a resolution continuum from cells to atoms

Abstract During the past five years, strategies have been developed for generating pseudo-atomic-resolution models of macromolecular complexes by combining the data from high-resolution structures of components with lower-resolution data for the entire complex.
Circulation to the head of barousaurus revisited: Theoretical considerations

Abstract Various means of driving blood to the head of the Barosaurus with a long neck have been postulated. The multiple hearts concept of Choy and Altman has not been received enthusiastically. We favor the siphon loop concept based on the interaction between viscous flow pressure (=QR) and the gravitational pressure (ϱgh). The actual pressure in all vessels of the head of the Barosaurus is calculated to have been negative. The notion that flow cannot occur under negative intravascular pressures in unjustified hemodynamiclly. The intracranial vessels are prevented from collapsing by the cerebrospinal fluid, which is also subjected to a similar negative pressure. The extracranial vessels can be prevented from collapsing by several possible means. (1) A very high aortic viscous flow pressure ( e.g. +740 mmHg) to counteract the negative gravitational pressure, assuming the gravitational zero pressure is at the level of the heart. (2) A relatively low aortic viscous flow pressure ( e.g. +300 mmHg) would result in a marked negativity in all the vessels of the head and neck, assuming the gravitational zero is at heart level. Collapse of these vessels may be prevented by thick vascular walls and dense connective tissue attached to a thick semirigid skin. (3) A relatively low aortic viscous flow pressure ( e.g. +300 mmHg) with gravitational zero at about the middle of the long neck would reduce the negativity of cranial vessels (as compared with the preceding model) and provide positive pressure for filling the thick-walled right ventricle.
Impact of Milieu Teaching on Communication Skills of Young Children with Autism Spectrum Disorder

This 5-month study examined the impact of a behaviorally based naturalistic teaching strategy, milieu teaching, on the communication skills of preschool-aged children with Autism Spectrum Disorder (ASD) in an early childhood special education (ECSE) classroom. A multiple baseline across participants design was used. Communication targets were selected based on each child’s Individualized Education Plan. Milieu teaching strategies were implemented in two activities per day per target. Generalization and maintenance effects were also determined. Results indicated that milieu strategies are an effective means of providing communication skills instruction for young children with ASD in an ECSE classroom.
Factors affecting distribution of airflow in a human tracheobronchial cast

Air velocity was measured at end airways of hollow replicate casts of the human tracheobronchial tree in order to determine the flow distribution within casts extending to 3 mm diameter airways. Measurements were made by hot-wire anemometry for constant inspiratory flow rates of 7.5, 15, 30 and 60 L.min-1. Average flow distribution among the lung lobes was as follows: right upper, 18.5%; right middle, 9.2%; right lower, 32.3%; left upper, 15.7%; and left lower, 24.3%. An empirical model derived from the experimental flow distribution data demonstrated the effect of various morphometric parameters of the hollow cast on the distribution of airflow. Airway cross-sectional area, branching angle and total path-length were found to have the greatest influence. As the tracheal flow rate decreased from 60 to 7.5 L.min-1, the influence of branching angle was reduced, while total path-length became more influential. These results provide evidence for the transition of flow regimes within the TB tree within normal physiological flow ranges.
Convergence of associational and commissural pathways on CA1 pyramidal cells of the rat hippocampus

Abstract The interaction of the commissural and associational systems to the CA1 region of the hippocampus was studied by recording extracellular field potentials and single unit activity in anesthetized rats. Associational fibers were activated by stimulating the stratum oriens of the CA1 region contralateral to recording: this stimulation activated the Schaffer collaterals by antidromically firing the pyramidal cells of the CA3 region on the side of recording. Commissural fibers were stimulated where they emerge from CA3 region. Both pathways excited both the basal and apical dendrites of the CA1 pyramidal cells. Commissural activation in stratum oriens was more efficient than associational path stimulation, while the opposite was seen in stratum radiatum. Responses elicited by associational path activation had their peak negativity 100–150 μm deeper in stratum radiatum than commissurally evoked responses. Both pathways were able to discharge pyramidal neurons. Both homonymous and heteronymous double pulse stimulation showed response facilitation. Simultaneous activation of both pathways induced a greater amplitude population spike than predicted by algebraic summation of the independent responses. Over 80% of the responsive CA1 cells could be fired by either pathway. These results show a considerable convergence of the commissural and associational pathways on CA1 pyramidal cells, although their predominant locus of excitation might be different.
A mitochondrial nuclease is modified in Drosophila mutants (mus308) that are hypersensitive to DNA crosslinking agents.

The mus308 mutants of Drosophila have previously been demonstrated to be defective in an enzyme that is designated Nuclease 3 (Boyd et al. 1990b). In this study that enzyme is shown to be present in mitochondria of both wild-type flies and embryos. Since the mus308 mutants are hypersensitive to DNA crosslinking agents, Nuclease 3 is potentially required for resistance of the mitochondrial genome to such agents. In support of this hypothesis, electron microscopic studies of mus308 mutant flies that had been exposed to nitrogen mustard revealed an increased frequency of mitochondrial abnormalities. Further investigation of the defect at the enzymological level revealed that the mutants possess a new nuclease activity that is apparently a modified form of the wild-type protein. In the earlier study, enzyme extracts from mus308 mutants were found to lack an enzyme with a pl of approximately 6.2. More precisely defined assay conditions in this study revealed the appearance of a new nuclease activity with a higher pI in extracts from mutants. This observation, together with the finding that only the normal enzyme form is present in heterozygous individuals, supports the hypothesis that the mus308 locus is not the structural gene for the enzyme. Rather, the mus308 gene product is necessary for Nuclease 3 to assume the lower pI. Nuclease 3 has been partially purified and characterized from wild-type embryos. Its activity is stimulated by Mg++ and ATP. Optimum activity is found at a pH of 5.5 and a NaCl concentration of 50–100 mM. Nuclease 3 exhibits a temperature optimum of 42°C and is insensitive to N-ethylmaleimide. The enzyme is probably membrane-associated because it exhibits a strong tendency to aggregate and detergent is required for full solubilization.
S UBCUTANEOUS E PINEPHRINE FOR O UT-OF -H OSPITAL T REATMENT OF A NAPHYLAXIS

(2002). S UBCUTANEOUS E PINEPHRINE FOR O UT-OF -H OSPITAL T REATMENT OF A NAPHYLAXIS. Prehospital Emergency Care: Vol. 6, No. 1, pp. 67-68.
Nonlinear Modeling and Theoretical Development of Tire Nonuniformity Induced Tangential Steering Wheel Vibrations

This paper describes a nonlinear modeling approach for a double wishbone suspension developed to investigate the nonlinear kinematics and dynamics in the closed, spatial kinematic chain configuration of the suspension. This model is linked to a nonlinear rack and pinion steering subsystem model in order to study the steering nibble (steering wheel rotational vibrations). The suspension mechanism is idealized as a four degree-of-freedom model for a power assisted rack and pinion steering system, with suspension members considered as rigid links and the bushings idealized as linear spring-damper elements. A system of relative coordinates is used in the suspension subsystem model to minimize the number of equations that would be necessary due to the large number of geometrical and kinematic constraints. The equations of motion for the analytical subsystem models are derived symbolically using Maple and solved numerically using Matlab. The results of simulation of the model subjected to a virtual Kinematics and Compliance (K&C) test are compared with the results generated by the developed ADAMS model based on the parameters obtained from a vehicle manufacturer subjected to the same virtual test. Based on the results of the virtual K&C tests and quasi static simulation of the ADAMS model and the analytical models of the vehicle suspension subsystem, the kinematics results match ADAMS model very closely.Copyright © 2005 by ASME
Infarct volume predicts critical care needs in stroke patients treated with intravenous thrombolysis

Introduction Patients receiving intravenous thrombolysis with recombinant tissue plasminogen activator (IVT) for ischemic stroke are monitored in an intensive care unit (ICU) or a comparable unit capable of ICU interventions due to the high frequency of standardized neurological exams and vital sign checks. The present study evaluates quantitative infarct volume on early post-IVT MRI as a predictor of critical care needs and aims to identify patients who may not require resource intense monitoring.
Understanding Facebook: Social Computing Isn't &#x2018;Just&#x2019; Social

By understanding how social network sites work, researchers can better assess their effects on different kinds of social interactions as well as the associated benefits and risks. The Web extra at http://youtu.be/_Dz9FR1Bf-U is a video interview with column editor John Riedl, who discusses the topics and writing styles that work best if you're interested in writing for the Social Computing column.
Acute hyponatremic dehydration

A 6-YEAR-OLI) Caucasian girl was admitted for the first time on July 2, 1963, because of shock developing on the day of admission. She had been in her usual state of good health until 6 days prior to admission when she developed fever, cough, and wheezing. The diagnosis of pneumonia was made by her private physician, and her symptoms abated after treatment with penicillin and erythromycin. Two days before admission she was again febrile and developed an erythematous rash that started on the face and spread to the trunk. She was again seen by her doctor who noted Koplik's spots and diagnosed rubeola. On the morning of admission she was found to be weak, cold, clammy, and cyanotic and was brought to the hospital. Physical examination revealed a temperature of 103 ~ F., a pulse rate of 120, a respiratory rate of 20, and a blood pressure of 50/0 ram. Hg. The patient appeared to be acutely ill, with pale, cold, clammy, and cyanotic extremities. She was normally developed. A maculopapular, somewhat hemorrhagic, noneonfluent eruption was noted over the face, neck, extremities, and trunk. Ecchymoses were present at the sites and previous injections. Hemorrhagic areas were present over the buecal mucosa and palate. The neck was supple, and there was no
Allocation of Attention Affects Perceived Heading Direction with Transparent Flow Fields

Transparent motion occurs whenever dynamic HUD or HMD symbology is overlaid on the scene available through the windscreen. Psychophysical research has shown that two-dimensional transparent motion can produce systematic errors in perceived motion direction. In two experiments, we examined: a) whether transparent radial expansion patterns that accompany observer motion and specify heading direction are subject to such errors, b) whether attentional allocation to different motion components affects these errors, and c) whether these errors can result in inappropriate control input. We found that significant errors in perception of heading direction do occur for transparent radial expansion patterns, that attentional allocation influences these errors, and that these errors result in inappropriate control input.
Completion of the FM-1 Machine

The Princeton Floating Multipole Machine, FM-1, has been assembled, and some tests have been performed. The device contains a 60-inch diameter superconducting ring and will be operated as a spherator. The assembly will be described with several unusual features of this new machine. Details of the unique components are presented in other papers of this conference.
Laboratory, Greenhouse, and Field Assessment of Fourteen Fungicides for Activity Against Claviceps africana, Causal Agent of Sorghum Ergot

ABSTRACT Commercial formulations of 14 fungicides representing seven chemical classes were assessed in vitro and in vivo for activity against Claviceps africana, causal agent of sorghum ergot. All fungicides markedly reduced spore germination in vitro on water agar, with effective concentration (EC)50 values (based on active ingredient) that ranged from 0.01 μg ml-1 for thiophanatemethyl and trifloxystrobin to 1.18 μg ml-1 for cyprodinil. In vivo assays included applications of fungicide on full bloom panicles of a male-sterile line, ATx623, and then inoculating panicles with a conidial suspension immediately after the fungicide had dried. In greenhouse trials and in the 2000 field evaluation, a single application of propiconazole, tebuconazole, triadimefon, myclobutanil, or azoxystrobin at a rate of 25 μg ml-1 markedly suppressed ergot severity on ATx623. In the 2001 field evaluation, tebuconazole applied at 25 μg ml-1 was most effective in reducing levels of ergot severity. Ergot control was greater whe...
Curative local therapy of rectal cancer.

When many if not most of us surgeons began practice, there were few options in the treatment of rectal cancer. Lesions above the level of the palpating finger on digital rectal examination could be reasonably managed by resection with anastomosis. Lesions within reach of the finger would be treated by Miles' resection. Advanced lesions or those occurring in poor-risk patients would be subjected to the uncertainties of external beam radiotherapy, rarely achieving more than a modest amount of palliation. The notion of local treatment was somewhat of a "new thing" despite the published work of those, such as Strauss [1], who were experienced with this modality. It has been stated that little has been achieved in improvement to survival rates over the past 2 to 3 decades for patients with rectal cancer. Yet we have witnessed the increasing role of sphincter-saving operations for lesions previously considered beyond the scope of these modalities, as adequacy of margins has been revised, emphasizing more the lateral and mesorectal clearance and less the distal margins [2, 3]. The focus towards colostomy avoidance and quality of life issues has carried over to the revisiting of the role of local treatment of rectal cancer. The advantages of local treatment are clear. The patient is spared: a colostomy, a major operation with all the attendant risks of a Miles' procedure; a long time away from work or social activities; and in most cases, significant expense. These notwithstanding, surgeons have been reluctant to advocate local treatment, mainly due to the uncertainties of preoperative staging techniques for rectal cancer. Yet increasing information and technology have emerged in the past decade that allow for increasingly informed use of local treatment modalities for selected patients with rectal cancer.
Neither Cargo Nor Cult: Ritual Politics and the Colonial Imagination In FIJI

Neither Cargo Nor Cult: Ritual Politics and the Colonial Imagination In FIJI. MARTHA KAPLAN. Durham, NC and London: Duke University Press, 1995. xviii + 226 pp., figures, bibliography, index.
Germanium nanowire growth below the eutectic temperature

Nanowires are conventionally assumed to grow via the vapor-liquid-solid process, in which material from the vapor is incorporated into the growing nanowire via a liquid catalyst, commonly a low-melting point eutectic alloy. However, nanowires have been observed to grow below the eutectic temperature, and the state of the catalyst remains controversial. Using in situ microscopy, we showed that, for the classic Ge/Au system, nanowire growth can occur below the eutectic temperature with either liquid or solid catalysts at the same temperature. We found, unexpectedly, that the catalyst state depends on the growth pressure and thermal history. We suggest that these phenomena may be due to kinetic enrichment of the eutectic alloy composition and expect these results to be relevant for other nanowire systems.
Acid sensitivity and water chemistry correlates of amphibian breeding ponds in northern Wisconsin, USA

Fifty-one amphibian breeding sites in northern Wisconsin were sampled in two surveys, in 1986 and 1987, to determine the chemical conditions and amphibian inhabitants present. All twenty-one ponds in 1986 and twenty-eight in 1987 were mildly acidic and sensitive to acidification. The pH levels encountered were generally not toxic to the resident amphibians, and may have been related to levels of phenolics in some cases. Soil type and forest canopy coverage appeared to influence the chemistry of these ponds and a direct relationship of amphibian species richness with pond size was found. Only larger ponds were long-lived enough for metamorphosis of amphibian larvae, suggesting an importance for recruitment. They were also the most sensitive ponds and the only ones to enter the chronically toxic pH range for ambystomatid salamanders, possibly placing them at risk to future acid inputs.
Marketing actions that influence estimates of others also shape identity

Consumers' social identities stem from comparisons between themselves and others. These identities help determine consumption decisions. Unfortunately, perceptions of comparative traits and characteristics are frequently biased, which can lead to similarly biased consumption decisions. Five studies show that two incidental but commonplace marketing decisions can influence consumers' estimates of their relative standing and thus their social identities by influencing estimates of how other consumers are distributed.
Interactive effects of ambient ozone and climate measured on growth of mature forest trees

GLOBAL increases in concentrations of tropospheric ozone are of worldwide concern because of its potential to affect both human and ecological health1. Ozone has been implicated in the declining health of some forest tree species2,3 because of its effects on many growth-related processes in controlled studies3–5. Despite strong evidence that growth of forest tree seedlings can be reduced by ambient levels of ozone6, there has been little basis for evaluating the threshold and magnitude of direct effects on growth of mature, economically important forest trees. We describe here a five-year study of serial changes in stem circumference of 28 mature loblolly pine (Pinus taeda L.) trees. This study has defined a rough ozone response threshold and quantified short- and longer-term components of growth responses to varying ozone and climate variables. Ozone exposures at ≩40 nl 1−1 interacted with low soil moisture and high air temperatures to reduce short-term rates of stem expansion. Annual growth was also inversely related to seasonal ozone exposure and soil moisture stress. Effects varied widely between individual trees and years. Future ozone effects on forests are likely to be influenced by climate change and by projected increases in regional ozone pollution in industrialized countries.
Use of variational techniques for the estimation of neutron detection efficiency

The neutron detection efficiency is a parameter required in the measurement of reactivity by the modified source technique. The direct solution of the detection efficiency at a perturbed state is costly. To solve for this, a particular variational functional, the Lewins' type variational functional, is presented. The functional is a ratio of two other functionals, each dealing with a reaction rate. The evaluation of this particular functional was done by treating the numerator and the denominator functionals separately. This leads to three flux equations, one for forward flux, and two for adjoint fluxes. The advantages of this formulation over, and the equivalence of this formulation to, the conventional functional presented in the literature are described in detail. The flexibility of the proposed functional is demonstrated by using it to estimate the detection efficiency with four different methods: variational interpolation, conventional variational, variational extrapolation, and multi- reference-state variational. Results are presented for one-dimensional and two- dimensional problems. All results are compared with direct calculations. In all cases, the results show that the variational interpolational method and the multi- reference-state variational method are efficient and practically acceptable.
Separation of p-xylene from multicomponent vapor mixtures using tubular MFI zeolite mmbranes

Abstract MFI zeolite membranes have been synthesized on tubular α-alumina substrates to investigate the separation of p -xylene (PX) from m -xylene (MX) and o -xylene (OX) in binary, ternary, and simulated multicomponent mixtures in wide ranges of feed pressure and operating temperature. The results demonstrate that separation of PX from MX and OX through the MFI membranes relies primarily on shape-selectivity when the xylene sorption level in the zeolite is sufficiently low. For an eight-component mixture containing hydrogen, methane, benzene, toluene, ethylbenzene, PX, MX, and OX, a PX/(MX + OX) selectivity of 7.71 with a PX flux of 6.8 × 10 −6 mol/(m 2 s) was obtained at 250 °C and atmospheric feed pressure. The addition of a small quantity of nonane to the multicomponent mixture caused drastic decreases in the fluxes of aromatic components and the PX separation factor because of the preferential adsorption of nonane in the zeolite channels. The nanoscale intercrystalline pores also caused serious decline in the PX separation factor. A new method of online membrane modification by carbonization of 1,3,5-triisopropylbenzene in the feed stream was found to be effective for reducing the intercrystalline pores and improving the PX separation.
On the cavalier attitude towards referencing

Abstract This short note concerns the cavalier attitude that seems to be prevalent now with regard to checking the accuracy of the references that are provided in research publications. Daunting difficulties confront, at times, those trying to check a source, especially when the source is several centuries old and/or in a language that the researcher is not conversant with. Compounding the problem further, at times, are insuperable difficulties with regard to deciding whom or what to accept as proper authority in the attribution of citations, nudging those that are not of sterner stuff to take the easy way out and conform to popular opinion that might be incorrect. In this short note I discuss the difficulties that a researcher might face with regard to proper attribution of ideas.
Plants tackle explosive contamination.

Another toxic explosive is now amenable to phytoremediation, but the political will to implement this technology remains in doubt.
Intracellular functions of galectins

Many galectin family members are detected primarily intracellularly in most of the systems studied, although certain members can be found both inside and outside of cells. Specific functions that are consistent with their intracellular localization have now been documented for some of the galectins. Galectin-1 and -3 have been identified as redundant pre-mRNA splicing factors. Galectin-3, -7, and -12 have been shown to regulate cell growth and apoptosis, being either anti-apoptotic or pro-apoptotic. Galectin-3 and -12 have been shown to regulate the cell cycle. In some cases, the mechanisms by which galectins exert their functions have been partially delineated in relation to known intracellular pathways associated with these processes. In addition, a number of intracellular proteins involved in these processes have been identified as the interacting ligands of certain galectins. This review summarizes the intracellular activities displayed by several galectins and discusses the possible underlying mechanisms.
Self-weakening in lithiated graphene electrodes

Abstract We present a molecular dynamics study of the fracture mechanisms of lithiated graphene. Our modeling results reveal that lithium diffusion toward the crack tip is both energetically and kinetically favored owing to the crack-tip stress gradient. The stress-driven lithium diffusion results in lithium aggregation around the crack tip, chemically weakening the crack-tip bond and at the same time causing stress relaxation. Our simulations show that the chemical weakening effect is the dominant factor, which manifests a self-weakening mechanism in lithiated graphene. The atomistic understanding of the degradation mechanism provides guidance for the lifetime extension in the design of graphene-based electrodes.
Schistocytosis and a thrombotic microangiopathy-like syndrome in hospitalized HIV-infected patients

Approximately 150 human immunodeficiency virus (HIV)-infected patients with a thrombotic microangiopathy (TMA)-like syndrome have been reported in the literature since the early 1980s. The prevalence of a TMA-like syndrome in our hospitalized patients was determined to discern whether it is a more common occurrence than previously recognized and, if possible, to delineate risk factors for its occurrence. A total of 350 patients admitted consecutively to the Johns Hopkins Hospital HIV inpatient service were assessed from May 1, 1996 through February 1, 1997. These patients were evaluated for the presence of anemia, thrombocytopenia, fragmented erythrocytes on peripheral blood smear (schistocytosis), renal dysfunction, neurologic dysfunction, and fever. The association of a TMA-like syndrome with demographic and clinical factors was analyzed. Schistocytosis was present in 24% of the patients and a TMA-like syndrome (anemia, thrombocytopenia, schistocytosis + renal dysfunction or neurologic dysfunction, and fever) was present in 7% of the patients. The patients who had a TMA-like syndrome were more likely to have a low CD4 lymphocyte count or CD4 percentage, Centers for Disease Control and Prevention stage C disease, and have bacterial sepsis. Age, race, HIV risk group, other diagnoses, and prescribed drugs were not associated. Patients were more likely to die if they had a TMA-like syndrome, independently of level of immunosuppression. Schistocytosis and a TMA-like syndrome are relatively common in hospitalized HIV-infected patients. This syndrome may contribute to mortality and morbidity, particularly in patients with more advanced disease. Am. J. Hematol. 60:116–120, 1999. © 1999 Wiley-Liss, Inc.
Diagenesis by Kohout Convection in Carbonate Platform Margins: ABSTRACT

Kohout convection is a large-scale, long-lived ground-water flow system in the margins of steep-sided active carbonate platforms. It was first postulated to occur in the subsurface of Florida by Francis Kohout in the 1960s. The flow is driven by buoyancy arising from subsurface differences in salinity, temperature, or both. Temperature differences alone drive Kohout convection in isolated platforms. Cold, dense seawater surrounding a platform at depth migrates inward, displacing warmer pore waters at the same elevation. This inflowing density current is, in turn, warmed within the platform and is buoyed upward to discharge on the platform shelf or margin. The result is a giant convective "half-cell" of circulating seawater occupying the platform margin. In carbonate shelv s, where regional meteoric ground-water flow may be present, the meteoric water mixes by dispersion with the convecting seawater, resulting in an increase of buoyancy enhancing the flow rate. Kohout convection may be modeled by systems of differential equations governing the fluid flow, heat transfer, and dispersive mass transfer. Approximate analytical and numerical solutions of these equations in the isolated platform setting show the effects of platform margin geometry and subsurface permeability on flow rates and flow patterns of Kohout convection. Kohout convection may be an important agent of mesogenetic diagenesis because it affects rocks deeply buried in a stratigraphic sense. Porosity may be developed and modified by dissolution by inflowing seawater undersaturated with respect to calcium carbonate phases, by cementation as the seawater warms and rises, and by dolomitization (if possible in these waters), leading to reservoir conditions in platform margins. End_of_Article - Last_Page 1430------------
HIV-associated chronic immune activation: current understandings and therapeutic intervention

The mechanisms by which HIV causes AIDS remain poorly understood. However, the generalized immune dysfunction associated with progressive HIV infection is clearly related to the levels of immune activation, which results in increased target cells for the virus, excessive apoptosis of uninfected T cells and, paradoxically, an impaired ability to control HIV replication. The causes of this chronic, aberrant immune activation are complex and are the consequences of both virus replication and the resultant immune damage and dysfunction. Of note, natural SIV hosts, which do not progress to AIDS despite lifelong infection, do not show chronic immune activation. Here we discuss the causes and consequences of the HIV-associated chronic immune activation, and potential therapeutic approaches to lower its impact.
Testosterone Inhibits Adipogenic Differentiation in 3T3-L1 Cells: Nuclear Translocation of Androgen Receptor Complex with β-Catenin and T-Cell Factor 4 May Bypass Canonical Wnt Signaling to Down-Regulate Adipogenic Transcription Factors

Testosterone supplementation in men decreases fat mass; however, the mechanisms by which it inhibits fat mass are unknown. We hypothesized that testosterone inhibits adipogenic differentiation of preadipocytes by activation of androgen receptor (AR)/beta-catenin interaction and subsequent translocation of this complex to the nucleus thereby bypassing canonical Wnt signaling. We tested this hypothesis in 3T3-L1 cells that differentiate to form fat cells in adipogenic medium. We found that these cells express AR and that testosterone and dihydrotestosterone dose-dependently inhibited adipogenic differentiation as analyzed by Oil Red O staining and down-regulation of CCAAT/enhancer binding protein-alpha and -delta and peroxisome proliferator-activated receptor-gamma2 protein and mRNA. These inhibitory effects of androgens were partially blocked by flutamide or bicalutamide. Androgen treatment was associated with nuclear translocation of beta-catenin and AR. Immunoprecipitation studies demonstrated association of beta-catenin with AR and T-cell factor 4 (TCF4) in the presence of androgens. Transfection of TCF4 cDNA inhibited adipogenic differentiation, whereas a dominant negative TCF4 cDNA construct induced adipogenesis and blocked testosterone's inhibitory effects. Our gene array analysis indicates that testosterone treatment led to activation of some Wnt target genes. Expression of constitutively activated AR fused with VP-16 did not inhibit the expression of CCAAT/enhancer binding protein-alpha in the absence of androgens. Testosterone and dihydrotestosterone inhibit adipocyte differentiation in vitro through an AR-mediated nuclear translocation of beta-catenin and activation of downstream Wnt signaling. These data provide evidence for a regulatory role for androgens in inhibiting adipogenic differentiation and a mechanistic explanation consistent with the observed reduction in fat mass in men treated with androgens.
Toxic psychosis: An unusual presentation of propranolol intoxication

Timely diagnosis of acute propranolol intoxication requires a high index of suspicion and a knowledge of the multiple ways in which thses patients may present to the emergency department. We report a case of severe propranolol intoxication that presented as an acute psychotic episode preceding cardiovascular decompensation and seizures by several hours. Though acute reversible psychosis has been appreciated after initiating or increasing propranolol dosage therapeutically, this association has not been reported in the literature regarding beta blocker overdose or intoxication. Propranolol psychosis and several other pertinent aspects of this case are discussed.
Thermal Noise Imaging Indicates a New Regime of Length-Dependent Persistence Length in Microtubules

Microtubules perform a diverse set of essential functions within the cell. Most of these functions are mechanical and, therefore, their mechanical properties and the extent to which these properties are tunable are of wide interest. It is known that the persistence length of microtubules depends on factors, such as type and concentration of associated proteins, binding of stabilizers, and their length. We present a new method for measuring microtubule persistence length using a recently developed technique known as three-dimensional thermal noise imaging. Thermal noise imaging is a three-dimensional scanning probe technique capable of probing soft matter at physiological conditions on the nanometer scale. Transverse fluctuations of microtubules have been imaged with thermal noise imaging, and subsequent analysis reveals mechanical properties of the filaments. A novel assay that allows for the isolation of single, grafted microtubules provides a method for measuring the persistence length of microtubules for contour lengths as small as 500 nm. Such a length regime has proven difficult to study using other techniques. We present data that indicates a length regime of microtubules in which the persistence length is significantly smaller than has been measured in longer filaments.
Persulfate‐initiated polymerization of acrylamide

A dilatometric technique was used to obtain conversion–time data for the polymerization of acrylamide initiated by potassium persulfate in water. The results are summarized by the empirical rate expression, −d[M1]/dt = Rp = k1.25[K2S2O8]0.5[M1]1.25, and k1.25 = 1.70 × 1011 exp {−16,900/RT} 1.0.75/mole−0.75-min. Persulfate was varied over the range 9.5 × 10−4 to 5.2 × 10×2 mole/l., and initial monomer concentration [M1] was varied from 0.05 to 0.4 mole/l. The temperature range was 30−50°C. Results of analysis of the kinetics and energetics of the polymerization favor a cage-effect theory rather than a complex-formation theory to explain the order with respect to monomer.
Spread of Creutzfeldt-Jakob disease virus along visual pathways after intraocular inoculation

We studied the targeting of spongiform lesions within the visual pathways after intraocular injection with the Fujisaki strain of Creutzfeldt-Jakob disease (CJD) virus. The first lesions were observed 18 weeks postinoculation in the most superficial layer of the superior colliculus and in the lateral geniculate body contralateral to the side of the inoculation. Asymmetrical lesions in the superior colliculus were found also in mice sacrificed at 19, 22, and 27 weeks postinoculation. These results demonstrate that CJD virus spreads within the CNS via central axons of the visual pathways following intraocular inoculation.
Bending of work-hardening metals under the influence of axial load

Abstract Stretch-forming operations, where bending moment and axial load are applied simulataneously to a work-hardening material, are widely used for the fabrication of airframe and automotive structural components. Determination of the combinations of axial load and bending moment to produce a given deformation is an important industrial problem, not only to achieve the desired shape, but also to select the appropriate machines to produce this shape. Elastic—fully plastic analysis of bending of beams under the influence of axial load is presented for work-hardening material where the stress—strain relationship is given by σ = K ϵ n . The variation of the applied bending moment with the axial force for the fully elastic, elastic—plastic, and fully plastic cases is given both in analytical and graphical form. Results for the case when n = 0 and those reported by Johnson and Yu (J. Mech. Work. Tech., 6 (1982) 5) for elastic—perfectly plastic (non-workhardening) material are compared.
How Therapists' Conceptual Perspectives Influence Early Intervention Evaluations

Portions of this paper were presented at The Occupational Science Symposium X, March 21, 1997, University of Southern California, Los Angeles, California. Occupational scientists are committed to developing a rich understanding of how occupation is enacted and how that knowledge can be used by occupational therapists to inform their work with patients. This paper describes two different practice perspectives that were used during the evaluation process in a pediatric setting. This type of description provides an understanding of how the occupational therapists framed their approach to the evaluation encounter and constructed their actions and behaviors in order to successfully enact the approach. In these ways the therapists reflected their understanding of their occupation. Four therapists were followed using a qualitative inquiry while they conducted the evaluations. Findings indicated that therapists approaches were representative of two distinct models, either medical or occupation based. The language...
Magnetic resonance imaging-directed stereotactic endoscopic third ventriculostomy.

Third Ventriculostomy has been proposed as the procedure of choice for many patients with acquired obstructive hydrocephalus. Various techniques have been used to perform this procedure. This report describes the use of magnetic resonance images to guide the performance of a stereotactic third ventriculostomy with a rigid endoscope, allowing continuous direct visualization. This procedure has been performed on three patients, yielding clinical improvement without the need for extracranial shunting. Magnetic resonance imaging allows accurate identification of the important anatomical landmarks (i.e., foramen of Monro and interpeduncular cistern), with axial, coronal, and sagittal images, and is readily used in conjunction with the Cosman-Roberts-Wells stereotactic apparatus.
Evaluation of the Cytotoxic Potential of Catechols and Quinones Structurally Related to Butylated Hydroxyanisole

The cytotoxicity of 2- and 3-butylated hydroxyanisole (BHA) and 18 related aromatic compounds has been determined employing cultured P388 and KB cells. The phenolic compounds, 3-BHA and 2-BHA, had moderately low cytotoxic activity. Their corresponding catechols had ED50 values that were much lower than those of the parent compounds. This substantial increase in the cytotoxic activity is attributed to the presence of the catechol group, which is known to undergo one-electron oxidation readily to give the corresponding semiquinone radical. Other related catechols had similar cytotoxic activity. In general, derivatization of the catechol functionality resulted in a decrease of the cytotoxic potential of the compounds. Monoacetylation or monomethylation of the catechols gave products that were less potent cytotoxic agents than the parent compounds. Further loss of activity was observed when both hydroxy groups of the catechol function were blocked. Substitution of a methoxy group in place of a hydrogen atom in these compounds resulted in a significant increase of cytotoxicity, whereas the replacement of a methoxy group with a methyl group reduced the cytotoxicity. The catechols and quinones derived from 2-BHA were more active when compared with those derived from 3-BHA. The t-butyl group adjacent to the catechol or quinone moiety in the 3-BHA derivatives appeared to exert a significant steric effect toward the cytotoxic potential of these compounds. These results suggest the potential use of o-quinones and catechols as cytotoxic and antitumor agents.
On a class of additive learning models: Error-correcting and probability matching

Abstract A general model for learning signal detection in a Yes-No task is considered in which (a) the decision criterion shifts upward and downward by equal steps, and (b) the probability that the criterion shifts on a trial depends on the stimulus-response pair on that trial. Conditions are given for this process to have a unique stationary distribution, and the behavior of the process, as the step-size decreases to zero, is studied. The special model where criterion shifts may occur only on error trials can account for the probability matching behavior and for the interaction between signal strength and signal probability typically observed when the payoff matrix is symmetrical. Further, when the shift probability is assumed to be an increasing function of the distance of the sensory input from the criterion, the stationary mean criterion values are less extreme than the values that yield probability matching. It is shown that the model provides a way of incorporating payoff matrix asymmetry. Finally, the standard error in the maximum likelihood parameter estimates is calculated and a statistic is proposed for discriminating the error-correcting model from the more general model.
From the draining lymph node to the liver: the induction and effector mechanisms of malaria-specific CD8+ T cells

Parasitic protozoa cause considerable disease in humans and, due to their intracellular life cycle, induce robust CD8(+) T cell responses. A greater understanding of the factors that promote and maintain CD8(+) T cell-mediated immunity against these pathogens is likely needed for the development of effective vaccines. Immunization with radiation-attenuated sporozoites, the infectious stage of the malaria parasite transmitted by mosquitoes, is an excellent model to study these questions as CD8(+) T cells specific for a single epitope can completely eliminate parasite infection in the liver. Furthermore, live, radiation-attenuated parasites represent the "gold standard" for malaria vaccination. Here, we will highlight recent studies aimed at understanding the factors required for the induction, recruitment, and maintenance of effector and memory CD8(+) T cells against malaria liver stages.
Observation of backward η production

Abstract The production of η mesons has been observed at high momentum transfer in the reaction π − p → n η . The ratio between this cross-section and that for backward charge exchange yields a value for the relative couplings g 2 η NN g 2 π NN .
Fast, Efficient Floating-Point Adders and Multipliers for FPGAs

Floating-point applications are a growing trend in the FPGA community. As such, it has become critical to create floating-point units optimized for standard FPGA technology. Unfortunately, the FPGA design space is very different from the VLSI design space; thus, optimizations for FPGAs can differ significantly from optimizations for VLSI. In particular, the FPGA environment constrains the design space such that only limited parallelism can be effectively exploited to reduce latency. Obtaining the right balances between clock speed, latency, and area in FPGAs can be particularly challenging. This article presents implementation details for an IEEE-754 standard floating-point adder and multiplier for FPGAs. The designs presented here enable a Xilinx Virtex4 FPGA (-11 speed grade) to achieve 270 MHz IEEE compliant double precision floating-point performance with a 9-stage adder pipeline and 14-stage multiplier pipeline. The area requirement is approximately 500 slices for the adder and under 750 slices for the multiplier.
Optimal Signature Design for Spread-Spectrum Steganography

For any given host image or group of host images and any (block) transform domain of interest, we find the signature vector that when used for spread-spectrum (SS) message embedding maximizes the signal-to-interference-plus-noise ratio (SINR) at the output of the corresponding maximum-SINR linear filter. We establish that, under a (colored) Gaussian assumption on the transform domain host data, the same derived signature minimizes host distortion for any target message recovery error rate and maximizes the Shannon capacity of the covert steganographic link. Then, we derive jointly optimal signature and linear processor designs for SS embedding in linearly modified transform domain host data and demonstrate orders of magnitude improvement over current SS steganographic practices. Optimized multisignature/multimessage embedding in the same host data is studied as well