cssi/SciSciGPT-SciSciNet huggingface dataset:
Thoracic epidural anesthesia and thoracic surgery in children

In children, postoperative analgesia after thoracic surgery is generally provided by parenteral narcotics and/or regional techniques. Regional anesthesia has gained widespread use in the management of pain in children. Both caudal and lumbar approaches to the epidural space are used extensively. Unfortunately, even though the spread of local anesthesia administered caudally or in the lumbar region has been well documented, the doses needed or required for the upper abdominal or thoracic dermatomes are high and potentially toxic. Recently, clinicians have been using the thoracic approach to the epidural space or placement of thoracic catheters through the caudal or lumbar approach. This has several advantages including, and perhaps the most important, superior pain relief. The techniques in the placement of the blocks are similar to those for adults, although some differences exist mainly in anatomical issues and drug dosages. Side effects are similar to those in adults and include the potential for spinal cord damage if dural puncture occurs, problems with the catheters, and problems associated with the use of both local anesthetics and opioids. This article will describe the experience with thoracic epidurals in children through thoracic, lumbar, and caudal approaches. A novel approach to the postoperative pain management in children after thoracic surgery is also presented.
Effects of chronic growth hormone and insulin-like growth factor 1 deficiency on osteoarthritis severity in rat knee joints.

Objective To determine the effects of chronic deficiency of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) on osteoarthritis (OA) severity. Methods Thirty-five rats were divided into 4 treatment groups at 4 weeks of age: 1 control group (normal GH/IGF-1 levels [heterozygous]) and 3 groups of dwarves with a genetic mutation that results in GH deficiency. The first dwarf group received GH for 64 weeks (GH replete) and the second received GH until 14 weeks of age, followed by saline for 50 weeks (adult-onset GH/IGF-1 deficiency [AO-GHD]). The third dwarf group received saline injections only (lifetime GH deficient [GHD]). Sections of the medial knee joint compartment were graded and measured histologically; data were summarized using factor analysis, and treatment effects were assessed using analysis of variance and adjusting for body weight. Results Terminal IGF-1 levels and body weights were significantly affected by treatment (P = 0.002 and P < 0.001, respectively). Factor analysis yielded a total of 5 factors, the first 3 of which were not significantly affected by treatment. Factor 4 (weighted by medial tibial plateau articular cartilage width and area) was significantly affected by treatment (P < 0.012), with larger values in the AO-GHD group than in the GHD group (P < 0.05). Factor 5 (weighted primarily by articular cartilage structure and loss of toluidine blue staining scores) also was significantly affected by treatment (P < 0.001), and was significantly lower (less severe lesions) in the GH replete group than in all other treatment groups (P < 0.05). Despite the presence of cartilage lesions, osteophytes and subchondral sclerosis were not observed in GH/IGF-1–deficient animals. Conclusion These results indicate that chronic GH/IGF-1 deficiency causes an increased severity of articular cartilage lesions of OA without the bony lesions normally seen in this disease.
The nonsurgical treatment of a class II open bite malocclusion

This case was treated by residents in the postgraduate orthodontic program at the University of Florida under the supervision of Dr. Hocevar. A treatment regimen that he developed to increase the strength and endurance of the masticatory muscles was used. The patient performed prescribed daily clenching and chewing exercise with resilient posterior bite-blocks and wore a hard acrylic posterior biteplane the remainder of the time. It was hoped that this approach would increase the chances of treatment success and stability.
Anomalous cosmic rays: Observations

The latitudinal gradients of galactic cosmic ray protons and anomalous cosmic ray (ACR) helium appear to be symmetrical about a plane displaced ∼10° south of the heliographic equator, similar to the displacement of the heliospheric current sheet (HCS). The radial gradient of ∼10 MeV/nuc ACR oxygen in the outer heliosphere is correlated with the amplitude of the tilt of the HCS. The form of the correlation depends on the magnetic polarity of the solar cycle. The observed radial gradients are the basis for an empirical model that reasonably describes the modulation of ∼2–3 GV ACR oxygen at low heliographic latitudes over a 25-year period.
Junior-level design experiment in a 10 week analog design course

This paper presents a newly designed laboratory project for the Oregon State University (OSU) Electronics II course for junior-level electrical and computer engineering (ECE) students. The previous course was taught using common-place single session laboratory experiments and was not well received by students. An open-ended multi-solution laboratory project designed to boost students' abilities on problem solving and innovation was chosen. The new laboratory project was developed to integrate design, communication, and system thinking into a single course. Integration of these soft-skills into the laboratory gives opportunities to use the skills in a technical context. This initial single term course better prepares students for later coursework. To assess the changes to this new laboratory, student pre and post surveys were used along side of laboratory observations. Topics of interest were student self-efficacy, student expectations of the laboratory, and student reflections on the course-laboratory connection. Results from the initial student self-efficacy survey results show an increase in student teamwork while the students' expectations of the course showed provable trends. Student reflections show the most variability and give insights into what aspects of the course worked the best.
Evolutionary changes in the information content of polypeptides

Thermal proteins arising from the self-sequencing of amino acids satisfy the necessary conditions required for them to become a candidate of the evolutionary precursors of contemporary proteins. The source matrix of information or, equivalently, the statistical ensemble of polypeptides, in reference to which the information content of each amino acid residue can be defined and determined, changes with time endogenously through the production of and the change in the mechanism of production of polypeptides. The change proceeds in the direction along which the order of autocatalysis, the number of autocatalytic polymers needed for synthesizing one such polymer, increases. The underlying dynamics is material flow equilibration working in any material aggregate open to material flow, saying that any open system changes its interaction with the exterior endogenously and successively so as to maintain the continuity of material flow there. The self-sequencing and the autocatalytic polymerization of amino acids are the forms of producing polypeptides. The change in the mechanism of producing polypeptides results from the incorporation of polynucleotides into the polypeptide synthesis. The earlier polymeric information translation proceeds from polypeptide to polynucleotide. The direction of translation is reversed at a later stage of evolution. All these evolutionary events are consistent with viewing thermal proteins produced by self-sequencing of amino acids as an evolutionary precursor of contemporary proteins.
Fully invariant and verbal congruence relations

A congruence relation θ on an algebra A is fully invariant if every endomorphism of A preserves θ. A congruence θ is verbal if there exists a variety \({\mathcal{V}}\) such that θ is the least congruence of A such that \({{\bf A}/\theta \in \mathcal{V}}\) . Every verbal congruence relation is known to be fully invariant. This paper investigates fully invariant congruence relations that are verbal, algebras whose fully invariant congruences are verbal, and varieties for which every fully invariant congruence in every algebra in the variety is verbal.
Correlates between hematopoiesis and neuropoiesis: neural stem cells.

There are many parallels between the neuropoietic and lymphohematopoietic systems. The lymphohematopoietic stem/progenitor cell system has been extensively characterized, but there are still major questions relating to the definitive stem cell assay, the structure of the system (i.e., hierarchical versus cell cycle-based), and the nature of differentiation (i.e., stochastic versus deterministic). Recent data have established the existence of an epidermal growth factor (EGF)-responsive neural stem cell in adult mice. We have studied these neural progenitor/stem cells in fetal (day 15) and 2-day postnatal mice and established a single-cell progenitor assay and a variety of putative uni-, bi-, and tripotential stem cells that form in response to EGF. Neurospheres are the EGF-responsive neural units that grow in liquid culture, and we have found that cells derived from these neurospheres express a wide array of cytokines and their receptors. This will provide a window on the hemopoietic progenitor system analogous to that created by the description of in vitro growth of clonal hematopoietic progenitors.
A Mechanistic Force Model for Contour Turning

In this paper a mechanistic force model for contour turning is presented. Analytical solutions are developed for evaluation of the mechanistic parameters (chip load, chip thickness, chip width, effective lead angle), as a function of the process parameters (tool geometry, workpiece geometry, and the tool path). The effect of these parameter variations on the cutting forces is analyzed. Simple straight turning tests are employed for model calibration. A workpiece with convex and concave contours is employed for model validation. Model simulations are found to match well with the experimental results. The analytical model is utilized to investigate the effect of process variables with a 2 6 full factorial design.
Non-linear dynamics in parkinsonism

Over the last 30 years, the functions (and dysfunctions) of the sensory-motor circuitry have been mostly conceptualized using linear modelizations which have resulted in two main models: the "rate hypothesis" and the "oscillatory hypothesis". In these two models, the basal ganglia data stream is envisaged as a random temporal combination of independent simple patterns issued from its probability distribution of interval interspikes or its spectrum of frequencies respectively. More recently, non-linear analyses have been introduced in the modelization of motor circuitry activities, and they have provided evidences that complex temporal organizations exist in basal ganglia neuronal activities. Regarding movement disorders, these complex temporal organizations in the basal ganglia data stream differ between conditions (i.e. parkinsonism, dyskinesia, healthy control) and are responsive to treatments (i.e. L-DOPA,DBS). A body of evidence has reported that basal ganglia neuronal entropy (a marker for complexity/irregularity in time series) is higher in hypokinetic state. In line with these findings, an entropy-based model has been recently formulated to introduce basal ganglia entropy as a marker for the alteration of motor processing and a factor of motor inhibition. Importantly, non-linear features have also been identified as a marker of condition and/or treatment effects in brain global signals (EEG), muscular activities (EMG) or kinetic of motor symptoms (tremor, gait) of patients with movement disorders. It is therefore warranted that the non-linear dynamics of motor circuitry will contribute to a better understanding of the neuronal dysfunctions underlying the spectrum of parkinsonian motor symptoms including tremor, rigidity and hypokinesia.
Imaging of dihydrofolate reductase fusion gene expression in xenografts of human liver metastases of colorectal cancer in living rats

Radionuclide imaging has been demonstrated to be feasible to monitor transgene expression in vivo. We hypothesized that a potential application of this technique is to non-invasively detect in deep tissue, such as cancer cells metastatic to the liver, a specific molecular response following systemic drug treatment. Utilizing human colon adenocarcinoma cells derived from a patient's liver lesion we first developed a nude rat xenograft model for colorectal cancer metastatic to the liver. Expression of a dihydrofolate reductase–herpes simplex virus 1 thymidine kinase fusion (DHFR-HSV1 TK) transgene in the hepatic tumors was monitored in individual animals using the tracer [124I]2'-fluoro-2'-deoxy-5-iodouracil-β-d-arabinofuranoside (FIAU) and a small animal micro positron emission tomograph (microPET), while groups of rats were imaged using the tracer [131I]FIAU and a clinical gamma camera. Growth of the human metastatic colorectal cancer cells in the rat liver was detected using magnetic resonance imaging and confirmed by surgical inspection. Single as well as multiple lesions of different sizes and sites were observed in the liver of the animals. Next, using a subset of rats bearing hepatic tumors, which were retrovirally bulk transduced to express the DHFR-HSV1 TK transgene, we imaged the fusion protein expression in the hepatic tumor of living rats using the tracer [124I]FIAU and a microPET. The observed deep tissue signals were highly specific for the tumors expressing the DHFR-HSV1 TK fusion protein compared with parental untransduced tumors and other tissues as determined by gamma counting of tissue samples. A subsequent study used the tracer [131I]FIAU and a gamma camera to monitor two groups of transduced hepatic tumor-bearing rats. Prior to imaging, one group was treated with trimetrexate to exploit DHFR-mediated upregulation of the fusion gene product. Imaging in the living animal as well as subsequent gamma counting of tissue samples showed increased signal and tracer accumulation, respectively, as compared to the group not treated with the antifolate. It is concluded that the two examined nucleotide imaging methods are feasible techniques for monitoring of DHFR-HSV TK fusion protein expression in hepatic colorectal tumor tissue in living animals.
The opioid contract in the management of chronic pain.

Although the “opioid contract” is widely used in the administration of chronic opioid therapy, its use has not been well defined and there are few guidelines for developing or revising such tools. We reviewed opioid contracts from 39 major academic pain centers and analyzed every statement for its core meaning. These statements were grouped into general categories and then into specific statement groups. Substantial diversity in the content of the 39 contracts was found. Statements could be grouped into 12 general categories, 43 statement groups, and 125 individual statements. Each of the 39 contracts reviewed contained 22.5% 6 10.9% of the entire list of 125 statements and 32.6% 6 11.2% of the 43 statement categories. Contract length averaged less than 3 pages (range: 1 to 1 mean 2.2). We describe frequent and infrequent themes that may be well suited for inclusion in any given contract. While there are many significant issues related to the usage of a formal contract in chronic opioid therapy, there was substantial consistency among the contracts in their universal attempts to improve care through dissemination of information, facilitate a mutually agreed-upon course, or enhance compliance. This study serves as an initial step in considering the risks and benefits of an opioid contract as well as its ideal content and presentation. J Pain Symptom Manage 1999;18:27‐37 . © U.S. Cancer Pain Relief Committee, 1999.
Structures of Ion-Pairs Derived from Dihydroanthracenes. I. Electronic Spectra

The optical spectra of the 9-lithium and sodium salts of 9,10-dihydroanthracene and its 10-alkyl substituted derivatives have been investigated in tetrahydrofuran over a wide temperature range (25 $^\circ$C to about -70$\circ$C). The spectra of the lithium salts indicate the coexistence of two species having a different degree of solvation, one absorbing at $\lambda\_{\max}$ = 400 nm, the other at $\lambda\_{\max}$ = 450 nm. Lower temperatures favour the latter. It has been found that the presence of an alkyl substituent on carbon 10 greatly increases the stability of that species which absorbs at the longer wavelength. Only one absorption peak is seen in the spectrum of the respective sodium salts. The absorption maximum of the unsubstituted ion-pair shifts with temperature, namely $\lambda_{\max}$ = 455 nm at -70$^\circ$C and 425 nm at + 20$^\circ$C. Similar behaviour was observed for the substituted salt. These observations suggest the need for a 'dynamic' model of ion-pairs in preference to the 'static' one in which the energy of the pair is uniquely determined by the interionic distance. Such models are discussed.
Simulation and comparison of several crack closure assessment methodologies

Abstract Three different methodologies for characterizing fatigue crack closure are compared using constant amplitude fatigue crack growth simulations. The adjusted compliance ratio (ACR), crack wake influence (CWI), and conventional Elber crack opening load approaches were considered, with the CWI approach reported in the literature generalized to allow a crack surface traction distribution. The ACR methodology consistently indicated lesser levels of crack closure or shielding, which were insensitive to the applied stress level, when compared with the CWI and opening load approaches for R > 0. Closure levels using the Elber and CWI methodologies compared well for lower values of applied stress. For R = −1, the three methodologies resulted in similar levels of crack tip shielding. No evidence was observed that applied loading below the conventional crack opening load becomes more significant in the near-threshold regime.
Nitroimidazole neurotoxicity: Are mouse studies predictive?☆

Abstract The purpose of this investigation was: (i) to determine if data on the relative neurotoxicity of nitroimidazole sensitizers in mice using different quantitative functional endpoints were similar, (ii) to compare misonidazole (MISO) with desmethylmisonidazole (DMM) in relation to central nervous system (CNS) versus peripheral nervous system (PNS) effects; neural tissue exposure dose and peak level; route of administration and mouse strain; and, (iii) to determine if inhibition of glycolysis was a potential mechanism of neurotoxicity. The data indicate good agreement between the functional endpoints used to determine relative neurotoxicity and the incidence of CNS and PNS pathology in mice. MISO is 2 times more toxic per administered dose and equitoxic per brain exposure dose compared with DMM in BALB/cka mice. C3H mice are approximately 2 times more sensitive than BALB/cka to both MISO and DMM. DMM (i.p., oral or i.v.) is slightly more toxic than MISO to the CNS of C3H mice. DMM given i.v. resulted in more severe PNS lesions than either i.p. or oral DMM or i.p. or oral MISO. In general, CNS and PNS lesion development coincided suggesting these effects are separate. Significant decreases in the lactate/ pyruvate ratio of the brain-stem of MISO treated mice indicates that inhibition of glycolysis is a potential mechanism of neurotoxicity. Results are discussed in relation to the predictive significance of mouse studies to the clinical testing of sensitizers.
A physical model for state transitions in black hole X-ray binaries

CN thanks NASA for support through the Einstein Fellowship Programme, grant PF2-130098. GS thanks the National Science Foundation for support through the Graduate Research Fellowship Programme.
Nonlinear Electron Cloud Modification of Satellite Modes

A one dimensional circuit analog of the modes of a triaxial satellite is derived. Self consistent one dimensional particle calculations utilizing this model are presented. The results suggest that electrons arriving at the satellite from tank walls and damper in an SGEMP experiment, can under some circumstances, materially affect the response of the satellite.
A comparative analysis of positron emission tomography and mediastinoscopy in staging non-small cell lung cancer.

Abstract Objectives Positron emission tomography has been demonstrated to improve the detection of distant metastases in patients with lung cancer. This study compares the efficacy of PET to mediastinoscopy in mediastinal staging of patients with non–small cell lung cancer. Methods Between May 1995 and May 2000, positron emission tomography was performed on 1988 patients with known or suspected non–small cell lung cancer at Duke University Medical Center. Cervical mediastinoscopy was subsequently performed in patients without demonstrable evidence of distant metastases. The efficacy of mediastinal staging was analyzed by comparing the prospective results of positron emission tomography with the histopathologic results of mediastinoscopy by nodal station. Results In this study 202 patients with non–small cell lung cancer (116 of whom were male) underwent mediastinoscopy after positron emission tomography. Of the 65 patients with positive results of positron emission tomography, only 29 patients had positive results of mediastinoscopy in the corresponding nodal station. Of the 137 patients with negative results of positron emission tomography, 16 patients were demonstrated to have N2 or N3 disease. The sensitivity, specificity, positive and negative predictive values, and accuracy for positron emission tomography were 64.4%, 77.1%, 44.6%, 88.3%, and 74.3%, respectively. Histologic findings in patients with non–small cell lung cancer and false-positive results of mediastinal positron emission tomography included granulomatous inflammation, sinus histiocytosis, and silicosis. Conclusions Positron emission tomography neither confirms nor excludes involvement of the mediastinum in patients with non–small cell lung cancer. Cervical mediastinoscopy with lymph node biopsy remains the criterion standard for mediastinal staging.
Phage display-guided nanocarrier targeting to atheroprone vasculature

In regions of the circulation where vessels are straight and unbranched, blood flow is laminar and unidirectional. In contrast, at sites of curvature, branch points, and regions distal to stenoses, blood flow becomes disturbed. Atherosclerosis preferentially develops in these regions of disturbed blood flow. Current therapies for atherosclerosis are systemic and may not sufficiently target these atheroprone regions. In this study, we sought to leverage the alterations on the luminal surface of endothelial cells caused by this atheroprone flow for nanocarrier targeting. In vivo phage display was used to discover unique peptides that selectively bind to atheroprone regions in the mouse partial carotid artery ligation model. The peptide GSPREYTSYMPH (PREY) was found to bind 4.5-fold more avidly to the region of disturbed flow and was used to form targeted liposomes. When administered intravenously, PREY-targeted liposomes preferentially accumulated in endothelial cells in the partially occluded carotid artery and other areas of disturbed flow. Proteomic analysis and immunoblotting indicated that fibronectin and Filamin-A were preferentially bound by PREY nanocarriers in vessels with disturbed flow. In additional experiments, PREY nanocarriers were used therapeutically to deliver the nitric oxide synthase cofactor tetrahydrobiopterin (BH4), which we have previously shown to be deficient in regions of disturbed flow. This intervention increased vascular BH4 and reduced vascular superoxide in the partially ligated artery in wild-type mice and reduced plaque burden in the partially ligated left carotid artery of fat fed atheroprone mice (ApoE(-/-)). Targeting atheroprone sites of the circulation with functionalized nanocarriers provides a promising approach for prevention of early atherosclerotic lesion formation.
Reliability and fault-tolerance in multistage interconnection networks

Reliability and fault-tolerance issues are important in the study of interconnection networks used in large multiprocessor systems because of the large number of components involved. In this paper we study these issues with respect to multistage networks which are typically built forN inputs andN outputs using 2 × 2 switching elements and log2N stages. In such networks, the failure of a switching element or connecting link destroys the communication capability between one or more pair(s) of source and destination terminals. Many techniques exist for designing multistage networks that tolerate switch and/or link failures without losing connectivity. Several approaches for achieving fault-tolerance in multistage interconnection networks are described in this paper. The techniques vary from providing redundant components in the network to making multiple passes through the faulty network. Quantitative measures are introduced for analysis of the reliability of these networks in terms of the component reliabilities. Several examples are given to illustrate the techniques.
Safety of Long‐Term Propafenone Therapy for Cardiac Arrhythmia ‐ Experience with 774 Patients

Long term propafenone therapy was initiated in 774 patients who were evaluated at 27 centers in the United States. The average duration of therapy was 183 days. During the treatment period, at least one toxic side effect occurred in 448 patients (58%). The most common reported adverse reactions were cardiovascular in 209 patients (27%), central nervous system in 160 patients (21%), and gastrointestinal in 159 patients (21%). Of those with cardiovascular side effects, 41 (5.3%) had aggravation of arrhythmia, 26 (3.4%) had the induction or worsening of congestive heart failure, and 65 (8.4%) had new conduction abnormalities. Although side effects were frequent, drug discontinuation due to the adverse reaction was necessary in only 114 patients (14.7%). The majority of side effects were dose related especially when 900 mg/day was administered. Additionally, the incidence of toxicity was directly related to age. We conclude that side effects are frequent during long-term propafenone therapy, but most are mild, dose related, and do not limit the use of the drug. Drug discontinuation because of an adverse reaction is only infrequently required. It is recommended that drug therapy begin with low doses (150 mg t.i.d) with careful and slow titration up to a maximum of 900 mg/day.
Reframing responsibility in the social justice classroom

This article examines a question that white students often ask when they learn about their role in systemic racial oppression: ‘Why am I responsible?’ I argue that the conception of responsibility that grounds this question is focused on causality and individual action and makes it difficult for white students to understand how within the context of structural injustice they are complicit in systemic racial injustice. Building on the work of feminist philosophers such as Iris Marion Young and Judith Butler, I propose a rearticulated notion of responsibility that is not focused on blame or fault and that understands that critique is at the heart of ethics. Implications for social justice education are discussed.
An Investigation of Likelihoods and Priors for Bayesian Endmember Estimation

A Gibbs sampler for piece‐wise convex hyperspectral unmixing and endmember detection is presented. The standard linear mixing model used for hyperspectral unmixing assumes that hyperspectral data reside in a single convex region. However, hyperspectral data is often non‐convex. Furthermore, in standard unmixing methods, endmembers are generally represented as a single point in the high dimensional space. However, the spectral signature for a material varies as a function of the inherent variability of the material or environmental conditions. Therefore, it is more appropriate to represent each endmember as a full distribution to incorporate the variability and utilize this information during spectral unmixing. A Gibbs sampler that searches for several sets of endmember distributions, i.e. a piece‐wise convex representation, is presented. The hyperspectral data is partitioned among the sets of endmember distributions using a Dirichlet process prior that also estimates the number of needed sets. The propose...
Estrogen Replacement and Brachial Artery Flow-Mediated Vasodilation in Older Women

It remains unclear whether estrogen therapy (with or without progestin) improves endothelial function in older postmenopausal women with or at risk for coronary heart disease. To address this issue, we analyzed brachial artery flow-mediated vasodilation in the Cardiovascular Health Study, a longitudinal study of cardiovascular risk factors in subjects over 65 years of age. At the tenth annual Cardiovascular Health Study examination, 1662 women returned for follow-up. Eighteen percent (n=291) were current users of estrogen replacement, most of whom (75.9%, n=221) took unopposed estrogen. Brachial artery ultrasound examinations measuring vasodilation in response to a flow stimulus (hyperemia) were performed on 1636 women. There were no statistical differences in brachial flow-mediated vasodilator responses between users and nonusers, even after adjustment for potential confounders. Absence of an effect was most notable in women over 80 years old and in those with established cardiovascular disease. However, among women without clinical or subclinical cardiovascular disease or its risk factors, there was a significant association between hormone replacement therapy use and flow-mediated vasodilator responses ( P =0.01). Among older postmenopausal women, favorable vascular effects of estrogen may be limited to those who have not yet developed atherosclerotic vascular disease. These data emphasize the importance of ongoing efforts to determine the role of hormone replacement therapy for primary prevention of cardiovascular disease.
Crossover near fluctuation-induced first-order phase transitions in superconductors

Crossover near the fluctuation-induced first-order transition in superconductors is studied to first order in $\ensuremath{\epsilon}=4\ensuremath{-}d$. We find that the effective exponent ${\ensuremath{\gamma}}_{\mathrm{eff}}$ for the susceptibility of type-II systems falls from its value for the chargeless system to the mean-field value unity well before the first-order transition occurs. Although such effects are probably unobservable in real superconductors, these calculations may have some relevance to the nematic to smectic-$A$ transition in liquid crystals.
Does Spelling Instruction Make Students Better Spellers, Readers, and Writers? A Meta-Analytic Review.

Despite the importance of spelling for both writing and reading, there is considerable disagreement regarding how spelling skills are best acquired. During this and virtually all of the last century, some scholars have argued that spelling should not be directly or formally taught as such instruction is not effective or efficient. We conducted a comprehensive meta-analysis of experimental and quasi-experimental studies to address these claims. The corpus of 53 studies in this review included 6,037 students in kindergarten through 12th grade and yielded 58 effect sizes (ESs) that were used to answer eight research questions concerning the impact of formally teaching spelling on spelling, phonological awareness, reading, and writing performance. An average weighted ES was calculated for each question and the quality of included studies was systematically evaluated. Results provided strong and consistent support for teaching spelling, as it improved spelling performance when compared to no/unrelated instruction (ES = 0.54) or informal/incidental approaches to improving spelling performance (ES = 0.43). Increasing the amount of formal spelling instruction also proved beneficial (ES = 0.70). Gains in spelling were maintained over time (ES = 0.53) and generalized to spelling when writing (ES = 0.94). Improvements in phonological awareness (ES = 0.51) and reading skills (ES = 0.44) were also found. The positive outcomes associated with formal spelling instruction were generally consistent, regardless of students’ grade level or literacy skills.
A joint product of the genes gag and pol of Avian Sarcoma Virus: a possible precursor of reverse transcriptase

A virus-specific protein of approximately 180,000 daltons has been identified in cells transformed by avian sarcoma virus. The protein, designated P180, includes immunological determinants of both viral core proteins and reverse transcriptase. Its tryptic peptides represent essentially the sum of those of the precursor of the core proteins (Pr76gag) and reverse transcriptase. Thus P180 must arise from the uninterrupted translation of gag and pol. The kinetics of its formation and decay suggest that P180 is the precursor of reverse transcriptase.
Separation of Specific and Non-Specific Effects of Chemicals on Plants

IN working with the effects of chemicals on plants, it is often difficult to determine which of the effects obtained is specific to the chemical applied. For example, 2,4-dichlorophenoxyacetic acid (2,4-D) has been shown to cause numerous effects on plants. A recent review by Woodford et al. 1 discusses this subject in detail. It has been shown that 2,4-dichlorophenoxyacetic acid causes varied tissue changes, affects phosphorus metabolism, increases respiration, decreases photosynthesis and, in general, affects a great many functions of the plant.
Does VWF bind collagen after all

Platelets adhere to sites of vascular injury to form an initial platelet plug, and this process requires von Willebrand factor (VWF) to bridge platelet membrane glycoprotein Ib (GPIb) and ligands in exposed connective tissue. The GPIb binding site is known to reside in VWF domain A1, which is 1 of 3
The partial molar volume, thermal expansivity, and compressibility of H2O in NaAlSi3O8 liquid: new measurements and an internally consistent model

The molar volumes of 19 hydrous albitic liquids (1.9 to 6.1 wt% H2Ototal) were determined at one bar and 505–765 K. These volume data were derived from density measurements on hydrous glasses at 298 K, followed by measurements of the thermal expansion of each glass from 298 K to its respective glass transition temperature. The technique exploits the fact that the volume of a glass is equal to that of the corresponding liquid at the limiting fictive temperature (Tf′), and that Tf′ can be approximated as the temperature near the onset of the rapid increase in thermal expansion that occurs in the glass transition interval. The volume data of this study were combined with available volume data for anhydrous, Na2O-Al2O3-SiO2 liquids to derive the partial molar volume (±1) of the H2O component \(\) in an albitic melt at ∼565 K and one bar. To extend the determination of \(\) to higher temperatures and pressures, the molar volumes of the hydrous albitic liquids determined in this study were combined with those measured by previous authors at 1023–1223 K and 480–840 MPa, leading to the following fitted values (±1) at 1673 K and one bar: \(\) (±0.46)×10−3 cm−3/mol-K, and dV¯H2Ototal/dP=−3.82 (±0.36)×10−4 cm3/mol-bar. The measured molar volumes of this study and those of previous authors can be recovered with a standard deviation of 0.5%, which is within the respective experimental errors. There is a significant difference between the values for \(\) derived in this study as a function of temperature and pressure and those obtained from an existing polynomial, primarily caused by the previous absence of accurate density measurements on anhydrous silicate liquids. The coefficients of thermal expansion (=4.72×10−4/K) and isothermal compressibility (T=1.66×10−5/bar) for the H2O component at 1273 K and 100 MPa, indicate that H2Ototal is the single most expansive and compressible component in silicate liquids. For example, at 1473 K and 70 MPa (conditions of a mid-ocean ridge crustal magma chamber), the presence of just 0.4 wt% H2O will decrease the density of a basaltic liquid by more than one percent. An equivalent decrease in melt density could be achieved by increasing the temperature by 175 degrees or the decreasing pressure by 230 MPa. Therefore, even minor quantities of dissolved water will have a marked effect on the dynamic properties of silicate liquids in the crustal environment.
Subxiphoid Anterior Mediastinal Exploration

A new surgical technique for anterior mediastinal exploration is described. The technique involves application of a Carlens mediastinoscope by means of a subxiphoid incision. The procedure provides complete exploration of the anterior mediastinal compartment and allows the surgeon to obtain a positive biopsy of the tumor or its lymph node metastases without sternotomy.
The Priority of Health Care

KIE: The economic recession, the mounting costs of medical technology, and the weakening of public support for welfare state ideals have led to philosophical qualification of the right of equal access to health care by writers like Norman Daniels and Lawrence Stern. Green rejects their arguments and reiterates the claim that a Rawlsian theory of justice provides an appropriate way of thinking about the right to health care, which should be treated on a par with basic civil liberties.
Subversive sounds: ethnic spectatorship and Boston's nickelodeon theatres, 1907–1914

This paper expands on previous accounts of nickelodeon history by focusing on one specific neighborhood, the South End of Boston, and how several local theaters catered to the area's ethnic and immigrant population. Special attention is given to the live portion of the bill at the Theatre Comique, Columbia, Castle Square and Back Bay theaters, particularly to their individualized presentation of musical performance.
Growth and population size of crayfish in headwater streams: individual‐ and higher‐level consequences of acidification

SUMMARY 1. Environmental stress may have indirect positive effects on population size through modification of food-web interactions, despite having negative effects on individuals. Here we evaluate the individual- and population-level effects of acidification on crayfish (Cambarus bartonii) in headwater streams of the Allegheny Plateau (PA, U.S.A.) with field experiments and survey data. Median baseflow pH of 24 study reaches in nine streams varied from 4.4 to 7.4, with substantial variation found both among and within streams. 2. Two bioassays were conducted to evaluate the relationship between stream pH and crayfish growth rates. Growth rates were always higher in circumneutral reaches than in acidic reaches. Crayfish originating in acidic water grew less when transplanted into neutral water than did crayfish originating in neutral water, providing some evidence for a cost of acclimation to acidity. 3. Stream surveys showed that fish were less abundant and crayfish more abundant in acidified streams than in circumneutral streams. Crayfish density was sixfold higher in reaches with the lowest pH relative to circumneutral reaches. Large crayfish made up a higher proportion of crayfish populations at sites with high fish biomass, consistent with the hypothesis that fish predation on small individuals may be limiting crayfish population size at these sites. 4. Although individual crayfish suffered lower growth in acidified streams, increased acidity appeared to cause an increase in crayfish population size and shifts in size structure, possibly by relieving predation pressure by fish.
Some first passage problems related to cusum procedures

Abstract Let X 1 , X 2 ,… be independent random variables, and set Wn = max(0,Wn-1 + Xn), W0 = 0, n ⩾ 1. The so-called cusum (cumulative sum) procedure uses the first passage time T(h) = inf{n ⩾ 1: Wn⩾h}for detecting changes in the mean μ of the process. It is shown that limh→∞ μET(h)/h = 1 if μ > 0. Also, a cusum procedure for detecting changes in the normal mean is derived when the variance is unknown. An asymptotic approximation to the average run length is given.
Computer-aided design of dither signals for binary display of images

The quality of binary images displayed using ordered dither is strongly dependent on the spatial arrangement of the thresholds in the dither signal. In the frequency domain, this dependence may be viewed as a consequence of aliasing. A computer-aided approach to the design of dither signals that uses a pairwise exchange algorithm to minimize a measure of susceptibility to aliasing is described. The susceptibility measure may be chosen to take into account many factors that affect perceived image quality. Experimental results are presented that illustrate the potential of the method.
FronTier and applications to scientific and engineering problems

We report significant developments of the FronTier code and applications in science and engineering. The progress includes the extraction of an independent software library from the front tracking code, robust and accurate locally grid based method, applications to fluid mixing problem, fuel injection jet and fusion pellet injection in a magnetically confined plasma, among other problems. 1 FronTier Library Front tracking method is a structured and organized particle method. It is intrinsically a Lagrangian method in which a continuous geometrical manifold are represented and approximated by a discrete set of marker points. Interface propagation is performed through solving an ODE along the local characteristics of each marker point. This method solves for the position of the marker particle accurately. It can give resolution at subgrid level and maintain sharp corners with acute angles. It is suitable for simulations with rigid body boundary as well as with fluid surface which undergoes complex rolling and deformation. New algorithms have been introduced to make the front tracking method more robust and efficient in topological bifurcation. Among them the most significant one is the locally grid based (LGB) method [1]. This method combines the accuracy of the generic grid free (GF) tracking [2] and the robustness of the grid based (GB) method in resolving the topological bifurcation, especially in three dimensions. A set of standardized functions have been constructed to serve as an user interface for application programs. This includes the start-up functions, initialization for front geometry and velocity functions, query functions to access interface entities such as vertices, simplexes and manifolds and functions for topological information. We have also built a set of function for interpolation and interaction between a moving front and the supporting rectangular mesh. The propagation of front points can be divided into two categories. The first is the propagation independent of interface geometry such as with a given velocity function of space and time or a velocity interpolated from the computational mesh. For this type of propagation, the order of accuracy in propagating the interface marker points can be made arbitrarily high as long as we use sufficiently high order Runge-Kutta method along the local characteristics. The CFL condition controlling the time step is hyperbolic. Figure 1 is an example of such problems. In the second type of propagation, the front velocity depends on the geometry of the interface. A typical case is the velocity in normal direction of the interface and as a function of curvature. Since any change of position of a given marker point will affect the calculation of these geometry-dependent variables. For this type of propagation, any predictor calculation must be carried out to the entire manifold so that the velocity
Polarization controller based on a fiber–recirculating delay line

A fiber-optic polarization control device constructed from a recirculating delay line is introduced and analyzed. This controller is found to be without a bulk optic counterpart and is notably different in design and operation from existing fiber polarization controllers. Full control is achieved by varying two birefringence terms and a phase delay term. The device is shown to be capable of handling arbitrary polarization-state transformations and control. The design technique for this system is also fundamentally different from that of previous polarization controllers.
Beam-type collisional activation of polypeptide cations that survive ion/ion electron transfer

Doubly protonated peptides that undergo an electron transfer reaction without dissociation in a linear ion trap can be subjected to beam-type collisional activation upon transfer from the linear ion trap into an adjacent mass analyzer, as demonstrated here with a hybrid triple quadrupole/linear ion trap system. The activation can be promoted by use of a DC offset difference between the ion trap used for reaction and the ion trap into which the products are injected of 12–16 V, which gives rise to energetic collisions between the transferred ions and the collision/bath gas employed in the linear ion trap used for ion/ion reactions. Such a process can be executed routinely on hybrid linear ion trap/triple quadrupole tandem mass spectrometers and is demonstrated here with several model peptides as well as a few dozen tryptic peptides. Collisional activation of the peptide precursor ions that survive electron transfer frequently provides structural information that is absent from the precursor ions that fragment spontaneously upon electron transfer. The degree to which additional structural information is obtained by collisional activation of the surviving singly charged peptide ions depends upon peptide size. Little or no additional structural information is obtained from small peptides (<8 residues) due to the high electron transfer dissociation (ETD) efficiencies noted for these peptides as well as the extensive sequence information that tends to be forthcoming from ETD of such species. Collisional activation of the surviving electron transfer products provided greatest benefit for peptides of 8–15 residues. Copyright © 2007 John Wiley & Sons, Ltd.
Ion dependent interstitial generation of implanted mercury cadmium telluride

The creation of Hg interstitials during ion implantation of mercury cadmium telluride is found to strongly depend on the preferred lattice position of the element implanted. Elements that substitute onto the cation sublattice create significantly more interstitials than elements that sit interstitially or on the anion sublattice. In particular, implants of column II elements Mg and Zn produced much larger interstitial concentrations than implants of column VI elements S and Se. Implants of B, which resides mostly as an interstitial, produced Hg interstitial concentrations intermediate between the column II and column VI ions. Recoils from implant damage also contributed to Hg interstitial formation in heavier mass implants (Zn and Se), but appear to have negligible influence on interstitial generation in implants of lighter ions.
Biochemical evidence for 1,25-dihydroxyvitamin D receptor macromolecules in parathyroid, pancreatic, pituitary, and placental tissues.

DNA-cellulose chromatography has been recently employed in our laboratory as an extremely effective and sensitive technique with which to identify macromolecules which specifically bind 1,25-dihydroxyvitamin D (1,25-(OH)2D). Chromatography of cytosols prepared from rachitic chick intestine, parathyroid gland, pancreas, pituitary gland, and normal rat placenta all demonstrate binding components for 1,25-(OH)2D which interact with the DNA affinity ligand under low salt conditions (< 0.15M), and can be eluted as a single macromolecular peak during a linear KCl gradient between 0.25–0.30M. Further, sucrose gradient analysis of these DNA-cellulose purified components under high salt conditions (0.3M KCl) indicates a common sedimentation coefficient of 3.3S. Since the receptor properties of this macromolecule in rachitic chick intestine have been previously characterized, it seems likely that these components in the parathyroid, pituitary, pancreas, and placenta represent typical receptors for 1,25-(OH)2D.