cssi/SciSciGPT-SciSciNet huggingface dataset:
Increased phantom limb painas an initial symptom of spinal neoplasia

Phantom limb pain is a common sequela of amputation. Studies suggest that over time, there is a decrease in frequency and intensity of phantom pain. Persistently increased phantom pain has been seen in benign lesions affecting the peripheral and central nervous system. We present a 74-year-old woman who had a left above-knee amputation for leiomyosarcoma of the foot 24 years previously. She had been free of disease and ambulated independently until 1 month before hospitalization, when she noted increasing pain in her phantom foot. At the time of admission, she had developed increasing low back pain and was diagnosed with adenocarcinoma of unknown primary. Work-up confirmed involvement of the L4 vertebral body with epidural and paraspinal disease. We believe this is the first reported case of worsening phantom limb pain resulting from a spinal metastasis. We review the literature on the potential implications of increased phantom pain.
Management of ventricular tachycardia complicating cardiac surgery

Sustained ventricular tachycardias occur in 1%–3% of patients undergoing cardiac surgery. Sustained monomorphic ventricular tachycardia usually indicates a scar-related arrhythmia substrate. Polymorphic arrhythmias can be due to transient events. The electrocardiographic characteristics of the arrhythmia and clinical characteristics of the patient are important considerations in the immediate and long-term management considerations.
Left ventricular hypertrophy: an overlooked cardiovascular risk factor

Left ventricular hypertrophy (LVH) is common in hypertensive patients, and it increases the risk of myocardial infarction, stroke, and death. Recent evidence indicates it is a modifiable risk factor that is not entirely dependent on blood pressure control. The authors review its pathogenesis, diagnosis, and treatment.
Using Bayesian inference to perform meta-analysis.

Bayesian modeling offers an elegant approach to meta-analysis that efficiently incorporates all sources of variability and relevant quantifiable external information. It provides a more informative...
Reliability of Voice Tests of Speech Discrimination

Three randomizations of a list of twenty-five words were recorded by a single talker on separate days and under identical conditions. One of the recordings was rerecorded three times and these dubb...
Chromic Acid Adsorbed on Aluminium Silicate: A New Reagent for Oxidation of Primary Alcohols to Aldehydes

Abstract That chromic acid adsorbed on aluminium silicate is a new reagent suitable for oxidation of primary alcohols to corresponding aldehydes is described.
The behavioral dynamics of clinical trials

Two ways of approaching the design of long-term clinical trials are presented and contrasted. The first, termed the "static" view, emphasizes close adherence to formal rules of study design. The second, termed the "dynamic" view, emphasizes the behavioral aspects of patient participation in trials of long duration. The dynamic view is discussed in detail, with discussion of how recruitment of participants, random assignment to conditions, compliance with protocol, and measurement of outcomes are affected by behavioral dynamics. Data from a recently completed tamoxifen toxicity trial are used to illustrate the points and to focus the discussion of behavioral dynamics on the design of a chemoprevention trial for breast cancer using tamoxifen.
The Cultures of Social Class and Religious Educational Practice

Abstract Although social class impacts the assumptions, values, and normative practices of Religious Education, the lack of public discourse on class diminishes awareness of and critical reflection on this impact. This article describes social class as a largely unarticulated and embodied performance of identity inflected through hierarchical practices of race, gender, and commodity consumption. The author provides examples of the impact of social-class bias on the practice of Religious Education in the context of youth ministry.
Conformational states of chromatin в bodies induced by urea

Monomer chromatin nu bodies (nu1) from chicken erythrocyte nuclei were exposed to 0-10 M urea plus 0.2 mM EDTA (PH 7). Alterations in nu1 conformation were examined using hydrodynamic methods (i.e., S, eta, and (formula: see text)), thermal denaturation, circular dichroism, reactivity of histone thiol groups to N-ethyl maleimide, and electron microscopy. The two domains of a nu body (i.e., the DNA-rich shell and the protein-rich core) aeared to respond differently to the destabilizing effects of increasing urea; DNA conformation and stability exhibited noncooperative changes; the core protein structure revealed cooperative destabilization between 4 and 7 M urea. Companion studies on the conformation of the inner histone "heterotypic tetramer" also revealed cooperative destabilization with increasing urea concentration.
STABILITY OF CONCENTRATED COLLOIDAL DISPERSIONS IN APOLAR MEDIA

Abstract The stability of concentrated colloidal dispersions of submicron carbon black particles in solutions of Aerosol-OT in p-xylene is discussed. Electrostatic and electrodynamic forces compete leading to coagulation of the primary particles resulting in increasing particle radius. Growth continues until electrostatic stabilisation dominates. These stable dispersions are characterised by particle size, electrophoresis and Theological measurements. The effect of ionic strength is studied and discussed in terms of fundamental electric double layer theory. This work is of significance to practical concentrated dispersions in media where the dielectric constant is very low
The effects of smokeless tobacco (oral snuff) on dynamic visual acuity

The effects of the use of smokeless tobacco (oral snuff) on observers’ ability to resolve moving targets were assessed under four levels of target velocity for both light and heavy tobacco users among college students. Each observer was tested in several sessions, half immediately following the use of tobacco and half with no preceding tobacco use. No differences were found across the two types of sessions for any of the velocity conditions. The results are discussed in terms of the practical consequences of nicotine nystagmus reported by previous investigators.
Weibull analysis of strength-length relationships in single Nicalon SiC fibres

Nicalon SiC fibre is naturally brittle and offers high-temperature application in fibrous composites. Due to the randomly distributed flaws along the fibre, the statistical variability in single-fibre strength is obvious. In this paper, the effect of heat-cleaning procedures on Nicalon fibres has been investigated, and the statistical strength and variability of single Nicalon fibres have been characterized in tension and compared. Experimental results show that the strengths of single Nicalon fibres among the three types of heat-cleaning procedures are less than that of as-received unsized fibres by 22–30%. In addition, both the failure load and the failure stress of the fibres, for a given gauge length (50 mm) and yarn cross-section, can be well fitted to a two-parameter Weibull distribution. The effect of gauge length over the range from 10–175 mm, holding the strain rate constant, was also studied. The logarithmic strength-length plots show that the strength of single Nicalon fibres follows the weakest-link rule.
Is Twofoldness Necessary for Representational Seeing

Richard Wollheim claimed that twofoldness is a necessary condition for the perception of pictorial representations and it is also a necessary condition for the aesthetic appreciation of pictures. Jerrold Levinson pointed out that these two questions are different and argued that though twofoldness may be a necessary condition for the aesthetic appreciation of pictures, it cannot be a necessary condition for the perception of pictorial representations. I argue that Wollheim's use of the term 'twofoldness' alternates between two concepts: the simultaneous visual awareness of the surface and of the represented object on the one hand and the simultaneous visual awareness of the represented object and the way it is represented on the other. Finally, I argue that twofoldness in the first sense is a necessary condition for the perception of pictorial representations, whereas twofoldness in the second sense is a necessary condition for the aesthetic appreciation of pictures.
Role of diacylglycerol kinases in T cell development and function

Diacylglycerol (DAG), a second messenger generated by phospholipase Cγ1 activity upon T cell receptor (TCR) engagement, triggers several signaling cascades that play important roles in T cell development and function. A family of enzymes called diacylglycerol kinases (DGKs) catalyzes the phosphorylation of DAG to phosphatidic acid, acting as a braking mechanism that terminates DAG-mediated signals. Two DGK isoforms, α and ζ, are predominantly expressed in T cells and synergistically regulate the development of both conventional αβ T cells and invariant NKT cells in the thymus. In mature T cells, the activity of these DGK isoforms aids in the maintenance of self-tolerance by preventing T cell hyper-activation upon TCR stimulation and by promoting T cell anergy. In CD8 cells, reduced DGK activity is associated with enhanced primary responses against viruses and tumors. Recent work has also established an important role for DGK activity at the immune synapse and identified partners that modulate DGK function. In addition, emerging evidence points to previously unappreciated roles for DGK function in directional secretion and T cell adhesion. In this review, we discuss the multitude of roles played by DGKs in T cell development and function, while emphasizing recent advances in the field.
Potential flows in general relativity: Nonlinear and time-dependent solutions.

We present several new calculations of subsonic relativistic fluid flows in fixed background spacetimes. For irrotational, isentropic, perfect-fluid flows, the relativistic Euler and continuity equations can be formulated as a potential problem which is very accessible to numerical and analytic techniques. Schwarzschild and Kerr background spacetimes are considered with the inner boundary condition determining whether the gravitating source is a black hole or a hard sphere. For stationary flows with a polytropic equation of state {ital P}={ital Kn}{sup {gamma}}, the potential equation is nonlinear and elliptic. We compute several examples of stationary, axisymmetric flows about a hard sphere moving through an asymptotically homogeneous medium. For a {ital P}={rho} (i.e., {gamma}=2) equation of state the potential equation is linear and can be solved analytically for steady-state flows. We solve the hyperbolic system to calculate various time-dependent two-dimensional flows past a hard sphere. For hard spheres larger than a critical size {ital R}{sub lim}/M, there is an asymptotic velocity (of the sphere through the medium) above which the steady state cannot be achieved. We use the time-dependent code to study the behavior of the stationary and nonstationary cases. The code is also employed to examine the transition to steady-state accretion flow ontomore » a black hole moving through a homogeneous medium. We also present a new, analytic, three-dimensional solution for flow past a rotating hard sphere. These flows represent excellent test problems for numerical relativity. Multidimensional fluid solutions may be used to benchmark codes as well as provide realistic numerical data for developing three-dimensional visualization methods. Because of the numerical tractability of the potential formulation, great precision can be achieved with modest computational resources.« less
On the Correspondence Between Physiological and Nonverbal Responses: Nonverbal Behavior Accompanying Challenge and Threat

Little is known regarding the covariance between physiological and nonverbal responses to “stressful” situations. We argue that physiological markers are especially likely to be accompanied by psychologically-meaningful nonverbal behavior. Within “stressful” motivated performance situations, complex patterns of cardiovascular (CV) reactivity mark challenge and threat motivational states relevant to confidence. We expected the CV challenge and threat markers to be distinguished on the basis of facial and vocal confidence. In a test of this hypothesis, participants’ cardiovascular (CV) responses were recorded during a videotaped social interaction. As expected, the CV challenge marker was associated with more vocal confidence and less facial confidence than the CV threat marker. These findings are related to the complexity of human responses to motivated performances.
Dating the First Stage of Planet Formation

The 53Mn-53Cr chronometer applied to bulk carbonaceous chondrites constrains the solar nebula volatile element fractionation, chondrule formation, and stage I planetary accretion timescale to within +0.91 to –1.17 Myr at 4568 Myr ago. The difference between the initial 53Cr/52Cr ratio of ordinary chondrites, defined by Chainpur (LL3.4) chondrules, and carbonaeous chondrites suggests that the former is coming from an isotopically evolved reservoir.
Slowing of decay processes by interactions with a medium.

A particle that decays by the simplest interaction into two other particles is placed in a space-periodic external potential that acts only on the initial particle. For a strong potential, the decay rate is slowed drastically under most initial conditions. Comparing to the second-order perturbation treatment of a model where the decaying particle is imbedded in a medium of heavy, uncorrelated particles, noninteracting except for a potential interaction with the decaying particle, we find similar rate modifications. There exist possible applications in the supernova and early Universe environment, as well as possible laboratory demonstration of the effect, which bears some relationship to the ``quantum Zeno'' effect.
A circular dichroic investigation of the secondary structure of lectins

The far-uv CD spectra of eight lectins are presented. These eight lectins, as well as others previously studied, are grouped into three classes according to their particular CD spectra. The eight lectins studied appeared to have secondary structure dominated by β-pleated sheet, which so far has been true of all lectins. An attempt was made to quantitate the three structural components (α-helix, β-pleated sheet, and aperiodic) in the lectins using the data for reference proteins given by Chen et al. [Biochemistry13,3350 (1974)]. For lectins in two of the classes, this method proved excellent and values for the three components are given. However, for the third class of lectins, which includes most of the lectins as well as Concanavalin A, this method of analysis proved to be unsatisfactory. This inadequacy was due to two factors: (1) the reference proteins used by Chen and (2) the unusual CD spectra of these lectins manifested by considerable ellipticity above 225 nm in a region where there are no known peptide electronic transitions.
Our Current Understanding of the Impact of Aerosols on Climate Change

Aerosols constitute a climate and health risk via both direct and indirect effects. In this Viewpoint, recent developments in aerosol research and available instrumentation are discussed in the context of environmental change.
P4 and P1′ optimization of bicycloproline P2 bearing tetrapeptidyl α-ketoamides as HCV protease inhibitors

Abstract With the aim of improving HCV protease inhibitors reported in our previous manuscripts, we synthesized and evaluated a series of 1a-based tetrapeptidyl α-ketoamides with additional P4 modification. The promising analog discovered through this SAR, 5a, was further derivatized at P1′ or P1 position. As a result of these efforts, we found that replacement of the P4 valine as seen in 1a with cyclohexylglycine (Chg) resulted in the discovery of 5a, 5c, and 5e endowed with improved cellular activity in comparison to 1a.
Optimal filter realization for a class of nonlinear systems with finite-dimensional estimation algebra*

A close relationship between the dimension of the estimation algebra and the existence of a finite-dimensional filter of a particular type has been established by several researchers. However, a general procedure for constructing the filter realization has not been developed. In this paper a realization is presented for a special class of nonlinear systems with finite-dimensional estimation algebra. The filter consists of two dynamic processes, one which is data independent and one which is data dependent
Changes in signalling molecule levels in 10-day hindlimb immobilized rat muscles

Aim: Hindlimb immobilization produces similar percentage decreases in muscle mass in the predominantly type I soleus and type II vastus lateralis muscles. Consequently we hypothesized that the percentage changes in potential regulatory molecules for atrophy would be similar in the two muscle fibre types. Methods: Therefore, the purpose of the current study was to measure phosphorylated p38 MAPK and JNK, as well as the protein levels of p53, growth arrest and DNA damage-inducible 45 (GADD45), and full-length poly(ADP-ribose) polymerase (PARP) to determine whether their changes in expression in the soleus and vastus lateralis muscles were similar at 10th day of hindlimb immobilization in young rats. Results: Unexpectedly, preferential increases in phosphorylation of p38 MAPK and JNK and in the protein levels of p53, GADD45, as well as decreases in full-length PARP occurred in the soleus muscle, while only p38 phosphorylation increased in the white portion of the vastus lateralis muscle at 10th day of hindlimb immobilization. Conclusion: Taken together, these results are interpreted to suggest that some of regulatory processes or kinetics in the atrophy of type I and II muscle fibres during limb immobilization may differ at the 10th day of limb immobilization.
Glutathione and thioredoxin type 1 cooperatively denitrosate HepG2 cells-derived cytosolic S-nitrosoproteins

In this study, we present experimental evidence that glutathione acts in concert with human thioredoxin type 1 in the denitrosation of cytosolic S-nitrosoproteins (PSNOs) from HepG2 cells.
13C-NMR of ribosyl A-A-A, A-A-G, AND A-U-G Synthesis and Assignment

Abstract The three RNA trinucleotides; ApApA, ApApG, and ApUpG, have been synthesized in sufficient quantity to obtain natural abundance 13 C{ 1 H}-NMR spectra at strand concentrations between 4 and 100 mM. Comparisons between 70°C spectra of the three trimers and their consistuent dimers ApA, ApG, ApU, and UpG allow secure assignments to be made for most of the resonances. This paper describes the syntheses and 13 C assignments of the oligomers.
D2-4: Failure on Cognitive Screening Predicts Increased Healthcare Utilization

Background/Aims Most physicians fail to diagnose dementia until the moderate-severe stages. Cognitive screening for dementia in the asymptomatic population is not routinely performed due to the absence of evidence showing improved health outcomes. HealthPartners has piloted the use of the Mini-Cog as a standardized screening tool for cognitive function in patients aged 65 and older in order to assess the impact of undetected cognitive impairment on chronic disease management and healthcare utilization.
Where are the causes of placebo analgesia

Environmental conditions that foster a placebo analgesic effect include prior exposure to an effective analgesic treatment and contextual cues associated with such treatment. This evidence for the role of classical conditioning in placebo analgesia suggests the potential use of animal models for studying this phenomenon and the possibility of understanding it at the level of neural mechanisms. In addition, cognitive dimensions, such as desire for and expectation of pain relief, can potentially extend explanations of how placebo analgesia occurs. Importantly, these experiential factors are measurable and could be incorporated into analyses of human placebo analgesia. Measures of experiential factors that may directly cause placebo analgesia, multiple measures of the different dimensions of pain, and adequate controls for the natural history could permit a refined analysis of the nature and mechanisms of placebo analgesia. Measurement of the critical experiential factors that cause placebo responses may have far-reaching implications for the evaluation of placebo effects in human clinical studies.
Microcracking due to grain boundary sliding in polycrystalline ice under uniaxial compression

Abstract This paper examines grain boundary sliding as a mechanism for nucleation and growth of microcracks in polycrystalline S2 ice, under uniaxial compression. The loading rate is fast enough so that the polycrystal response is almost linear. A unit cell model is set up and the resulting boundary value problem solved using the finite element method. Simulations show that by allowing grain boundary sliding a defect originating at the triple point grows stably, reaches a critical length and then propagates unstably to the neighboring triple point. The influence of the elastic mismatch between neighboring grains on microcracking stress is not strong. The stress causing microcrack growth is found to be inversely proportional to the square root of the grain size. If no grain sliding takes place, and only the elastic anisotropy mechanism operates, the stresses required for microcrack nucleation and growth are unrealisticly high; the resulting microcracks are also too short.
Re-cinematography: improving the camera dynamics of casual video

This paper presents an approach to post-processing casually captured videos to improve apparent camera movement. Re-cinematography transforms each frame of a video such that the video better follows cinematic conventions. The approach breaks videos into shorter segments. For segments of the source video where the camera is relatively static, re-cinematography uses image stabilization to make the result look locked-down. For segments with camera motions, camera paths are keyframed automatically and interpolated with matrix logarithms to give velocity-profiled movements that appear intentional and directed. The approach automatically balances the tradeoff between motion smoothness and distortion to the original imagery. Results from our prototype show improvements to poor quality home videos.
Low-power divider

The general objective of our work is to develop methods to reduce the energy consumption of arithmetic modules while maintaining the delay unchanged and keeping the increase in the area to a minimum. Here, we illustrate some techniques for dividers realized in CMOS technology. The energy dissipation reduction is carried out at different levels of abstraction: from the algorithm level down to the implementation, or gate, level. We describe the use of techniques such as switching-off not active blocks, retiming, dual voltage, and equalizing the paths to reduce glitches. Also, we describe modifications in the on-the-fly conversion and rounding algorithm and in the redundant representation of the residual in order to reduce the energy dissipation. The techniques and modifications mentioned above are applied to a radix-4, divider, realized with static CMOS standard cells, for which a reduction of 40 percent is obtained with respect to the standard implementation. This reduction is expected to be about 60 percent if low-voltage gates, for dual voltage implementation, are available. The techniques used here should be applicable to a variety of arithmetic modules which have similar characteristics.
Mechanisms Involved in Calcitonin Gene-Related Peptide-Induced Relaxation in Pregnant Rat Uterine Artery

Human and rodent studies have demonstrated that calcitonin gene-related peptide (CGRP), a potent vasodilator, relaxes uterine tissue during pregnancy but not during labor. The vascular sensitivity to CGRP is enhanced during pregnancy, compared to nonpregnant human uterine arteries. In the present study, we hypothesized that uterine artery relaxation effects of CGRP are enhanced in pregnant rats compared to nonpregnant diestrus rats (NP-DE) and that several secondary messenger systems are involved in this process. We also hypothesized that the expression of CGRP-A receptor components, calcitonin receptor-like receptor (CRLR), receptor activity-modifying protein (RAMP1), and CGRP-B receptors are greater in pregnant rats. For vascular relaxation studies, uterine arteries from either NP-DE or Day 18 pregnant rats were isolated, and responsiveness of the vessels to CGRP was examined with a small vessel myograph. CGRP-A and CGRP-B receptor expressions were assessed by RT-PCR and Western immunoblotting, respectively. CGRP (10 210 ‐10 27 M) produced a concentration-dependent relaxation of norepinephrine-induced contractions in both NP-DE and Day 18 pregnant rat uterine arteries. Pregnancy increased the vasodilator sensitivity to CGRP significantly (P , 0.05) compared to NP-DE rats. CGRP receptor antagonist, CGRP8-37, inhibited CGRP-induced relaxation of pregnant uterine arteries. The CGRP-induced relaxation was not affected by N G
Dose/Dose-Rate Responses of Shrimp Larvae to UV-B Radiation *

Previous work indicated dose-rate thresholds in the effects of UV-B on the near-surface larvae of three shrimp species. Additional observations suggest that the total dose response varies with dose-rate. Below 0.002 Wm-2 [DNA] irradiance no significant effect is noted in activity, development, or survival. Beyond that dose-rate threshold, shrimp larvae are significantly affected if the total dose exceeds about 85 Jm-2 [DNA]. Predictions cannot be made without both the dose-rate and the dose. These dose/dose-rate thresholds are compared to four-year mean dose/dose-rate solar UV-B irradiances at the experimental site, measured at the surface and calculated for 1 m depth. The probability that the shrimp larvae would receive lethal irradiance is low for the first half of the season of surface occurrence, even with a 44% increase in damaging UV radiation.
Student Willingness to Seek Help for Threats of Violence in Middle School.

This study examined factors that influence a student's willingness to seek help for a threat of violence. The sample consisted of 542 middle school students who completed an anonymous survey that asked students how likely they would be to seek help in response to being bullied or threatened. The survey also included measures of type of bullying, attitudes toward aggressive behavior, and perceptions of teacher tolerance for bullying. Stepwise multiple regression analyses indicated that willingness to seek help is lower in higher grade levels and among males. Students who hold aggressive attitudes and perceive the school climate to be tolerant of bullying were less likely to report a willingness to seek help. Implications for improving student willingness to seek help are discussed.
The Energetic Cost of Parasitism in Isopods

Abstract: Assessment of the energetic costs of parasitism is central to understanding the role of parasites in their hosts' foodwebs, but few studies have directly measured these costs. This study demonstrates that infection with the acanthocephalan parasite Acanthocephalus tehlequahensis causes a significant and direct energetic cost to its freshwater isopod intermediate host Ceacidotea communis at both individual and population levels. Bomb calorimetry was used to measure energy (kj·m-2·y-1) allocated to host growth, reproduction, and respiration in infected and uninfected isopods and to parasite tissue in infected isopods. Infected isopod individuals allocated ∼21% of their net production energy to parasite growth, and they were larger (length), consumed more leaf detritus, and lost significantly more energy to respiration than uninfected controls (P ≤ 0.05). They also allocated proportionally less energy to tissue growth, allocated zero energy to reproduction, and were less efficient at converting ene...
NCBI Viral Genomes Resource

Recent technological innovations have ignited an explosion in virus genome sequencing that promises to fundamentally alter our understanding of viral biology and profoundly impact public health policy. Yet, any potential benefits from the billowing cloud of next generation sequence data hinge upon well implemented reference resources that facilitate the identification of sequences, aid in the assembly of sequence reads and provide reference annotation sources. The NCBI Viral Genomes Resource is a reference resource designed to bring order to this sequence shockwave and improve usability of viral sequence data. The resource can be accessed at http://www.ncbi.nlm.nih.gov/genome/viruses/ and catalogs all publicly available virus genome sequences and curates reference genome sequences. As the number of genome sequences has grown, so too have the difficulties in annotating and maintaining reference sequences. The rapid expansion of the viral sequence universe has forced a recalibration of the data model to better provide extant sequence representation and enhanced reference sequence products to serve the needs of the various viral communities. This, in turn, has placed increased emphasis on leveraging the knowledge of individual scientific communities to identify important viral sequences and develop well annotated reference virus genome sets.
The Spanish Attempt to Tribalize the Darién, 1735-50

Spanish officials in eastern Panama believed that Christianized Indians would serve as surrogates for Spanish settlers or troops, and their attempts to administer the region were grounded upon establishing alliances with selected Indian leaders. At the same time, pirates and other intruders also saw the need for alliances with Indian men in order for their endeavors to succeed. Through a process in which Europeans and Indians played an equal part, the early modern period saw the creation of several new indigenous leaders. The chieftains who interacted with outsiders were forced to create new ways of ruling on the ground as they navigated through an evolving colonial world in the Darien. This world was clearly built upon indigenous models, though it was not exactly indigenous. And though it drew upon European administrative forms and symbols for a good portion of its legitimacy, it was not recognizably European either.
The self-consistent simulation of the modulation responses of quantum well lasers

Summary form only given. A self-consistent simulation (called MINILASE) that solves simultaneously the electrostatic, carrier transport, and optical problems in all areas of the device has been developed and used to calculate self-consistent modulation responses for a laser diode. The frequency responses of three single buried quantum well GaAs/AlGaAs lasers, each with a different type of cladding region, have been compared. One cladding region has constant Al concentration; another has a quadratically graded Al mole fraction; and the third is linearly graded. The calculations clearly show that the modulation response can be improved by exploiting the gradient in crystal potential that accompanies a graded cladding region. >
Specific Binding of Integrase to the Origin of Transfer (oriT) of the Conjugative Transposon Tn916

Purified integrase protein (Int) of the conjugative transposon Tn916 was shown, using nuclease protection experiments, to bind specifically to a site within the origin of conjugal transfer of the transposon, oriT. A sequence similar to the ends of the transposon that are bound by the C-terminal DNA-binding domain of Int was present in the protected region. However, Int binding to oriT required both the N- and C-terminal DNA-binding domains of Int, and the pattern of nuclease protection differed from that observed when Int binds to the transposon ends and flanking DNA. Binding of Int to oriT may be part of a mechanism to prevent premature conjugal transfer of Tn916 prior to excision from the donor DNA.
A general model for effects of temperature on ectotherm ontogenetic growth and development

The temperature size rule (TSR) is the tendency for ectotherms to develop faster but mature at smaller body sizes at higher temperatures. It can be explained by a simple model in which the rate of growth or biomass accumulation and the rate of development have different temperature dependence. The model accounts for both TSR and the less frequently observed reverse-TSR, predicts the fraction of energy allocated to maintenance and synthesis over the course of development, and also predicts that less total energy is expended when developing at warmer temperatures for TSR and vice versa for reverse-TSR. It has important implications for effects of climate change on ectothermic animals.
Quantitative, Simultaneous PET/MRI for Intratumoral Imaging with an MRI-Compatible PET Scanner

Noninvasive methods are needed to explore the heterogeneous tumor microenvironment and its modulation by therapy. Hybrid PET/MRI systems are being developed for small-animal and clinical use. The advantage of these integrated systems depends on their ability to provide MR images that are spatially coincident with simultaneously acquired PET images, allowing combined functional MRI and PET studies of intratissue heterogeneity. Although much effort has been devoted to developing this new technology, the issue of quantitative and spatial fidelity of PET images from hybrid PET/MRI systems to the tissues imaged has received little attention. Here, we evaluated the ability of a first-generation, small-animal MRI-compatible PET scanner to accurately depict heterogeneous patterns of radiotracer uptake in tumors. Methods: Quantitative imaging characteristics of the MRI-compatible PET (PET/MRI) scanner were evaluated with phantoms using calibration coefficients derived from a mouse-sized linearity phantom. PET performance was compared with a commercial small-animal PET system and autoradiography in tumor-bearing mice. Pixel and structure-based similarity metrics were used to evaluate image concordance among modalities. Feasibility of simultaneous PET/MRI functional imaging of tumors was explored by following ^(64)Cu-labeled antibody uptake in relation to diffusion MRI using cooccurrence matrix analysis. Results: The PET/MRI scanner showed stable and linear response. Activity concentration recovery values (measured and true activity concentration) calculated for 4-mm-diameter rods within linearity and uniform activity rod phantoms were near unity (0.97 ± 0.06 and 1.03 ± 0.03, respectively). Intratumoral uptake patterns for both ^(18)F-FDG and a ^(64)Cu-antibody acquired using the PET/MRI scanner and small-animal PET were highly correlated with autoradiography (r > 0.99) and with each other (r = 0.97 ± 0.01). On the basis of these data, we performed a preliminary study comparing diffusion MRI and radiolabeled antibody uptake patterns over time and visualized movement of antibodies from the vascular space into the tumor mass. Conclusion: The MRI-compatible PET scanner provided tumor images that were quantitatively accurate and spatially concordant with autoradiography and the small-animal PET examination. Cooccurrence matrix approaches enabled effective analysis of multimodal image sets. These observations confirm the ability of the current simultaneous PET/MRI system to provide accurate observations of intratumoral function and serve as a benchmark for future evaluations of hybrid instrumentation.
How do students define their roles and responsibilities in online learning group projects

The goal of this study was to explore the processes of group role formation in online class settings. Qualitative analysis was used to code chat logs and discussion threads in six undergraduate Family and Consumer Sciences online courses that required online group projects. Four themes related to the process of group role formation emerged: testing the waters, apologies as being nice, tag – you’re it, and struggling to find one’s role. Students created roles of leader, wannabe, spoiler, agreeable enabler, coat‐tails, and supportive worker as the group process evolved over the course of the semester. Results lend support for a balance between allowing students to create and experience roles on their own and faculty assignment of roles. Questions are raised related to faculty approaches toward directing and scaffolding the group process.
From competition to collaboration: the challenge of commercial-class aircraft manufacturing

Sectoral analyses reveal an emerging tension between a global market and an anarchic political system and oblige scholars to examine the dynamic and reciprocal relationship between states and markets. This analysis of commercial-class aircraft manufacturing, a strategic industry, demonstrates how corporate behavior affects political choices and vice versa. It suggests that corporate and political policymaking is a messy process: first, policymakers must respond to multiple and often conflicting demands, from both domestic and international constituencies; second, they are influenced by a number of variables, including ideology, interest group activity, consequences of previous policies, perceptions about their state's position in the international system, and available knowledge about how to realize specific goals. Sets of competing variables which act as centripetal and centrifugal forces are identified and analyzed in terms of how they have impelled corporations to seek transnational production arrangements. Three prototypical structures of international production are delineated, and the potential consequences for states and corporations participating in each model are discussed. The key objectives of the article are to encourage the use of multivariate analyses to explain change in the international system and to provoke further debate about the appropriate policies to pursue to achieve global economic competitiveness across a number of industry sectors.
Letter of Hope

I open this letter to you with a quote from Dr. Wangari Maathai’s 2004 Nobel Lecture: In the course of history, there comes a time when humanity is called to shift to a new level of consciousness, to reach a higher moral ground. A time when we have to shed our fear and give hope to each other. That time is now (Maathai, 2004).
Estrogen- and Progesterone-Receptor Status in ECOG 2197: Comparison of Immunohistochemistry by Local and Central Laboratories and Quantitative Reverse Transcription Polymerase Chain Reaction by Central Laboratory

Purpose Central and local laboratory concordance for hormone receptor measurement is therapeutically important. This study compares estrogen receptor (ER) and progesterone receptor (PR) measured by local laboratory immunohistochemistry (IHC), central IHC, and central reverse-transcriptase polymerase chain reaction (RT-PCR) using a proprietary 21-gene assay. Patients and Methods A case-control sample of 776 breast cancer patients from Eastern Cooperative Oncology Group (ECOG) study E2197 was evaluated. Central IHC Allred score for ER and PR was obtained using tissue microarrays and 1D5 ER antibody and 636 PR antibody. Quantitative RT-PCR for ER and PR in whole sections was performed using the 21-gene assay. Results For ER, the concordance between local and central IHC was 90% (95% CI, 88% to 92%), between local IHC and central RT-PCR was 91% (95% CI, 89% to 93%), and between central IHC and central RT-PCR was 93% (95% CI, 91% to 95%). For PR, the concordance between local IHC and central IHC was 84% (95% CI, 82% to 87%), between local IHC and central RT-PCR was 88% (95% CI, 85% to 90%), and between central IHC and central RT-PCR was 90% (95% CI, 88% to 92%). Although concordance was high, IHC ER-negative cases that were RT-PCR positive were more common than IHC ER-positive cases that were RT-PCR negative. In ER-positive patients, ER expression by central IHC Allred score was marginally associated with recurrence (P .091), and ER expression by central RT-PCR was significantly associated with recurrence (P .014). However, recurrence score, which incorporates additional genes/pathways, was a highly significant predictor of recurrence (P .0001). Conclusion There is a high degree of concordance among local IHC, central IHC, and central RT-PCR by the proprietary gene assay for ER and PR status. Although ER expression is marginally associated with relapse in ER-positive patients treated with chemohormonal therapy, recurrence score is a highly significant predictor of recurrence.
A TECHNIQUE EOR PREDICTING THE EFEECT OF TREATMENT

A common method for evaluating the effect of a treatment is by analysis of variance with one of the classifications being treatment contrasted with control. Even when the treatment is successful on many Ss there are usually some Ss for whom the treatment is a failure or at least not very effective. This paper is concerned with a multivariate method for predicting treatment success and failure. The experiment at hand concerns electroencephalograms of patients treated with psychotropic drugs. From the experiment at hand it is possible to conclude that the response of mental patients to a comhination of chlorpromazine and procyclidine and to imipramine is detectable in their electroencephalograms, and also that the response to chlorpromazine in combination with procyclidine is quite likely to he predictable from their pretreatment electroencephalograms. Pronounced systematic differences in electroencephalograms were also found hetween the sexes.
Linking conformation change to hemoglobin activation via chain-selective time-resolved resonance Raman spectroscopy of protoheme/mesoheme hybrids

Time-resolved resonance Raman (RR) spectra are reported for hemoglobin (Hb) tetramers, in which the α and β chains are selectively substituted with mesoheme. The Soret absorption band shift in mesoheme relative to protoheme permits chain-selective recording of heme RR spectra. The evolution of these spectra following HbCO photolysis shows that the geminate recombination rates and the yields are the same for the two chains, consistent with recent results on 15N-heme isotopomer hybrids. The spectra also reveal systematic shifts in the deoxyheme ν 4 and ν Fe–His RR bands, which are anticorrelated. These shifts are resolved for the successive intermediates in the protein structure, which have previously been determined from time-resolved UV RR spectra. Both chains show Fe–His bond compression in the immediate photoproduct, which relaxes during the formation of the first intermediate, Rdeoxy (0.07 μs), in which the proximal F-helix is proposed to move away from the heme. Subsequently, the Fe–His bond weakens, more so for the α chains than for the β chains. The weakening is gradual for the β chains, but is abrupt for the α chains, coinciding with completion of the R–T quaternary transition, at 20 μs. Since the transition from fast- to slow-rebinding Hb also occurs at 20 μs, the drop in the α chain ν Fe–His supports the localization of ligation restraint to tension in the Fe–His bond, at least in the α chains. The mechanism is more complex in the β chains.
Behavioral simulation of a 3-bit flash ADC

A behavioral-level simulation of a 3-b flash analog-digital converter (ADC) is presented. This application illustrates the usefulness of higher-level modeling of analog circuits. Such models allow efficient simulation of analog or mixed analog-digital systems while providing meaningful results. This particular example illustrates how comparator delays affect the functionality of a flash ADC and how behavioral-level simulation can preserve this information. >
Design impacts of stochastically-varying input parameters on advanced thermoelectric conversion systems

Advanced, direct thermal energy conversion technologies are receiving increased research attention in order to recover waste thermal energy in advanced vehicles and industrial processes. Advanced thermoelectric (TE) systems necessarily require integrated system-level analyses to establish accurate optimum system designs. Past system-level design and analysis has relied on well-defined deterministic input parameters even though many critically important environmental and system design parameters in the above mentioned applications are often randomly variable, sometimes according to complex relationships, rather than discrete, well-known deterministic variables. This work describes new research and development creating techniques and capabilities for probabilistic design and analysis of advanced TE power generation systems to quantify the effects of randomly uncertain design inputs in determining more robust optimum TE system designs and expected outputs. Selected case studies involving stochastic TE .material properties and coupled multi-variable stochasticity in key environmental and design parameters are presented and discussed to demonstrate key impacts from considering stochastic design inputs on the TE design optimization process. Critical findings show that: 1) stochastic Gaussian input distributions may produce Gaussian or non-Gaussian outcome probability distributions for critical TE design parameters, and 2) probabilistic input considerations can create design effects that warrant significant modifications to deterministically-derived optimum TE system designs. Magnitudes and directions of these design modifications are quantified for selected TE system design analysis cases.
Mammalian mRNA splice-isoform selection is tightly controlled.

Post-transcriptional RNA processing is an important regulatory control mechanism for determining the phenotype of eukaryotic cells. The processing of a transcribed RNA species into alternative splice isoforms yields products that can perform different functions. Each type of cell in a multi-cellular organism is presumed to actively control the relative quantities of alternative splice isoforms. In this study, the alternatively spliced isoforms of five mRNA transcription units were examined by quantitative reverse transcription–PCR amplification. We show that interindividual variation in splice-isoform selection is very highly constrained when measured in a large population of genetically diverse mice (i.e., full siblings; N = 150). Remarkably, splice-isoform ratios are among the most invariant phenotypes measured in this population and are confirmed in a second, genetically distinct population. In addition, the patterns of splice-isoform selection show tissue-specific and age-related changes. We propose that splice-isoform selection is exceptionally robust to genetic and environmental variability and may provide a control point for cellular homeostasis. As a consequence, splice-isoform ratios may be useful as a practical quantitative measure of the physiological status of cells and tissues.
Upper Esophageal Sphincter and Gastroesophageal Junction Pressure Changes Act to Prevent Gastroesophageal and Esophagopharyngeal Reflux During Apneic Episodes in Patients With Obstructive Sleep Apnea

Background Gastroesophageal reflux (GER) is thought to be induced by decreasing intraesophageal pressure during obstructive sleep apnea (OSA). However, pressure changes in the upper esophageal sphincter (UES) and gastroesophageal junction (GEJ) pressure during OSA events have not been measured. The aim of this study was to determine UES and GEJ pressure change during OSA and characterize the GER and esophagopharyngeal reflux (EPR) events during sleep. Methods We studied 15 controls, nine patients with GER disease (GERD) and without OSA, six patients with OSA and without GERD, and 11 patients with both OSA and GERD for 6 to 8 h postprandially during sleep. We concurrently recorded the following: (1) UES, GEJ, esophageal body (ESO), and gastric pressures by high-resolution manometry; (2) pharyngeal and esophageal reflux events by impedance and pH recordings; and (3) sleep stages and respiratory events using polysomnography. End-inspiration UES, GEJ, ESO, and gastric pressures over intervals of OSA were averaged in patients with OSA and compared with average values for randomly selected 10-s intervals during sleep in controls and patients with GERD. Results ESO pressures decreased during OSA events. However, end-inspiratory UES and GEJ pressures progressively increased during OSA, and at the end of OSA events were significantly higher than at the beginning (P Conclusions Despite a decrease in ESO pressure during OSA events, compensatory changes in UES and GEJ pressures prevent reflux.