cssi/SciSciGPT-SciSciNet huggingface dataset:
Synergistic enhancement of cancer therapy using a combination of heat shock protein targeted HPMA copolymer–drug conjugates and gold nanorod induced hyperthermia

In the field of nanomedicine, selective delivery to cancer cells is a common goal, where active targeting strategies are often employed to increase tumor accumulation. In this study, tumor hyperthermia was utilized as a means to increase the active delivery of heat shock protein (HSP) targeted N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-drug conjugates. Following hyperthermia, induced expression of cell surface heat shock protein (HSP) glucose regulated protein 78 kDa (GRP78) was utilized for targeted drug therapy. Conjugates bearing the anticancer agents aminohexylgeldanamycin (AHGDM), docetaxel (DOC), or cisplatin and the GRP78 targeting peptide WDLAWMFRLPVG were synthesized and characterized. Binding to cell surface expressed heat shock protein GRP78 on the surface of human prostate cancer DU145 cells was evaluated. HSP targeted AHGDM and DOC conjugates demonstrated active binding comparable to native targeting peptide. They were then assessed in vitro for the ability to synergistically induce cytotoxicity in combination with moderate hyperthermia (43 °C, 30 min). HSP targeted DOC conjugates exhibited high potency against DU145 cells with an IC₅₀ of 2.4 nM. HSP targeted AHGDM and DOC conjugates demonstrated synergistic effects in combination with hyperthermia with combination index values of 0.65 and 0.45 respectively. Based on these results, HSP targeted DOC conjugates were selected for in vivo evaluation. In DU145 tumor bearing mice, a single treatment of tumor hyperthermia, induced via gold nanorod mediated plasmonic photothermal therapy, and intravenous administration of HSP targeted HPMA copolymer-docetaxel at 10mg/kg resulted in maintained tumor regression for a period of 30 days. These results demonstrate the potential for tumor hyperthermia to increase the delivery of HSP targeted macromolecular chemotherapeutics.
Developments and prospects in synoptic climatology

Developments in synoptic climatology in the 1990s included advances in traditional synoptic climatology, empirical downscaling, and dynamical downscaling (i.e. regional climate modelling). The research emphasis in traditional, empirical–statistical approaches to synoptic climatology shifted from methodological development to applications of widely accepted classification techniques, including manual, correlation-based, eigenvector-based, compositing and indexing schemes. In contrast, most efforts in empirical downscaling, which became a well-established field of synoptic climatology during the 1990s, were directed to model development; applications were of secondary concern. Similarly, regional climate models (RCMs) burst onto the scene during the decade and focused on model development, although important progress was made in linking or coupling RCMs to regional or local surface climate systems. This paper discusses prospects for the future of traditional synoptic climatology, empirical downscaling and regional climate modelling. It concludes by looking at the present role of geographic information system (GIS) concepts in synoptic climatology and the potential future role of GIS to the field. Copyright © 2001 Royal Meteorological Society
Classical and quantum statistical mechanics in one and two dimensions: two-component Yukawa- and Coulomb systems

We estimate the canonical and grand canonical partition function in a finite volume and prove stability and existence of the thermodynamic limit for the pressure of two component classical and quantum systems of particles with charge ±e interacting via two body Yukawa — or Coulomb forces. In the case of Coulomb forces we require neutrality. For the classical system in two dimensions there exists a critical temperatureTc at and below which the system collapses. For the classical Yukawa system the correlation functions exist for arbitrary fugacity and the general structure of the pure phases can be analyzed completely.
Urothelial cell platelet-activating factor production mediated by calcium-independent phospholipase A2γ.

Objectives To determine the effect of phospholipase A2 (PLA2) inhibitors on urothelial cell platelet-activating factor (PAF) production in response to tryptase stimulation. Methods Urothelial cells isolated from normal human ureters were immortalized with the human papillomavirus type 16E6E7 cell line (TEU-2 cells). PLA2 activity in TEU-2 cells was measured using (16:0, [3H]18:1) plasmenylcholine and phosphatidylcholine substrates in the presence and absence of calcium. [3H]PAF production was measured in TEU-2 cells prelabeled with [3H] acetic acid. PAF-acetylhydrolase activity was measured by determining the amount of [3H] acetate hydrolyzed from [3H]PAF incubated with TEU-2 cellular protein. Adherence of human polymorphonuclear leukocyte (PMN) to TEU-2 cells was assessed by measuring myeloperoxidase activity in adherent PMNs after incubation with TEU-2 cells. Results Most PLA2 activity measured in TEU-2 cells was determined to be membrane-associated, calcium-independent PLA2 and selective for plasmenylcholine substrate. Stimulation of TEU-2 cells with tryptase results in increased production of PAF and increased PMN adherence that were inhibited completely by pretreatment with the membrane-associated, calcium-independent PLA2γ-selective inhibitor (R)-bromoenol lactone. Pretreatment with the cytosolic PLA2 inhibitor methyl arachidonyl fluorophosphonate resulted in potentiation of tryptase-stimulated PAF production and PMN adherence to TEU-2 cells that is a result of PAF-acetylhydrolase inhibition. Conclusions Tryptase stimulation of TEU-2 cells results in activation of membrane-associated, calcium-independent PLA2γ, leading to an increase in PAF production and increased PMN adherence. Inhibition of TEU-2 cell PAF-acetylhydrolase activity with methyl arachidonyl fluorophosphonate potentiated tryptase-stimulated PAF production and PMN adherence.
Tool Wear Influence on Surface Integrity and Fatigue Life of Hard Milled Surfaces

In machining, the interfacial friction between cutting tool and work material leads to tool wear which is considered a critical factor for surface quality of machined components. Surface integrity and fatigue life of machined components will deteriorate when tool flank wear progresses in machining. Hard milling experiments on AISI H13 tool steel (50 ± 1 HRC) using PVD coated tools with different levels of flank wear were conducted in this study. Surface integrity of the machined components with flank wear VB = 0 mm, 0.1 mm and 0.2 mm was characterized. The effects of cutting speed, feed, and radial depth-of-cut on surface integrity were investigated respectively at the three levels of tool flank wear. In addition, four-point bending fatigue tests were performed on the milled samples at five levels of different flank wear (VB = 0, 0.05, 0.10, 0.15, 0.20 mm) to evaluate the trend of fatigue life evolution with the increased tool flank wear.Copyright © 2011 by ASME
The Effects of Vitamin E, Vitamin B6, and Vitamin B12 on Immune Function

Many nutrients can have significant impacts on immunocompetence during periods of deficiency and supplementation. Current evidence indicates a beneficial role of numerous vitamins on immunity, including vitamins E, B6, and B12. Of these three nutrients, the strongest evidence exists for vitamin E, which has been shown to improve cell-mediated and humoral immunity in both animal and human studies. Vitamin E supplementation was found to reverse the age-associated decline in immune response with levels above the current RDA. This increase in immune response can have benefits in elderly or other immunocompromised patients. Human and animal data indicate that both B6 and B12 play a critical role in nucleotide synthesis and subsequent cell growth. Therefore, insufficient levels of B6 and B12 would inhibit the immune system's ability to respond to pathogenic challenge. B6 deficiency impairs both cell-mediated and humoral immunity in animals and humans, which is reversed following B6 supplementation. Clinical evidence suggests that B6 supplementation may improve immune function in patients with rheumatoid arthritis and HIV infection. Although few studies have been conducted with B12, limited evidence suggests a beneficial effect of B12 on immune function with HIV infection. More research is needed to elucidate clinical benefits and mechanisms of the immunostimulatory effect of these vitamins.
Parallel image normalization on a mesh connected array processor

Abstract Image normalization is a basic operation in various image processing tasks. A parallel algorithm for fast binary image normalization is proposed for a mesh connected array processor. The principal operation in this algorithm is pixel mapping. The basic idea of parallel pixel mapping is to utilize a store and forward mechanism which routes pixels from their source locations to destinations in parallel along the paths of minimum length. The routing is based on a simple yet powerful concept of flow control patterns . This can form the basis for designing other parallel algorithms for low level image processing. The normalization process is decomposed into three procedures: translation, rotation and scaling. In each procedure, a mapping algorithm is employed to route the object pixels from source locations to destinations. Simulation results for the parallel image normalization on generated images are provided.
Computed Tomography of Pediatric Stroke

The causes of stroke in the children are varied. Magnetic resonance imaging (MRI) is generally accepted as the study of choice for definitive diagnosis of ischemic injury. However, often times MRI is not immediately available in the acute setting. This review highlights some of the major causes of stroke in children and the current role of computed tomography (CT), and more specifically, CT angiography in the pediatric setting.
The nucleotide sequence of asparagine tRNA from Escherichia coli

Abstract The nucleotide seuquence of Escherichia coli asparagine tRNA was determined to be pU-C-C-U-C-U-G-s4U-A-G-U-U-C-A-G-D-C-G-G-D-A-G-A-A-C-G-G-C-G-G-A-C-U-Q-U-U-t6A-A-phi-C-C-G-U-A-U-m G-U-C-A-C-U-G-G-T-phi-C-G-A-G-U-C-C-A-G-U-C-A-G-A-G-G-A-G-C-C-AOH. Its D-stem and D-loop have almost the same sequence as Escherichia coli aspartate tRNA.
Sialolipoma of the parotid gland: Case report with literature review comparing major and minor salivary gland sialolipomas

Sialolipoma is a rare tumor found within both major and minor salivary glands. Here we discuss sialolipoma of the parotid gland and briefly review the English literature. Including our case, a total of 35 sialolipomas have been reported, 18 within major salivary glands and 17 within minor salivary glands. Major gland sialolipomas most often are presented in the parotid gland (77%) and those from minor glands were most often seen in the palate (41%). All lesions were well circumscribed and contained mature adipose tissue intimately admixed with benign salivary gland components. Ductal dilatation was found in 100% of minor salivary gland sialolipomas but in only 28% of major salivary gland tumors. Nerve entrapment has also rarely been noted in major salivary glands (14%) whereas myxoid degeneration has been identified in rare minor salivary glands tumors (13%). Treatment is surgical excision and is curative with no reports of recurrence.
Musculoskeletal performance and hydration status.

Maximal performance during competition is the drive many competitors use to train harder. However, there are several variables that contribute to impair a competitor’s performance. These variables work by altering the homeostatic mechanisms within the body. Once homeostasis is altered the competitor’s body is no longer optimized to face the stresses of the athletic competition. The environment works as an all encompassing variable that will affect sweat rate. During increased environmental heat strain, one must adjust for critical variables, such as temperature regulation, hydration status, and electrolyte levels, as they can contribute to impaired performance. Acclimatization through training and competition will reduce or slow down the effects of these stress factors. Ever evolving recommendations are produced to aid competitors in maintaining homeostasis. Despite all the generic recommendations that are made, however, every athlete needs to individualize their training and competition regimens to optimize personal performance.
Locating Community Boundaries: an Integration of Theory and Empirical Techniques:

Utilizing the Kaufman (1959) and Sutton-Kolaja (1960a, 1960b) conceptualization of community, empirical techniques are developed to identify community boundaries. These techniques are unique because they allow simultaneous consideration of boundary and interaction aggregation problems. A sociological conceptualization of community is coordinated with layman respondent's perceptions so empirical data, faithful to both perspectives, may be gathered from community residents. Community boundaries are identified from conditional probability matrices applied to residents identified as business, education, and government leaders in ten rural areas of Illinois. Township boundaries regularly coincide with community boundaries. Techniques developed here appear widely applicable to identifying community and other boundaries.
Pulsed nuclear magnetic resonance and soliton lattice in /sup 3/He-A

When the magnetization of /sup 3/He-A is tipped by a finite angle, the magnetization precesses with definite angular velocity reflecting the underlying texture. We analyze theoretically the precession frequency in the presence of composite solitions in /sup 3/He-A and compare the results with recent experiments of Giannetta et al. and of Gould et al. .AE
WOMEN IN DOCTORAL EDUCATION: CLUES AND PUZZLES REGARDING INSTITUTIONAL DISCRIMINATION*

This paper begins by asking what evidence would be needed in order to determine whether or not women graduate students are treated unfairly. Historical patterns of doctoral awards by sex are discussed, including share of bachelor's recipients who get doctorates, time between B.A. and Ph.D., and field distribution of doctorates. Then more refined data for a few schools and several fields are presented with the conclusion that more data on application and admission rates by sex and application rates for and awards of fellowships would be extremelv useful if available for a more representative sample of schools. Dropout rates by sex are discussed. Evidence on geographic mobility is analyzed; the results seem to demonstrate that women are less mobile than men. Statistics are presented to show that although female doctoral holders demonstrated higher ability while in high school, women tended to graduate from lower quality institutions than men in fields where women were comparatively highly represented, but from equal or higher quality schools when doctorates were received in what have been considered male fields.
Levels of depression on the ST-Depression Adjective Check Lists as measured by the MMPI-D Scale, the Beck Depression Inventory, and the Center For Epidemiologic Studies Depression Scale.

Four levels of depression were established on the ST-Depression Adjective Check Lists in terms of the following criterion measures : the Beck Depression Inventory, the MMPI Depression Scale, and the Center for Epidemiologic Studies Depression Scale.
Attitude accessibility as a determinant of object construal and evaluation

Abstract Attitude accessibility, the ease with which a given attitude comes to mind, has been demonstrated to affect attention. The current experiments focus on the construal of multiply categorizable objects. They seek to provide evidence that (a) construals toward which individuals have more accessible attitudes, i.e., those that are more attitude-evoking, are more likely to influence the evaluation of related objects and that (b) this effect of attitude accessibility on construal processes can be extended to a whole series of objects which vary along multiple dimensions. Experiment 1 provides evidence that construals whose related attitudes were made more accessible via attitude rehearsal were more likely to influence the evaluation of a related target. Experiments 2 and 3 extend these findings to the domain of foods, which vary along two potential construal continua (healthiness versus tastiness), and demonstrate that if participant attitudes toward fitness are made more accessible, participants' judgments about eating a variety of specific foods are guided more by the healthiness of the foods.
Estimate of radiation dose to the lens in balloon sinuplasty

ObjectivesTo estimate radiation dose to the lens during fluoroscopy-assisted balloon dilation of sinus ostia and to estimate the length of fluoroscopy time that will be tolerated.MethodsRadiation dose to the lens per unit fluoroscopy time was extrapolated from published data in fluoroscopically-guided balloon dacrocystoplasty.ResultsMean exposure varies from 0.041 (right eye) to 0.284 (left eye) mGy/sec (P = 0.037) because the left eye is closer to the radiation source during the lateral projection. Threshold for lenticular opacity has been estimated as 500 mGy, which would be attained in the left eye after approximately 29 minutes of fluoroscopy.ConclusionsThe lens may tolerate <30 minutes of fluoroscopy during balloon sinuplasty. The left eye receives a potentially greater radiation dose because of its proximity to the source in the lateral projection. Dedicated studies are indicated to specifically examine this issue during balloon sinuplasty.
Adjustment Asymmetries and Hysteresis in Simple Dynamic Models

We consider the formal modelling of hysteresis in the light of the notion that this process is a special case, contingent on the existence of unit roots in first-order difference equations. It is argued that variables displaying adjustment asymmetries along disequilibrium time paths can generate hysteresis, irrespective of the existence of unit roots. Examples of adjustment asymmetries and hysteresis in investment and in the Phillips curve are provided.
KERMA ratios vs. SSDE: is one better at estimating pediatric CT radiation doses?

Reasonable estimates of pediatric CT radiation doses are necessary to better understand the potential radiation risks of this modality. This issue of Pediatric Radiology includes a paper titled “KERMA Ratios in Pediatric CT Dosimetry” [1] that presents a method to estimate organ doses in pediatric CT patients. In 2011, the American Association of Physicists in Medicine (AAPM) published a different approach to estimating pediatric radiation doses associated with CT scanning [2]. Is one of these methods better suited to the task or preferred over the other?
A framework for quality improvement: An analysis of factors responsible for improvement at hospitals participating in the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the ACC/AHA Guidelines (CRUSADE) quality improvement initiative

Background Hospitals are under increasing pressure to improve their quality of care. However, a key question remains: how can hospitals best design and implement successful quality improvement (QI) programs? Hospitals currently employ a variety of QI initiatives but have little empirical evidence on which to base their quality efforts. Methods We designed and applied a hospital cross-sectional survey to 212 hospitals participating in CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the American College of Cardiology/American Heart Association Guidelines), a voluntary QI initiative of patients with non–ST-segment elevation acute coronary syndromes (NSTE ACS). We factor analysis and an ordinary least squares regression model to determine the key hospital factors most associated with unexpected improvements in institutional QI in the treatment of NSTE ACS. Results From 2002 to 2004, the following factors had a significant association with unexpected increases in the 2004 QI in NSTE ACS treatment: the use of CRUSADE QI tools, clinical commitment to quality by a cardiology coadvocate, institutional financial commitment to quality, and barriers to QI related to resource availability and cultural resistance to change (all P Conclusions We identified several institutional factors associated with improved quality of care in the treatment of high-risk NSTE ACS. We hope that this evidence-based framework will help guide the development and implementation of future QI programs in order to improve the institutional quality of care for NSTE ACS.
Finite presentation of mapping class groups of certain three-manifolds

Let M be a compact, orientable irreducible 3-manifold. Let F be a compressible boundary component of M and V an incompressible neighborhood of F in M; let M'=(M−V)−. Since there is an exact sequence of mapping class groups: H+(Vrel∂V−F)→H+(M, V)→H+(M',∂V−F)→1 , we can prove that H(M) is finitely presented by proving that +(Vrel∂V−F) and the mapping class group of a boundary-incompressible Haken 3-manifold are finitely presented. The latter case is a result of Waldhausen. To prove that H+(Vrel∂V−F) is finitely presented, we construct a simply connected simplicial complex with vertices the isotopy classes of compressing discs in V and study the action of the mapping class group on this complex.
Stability and limiting distributions of one and two species stochastic population models

Abstract Requirements for stability w.p.l. are developed for a variety of stochastic population models using the Ito formulation. These conditions are comparable, but different, from previously published research concerning requirements for stability in the second moment. Exact conditions for stability w.p.l. are presented for the two species Lotka-Volterra competition equations. These conditions are met by any deterministically stable set of such equations. As a byproduct of our study, log-normal type limiting distributions of populations are also explicitly obtained.
Synthesis of a Double Transmembrane Domain Fragment of Ste2p by Native Chemical Ligation

Native chemical ligation (NCL) approaches have been applied extensively to soluble proteins. Fewer successes have been achieved with membrane peptides. In this report, the synthesis and semisynthesis by NCL of peptides corresponding to 1.7 transmembrane domains of the α-factor receptor from Saccharomyces cerevisiae is described. Synthesis was achieved when the ligation point was approximately in the middle of the loop joining the two transmembrane regions. In contrast, little to no ligation was observed when the ligation point was at the putative membrane interface of the sixth transmembrane domain (TM6) and the third extracellular loop (EL3). Ligations of a chemically synthesized 22-residue thioester with a synthetic 29-residue N-Cys peptide and a biosynthetic 73-residue N-Cys peptide were successfully achieved in both trifluoroethanol/guanidinium hydrochloride (TFE/GnHCl) and sodium dodecyl sulfate (SDS) media when mercaptoethanesulfonic acid (MESNA) was used as a catalyst. The resulting 51-residue and 95-residue ligation products were purified by reversed phase HPLC and recovered on a mg scale. Both peptides were >95% pure as determined by HPLC and had the expected molecular weight as judged by mass spectrometry. Segmental labeling of the 95-residue fragment, in which the N-Cys portion was [15N] labeled, resulted in a peptide that gave an NMR spectrum which was comparable to that of the unligated 73-residue peptide alone.
MRI detection of myocardial perfusion changes by gadolinium-DTPA infusion during dipyridamole hyperemia.

To detect abnormal regional myocardial coronary flow reserve, serial spin-echo MR tomograms of four control dogs and six with a partial balloon occlusion of the left anterior descending (LAD) coronary artery were acquired before and after dipyridamole infusion and during the paramagnetic effect of a bolus plus infusion of gadolinium-DTPA. Microsphere myocardial blood flow was measured for correlation with serial regional changes in MR signal intensity. Significant difference in gadolinium-enhanced MR signal intensity existed between the hypoperfused LAD and the hyperemic left circumflex perfusion beds (46 ± 22% vs 78 ± 29% above baseline, respectively; P < 0.05). The percentage changes in gadolinium-enhanced MR signal and microsphere myocardial blood flow were significantly correlated (r2 = 0.93). © 1989 Academic Press, Inc.
Immunohistochemical detection of human herpes virus-8 latent nuclear antigen-1 is useful in the diagnosis of Kaposi sarcoma

Kaposi sarcoma is a low-grade vascular neoplasm that has been shown by molecular analysis to uniformly express the latent nuclear antigen-1 of human herpes virus 8. Differentiating Kaposi sarcoma from other benign or malignant vascular tumors, as well as other nonvascular spindle cell soft-tissue neoplasms, can be challenging. Thus, detection of human herpes virus 8 in fixed tissues would be diagnostically useful. Recently, a monoclonal antibody to human herpes virus 8 latent nuclear antigen-1 has become commercially available for immunohistochemical analysis. We sought to study the sensitivity and specificity of this antibody in the detection of human herpes virus 8 latent nuclear antigen-1 in Kaposi sarcoma. Fixed, paraffin-embedded tissue sections from 21 cases of Kaposi sarcoma, nine cases of spindle cell hemangioma, five cases of cutaneous angiosarcoma, five cases of dermatofibrosarcoma protuberans, one case of vascular transformation of a lymph node, four cases of pilar leiomyoma, four cases of stasis dermatitis, four cases of pyogenic granuloma, and three cases of spindled melanoma were examined immunohistochemically using the rat monoclonal antibody to human herpes virus 8 latent nuclear antigen-1, open reading frame-73 (Advanced Biotechnologies Inc.). Tissue sections were stained with automated immunostainers (Ventana) using heat-induced epitope retrieval and a standard DAB detection kit (Ventana) modified to detect rat Ab. Strong, diffuse, nuclear staining in >10% of tumor cells was considered a positive result. In all, 21/21 cases of Kaposi sarcoma showed strong, diffuse, nuclear staining for human herpes virus 8 latent nuclear antigen-1 (100%), whereas all cases of spindle cell hemangioma, cutaneous angiosarcoma, dermatofibrosarcoma protuberans, vascular transformation of lymph node, pilar leiomyoma, stasis dermatitis, pyogenic granuloma, and spindled melanoma were negative for this antigen. The monoclonal antibody to human herpes virus 8 latent nuclear antigen-1, open reading frame-73, is a highly sensitive and specific marker of human herpes virus 8 infection in paraffin-embedded tissue sections of Kaposi sarcoma. As such, it is an extremely useful tool for differentiating between Kaposi sarcoma and other vascular and nonvascular spindle cell lesions, which do not express human herpes virus 8 latent nuclear antigen-1.
Evidence-based pediatric pulmonary medicine : How can it help?

Evidence-based medicine aims to identify, critically appraise, and apply the best available evidence in making decisions about the care of patients. These aims are similar to those conscientious clinicians have always sought to achieve, but an evidence-based approach applies a systematic and rigorous methodology to this process to ensure that the evidence applied is relevant and of high quality. Because of the volume of potentially relevant information that needs to be accessed from the medical literature, many clinicians rely on reviews of the evidence. Systematic reviews provide summaries of the results of evidence-based healthcare, which can be made available to clinicians, healthcare administrators, and patients. The use of explicit, systematic methods in reviews limits bias (systematic errors) and reduces random errors (simple mistakes), thus providing reliable results on which to draw conclusions and make decisions. Meta-analysis is the use of statistical methods to summarize the results of independent studies. When used appropriately, meta-analysis can provide more precise estimates of the effects of healthcare than those derived from the individual studies included in a review. Childhood respiratory diseases can be a challenging area in which to undertake clinical research. These challenges include diagnostic uncertainty, lack of objective endpoints, and aspects of generalizability of randomized controlled trials. Despite these difficulties, there are now many examples of systematic reviews and evidence-based approaches in pediatric pulmonology. If applied appropriately, they can ensure that management of patients is based on clinically useful diagnostic tests and treatments that have been shown to be effective and not harmful.
Nonlinear dynamics of filaments I. Dynamical instabilities

Abstract The Kirchhoff model provides a well-established mathematical framework to study, both computationaly and theoretically, the dynamics of thin filaments within the approximations of linear elasticity theory. The study of static solutions to these equations has a long history and the usual approach to describing their instabilities is to study the time-dependent version of the Kirchhoff model in the Euler angle frame. Here we study the linear stability of the full, time-independent, equations by introducing a new are length preserving perturbation scheme. As an application, we consider the instabilities of various stationary solutions, such as the planar ring and straight rod, subjected to twisting perturbations. This scheme gives a direct proof of the existence of dynamical instabilities and provides the selection mechanism for the shape of unstable filaments.
Incorporation of absorbed iron from different dietary sources into hemoglobin

Abstract The objective of this research was to determine if the incorporation of absorbed iron into hemoglobin is affected by dietary iron source and food processing. Effectiveness of erythropoiesis (EOE), the percent of absorbed iron incorporated into hemoglobin, was determined two ways for comparison; from dietary iron balance data and from extrinsic 59 Fe absorption data obtained simultaneously from the same animals. Ferrous sulfate, meat, bread, soy protein isolate, spinach and fortification iron were studied as dietary iron sources because of their wide variability in iron absorption. The EOE calculated by balance from dietary iron absorption data correlated highly with EOE calculated from extrinsic 59 Fe absorption data for each iron source; ferrous sulfate (r=1.0), nine dietary iron treatments (r=.75; meat, white and whole wheat bread, spinach, soy and ferrous sulfate), and nine meat:bread mixtures (r=.69). EOE varied from 50 to 102% among iron sources, suggesting that biological utilization of absorbed iron is affected by food source and processing.
The relative importance of factors affecting age-specific seedling survival of two co-occurring oak species in southern California

Abstract As has been reported in other oak habitats throughout the Northern Hemisphere, natural recruitment rates of young oaks in California are very low for some species and in some regions. The majority of experimental studies that contribute to our understanding of this oak recruitment pattern in California have been relatively short-term, conducted on a small-scale. Thus, while we have valuable information about the array of factors that are able to limit seedling establishment, we know much less about their relative importance, and how they vary across years, sites, or age classes. To investigate the impacts of factors limiting seedling and sapling establishment of valley oak (Quercus lobata) and coast live oak (Quercus agrifolia) across a landscape and over time we replicated experiments in four different years in Santa Barbara County, California. Experimental factors manipulated included cattle grazing, and access by deer and small mammals. Plots were distributed across three sites with a cumulative area of 200-ha, and seedling survival was recorded for a minimum of 5 years. We used classification and regression tree analysis (CART) to examine the relative importance of factors influencing survival of planted oaks at different life stages. The relative importance of limiting factors varied among age classes for both species. For initial seedling emergence and survival to 6 months planting year was the most important factor and rodent access was the second most important factor for both Q. lobata and Q. agrifolia. For survival of seedlings through their 1st year rodents, planting year, and site were major limiting factors, though their relative importance varied between the two species. For survival from 1.5 to 5 years, Q. lobata was strongly affected by rodents and site, while Q. agrifolia was mainly affected by site, deer browsing (which reduced survival), and indirect effects of winter–spring cattle grazing (which improved survival). Contrary to our expectations, based on observed patterns of natural recruitment, Q. agrifolia had equivalent or lower survivorship than Q. lobata in all seedling age classes. Overall, in addition to other factors, there were strong year and site effects controlling oak seedling emergence and survival and the relative importance of limiting factors depended on seedling age. Our results suggest that large-scale, long-term experiments encompassing multiple sites will improve our understanding of controls on recruitment in oak woodlands in California and elsewhere.
Initial observations of plasma waves in the sub-auroral polarization stream with the Van Allen Probes

The Sub-Auroral Polarization Stream (SAPS) is a geospace boundary layer phenomenon associated with the interaction of the warm plasma of the magnetospheric ring current with the cold ions and electrons of the outer plasmasphere [1]. Driven by ring current enhancements during magnetospheric disturbances, SAPS location, intensity, and characteristics are greatly influenced by the underlying ionosphere. Strong M-I coupling by means of field-aligned currents creates a high-speed (>1000 m/s) westward plasma flow channel in the ionosphere at pre-midnight/post-noon local times which is readily observable by incoherent scatter [2] and HF radars and in plasma drift observations by low-altitude spacecraft (e.g. DMSP). The fast ionospheric flows generate E-region irregularities providing for additional diagnostics using coherent backscatter techniques [3]. SAPS plays a significant role in the redistribution of cold plasma through the geospace system at both ionospheric and magnetospheric heights. Where the SAPS flow channel overlaps the mid-latitude ionosphere and outer plasmasphere, streams of cold plasma are carried westward and sunward as plumes of storm enhanced density (SED) in the ionosphere and as plasmasphere erosion plumes at high altitude. Ground-based maps of GPS total electron content (TEC) serve to visualize the spatial extent and evolution of the SAPS and SED. Mapping these features to magnetospheric altitudes along magnetic field lines permits direct intercomparison with in situ spacecraft observations. The recently launched Van Allen Probes twin satellites (RBSP-A & RBSP-B) are in near-equatorial orbits well suited for studies of the SAPS and related phenomena at the apex of field lines threading the plasmasphere boundary layer. Simultaneous near magnetic field aligned observations of SAPS at DMSP altitude (∼800 km) and by RBSP-A at ∼20,000 km show close correspondence of SAPS location and characteristics between the ionosphere and magnetosphere. In highly elliptical orbits with apogee near 5.5 Re, the RBSP spacecraft often spend hours at a time skimming the outer plasmasphere within the SAPS region. A great variety of wave phenomena are observed. Here we describe long-duration large amplitude (+/− 5 mV/m) electric field oscillations with 3 min–5 min period seen in the magnetospheric equatorial plane within the SAPS/erosion plume region.
The hand that rocks the cradle: Disciplinary socialization at the American Accounting Association's Doctoral Consortium

Abstract Motivated by the current turbulence in academic accounting in the USA, this paper problematizes the disciplinary socialization that occurs beyond school-specific educational processes. Using data pertaining to the American Accounting Association's Doctoral Consortium, this paper illustrates that the most important lesson about academic accounting may have been the righteousness of the fields’ stratification hierarchy. In other words, learning one's place in the US academy may be more important than any theory or technique within academic accounting. The conduct of the Consortium casts doubt on a substantive socialization agenda.
Gap junctions, homeostasis, and injury.

Gap junctions (Gj) play an important role in the communication between cells of many tissues. They are composed of channels that permit the passage of ions and low molecular weight metabolites between adjacent cells, without exposure to the extracellular environment. These pathways are formed by the interaction between two hemichannels on the surface of opposing cells. These hemichannels are formed by the association of six identical subunits, named connexins (Cx), which are integral membrane proteins. Cell coupling via Gj is dependent on the specific pattern of Cx gene expression. This pattern of gene expression is altered during several pathological conditions resulting in changes of cell coupling. The regulation of Cx gene expression is affected at different levels from transcription to post translational processes during injury. In addition, Gj cellular communication is regulated by gating mechanisms. The alteration of Gj communication during injury could be rationalized by two opposite theories. One hypothesis proposes that the alteration of Gj communication attenuates the spread of toxic metabolites from the injured area to healthy organ regions. The alternative proposition is that a reduction of cellular communication reduces the loss of important cellular metabolisms, such as ATP and glucose. © 2002 Wiley-Liss, Inc.
3718 SMALL CALIBER ESOPHAGOGASTRODUODENOSCOPY WITHOUT SEDATION: LESS EXPENSIVE AND LESS TIME CONSUMING THAN CONVENTIONAL ENDOSCOPY.

Background: A significant portion of the costs and complications of esophagogastroduodenoscopy (EGD) are related to the use of sedation. Small caliber EGD (scEGD) without sedation has been proposed as an alternative. The feasibility and tolerability of scEGD has been evaluated; however, there is limited data concerning time and costs associated with this procedure. Aim: To prospectively compare time and costs associated with scEGD without sedation to conventional endoscopy (cEGD) with sedation. Patient tolerability, preference, and technical feasibility were also assessed. Methods: Sixteen patients were recruited and underwent scEGD using the Pentax EG-1840 (outside diameter 6 mm, biopsy channel 2 mm) without sedation (20% topical benzocaine spray). One investigator (ABG) performed all procedures. Immediately after the procedure patients completed a survey using visual-analogue scale to assess degree of choking, discomfort, sore throat, overall tolerability, willingness to repeat the procedure without sedation, and preference regarding sedation for future procedures.A control group of 16 patients was chosen matched for age, sex, day and indication of procedure. The time of procedure (scope in to scope out), time in procedure room, time in recovery room, and procedure costs were determined in both the study and control groups. Costs were obtained from the TSI accounting system at our institution. When costs were not available standardized cost to charge ratios were applied. Statistical analysis was performed using t-tests for continuous variables and chi square for dichotomous variables. Results: Procedure time, total time in room and recovery room time were 5.2, 16.3, and 9 min for scEGD and 13.5, 34.9, and 41.3 min for cEGD, respectively (p
Activation by lithium ions of the inside sodium sites in (Na+ + K+)-ATPase.

Abstract 1. 1. Purified pig kidney ATPase was incubated in 30–160 mM Tris-HCl with various monovalent cations. 130 mM LiCl stimulated a ouabain-sensitive ATP hydrolysis (about 5% of the maximal (Na + + K + ) activity), whereas 160 mM Tris-HCl did not stimulate hydrolysis. Similar results were obtained with human red blood cell broken membranes. 2. 2. In the absence of Na + and with 130 mM LiCl, the ATPase activity as a function of KCl concentration showed an initial slight inhibition (50 μM KCl) followed by an activation (maximal at 0.2 mM KCl) and a further inhibition, which was total at 25 mM KCl. In the absence of LiCl, the rate of hydrolysis was not affected by any of the KCl concentrations investigated. 3. 3. The lithium-activation curve for ATPase activity in the absence of both Na + and K + had sigmoid characteristics. It also showed a marked dependence on the total LiCl + Tris-HCl concentration, being inhibited at high concentrations. This inhibition was more noticeable at low LiCl concentrations. 4. 4. In the absence of Na + , 130 mM Li + showed promoted phosphorylation of ATPase from 1 to 3 mM ATP in the presence of Mg 2+ . In enzyme treated with N -ethylmaleimide, the levels of phosphorylation in Li + -containing solutions, amounted to 40% of those in Na + - and up to 7 times of those in K + -containing solutions. 5. 5. The total (Na + + K + )-ATPase activity was markedly inhibited at high buffer concentrations (Tris-HCl, Imidazole-HCl and tetramethylammonium-HEPES gave similar results) in cases when either the concentration of Na + or K + (or both) was below saturation. On the other hand, the maximal (Na + + K + )-ATPase activity was not affected (or very slightly) by the buffer concentration. 6. 6. Under standard conditions (Tris-HCl + NaCl = 160 mM) the Na + -activation curve of Na + -ATPase had a steep rise between 0 and 2.5 mM, a fall between 2.5 and 20 mM and a further increase between 20 and 130 mM. With 30 mM Tris-HCl, the curve rose more steeply, inhibition was noticeable at 2.5 mM Na + and was completed at 5 mM Na + . With Tris-HCl + NaCl = 280 mM, the amount of activation decreased and inhibition at intermediate Na + concentrations was not detected.
Is There a Strategy for Preventing Bronchopulmonary Dysplasia? Absence of Evidence Is Not Evidence of Absence

Bronchopulmonary dysplasia (BPD) is a serious health problem associated with mortality and high morbidity among graduates of the NICU.1 The cost of BPD is tremendous. It is associated with prolonged hospitalization of the preterm infant, multiple rehospitalizations during the first few years of life, and survival with developmental delay and/or cerebral palsy.1,2 It becomes, therefore, a major goal for the neonatal community to prevent or at least partially control the incidence of BPD. In an effort to scientifically ameliorate the incidence of BPD, Walsh et al3 examined the 3 best-performing NICUs among the 17 units of the National Institute of Child Health and Human Development Neonatal Network. The study team determined some practices in these 3 units that they could adopt in a clinical trial. They then initiated a cluster-randomized, controlled trial among the remaining 14 units; 7 of these units changed their practices accordingly, and the other 7 units continued their routine care. Early administration of surfactant, use of vitamin A, and maintaining lower oxygen saturation were among the adopted practices in this randomized trial. Early nasal continuous positive airway pressure (CPAP) was not one of the targeted practices to change, because there was “insufficient evidence” to support its use. In fact, when compared with the control group, the 7 NICUs in the intervention group used more endotracheal intubation (77% vs 66%) and less CPAP (16% vs 27%) in the delivery room. During the first week of life, mechanical ventilation was more prolonged in the intervention-group … Address correspondence to Hany Aly, MD, 900 23rd St NW, Suite G2092, Washington, DC 20037. E-mail: haly{at}mfa.gwu.edu
Perplastic SiAION—A Bird's Eye View of Silicon Nitride Ceramics

Superplastic Sialons have very fine microstructures containing submicron grains and transient phases. Fabrication of these materials requires processing at relatively low temperatures. As a result, different stages of phase evolution, including oxide melt formation, nitride dissolution, α’ and β’-SiAlON nucleation, and Sialon growth with and without concurrent deformation, can be captured in the development of these materials. In addition, only very low flow stresses are required for large strain deformation which, in turn, allows grain boundary and liquid phase processes to be manifested in the deformation behavior. Highlights of investigation of these aspects are reviewed here to shed light on the phase relationship, microstructural development, and grain boundary characteristics of silicon nitride.
Magnetic Platelets in a Nematic Liquid Crystal

Abstract Results are presented for a theoretical and experimental investigation of magnetic platelets introduced into a nematic liquid crystal. The equilibrium positions of the platelets and nematic director as a function of applied field are calculated and compared with experiment.
New calculation of the properties of the positronium ion

The positronium negative ion Ps(-), the system composed of two electrons and a positron, has been reinvestigated theoretically. Using a Hylleraas wave function with two nonlinear parameters and more than 200 linear terms, excellent values of binding energy and annihilation lifetime of the particle-stable 1Se ground state have been obtained. In addition, the question of stability of the 3Pe state discussed by Mills has been examined and it is agreed with his conclusion that the state is probably not stable against breakup into Ps(n = 2) + e(-). Improved limits on the critical 'positron' mass for binding the 3Pe state have also been obtained.
Effect of Rigid Contact Lens Oxygen Transmissibility on Stromal PH in the Living Human Eye

Abstract Corneal stromal pH was measured fluorometrically in nine human subjects after 1.5 hours of eye closure while wearing hard gas permeable contact lenses. Six lens types providing a wide range in oxygen transmissibilities (Dk/L)o 2 from 0.15 to 55.0 × 10 −9 (cm ml O 2 /seconds of ml mmHg) were used. Stromal pH upon opening the eyes was directly related to (Dk/L)o 2 and ranged from 7.01 to 7.26. These pH values were all significantly lower than the control (no lens), which had a pH of 7.38 ( P P 2 . The authors conclude that the lenses presently available provide insufficient gas exchange to prevent alteration of corneal pH and suggest that the measurement of stromal pH may provide a sensitive index for evaluating the metabolic effects of contact lens wear.
Laparoscopic Gastric Bypass Complicated by Gastric Pouch Necrosis: Considerations in Gastroesophageal Reconstruction

Gastric pouch necrosis and intraabdominal sepsis is an uncommon complication following laparoscopic gastric bypass. The intraoperative management of this complication centers on resection of the necrotic pouch, esophageal diversion, drainage, and enteral access for nutrition. Reestablishing gastrointestinal continuity at a later surgery following this complication can be challenging. We present a case in which the colon was found to be unacceptable for use in reconstruction; the remaining stomach was used as the conduit for a transhiatal reconstruction of gastrointestinal continuity instead.