cssi/SciSciGPT-SciSciNet huggingface dataset:
Escherichia coli Membranes Depleted of SecYEG Elicit SecA-Dependent Ion-Channel Activity but Lose Signal Peptide Specificity

We have developed a sensitive method to detect the opening of SecA-dependent, protein-conducting channels in Xenopus oocytes. In this study, we determined the ionic current activities of the SecA-dependent channel from membrane vesicles depleted of SecYEG. We found that these SecYEG-depleted membranes produced SecA-dependent ionic currents in the oocytes, as did membranes containing SecYEG. However, reconstituted membranes depleted of SecYEG required higher concentrations of SecA to elicit ionic currents like those in membranes containing SecYEG. In contrast to membranes containing SecYEG, the proofreading capacity of signal peptides was lost for those membranes lacking SecYEG. These findings are consistent with loss of signal peptide specificity in channel activity from membranes of SecY suppressor or SecY plug domain mutants. The signal peptide specificity of the reconstituted membranes, like SecA-liposomes, can be restored by the addition of SecYEG proteoliposomes. On the other hand, the channel activity efficiency of reconstituted membranes was fully restored, while SecA-liposomes could only be partially enhanced by the addition of SecYEG, indicating that, in addition to SecYEG, other membrane proteins contribute to the efficiency of channel activity. The SecA-dependent channels in membranes that lacked SecYEG also lost ion selectivity to monovalent cations but retained selective permeability to large anions. Thus, the electrophysiological evidence presented here indicates that SecYEG is not obligatory for the channel activity of Escherichia coli membranes, as previously shown for protein translocation, and that SecYEG is important for maintenance of the efficiency and specificity of SecA-dependent channels.
Standard oxygen consumption of seasonally acclimatized cownose rays, Rhinoptera bonasus (Mitchill 1815), in the northern Gulf of Mexico.

Standard oxygen consumption rate (MO2) was determined for 19 cownose rays (Rhinoptera bonasus) using flow-through respirometry. Rays ranged in size from 0.4 to 8.25 kg (350–790 mm DW). Respirometry experiments were conducted on seasonally acclimatized rays at temperatures from 19.0 to 28.8 °C. Estimates of mass-dependent MO2 ranged from 55.88 mg O2 kg−1 h−1 for an 8.25 kg ray to 332.75 mg O2 kg−1 h−1 for a 2.2 kg animal at 22−25°C. Multiple regression analysis examining the effect of temperature, salinity, and mass on standard mass-independent MO2 found temperature (P 0.05). Q10 was calculated as 2.33 (19–28 °C), falling between the estimates determined for two other batoid species, the bull ray (Myliobatos aquila; Q10 = 1.87) and the bat ray (Myliobatis californica; Q10 = 3.00). The difference in the Q10 estimates may be attributed to the use of seasonally acclimatized as opposed to laboratory-acclimated animals.
Principals and Counselors Collaborative Roles in Reducing Teacher Stress

Principals and counselors, working together, can prevent stress and burnout in teachers. The result-a healthier school climate.
Maximum Entropy Inference and Stimulus Generalization

Abstract Maximum entropy inference is a method for estimating a probability distribution based on limited information expressed in terms of the moments of that distribution. This paper presents such a maximum entropy characterization of Shepard's theory of generalization. Shepard's theory assumes that an object has an important consequence for an individual only if it falls in a connected set, called the consequential region, in the individual's representational space. The assumption yields a generalization probability that decays exponentially with an appropriate psychological distance metric—either the city-block or the Euclidean, depending on the correlational structure between extensions of the consequential region along the dimensions. In this note we show that a generalization function similar to that derived by Shepard (1987) can be obtained by applying maximum entropy inference on limited information about interstimulus distances between two objects having a common consequence. In particular, we show that different shapes of equal generalization contours may be interpreted as optimal utilization—in the maximum entropy sense—of the correlation structure of stimulus dimensions, similar to the explanation by Shepard's theory.
Relationships Between Maternal Immunity to Herpes Simplex Virus and the Risk of Neonatal Herpesvirus Infection

Current seroepidemiologic studies performed with assays that measure type-specific antibodies to herpes simplex virus (HSV) type 2 have demonstrated that infection due to the virus is common among women of child-bearing age. With regard to perinatal transmission of HSV, the virus infects nearly 50% of infants whose mothers have primary genital herpes, whereas less than 5% of infants exposed to recurrent maternal infection at the time of delivery become infected. Maternal immunity may also influence the clinical manifestations of neonatal herpes, with primary maternal infection more likely to be associated with disseminated disease in the infant. An effective HSV vaccine could alter the prevalence of neonatal herpes by (1) reducing women's risk of acquiring primary genital herpes during pregnancy and (2) boosting immunity in mothers for whom serologic evidence of previous infection due to HSV type 2 has been noted, which will enhance the transplacental transfer of virus-specific antibodies.
The effects of a multicomponent smoking cessation program with chronic obstructive pulmonary disease outpatients.

Abstract While a number of multicomponent treatments have been utilized to control smoking, many of these are not suitable for some populations such as chronic obstructive pulmonary disease (COPD) patients because they consist of aversion procedures which can stress the body's cardiovascular system. Little research has been published regarding nonaversive approaches to smoking control in a COPD patient population. This study examined the long-term effects of a nonaversive multicomponent smoking cessation program consisting of brand fading and stimulus cintrol with a COPD outpatient populatio as measured by self-report. Using four COPD outpatients, this study employed a multiple baseline design across subjects for a visual analysis of treatment effects. At 3- and 6-month follow-up, one subject had quit smoking. Two subjects who continued to smoke reduced their smoking frequency and drastically reduced their nicotine intake by brand fading to a cigarette containing lower amounts of nicotine. A fourth subject returned to her original brand of cigarettes, although she reduced her smoking frequency. Collaborators and measurements of thiocyanate levels were used as reliability checks on subjects′ self-report.
Mass transfer to droplets formed by the controlled breakup of a cylindrical jet—physical absorption

Abstract A novel experimental system, well suited for mass transfer studies in liquids dispersed as droplets in a gas, was constructed. This system produces monodisperse droplets by the controlled breakup of a cylindrical jet by a vibrating orifice. Carbon dioxide-water was chosen as the gas-liquid system for study. Attention was confined throughout this study to the liquid-side mass transfer coefficient. The droplets formed by the breakup of a cylindrical jet are not internally stagnant. Convection within the droplet, due to the formation process, tremendously enhances the mass transfer rate. The experimentally observed mass transfer rates into a stream of closely spaced, well-mixed droplets are well correlated by the Levich theory of mass transfer into a turbulent fluid.
Effect of hyperbaric oxygenation on normal and chronic streptozotocin diabetic peripheral nerves

Hyperbaric oxygenation is known to affect energy metabolism and endothelial cell structure and function, but its effects on peripheral nerve have not been reported. We investigated whether it would (i) reverse established streptozotocin-induced diabetic neuropathy, a condition in which endoneurial hypoxia exists; (ii) affect energy metabolism in nerve; and (iii) alter the blood-nerve barrier. Sprague-Dawley rats that had been diabetic for 3 months and age-matched controls were used in these studies. One diabetic group and one control group were treated with hyperbaric oxygenation (2 atm for 2 h, 5 days/week) for 4 weeks. Identical groups remained in room air. Sciatic nerve adenosine triphosphate (ATP), creatine phosphate, lactate, and glucose concentrations showed similar changes at rest in both room air and after hyperbaric oxygenation. Nerves of control and diabetic groups exhibited increased lactate production and increased utilization of glucose, ATP, and creatine phosphate after 15 min of anoxia. The albumin blood-nerve barrier index was increased in control and diabetic nerves after hyperbaric treatment. Nerve conduction velocity was reduced in the diabetic-room air group and not improved by hyperbaric oxygenation. Caudal nerve action potential, which was significantly reduced in this group, was normalized after hyperbaric treatment. Resistance to ischemic conduction failure was increased in untreated diabetic nerve but not significantly different from controls after hyperbaric exposure. These findings indicate that treatment with hyperbaric oxygenation will partially reverse the neuropathy encountered in chronic diabetes. The biochemical changes are suggestive of enhanced nerve energy metabolism induced by hyperbaric oxygenation. The altered albumin blood-nerve barrier index presumably results from the action of free radicals on endothelial cells.
An integral equation for the problem of smooth indentation of orthotropic beams

Abstract An integral equation for the problem of smooth contact between a rigid indenter and an orthotropic beam is formulated using an approximate Green's function for surface displacements in the beam, which is obtained as the sum of half-plane solutions for surface displacements, and beam theory deflections. The left and right Green's functions for beam slope are approximated as a single function with continuous derivatives using a least squares error procedure. A closed form solution is obtained for the integral equation. Solutions are obtained for two cases: symmetric indentation of simply supported orthotropic beams and indentation of cantilever beams. Closed form expressions are derived for contact stresses and the contact force-contact length relation in terms of a nondimensional beam parameter B and a nondimensional contact parameter β.
Creative Shipwrecks: Coleridge’s The Rime of the Ancient Mariner and Byron’s Don Juan

Contemporary discussions of English Romantic philosophers and their theories often include such names as William Wordsworth, Samuel Taylor Coleridge, William Hazlitt, Thomas DeQuincey, and Charles Lamb, but rarely do they treat of George Gordon, Lord Byron. While Byron’s reputation was not built upon complex philosophical explications of literary theory, the passion of his life did not preclude that of his mind. He has left us with no overtly philosophical work, and yet, many of the digressions in Don Juan are directed at the poets and philosophers of his time and some others seem to point us to a coherent system of thought about literature and how it works. Specifically, Juan’s voyage at sea contains several passages which parody Coleridge’s Rime of the Ancient Mariner. Some of these similarities have been explored, but are frequently treated as if Byron were simply creating a pastiche of contemporary literature. However, Coleridge had used the Rime to elucidate a portion of his understanding of how literature works. It seems possible that Byron is purposely answering Coleridge in the second canto of Don Juan. Thus, we may be able to use Byron’s natural imagery and poetic technique to piece together a philosophical statement from that most unphilosophical of Romantics, Lord Byron.
Optimal oxygenation during and after cardiopulmonary resuscitation

Purpose of reviewReversal of tissue hypoxia, particularly in the heart and brain, is a fundamental goal of cardiopulmonary resuscitation. However, a growing body of evidence suggests that hyperoxia, especially after return of spontaneous circulation (ROSC), may worsen outcomes. The purpose of this r
Progress toward a crystal streak camera using tungsten bronze crystals for the electrooptic material

Currently, the Hamamatsu and Sandia Corporations use lithium niobate (LiNbO3) in their crystal streak cameras. However, these systems have low resolution due to the low electrooptic coefficient of LiNbO3, 30 x 10-12, which requires excessive voltage drives for the system. For a practical system, new tungsten bronze crystals such as barium niobate [Sr1-xBaxNb2O6, or SBN:1-x(%) for short] must be used to achieve higher resolution and lower voltage drive requirements. Electrooptic coefficients of 400 x 10-12 m/V for SBN:60 and 1400 x 10-12 m/V for SBN:75 give improvements in resolution of 13 and 47, respectively. In this paper, we discuss the highlights of a light deflector developed at Lawrence Livermore National Laboratory (LLNL) for a streak camera that uses tungsten bronze crystals grown at Rockwell International Science Center. We address the design and fabrication of these crystals and include experimental results from our deflector experiment, the purpose of which is to determine the feasibility and expected performance of the crystal streak camera using tungsten bronze crystals.© (1987) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Spin-Echo and Free-Induction-Decay Measurements in Pure Fe and Fe-Rich Ferromagnetic Alloys: Domain-Wall Dynamics

Measurements were made of the free-induction-decay (FID) and spin-echo amplitudes of ${\mathrm{Fe}}^{57}$ in pure Fe and some of its alloys. Complex spectra are observed consisting of many oscillations often covering a range of many Mc/sec. The amplitudes are very dependent on the pulse length $\ensuremath{\tau}$, the applied rf field ${B}_{1}$, and the exciting frequency $\ensuremath{\omega}$. Excellent agreement is found between the experimental and calculated amplitudes when a model for domain-wall motion is used which takes into consideration the following features: 1. There is an averaging over the orientation of ${\mathbf{B}}_{1}$ with respect to the local magnetization. 2. There is a variation of the enhancement factor across the domain wall due to the spin arrangement in the wall. 3. The domain wall is considered to be composed of area segments which are immobile along their perimeters and whose motion resembles that of a vibrating drumhead. 4. These domain-wall segments have a distribution in areas. The restricted motion of the domain walls imposed by the last two features is essential in order to obtain agreement with the experimental results. This is in contrast to the usual model, which represents the domain-wall motion as given by rigid simple-harmonic-like oscillations; such a model shows great discrepancy with the experimental results presented here. In some of the spectra, asymmetries are observed in the variation of the amplitudes as a function of frequency. No satisfactory explanation for these asymmetries is known although some possible sources are suggested. Such asymmetries make it appear very doubtful that the Fe-alloy spectra obtained with this technique can be reliably unfolded to give the variation of the internal field for second- or higher-neighbor impurity atoms. FID amplitude measurements were also made on Fe in an externally applied dc field. No variation in the value of the maximum enhancement factor was observed for dc fields varying from 0 to about 5 kG.
Distributed reconfiguration of hexagonal metamorphic robots in two dimensions

The problem addressed in the distributed reconfiguration of a metamorphic robotic system composed of any number of two dimensional hexagonal modules from specific initial to specific goal configurations. The initial configuration considered is a straight chain of modules, while the goal configurations considered satisfy a more general admissibility condition. A centralized algorithm is described for determining whether an arbitrary goal configuration is admissible. The main result of the paper is a distributed algorithm for reconfiguring a straight chain into an admissible goal configuration. Different heuristics are proposed to improve the performance of the reconfiguration algorithm and simulation results demonstrate the use of these heuristics.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Molecular dynamics simulations of lattice thermal conductivity and spectral phonon mean free path of PbTe: Bulk and nanostructures

In this work, molecular dynamics (MD) simulations are performed to predict the lattice thermal conductivity of PbTe bulk and nanowires. The thermal conductivity of PbTe bulk is first studied in the temperature range 300–800 K. Excellent agreement with experiments is found in the entire temperature range when a small vacancy concentration is taken into consideration. By studying various configurations of vacancies, it is found that the thermal conductivity in PbTe bulk is more sensitive to the concentration rather than the type and distribution of vacancies. Spectral phonon relaxation times and mean free paths in PbTe bulk are obtained using the spectral energy density (SED) approach. It is revealed that the majority of thermal conductivity in PbTe is contributed by acoustic phonon modes with mean free paths below 100 nm. The spectral results at elevated temperatures indicate molecular scale feature sizes (less than 10 nm) are needed to achieve low thermal conductivity for PbTe. Simulations on PbTe nanowires with diameters up to 12 nm show moderate reduction in thermal conductivity as compared to bulk, depending on diameter, surface conditions and temperature.Copyright © 2012 by ASME
Grazing-Tolerant Alfalfa Cultivars Perform Well under Rotational Stocking and Hay Management

Grazing-tolerant alfalfa (Medicago saliva L.) cultivars are developed using continuous stocking with beef cattle (Bos taurus) during screening and selection. Alfalfa is mainly recommended for use in hay making and under rotational stocking rather than continuous stocking. Performance of alfalfa cultivars selected under the specificity of intensive, continuous stocking in recommended management systems is unknown. This study was conducted to test survival and performance of alfalfa populations selected with continuous stocking against their parental cultivar germplasms ('Apollo', 'Diamond', '5432', and 'Florida 77') at two Georgia locations (Eatonton and Tifton) under the following management conditions: grazing to close stubble heights (5-7 cm) with continuous stocking, grazing to close stubble heights (5-7 cm) with rotational stocking (7 d grazing and 28 d rest), and standard hay harvesting. At Eatonton, plant survival was similar (52-53%) for the rotational stocking and hay harvest treatments, with all entries in these treatments exhibiting better survival than in the continuously stocked treatment (38%). At Tifton, stand survival improved as management changed from continuous stocking (24%) to rotational stocking (46%) to hay harvest management (63%). At both test locations, grazing-tolerant entries demonstrated higher plant survival rates than parental populations when averaged across all management treatments. Dry matter yields of the grazing-tolerant entries were no different, or were higher during 1 yr at Tifton, than their parental populations. It is therefore a good strategy for producers practicing continuous stocking, rotational stocking, or hay making to use grazing-tolerant cultivars rather than cultivars not selected for grazing tolerance.
On Y2 = X3 + k and the Thue rank of cubic curves

Abstract The intersection of cords and tangents with the curve Y 2 = X 3 + k is exploited to locate additional lattice points and to define the Thue rank of the curve.
Different effects of A23187 and PMA on palmitoylated platelet proteins.

Abstract The effect of agonists on palmitoylated proteins was examined in platelets prelabeled with [ 3 h]palmitic acid. Non-reduced gels revealed major labeled proteins with masses from 30–38 kDa. One of these proteins was modified by A23187, which led to a loss of radioactivity, and PMA, which altered its electrophoretic mobility. A possible link between the A23187-induced loss of label associated with the protein and the activation of calpain was suggested by the following experiments. (1) There was a good correlation between the loss of label and the proteolysis of proteins in A23187-activated platelets. (2) The permeant calpain inhibitor, E64d, blocked the loss of label as well as the proteolysis of proteins. (3) The loss of label also occurred in a Triton lysate, where calpain was known to be activated. The effect of PMA on the palmitoylated protein was observed only in prelabeled platelets. The protein kinase inhibitor, staurosporine, abolished the PMA-induced platelet aggregation as well as the mobility shift of the labeled protein.
Retroactive facilitation of memory in goldfish by flurothyl.

The spontaneous upstream swimming of goldfish (N=1318) into a quiet well was suppressed in one trial by electric shock (2.0 V/cm). Independent groups of fish, at 25‡ C, retained this learned avoidance 1, 4, 16, and 64 h after training but not 256 h after training. When trained fish were treated, 3 min after training, with a 16-min exposure to convulsive solutions of flurothyl (Indoklon®), their retention of avoidance 16, 64, or 256 h later was facilitated. This retroactive facilitation (RF) of long-term memory in goldfish by flurothyl could not be attributed to proactive or aversive effects of the treatment. Goldfish treated in water saturated with carbon dioxide (80% CO2∶20% O2) showed retrograde amnesia (RA). Neither the RF from flurothyl nor the RA from CO2-treatment were diminished when training and treatment were given to goldfish at 20‡ or 15‡ C. The memory-enhancing effect of flurothyl convulsions, and its delayed onset, may relate to the dual stimulant-depressant action of the drug and differ from the RA effect reported for mice and chicks.
Positive-tone silylation processes at 193 nm

Abstract A silylation process based on laser induced crosslinking has been developed using novolac, novolac/ diazoquinone blends and chemically amplified resists. Dimethylsilyldimethylamine was used as a silylating reagent. The diffusion characteristics show a change at the polymer glass transition temperature. The profile of diffused silicon is anisotropic, and diffusion in unexposed regions of the film is affected by the extent of exposure in adjacent regions of the film.
Ethics in Global Surgery

Global surgery, while historically a small niche, is becoming a larger part of the global health enterprise. This article discusses the burden of global surgery, emphasizing the importance of addressing surgical needs in low- and middle-income countries. It describes the barriers to surgical care in the developing world, the ethical challenges that these barriers create, and strategies to overcome these barriers. It emphasizes the crucial role of preparation for global surgical interventions as a way to maximize benefits as well as minimize harms and ethical challenges. It ends with the cautionary statement that preparation does not eliminate ethical problems, so surgical volunteers must be prepared not only for the technical challenges of global surgery but also for the ethical challenges.
Scanning electron microscopical and cross-sectional analysis of extraterrestrial carbonaceous nanoglobules

Carbonaceous nanoglobules are ubiquitous in carbonaceous chondrite (CC) meteorites. The Tagish Lake (C2) meteorite is particularly intriguing in containing an abundance of nanoglobules, with a wider range of forms and sizes than encountered in other CC meteorites. Previous studies by transmission electron microscopy (TEM) have provided a wealth of information on chemistry and structure. In this study, low-voltage scanning electron microscopy (SEM) was used to characterize the globule forms and external structures. The internal structure of the globules was investigated after sectioning by focused ion beam (FIB) milling. The FIB-SEM analysis shows that the globules range from solid to hollow. Some hollow globules show a central open core, with adjoining smaller cores. The FIB with an SEM is a valuable tool for the analysis of extraterrestrial materials, even of sub-micron "soft" carbonaceous particles. The rapid site-specific cross-sectioning capabilities of the FIB allow the preservation of the internal morphology of the nanoglobules, with minimal damage or alteration of the unsectioned areas.
[15O]water pharmacokinetics: influence of age and gender in normal subjects.

Abstract Purpose: To compile a normal database for the characterization of global [ 15 O]water pharmacokinetic behavior. Procedures: The influences of age, gender, and body habitus on the pharmacokinetics of [ 15 O]water were investigated in a series of normal subjects, N = 100 (50 males, 50 females, age = 19–79) who were participants in cognitive activation studies. Arterial blood was analyzed by autosampler and parametric images were constructed using a 40-second summed image and the autoradiographic model. Results: Males and females were comparable with respect to age, number of injections administered, and dose (mCi) administered per injection but differed significantly with respect to height, weight, and normalized dose (mCi/kg). There were significant gender-based differences in the bolus arrival time, global cerebral blood flow (gCBF), area-under-the-curve (AUC), summed image concentration, and dose-normalized concentration but not dose-normalized AUC. Bolus arrival time, gCBF and dose-normalized AUC were significantly influenced by age. Conclusion: Age and gender are significant determinants of [ 15 O]water pharmacokinetic behavior. (Mol Imag Biol 2002;4:129–137)
Preparation of silica glass microspheres by sol-gel processing

A method for making glass microspheres by the sol-gel process has been developed. Porous silica microspheres were produced at temperatures as low as 500 °C and densified silica microspheres were prepared at 800 °C. The size of the microspheres was controlled by adjusting the feed rate of the raw materials and the frequency of the droplet generator so that uniform spheres were obtained. Glass microspheres prepared by this method were characterized by Nuclear Magnetic Resonance (NMR), Differential Thermal Analysis (DTA), Thermogravimetric Analysis (TGA), and optical microscopy.
Education and Technology: A Cultural Faustian Bargain

American government and industry are encouraging educators to adopt the computer as a primary educational medium. However, efforts to use educational software have been disappointing and computer literacy has not been widely adopted as a basic literacy skill. This article will explore the advantages and disadvantages of integrating computers into education and describe their cultural implications for educational policy.
Narrative and Poetic Art in the Book of Ruth

Although the Book of Ruth is in many respects a classic example of biblical Hebrew narrative, with its stripped-down style and the opaqueness of its character's inner lives and motivations, there are two examples of formal poetry in the book (1:16–17 and 1:20–21). Biblical poetry works with a very different set of literary conventions than narrative, and by taking note of those conventions, we can see the distinctive contributions made by these poems to the book as a whole.
A measurement-based approach for multilevel admission of heterogeneous traffic in wireless ad-hoc networks

General dynamics C4S has developed a QoS solution for the Army's warfighter information network tactical (WIN-T). This solution is also being applied to other QoS applications in tactical networks. When using an encryption device, any information exchange between the LAN where call admission control (CAC) decisions are made, and the WAN where traffic shaping is made is prevented by the encryptor. This solution was developed and tested using OPNET modeler. The core of this solution is a measurement based admission control (MBAC) type algorithm. This MBAC algorithm regulates the flow of heterogeneous traffic entering a tactical wireless ad-hoc network based on a computed end-to-end congestion level. Traffic can be of different types (voice, video and data) and have multiple levels of importance (survivability) and different real-time requirements. The algorithm prioritizes the admission of calls/sessions (at a source node) based on the QoS attributes of each class of service and the condition of the path to the destination node.
Deformations of Codimension 2 Toric Varieties

We prove Sturmfels' conjecture that toric varieties of codimension two have no other flat deformations than those obtained by Grobner basis theory.
Schizotypal and paranoid personality disorder in the relatives of patients with schizophrenia and affective disorders: a review

This review considers the possible familial relationship of schizotypal and paranoid personality disorders (SPD, PPD) to schizophrenia (SCZ) and affective disorders (AD). There have been few controlled studies on familial risk of SPD and PPD based on direct semi-structured interviews of relatives, blind to proband diagnosis. Three of six studies reported increased familial risk of SPD for SCZ probands, but with considerable variability in estimates of this risk. None of four studies reported a significant relationship between AD and familial SPD. There is substantial but less consistent evidence for a familial relationship between PPD and SCZ: three of six studies supported such a relationship, but one large study reported increased familial risk of PPD for AD and not for SCZ probands. There is also some evidence that negative symptoms are most characteristic of SPD in relatives of SCZ probands. Also discussed are issues concerning the adequacy of current criteria for defining schizophrenia spectrum pathology, and of diagnostic methods in this area.
Food-web dynamics in a large river discontinuum

Nearly all ecosystems have been altered by human activities, and most communities are now composed of interacting species that have not co-evolved. These changes may modify species interactions, energy and material flows, and food-web stability. Although structural changes to ecosystems have been widely reported, few studies have linked such changes to dynamic food-web attributes and patterns of energy flow. Moreover, there have been few tests of food-web stability theory in highly disturbed and intensely managed freshwater ecosystems. Such synthetic approaches are needed for predicting the future trajectory of ecosystems, including how they may respond to natural or anthropogenic perturbations. We constructed flow food webs at six locations along a 386-km segment of the Colorado River in Grand Canyon (Arizona, USA) for three years. We characterized food-web structure and production, trophic basis of production, energy efficiencies, and interaction-strength distributions across a spatial gradient of pertu...
Follicular thyroid cancer cell growth inhibition by proteosome inhibitor MG132.

BACKGROUND Effective therapies for the subset of follicular thyroid cancer (FTC) patients with aggressive, metastatic disease are lacking. Therefore, we sought to determine the effects of proteosome inhibition, an emerging class of chemotherapeutic agents, on metastatic FTC cells. MATERIALS AND METHODS Human metastatic FTC cells (FTC236) were treated in vitro with the proteosome inhibitor MG132 (0 to 800 nM). Western blot analysis was performed on whole cell lysates isolated after 2 d. To measure cell growth, we performed an MTT cellular proliferation assay over 6 d. RESULTS Treatment of FTC236 cells with MG132 led to dose-dependent cell growth inhibition. Increases in inactive, phosphorylated GSK-3beta, and active beta-catenin also were observed. With 800 nM MG132, growth was reduced by 87% at 6 d (P < 0.0001). This reduction in cellular proliferation correlated with the degree of GSK-3beta inhibition. MG132 treatment also caused increased p21(Waf1/Cip1) and decreased cyclin D1 expression, suggesting that growth suppression may occur through cell cycle arrest. CONCLUSION Growth of metastatic human FTC cells appears to be suppressed by proteosome inhibition. Whether this effect is directly due to cell cycle arrest and inactivation of GSK-3beta signaling is unclear. Nonetheless, these compounds may become novel treatments for aggressive, metastatic FTC.
Pseudo-cardioversion of atrial fibrillation.

To the Editor: In the management of atrial fibrillation (AF), the dispute between proponents of heart rate control vs. restoration of sinus rhythm (SR) has finally been settled recently by four trials: Pharmacological Intervention in Atrial Fibrillation (PIAF) [1], Strategies of Treatment of Atrial Fibrillation (STAF) [2], Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) [3] and Rate Control versus Electrical Cardioversion (RACE) [4,5]. According to these four trials, there is no difference between the two treatments. However, we have all seen patients whose AF, during acute rate control following intravenous administration of either diltiazem or digoxin, spontaneously reverted to SR. It was very hard for me to convince the young house staff that the restoration of SR in these patients was spontaneous rather than due to diltiazem or digoxin. From the pharmacological standpoint, neither diltiazem nor digoxin is supposed to convert AF to SR; they only slow the ventricular response to AF. As a matter of fact, diltiazem, by shortening the AF cycle length, unwittingly prolongs the duration of recent onset AF [6]. The recent report of the ACUTE trial ancillary study [7] finally provided support to my teaching, because 16% of patients with AF scheduled for electrical cardioversion underwent spontaneous conversion to SR. In another word, one of every six patients with AF scheduled for cardioversion, whether electrical or pharmacological, will spontaneously convert to SR. This phenomenon of coincidence in medicine has been seen in the so-called pseudo-complication of cardiac catheterization [8,9]. Patients suffering from serious cardiovascular diseases may experience major cardiovascular catastrophes (myocardial infarction, thromboembolism, bleeding, ventricular fibrillation, stroke and sudden death) as part of natural history of their disease. If one of these events happens during or in close proximity of cardiac catheterization, either diagnostic or therapeutic, it would be natural to
Cognitive and affective predictors of smoking after a sentinel health event.

Objective: This study examined how smoking-related causal attributions, perceived illness severity, and event-related emotions relate to both intentions to quit and subsequent smoking behavior after an acute medical problem (sentinel event). Methods: Three hundred and seventy-five patients were enrolled from 10 emergency departments (EDs) across the USA and followed for six months. Two saturated, manifest structural equation models were performed: one predicting quit attempts and the other predicting seven-day point prevalence abstinence at 14 days, three months, and six months after the index ED visit. Stage of change was regressed onto each of the other predictor variables (causal attribution, perceived illness severity, event-related emotions) and covariates, and tobacco cessation outcomes were regressed on all of the predictor variables and covariates. Results: Non-White race, baseline stage of change, and an interaction between causal attribution and event-related fear were the strongest predictors o...
MCDB: a monte carlo approach to managing uncertain data

To deal with data uncertainty, existing probabilistic database systems augment tuples with attribute-level or tuple-level probability values, which are loaded into the database along with the data itself. This approach can severely limit the system's ability to gracefully handle complex or unforeseen types of uncertainty, and does not permit the uncertainty model to be dynamically parameterized according to the current state of the database. We introduce MCDB, a system for managing uncertain data that is based on a Monte Carlo approach. MCDB represents uncertainty via "VG functions," which are used to pseudorandomly generate realized values for uncertain attributes. VG functions can be parameterized on the results of SQL queries over "parameter tables" that are stored in the database, facilitating what-if analyses. By storing parameters, and not probabilities, and by estimating, rather than exactly computing, the probability distribution over possible query answers, MCDB avoids many of the limitations of prior systems. For example, MCDB can easily handle arbitrary joint probability distributions over discrete or continuous attributes, arbitrarily complex SQL queries, and arbitrary functionals of the query-result distribution such as means, variances, and quantiles. To achieve good performance, MCDB uses novel query processing techniques, executing a query plan exactly once, but over "tuple bundles" instead of ordinary tuples. Experiments indicate that our enhanced functionality can be obtained with acceptable overheads relative to traditional systems.
Effects of Magnetoelectric Ordering Due to Interfacial Symmetry Breaking

We examine the effects of interfacial symmetry breaking between ferroelectric and ferromagnetic (FM) materials. Using a standard Ginzburg-Landau formalism, we show that the presence of a linear coupling between electric polarization and magnetization produces spatial modulations of the ordered states. This coupling can also induce interfacial order from a non-ordered state. In the case of the paramagnetic state, this coupling produces a shift of the transition temperature and can drive the system from non-ordered to ordered at the interface. For the paraelectric state, an induced interfacial polarization emerges due to the FM state in the adjacent material.
A Dual Interface Determines the Recognition of RNA Polymerase II by RNA Capping Enzyme

RNA capping enzyme (CE) is recruited specifically to RNA polymerase II (Pol II) transcription sites to facilitate cotranscriptional 5′-capping of pre-mRNA and other Pol II transcripts. The current model to explain this specific recruitment of CE to Pol II as opposed to Pol I and Pol III rests on the interaction between CE and the phosphorylated C-terminal domain (CTD) of Pol II largest subunit Rpb1 and more specifically between the CE nucleotidyltransferase domain and the phosphorylated CTD. Through biochemical and diffraction analyses, we demonstrate the existence of a distinctive stoichiometric complex between CE and the phosphorylated Pol II (Pol IIO). Analysis of the complex revealed an additional and unexpected polymerase-CE interface (PCI) located on the multihelical Foot domain of Rpb1. We name this interface PCI1 and the previously known nucleotidyltransferase/phosphorylated CTD interface PCI2. Although PCI1 and PCI2 individually contribute to only weak interactions with CE, a dramatically stabilized and stoichiometric complex is formed when PCI1 and PCI2 are combined in cis as they occur in an intact phosphorylated Pol II molecule. Disrupting either PCI1 or PCI2 by alanine substitution or deletion diminishes CE association with Pol II and causes severe growth defects in vivo. Evidence from manipulating PCI1 indicates that the Foot domain contributes to the specificity in CE interaction with Pol II as opposed to Pol I and Pol III. Our results indicate that the dual interface based on combining PCI1 and PCI2 is required for directing CE to Pol II elongation complexes.
Estrogen--a cause of gynecologic cancer?

The "estrogen hypothesis" relating estrogen stimulation of the endometrium to the eventual production of endometrial neoplasia arose from observations regarding: 1) increased incidence of endometrial hyperplasia and adenocarcinoma in patients with chronic anovulation estrogen-secreting tumors and adenomatous endometrial hyperplasia; 2) development of endometrial cancer in estrogen-treated animals and in patients with dysgenetic gonads after long-term estrogen therapy; 3) successful treatment of endometrial hyperplasia and well-differentiated carcinoma with anti-estrogens. Case control studies carried out since 1975 positively correlated the increased risk of endometrial cancer among estrogen users with duration of use and dose. Risk ratio among estrogen users varies from 2 to 14 with the most common estimate being between 3 and 8. The cumulative risk starting at age 50 of developing endometrial cancer has been calculated to be 1% after 5 years and 3.6% after 10 years for estrogen users and 0.3% at 5 years and 0.8% at 10 years for nonestrogen users. The effect of exogenous estrogen therapy with the exception of long-term high dose estrogen therapy on breast cancer is not well established. The incidence of breast cancer has not changed significantly in the last 2 decades unlike that of endometrial cancer. Many established breast cancers contain estrogen receptors and are sensitive to changes in serum estrogen levels. It is not known whether estrogens per se cause any cancer in humans although long-term estrogen use is known to promote the development of a subgroup of endometrial cancers that are usually well differentiated and associated with low mortality. Many cancers are known to occur in estrogen-sensitive tissues in women who have never been estrogen users are not obese have normal reproductive histories and are otherwise healthy. It is also suggested that low dose estrogen replacement therapy provides benefits which often outweigh the risks of developing cancer.
Use of Mass spectrometry for imaging metabolites in plants

We discuss and illustrate recent advances that have been made to image the distribution of metabolites among cells and tissues of plants using different mass spectrometry technologies. These technologies include matrix-assisted laser desorption ionization, desorption electrospray ionization, and secondary ion mass spectrometry. These are relatively new technological applications of mass spectrometry and they are providing highly spatially resolved data concerning the cellular distribution of metabolites. We discuss the advantages and limitations of each of these mass spectrometric methods, and provide a description of the technical barriers that are currently limiting the technology to the level of single-cell resolution. However, we anticipate that advances in the next few years will increase the resolving power of the technology to provide unprecedented data on the distribution of metabolites at the subcellular level, which will increase our ability to decipher new knowledge concerning the spatial organization of metabolic processes in plants.
Excellent emergency medicine educators adapt teaching methods to learner experience level and patient acuity

Objectives: This study investigates whether instructional methods used by excellent emergency medicine residency teachers change with changing conditions of learner level of training, patient acuity and department census. Methods: Four excellent, purposively selected, emergency medicine teachers consented to participate in this nonparticipant observational study. Teachers were observed for 32 hours in the emergency department, using a structured observation form focused on: teaching methods used, context learner level of training, emergency department patient census and patients’ illness severity. Data was analyzed qualitatively using constant comparative analysis. Results: Fifteen (15) categories of teaching methods were observed. The 4 most frequently observed methods were: Questioning (used in 47% of teaching encounters), Advice Giving (33%), Limited Teaching Points (31%) and Patient Updates (22%). Patient Updates were more often used with senior residents. Multiple methods were used in most encounters. Teaching methods did not vary significantly with increased emergency department volume, but faculty and residents relied more heavily on a single method of teaching per encounter as patient acuity increased to Triage levels One and Two. Conclusions: Excellent emergency medicine teachers teaching methods were classified into 15 categories. They typically rely heavily on four methods, adapting to resident training level and patient illness severity, rather than patient volume. The observed teaching methods provide teachers who have high clinical productivity expectations and/or demanding emergency care settings with an enriched repertoire of teaching strategies.
The Images of Artemis Ephesia and Greco-Roman Worship: A Reconsideration

In a recent essay, Nicole Loraux identified a pattern of scholarly dependence on the origins of a particular deity for the interpretation of how human beings at various, specific times and places related to and used that figure to meet the needs of their lives. Shifting social and political conditions, such as the development and modification of the Athenian polis, led to changes in people's religious needs and are reflected by modifications, sometimes radical, in the conceptualization and worship of their gods. Loraux discussed the problems that this scholarly perspective brought to the study of goddesses in particular, where focus on the origins of many goddesses in a hypothesized worship of a Great Goddess of fertility can obscure our understanding of the ways in which these figures met the needs of individuals and cities at specific points in antiquity.
Endo-β-mannanase activity is associated with the completion of embryogenesis in imbibed carrot ( Daucus carota L.) seeds

Development of the rudimentary embryo in mature carrot (Daucus carota) seed during imbibition was characterized. The small embryo in the carrot seed, located in the micropylar region, elongated into the lateral part during imbibition and attained about two-thirds the length of the seed before radicle protrusion. Developing embryos excised from imbibed seeds were only capable of germinating in both water and Murashige–Skoog (MS) medium when they reached maximum size. The corrosion cavity into which the embryo grew enlarged concomitantly with endosperm degradation. The expression of endo-β-mannanase (EC 3.2.1.78), which is assumed to be involved in endosperm degradation, was characterized. A cDNA encoding an endo-β-mannanase was obtained by reverse transcription polymerase chain reaction (RT-PCR) using total RNA extracted from 24-h-imbibed carrot seeds. The full-length cDNA (DcMAN1) exhibited 64% deduced amino acid sequence identity with tomato (Lycopersicon esculentum) seed germination-associated mannanase (LeMAN2). DcMAN1 mRNA and endo-β-mannanase activity were first detected in the micropylar-half seed and then in the lateral-half seed. The timing of the appearance of DcMAN1 mRNA and endo-β-mannanase activity in the lateral-half seed corresponded with that of embryo development into this region. These results suggest that the expression of DcMAN1 and endo-β-mannanase activity in imbibed carrot seeds is associated with the enlargement of the corrosion cavity, which accompanies embryogenesis.