cssi/SciSciGPT-SciSciNet huggingface dataset:
Identification and quantitation of benzo[a]pyrene-derived DNA adducts formed at low adduction level in mice lung tissue ☆

The two major metabolic pathways of benzo[a]pyrene (BP) that lead to DNA lesions are monooxygenation that results in diolepoxides (BPDE) and one-electron oxidation that yields a BP radical cation. These pathways result in formation of stable and depurinating DNA adducts, respectively. Most in vivo animal studies with BP, however, have employed dosage/DNA adduct levels several orders of magnitude higher than the DNA damage level expected from environmentally relevant exposures. Presented are results of experiments in which A/J strain mice were intraperitoneally exposed to 50-μg/g doses of BP. It is shown that non-line-narrowed fluorescence and fluorescence line-narrowing spectroscopies possess the selectivity and sensitivity to distinguish between helix-external, base-stacked, and intercalated conformations of DNA–BPDE adducts formed in lung tissue. Concentrations measured by 32P postlabeling 2 and 3 days after intraperitoneal injection were 420–430 and 600–830 amol BPDE-type adducts per μg DNA. The external and base-stacked conformations are attributed mainly to (+)-trans-anti-BPDE-N2dG and the intercalated conformations to (+)-cis-anti adducts. A stable adduct derived from 9-OH-BP-4,5-epoxide was also detected at a concentration about a factor of 10 lower than the above concentrations. The DNA supernatants were analyzed for the presence of depurinating BP-derived adducts by capillary electrophoresis laser-induced fluorescence and high-performance liquid chromatography mass spectrometry.
Structural and foaming properties of egg albumen subjected to different pH-treatments in the presence of calcium ions

The influence of low (pH 1.5–3.5) and high (10.5–12.5) pH-induced unfolding followed by refolding to pH 4.5–8.5 in the presence of Ca2+ on the structural, functional and viscoelastic properties of egg albumen was investigated. pH-induced unfolding significantly improved overrun, stability and reduced liquid drainage of egg albumen for most pH-treatments compared to untreated control. Unfolding at pH 12.5 led to the largest improvements, overall. Improvements in foam overrun and stability were found to be mostly due to pH-treatments, with Ca2+ having a small effect when compared to prior studies. Inclusion of Ca2+ did however reduce liquid drainage, and was found to significantly modify the rheological properties of the foams, making them stiffer and stronger. Inclusion of Ca2+ during pH-treatment led to more exposed –SH groups compared to albumen pH-treated in its absence. The pH-treatments also produced albumens with higher surface hydrophobicity, which was determined mostly to come from the pH unfolding, with Ca2+ having little impact.
“Critical Thinking” in Dance Science Education

Abstract High expectations for the transformative influence of dance science education on dance training exist among experts in the field. In order to realize these goals, dance science educators must foster the development of critical thinking skills in their students. Dance science teaching methodology is presented that is based on the premise that learning to think critically involves the integration of three forms of knowledge: declarative knowledge, procedural knowledge, and metacognition.
Computer Graphics Using OpenGL, 3rd ed.[Book Review]

This book (a third edition textbook) consists of 12 chapters and five appendices. The main text of each chapter discusses the mathematics and algorithms, with exercises and case studies given at the end of each chapter. Although the majority of the book's content is the same as in previous editions, the current edition reflects the significant developments that have appeared since the second edition which was released in 2000.
The evolution of capacity markets in the USA

The primary goals for moving from a regulated electric supply industry to a deregulated market were to reduce the average costs paid by customers and to promote efficient long-term investment. However, it is still highly debatable whether either of these goals has been realized in the northeastern states. Regulators have rejected the rationale for long-run competitive prices in an energy-only market, and instead, they have adopted short-run competitive prices as the criterion for judging the performance of a spot market. Although they have been reasonably successful in maintaining this strategy, by doing so, they have introduced the problem of “missing money” for generators. As a result, the northeastern states have adopted or proposed some form of Installed CAPacity market (ICAP) to provide generators with additional income to cover the missing money. Although most regulators agree that generators need some supplementary income, there is no general agreement about how this extra income should be provided. The objective of this paper is to discuss and evaluate how and why the designs of an ICAP market have evolved from New York to PJM to New England. In this paper, we explained 1) why investors have been reluctant to build new generating capacity in New York, and 2) the rationale for the alternative designs proposed in PJM and New England. Finally, we presented the results of economic experiments that conducted in February 2007 and October 2007 by the Power System Engineering Research Center (PSERC) at Cornell University to test the performance of a simplified Forward Capacity Market (FCM) proposed for New England.
Targeted disruption of the mouse villin gene does not impair the morphogenesis of microvilli

The small intestine is functionally dependent on the presence of the brush border, a tightly packed array of microvilli that forms the amplified apical surface of absorptive cells. In the core of each microvillus, actin filaments are bundled by two proteins, villin and fimbrin. Previous in vitro studies using antisense approaches indicated that villin plays an important role in the morphogenesis of microvilli. To examine the in vivo consequences of villin deficiency, we disrupted the mouse villin gene by targeted recombination in mouse embryonic stem cells. A beta-galactosidase cDNA was also introduced into the villin locus by the targeting event. Homozygous villin-deficient mice are viable, fertile, and display no gross abnormalities. Intact microvilli are present in the small intestine, colon, kidney proximal tubules, and liver bile canaliculi. Although subtle ultrastructural abnormalities can be detected in the actin cores of small intestinal microvilli, localization of sucrase isomaltase, brush border myosin I, and zonula occludens I to the microvillar surface of the small intestine is normal. Thus, in vivo, villin plays a minor or redundant role in the generation of microvilli in multiple absorptive tissues.
Strategic Planning in an Accounting Department using Causal Maps and Cognitive Factions

Strategic planning can be a time-consuming task for academic departments. As such, an effective and efficient strategic planning approach is paramount. This paper presents a strategic planning approach using causal mapping to uncover the factors which faculty members believed would make their department (in the USA) more successful. The information gathered during the session was used as part of an AACSB accounting maintenance of accreditation process. The approach applied here elicits faculty involvement in ways which bring to the surface perspectives held by subgroups/factions of faculty. Additional perspectives are positive in a strategic planning context as they can contribute to devising strategies that might not have resulted by considering only majority views. Content analysis of the strategic plan suggests the range of views uncovered were integrated into the plan, including both the strategic factors and the relative importance of the factors.
The daughterless gene product in Drosophila is a nuclear protein that is broadly expressed throughout the organism during development

The daughterless (da) gene in Drosophila functions in the regulation of at least three significant developmental pathways: sex determination, neurogenesis and oogenesis. As a member of the helix-loop-helix (HLH) family of DNA binding proteins, the da gene product appears to act as a transcription factor. Based on the genetic and molecular characterization of da, it has been proposed that the da protein (Da) functions as a generic member of this family, serving throughout development as a necessary binding partner for an assortment of other HLH proteins. As a result of temporally and/or spatially restricted expression, these binding partners would provide some regulatory specificity to the functional transcription complex. In order to participate in this way in the regulation of multiple genes, Da must be expressed in numerous times and places during development. Using anti-Da antibodies, we validate two predictions of this scenario of Da function: (1) Da protein is not only nuclear localized, but also associated with chromosomes in vivo; and (2) Da protein is widely distributed, both spatially and temporally, throughout development. With regard to the essential role of maternal da+ in progeny sex determination, little, if any, Da protein is synthesized in the maternal germline. This suggests that the female-specific germline function of da+ is provided to the zygote as maternally synthesized RNA that becomes translated early in embryogenesis.
Lactobacillic and methyl-branched olefinic acids inByrsocarpus coccineus seed oil

A detailed investigation of the seed oil ofByrsocarpus coccineus Schum. and Thonn. has disclosedcis-11,12-methyleneoctadecanoic (lactobacillic) (13%) and two branched octadecenoic acids (0.1%). Other fatty acids in the oil are those normally associated with seed lipids except for an unusually high proportion (12%) ofcis-11-octadecenoic acid. Lactobacillic acid has long been known as a constituent of certain bacterial lipids, but this is the first report of its presence in a seed oil. The branched olefinic acids have not heretofore been found to occur in plants.
A review of measures of lymphedema.

BACKGROUND. Lymphedema usually is identified by patients, and rarely is it screened for routinely. Many assessments have been reported and have been used in evaluating a variety of treatments for lymphedema. METHODS. A review of the literature was undertaken. RESULTS. Five frequently used measures of lymphedema include circumferential measures of limbs at various points (usually at bony landmarks); volumetric measures using limb submersion in water; skin tonometry, in which soft tissue compression is quantified; imaging techniques to describe tissue characteristics as well as to quantify soft tissue swelling (magnetic resonance imaging and computerized tomography; and ultrasound with and without Doppler flow studies for volumetric measures. Circumferential measures with calculations designed to compute limb volumes and volumetric measures are used most frequently, but these have some difficulty with reliability. No significant effort has been made to develop a patient based questionnaire that describes the size as well as the impact of lymphedema on an individual's functional level. CONCLUSIONS. Existing physical measures of lymphedema are available that are easy to use, inexpensive, have limited reliability, and do not address the issue of functional impact. Imaging techniques may provide valuable qualitative and quantitative information in selected populations.
Effect of steroids on definitive localization of primordial germ cells in the chick embryo.

It has been suggested that PGCs are attracted to developing gonads by a chemotactic-like agent secreted by the gonads and that this agent might be steroidal in nature. This study was undertaken to ascertain whether specific exogenous steroid hormones exert an influence on germ cell colonization of the gonads, by enhancing, inhibiting or otherwise interfering with it. Testosterone cypionate in cottonseed oil, crystalline testosterone propionate, estrone in aqueous suspension and crystalline estradiol-17β were administered to chick embryos at 33 hours incubation. Normally developed embryos, those receiving cottonseed oil (vehicle for testosterone cypionate) and those receiving cholesterol served as controls. A decrease in the number of germ cells in the gonadal area at five days of incubation occurred in all groups receiving the androgens and estrogens. However, in only one group (that receiving testosterone cypionate) was this decrease found to be significant. The mean number of germ cells found in the cottonseed oil controls and the cholesterol controls closely paralleled that of the normally developed controls. Normal asymmetry in the distribution of the germ cells favoring the left side in the chick was not affected in any of the groups; however, the percentage distribution of the germ cells between the right and left gonads at this early stage appeared to be affected.
866 RELATIVE EFFECT OF BLOOD OXYGEN (O 2 ) TRANSPORT CHARACTERISTICS ON OPTIMAL OXYGEN DELIVERY TO THE TISSUES

The present study investigates the relative importance of altering O2 content and/or hemoglobin O2 affinity (P50) in changing cardiac output (C.O.) and O2 delivery to the tissues. 18 newborn (NB) lambs were divided into 3 groups. Blood gases, [Hb], P50 (mm Hg), regional blood flow (ml/min/100g tissue) and C.O. (ml/min/kg) were measured before and 2 hrs after alteration of O2 affinity and/or content by means of exchange transfusing the lambs with fetal or maternal blood of varying Hct. O2 content was increased 38% in Gr 1 (n=6) with no change in P50. O2 content and P50 were increased 9% and 32% in Gr 2 (n=5), and 38% and 32% in Gr 3 (n=7), respectively. C.O. decreased 39% (364-221), 45% (324-177) and 48% (318-166) in groups 1,2 and 3, respectively. Systemic O2 delivery decreased 22% in Gr 2 (52.9-32.4) and 26% in Gr 3 (45-33) and was unchanged in Gr 1. PVO2 increased in Gr 2 from 31.8 to 34.6 and in Gr 3 from 23.4 to 32.3. O2 consumption was unchanged in all groups. These data suggest that in the NB lamb an increased P50 associated with increased Hct provides the same reduction of C.O. as a 4-fold increased Hct without change in P50. Higher increase in O2 content provides no further reduction in C.O. but a greater increase in PVO2, suggesting enhanced O2 availability to the tissues. These data suggest that the combined effect of increased P50 and increased O2 content achieves optimal O2 delivery, presumably at the greatest economy of the cardiovascular system.
Nonlinear Statistical Signal Processing: A Particle Filtering Approach

A introduction to particle filtering is discussed starting with an overview of Bayesian inference from batch to sequential processors. Once the evolving Bayesian paradigm is established, simulation-based methods using sampling theory and Monte Carlo realizations are discussed. Here the usual limitations of nonlinear approximations and non-gaussian processes prevalent in classical nonlinear processing algorithms (e.g. Kalman filters) are no longer a restriction to perform Bayesian inference. It is shown how the underlying hidden or state variables are easily assimilated into this Bayesian construct. Importance sampling methods are then discussed and shown how they can be extended to sequential solutions implemented using Markovian state-space models as a natural evolution. With this in mind, the idea of a particle filter, which is a discrete representation of a probability distribution, is developed and shown how it can be implemented using sequential importance sampling/resampling methods. Finally, an application is briefly discussed comparing the performance of the particle filter designs with classical nonlinear filter implementations.
Dynamic delamination of fire insulation applied on steel structures under impact loading

Abstract This paper presents an experimental-numerical approach for evaluating dynamic fracture and delamination of fire insulation from steel structures during impact loading. The experiments encompass drop mass impact tests on steel beams insulated with three types of sprayed applied fire resistive material (SFRM), namely Portland cement-based, gypsum-based and mineral fiber-based, commonly utilized in steel construction. The impact tests are conducted at two kinetic energy levels to evaluate the strain rate-dependency of fracture energy and extent of delamination at steel-SFRM interface. Results from experiments show that the cracking and delamination of SFRM is mainly localized on the bottom flange with slight extension into lower part of web of beam at the mid span. Further, Portland cement-based SFRM can withstand the applied impact energy and no delamination or substantial cracking in SFRM occurs, whereas two other types of SFRM experienced significant fracture and delamination on the bottom flange. A fracture mechanics-based numerical approach is subsequently employed to simulate the conducted experiments using LS-DYNA finite element code. In the explicit numerical model, cohesive zone approach is adopted to model fracture process zone at the interface of steel and SFRM. By quantifying and calibrating the extent of delamination on the bottom flange, the dynamic increase factor of fracture energy and stress–displacement relationships, determined through previous static fracture tests, is estimated. According to numerical simulations, extent of delamination in mineral fiber-based SFRM is not dependent on strain rate, whereas in the case of gypsum-based and Portland cement-based SFRM extent of delamination is a function of strain rate.
Adrenal and testicular deficiency; a comparison based on similarities in androgen deficiency, androgen and 17-ketosteroid excretion, and on differences in their effects upon pituitary activity.

ACCORDING to the theory that there is a second testicular hormone (inhibin), deficiency of this factor, as in the human castrate or in severe testicular failure, is chiefly responsible for the ensuing pituitary hyperactivity. It is generally conceded that androgens arise in the cortex of the adrenal gland as well as in the Leydig cells of the testes. The androgens arising in the testes, together with the androgens and other related substances arising in the cortex of the adrenal, are largely represented in the urine as a group of substances known as 17-ketosteroids. Measurement of these is frequently used to estimate certain hormonal activities of the testes and the adrenal glands. Androgenic activity per se is measurable biologically. In women with ovarian deficiency the cause of pituitary hyperactivity apparently is the loss of estradiol. The high levels of urinary follicle-stimulating hormone (F.S.H.) occurring after castration or the menopause can be reduced by small amounts of estradiol or other estr...
Complete Complementary Orthogonal (CCO) Code-Based CDMA Using Natural Mapping QAM Constellations

In this short paper we propose a CCO code-based CDMA system that uses a natural mapping QAM scheme, in order to conserve both bandwidth and average transmitted power. We also suggest a design approach to obtain an optimal QAM mapping to further improve system performance. This is in contrast to the original CCO code-based system which used PAM transmission over twice as many channels. Here we present preliminary results for the 2-user case and the downlink.
Glyburide increases cytosolic-free calcium concentrations in normal rat pancreatic islet cells.

Abstract We have attempted to delineate the effect of glyburide on the regulation of cytosolic-free calcium concentrations, [Ca2+]i, in normal rat pancreatic islet cells. In the presence of extracellular calcium (1 mmol/L), glyburide increased [Ca2+]i from 70 nmol/L to 260 nmol/L in a dose-dependent manner. The maximal effect was seen at a concentration of 2 μmol/L with half-maximal stimulation observed at .25 μmol/L. The effect of glyburide (.25 μmol/L) was inhibited 90% by the calcium channel blocker, verapamil (30 μmol/L). At a maximally effective concentration of glyburide (2 μmol/L), the inhibitory effect of verapamil was only 17%. In the absence of extracellular calcium, glyburide increased [Ca2+]i from 55 nmol/L to 107 nmol/L, indicating its ability to mobilize intracellular calcium stores. These results correlated well with the ability of glyburide (2 μmol/L) to stimulate insulin secretion both in the presence (from 38 ± 5 μmol/L/10 islets to 131 ± 28 μU/10 islets) and in the absence ( from 49 ± 4 μU 10 islets to 93 ± 7 μU 10 islets ) of extracellular Ca2+. The present observations suggest that glyburide promotes calcium influx via voltage-dependent calcium channels and may mobilize intracellular calcium stores.
Mechanical Design of a Delay Line for the Astron Linear Accelerator Beam Transport

The Astron concept for Thermonuclear research requires a layer of circulating electrons of sufficient density to confine and heat a plasma. This layer, called the E-layer, is formed by an accelerator injecting 6 Mev electrons at a 4° angle from perpendicular. The accelerator produces a 600 amp pulsed beam of 300 ns duration. A delay line has been built for the purpose of increasing the peak injection current. The 300 ns pulsed beam is split in half by a kicker and the first half is delayed so it can be injected on the opposite side of the trapping solenoid simultaneously with the second half of the beam. Thus two short pulses of 150 ns each are injected into Astron with one pulse traveling through a transport system of five bends and straight sections. (Figure I).
Conceptions of Teaching Science Held by Novice Teachers in an Alternative Certification Program

Case studies to investigate the conceptions of teaching science held by three novice teachers participating in an alternative secondary science teacher certification program were conducted, along with the relationships between their conceptions of science teaching and their science teaching practice. Data used to build the cases included the participants' responses to two surveys and transcripts of audiotaped interviews with the participants and their university supervisors who observed them teach. Findings revealed that novice teachers hold ideal and working conceptions of teaching science, the novices' conceptions can serve as referents for their classroom practice, and the conceptions of teaching science held by the novice teachers were resistant to change, even in the face of well-intentioned instruction.
Invertebrate predation of leaf‐miners at low densities

. 1 Predation on a species of leaf-mining insect, Eriocraniella sp., by two species of ants, Crematogaster ashmeadii Mayr and Pseudomyrmex brunnea F. Smith, is documented. 2 Exclusion experiments show that ants and other terrestrial invertebrates can greatly contribute to mortality of leaf-miners and significantly decrease survivorship of the larval stages even when densities are low. 3 Comparison of two leaf-mining species, Eriocraniella sp. and Cameraria sp. nov. Davis, indicates that factors of mortality depend on the maturity of the leaf being mined.
Restrictions on Transversal Encoded Quantum Gate Sets

Transversal gates play an important role in the theory of fault-tolerant quantum computation due to their simplicity and robustness to noise. By definition, transversal operators do not couple physical subsystems within the same code block. Consequently, such operators do not spread errors within code blocks and are, therefore, fault tolerant. Nonetheless, other methods of ensuring fault tolerance are required, as it is invariably the case that some encoded gates cannot be implemented transversally. This observation has led to a long-standing conjecture that transversal encoded gate sets cannot be universal. Here we show that the ability of a quantum code to detect an arbitrary error on any single physical subsystem is incompatible with the existence of a universal, transversal encoded gate set for the code.
KNOWTRAN: An artificial intelligence system for solving heat transfer problems

Abstract The detailed design specifications of an artificial intelligence system called KNOWTRAN are developed in this work. The design philosophy behind this system calls for a general and flexible program for acquiring, representing, storing and applying heat transfer knowledge. These ideas lead to the adoption of a knowledge-based approach to artificial intelligence programming. Furthermore, ideas about knowledge representation are developed to meet the requirements of a general heat transfer problem solver. This involves a hierarchical knowledge base managed by a flexible knowledge acquisition system. Finally, spacial representations are developed to accommodate objects and relationships in heat transfer problems.
Conjunctival lymphoma masquerading as chronic conjunctivitis

Abstract Objective Malignant lesions of the conjunctiva may present with slowly evolving signs resembling inflammation. The authors describe the clinical and histopathologic findings of two patients with bilateral conjunctival lymphoma who presented with a history of chronic conjunctivitis without clinically noticeable subconjunctival nodules. Design Case report. Participants Two patients. Intervention Both patients underwent conjunctival biopsy for evaluation of persistent conjunctival inflammation that did not respond to various medical treatment methods. Results Histopathologic examination revealed extranodal marginal zone B-cell lymphoma (mucosa-associated lymphoid tissue type) in one patient and follicle center lymphoma in the other patient. Both patients subsequently received radiation therapy and achieved a complete remission with no evidence of recurrence in the follow-up period of 20 and 16 months, respectively. Conclusions Conjunctival lymphoma should be included in the differential diagnoses of chronic conjunctivitis. Persisting signs and symptoms of conjunctivitis not responding to standard treatment should prompt biopsy.
En Bloc Removal of Intrinsic Neoplasms of the Lacrimal Gland

The management of intrinsic neoplasms primary in the lacrimal gland is of serious concern because (1) some of the most malignant primary tumors of the orbit occur in this glandular structure and (2) present surgical techniques may easily disseminate the neoplasm and contribute to death or recurrences. We propose a surgical approach in which the tumor and adjacent adnexa are removed in a one-stage procedure, that is, an en bloc resection of the neoplasm, its periorbital base, and surrounding bone. This technique will minimize seeding of the tumor, provide a more complete eradication of the neoplasm without loss of the eye, and hopefully, assure either a cure or a longer interval free of local recurrences or metastasis than is presently attainable.
A RAPID COMPATIBILITY ANALYSIS OF POTENTIAL OFFSHORE SAND SOURCES FOR BEACHES OF THE SANTA BARBARA LITTORAL CELL

The beaches of the Santa Barbara Littoral Cell, which are narrow as a result of either natural and/or anthropogenic factors, may benefit from nourishment. Sand compatibility is fundamental to beach nourishment success and grain size is the parameter often used to evaluate equivalence. Only after understanding which sand sizes naturally compose beaches in a specific cell, especially the smallest size that remains on the beach, can the potential compatibility of source areas, such as offshore borrow sites, be accurately assessed. This study examines sediments on the beach and in the nearshore (5-20m depth) for the entire Santa Barbara Littoral Cell east of Point Conception. A digital bed sediment camera, the Eyeball©, and spatial autocorrelation technique were used to determine sediment grain size. Here we report on whether nearshore sediments are comparable and compatible with beach sands of the Santa Barbara Littoral Cell.
Long-wavelength VCSELs on InP grown by MOCVD

High efficiency continuous wave operation of 1.53 μm vertical-cavity surface-emitting lasers (VCSELs) grown by metal organic chemical vapor deposition (MOCVD) has been demonstrated. Devices show a high differential quantum efficiency of 58% and a single-mode power of 1.38 mW with a side mode suppression ratio (SMSR) of 45 dB. Lasing wavelength is 1537 nm. Lasing operation up to 90° C has been achieved with 0.16 mW power at 85° C. A symmetric and narrow far field angle of less than 12° was observed. An error free transmission at 2.488 Gbps with a -26 dBm minimum average receiver power was demonstrated.
Challenges and Opportunities for Intervening with Couples in the Aftermath of the Global War on Terrorism

The unique culture of the military family in the early part of the twenty-first century will be examined, including the high operational tempo, frequent geographic moves, high rates of service among women, and the unique constellation of deployed troops from Active Duty, National Guard and Reserve components. Challenges faced by these couples are described, followed by key issues for clinicians to assess. Several developing couple-based interventions will be described, followed by a vignette which will highlight the issues and opportunities for these couples. In addition to reviewing common difficulties among military families, the authors will highlight strengths inherent to the military culture that clinicians can utilize in helping families develop resiliency.
Geomagnetic polarity reversals in a turbulent core

Abstract The behavior of the main magnetic field components during a polarity transition is investigated using the α 2 -dynamo model for magnetic field generation in a turbulent core. It is shown that rapid reversals of the dipole field occur when the helicity, a measure of correlation between turbulent velocity and vorticity, changes sign. Two classes of polarity transitions are possible. Within the first class, termed component reversals, the dipole field reverses but the toroidal field does not. Within the second class, termed full reversals, both dipole and toroidal fields reverse. Component reversals result from long term fluctuations in core helicity; full reversals result from short term fluctuations. A set of time-evolution equations are derived which govern the dipole field behavior during an idealized transition. Solutions to these equations exhibit transitions in which the dipole remains axial while its intensity decays rapidly toward zero, and is regenerated with reversed polarity. Assuming an electrical conductivity of 3 × 10 5 mho m −1 for the fluid core, the time interval required to complete the reversal process can be as short as 7500 years. This time scale is consistent with paleomagnetic observations of the duration of reversals. A possible explanation of the cause of reversals is proposed, in which the core's net helicity fluctuates in response to fluctuations in the level of turbulence produced by two competing energy sources—thermal convection and segregation of the inner core. Symmetry considerations indicate that, in each hemisphere, helicity generated by heat loss at the core-mantle boundary may have the opposite sign of helicity generated by energy release at the inner core boundary. Random variations in rates of energy release can cause the net helicity and the α-effect to change sign occasionally, provoking a field reversal. In this model, energy release by inner core formation tends to destabilize stationary dynamo action, causing polarity reversals.
Rational, biologically based treatment of EGFR -mutant non-small-cell lung cancer

Epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC) was first recognized in 2004 as a distinct, clinically relevant molecular subset of lung cancer. The disease has been the subject of intensive research at both the basic scientific and clinical levels, becoming a paradigm for how to understand and treat oncogene-driven carcinomas. Although patients with EGFR-mutant tumours have increased sensitivity to tyrosine kinase inhibitors (TKIs), primary and acquired resistance to these agents remains a major clinical problem. This Review summarizes recent developments aimed at treating and ultimately curing the disease.
Aortic Valve Replacement in the Young Child

Abstract Aortic valvotomy is a satisfactory procedure to relieve significant valvular stenosis in the young child in most instances. Intraoperative measurement to determine the reduction or elimination of a gradient across the valve confirms the adequacy of the orifice achieved by commissurotomy. This paper concerns itself with the occasional patient in whom a bicuspid valve is found for which little can be accomplished by operation because there is minimal or no commissural fusion. The valve orifice is adequate anatomically, but functionally it is severely obstructive. Recent experience with 2 children (aged 7 and 8 years) in whom aortic prosthetic valves were inserted after valvotomy suggests that in those rare circumstances in which life-threatening, severe obstruction cannot be relieved, valve replacement at the time of the initial operation may be appropriate.
Comparison of wound strength with and without a hydrogel liquid ocular bandage in human cadaver eyes

Purpose To determine whether a hydrogel liquid ocular bandage improves wound strength. Setting John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Design Laboratory investigation. Methods The wound strength of 2.8 mm clear corneal incisions and 23-gauge scleral incisions was tested in cadaver eyes by raising the intraocular pressure (IOP) until leakage occurred. The pressure at the first sign of incision leakage with the liquid bandage and without the liquid bandage was determined. Results Four corneal incisions and 4 scleral incisions were made in 5 cadaver eyes. The mean pressure at the first sign of corneal incision leakage was 59.5 mm Hg ± 21.0 (SD) without the liquid bandage and 198.1 ± 57.6 mm Hg with the liquid bandage ( P P P = .002). Conclusion With application of a hydrogel liquid ocular bandage, incisions withstood significantly higher IOP before leakage occurred than when no liquid bandage was used. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.
Cloning and expression of the mouse homolog of the human α2-C2 adrenergic receptor

Summary Three subtypes of α2 adrenergic receptors have been identified in the human and rat. The subtype located on human chromosome 2 (α2-C2) is unique in that it is expressed mainly in the peripheral tissues and lacks sites for N-linked glycosylation. We isolated the gene encoding the mouse homolog of the human α2-C2 adrenergic receptor (Mα2-2H). The deduced amino acid sequence of the Mα2-2H shows 82% and 96% identity to the human α2-C2 and the rat RNGα2 adrenergic receptors, respectively. Southern blot analysis demonstrated that the Mα2-2H was encoded by a single copy gene and was distinct from the mouse homologs of the α2-C4 and α2-C10 adrenergic receptors. When expressed in COS-7 cells, the Mα2-2H exhibited a pharmacological profile similar to the human α2-C2 and rat RNGα2 receptors.
A modified Gummel method for the basic semiconductor device equations

A modification of H.K. Gummel's (1964) method for the iterative solution of the basic semiconductor device equations is presented. The method uses an approximation of an appropriately preconditioned Jacobian matrix and is designed to improve the convergence of Gummel's method for large currents. Performance is tested on a model problem. >
Vasopressin, oxytocin, corticotrophin-releasing factor, and sodium responses during fluoxetine administration in the rat

Hyponatremia has been observed in elderly patients treated with the selective serotonin reuptake inhibitor (SSRI) fluoxetine. The pathogenesis of this effect is not known, but enhanced release of vasopressin (VP) and its renal actions may be a possible mechanism. Excess secretion of VP in combination with large fluid intake is known to induce hyponatremia. We determined if chronic fluoxetine administration in association with liberal fluid intake will induce hyponatremia via enhanced release of VP. We used a previously described model in which fluid intake is forced by administering rats a nutritionally balanced liquid diet. Male Sprague-Dawley rats in groups of 10 were randomized to solid and liquid diets, and each diet group administered daily ip injections of fluoxetine (10 mg/kg) or saline for 10 d. Water was given ad libitum to all groups. Daily weight, fluid and food intake, and urine output were measured. On d 10, rats were killed by rapid guillotine decapitation 1–3 h after injection. Trunk blood was collected for measurements of plasma VP and oxytocin (OT) and serum sodium (Na), BUN, creatinine, and glucose. Pituitary glands were assayed for VP and OT content. VP mRNA in the paraventricular and supraoptic nuclei (PVN and SON) and corticotrophin-releasing factor (CRF) mRNA in the PVN were measured by in situ hybridization histochemistry. Fluid intake was significantly higher in groups maintained on liquid vs solid diet (p < 0.0001), as was urine output (p < 0.0001). Fluoxetine-treated rats gained significantly less weight than placebotreated rats (p = 0.01), in keeping with fluoxetine’s anorexigenic properties. However, no significant differences were found among the groups in Na, plasma VP or OT, pituitary VP or OT, or PVN CRF or VP mRNA levels. We conclude that administration of fluoxetine to laboratory rats in the dose and duration used in this study does not significantly affect hypothalamic expression, pituitary stores, or peripheral secretion of VP.
AC electrothermal enhancement of heterogeneous assays in microfluidics

AC-driven electrothermal flow is used to enhance the temporal performance of heterogeneous immuno-sensors in microfluidic systems by nearly an order of magnitude. AC electrokinetic forces are used to generate electrothermal flow, which in turn produces a circular stirring fluid motion that enhances the transport of diffusion-limited proteins. This provides more binding opportunities between suspended antigens and wall-immobilized antibodies. We investigate experimentally the effectiveness of electrothermal stirring, using a biotin–streptavidin heterogeneous assay, in which biotin is immobilized, and fluorescently-labeled streptavidin is suspended in a high conductivity buffer (σ = 1.0 S m−1). Microfabricated electrodes were integrated within a microwell and driven at a frequency of f= 200 kHz and 10 Vrms. Fluorescent intensity measurements show that for a five minute assay, electrothermal stirring increases the binding rate by a factor of almost nine. Similar binding improvement was measured for longer assays, up to fifteen minutes. The electrothermal enhancement of this assay was modeled numerically and agrees with experimental binding rates. The measured fluid velocity of 22 ± 2 µm s−1 was significantly lower than that predicted by the numerical model, 1.1 mm s−1, but nevertheless shows the same fourth power dependence on applied potential. The results demonstrate the ability for electrothermal stirring to reliably improve the response time and sensitivity within a given time limit for microfluidic diffusion-limited sensors.
Effects Of Antiviral Therapy On The Production Of Anti-Human Immunodeficiency Virus-Specific Immunoglobulin In Infants And Children

The effect of zidovudine therapy on human immunodeficiency virus (HIV)-specific antibody production was studied in 64 HIV-1-infected infants and children > 6 months old. HIV-specific in vitro antibody production (IVAP) was measured in cultures of peripheral blood mononuclear cells (PBMC). IVAP decreased in 85% of children after zidovudine was initiated (mean decline, 1 log within 2 months). Effects were seen as early as 1 week after starting zidovudine. No change in IVAP was seen in children not treated. In comparison, plasma core (p24) antigen levels declined and CD4+ lymphocytes increased in only 42% and 52%, respectively, of treated subjects. Thus, the production of antibody to HIV-1 decreases rapidly after the initiation of antiretroviral therapy. This response to therapy may provide a simple and sensitive method of monitoring antiretroviral therapy.
Plastic modules for free-space optical interconnects

A combined optoelectronic and optomechanical packaging technique for the construction of snap-together free-space optical interconnect systems is described. The modules integrate relaying and routing functions by use of transparent optical molded plastic, which can achieve sufficient alignment precision that further adjustment is not required during system assembly. Methods to integrate the optoelectronic chips, such as vertical-cavity surface-emitting laser and receiver arrays with these plastic optical modules are described. Other chips can also be integrated to form optoelectronic multichip modules. These modules can also be designed to accommodate coupling to or from optical fiber arrays. A test-bed system to demonstrate the concept was assembled to a lower precision by use of conventional machining techniques.
Friends (and Sometimes Enemies) With Cognitive Benefits: What Types of Social Interactions Boost Executive Functioning?

Recent findings indicate interventions can boost executive functions—mental processes that have long been thought to be static and not open to change. The authors examined whether and how short-term social interactions could create such cognitive benefits. Study 1 found that basic get-to-know-you interactions (with or without an explicit cooperative goal) boosted executive function relative to controls and as much as nonsocial intellective activities. In contrast, interactions involving a competitive goal resulted in no boosts. Studies 2 and 3 tested a proposed mechanism for the results—that people need to engage with others and take their perspective to realize cognitive boosts. The findings show that competitive interactions, if structured to allow for interpersonal engagement, can boost executive functions. The results highlight how social functioning can enhance core mental capacities.
Automatic 3D modeling using range images obtained from unknown viewpoints

In this paper, we present a method for automatically creating a 3D model of a scene from a set of range images obtained from unknown viewpoints. Existing 3D modeling approaches require manual interaction or rely on mechanical methods to estimate the viewpoints. Given a set of range images (views), we use a surface matching system to exhaustively register all pairs of views. The results are verified for consistency, but some incorrect matches may be locally undetectable and correct matches may be missed. We then construct a consistent model from these potentially faulty matches using a global consistency criterion to eliminate incorrect, but locally consistent, matches. The procedure is demonstrated through an application called hand-held modeling, in which a 3D model is automatically created by scanning an object held in a person's hand.
Species diversity patterns of choanoflagellates in the Pettaquamscutt River Estuary, Rhode Island, USA

Choanoflagellates are a large group of heterotrophic protists that play an important role in carbon transfer through the microbial loop, as they consume bacterioplankton and have also been found to be a major food source for macrozooplankton. Although many choanoflagellate species are cosmopolitan, species diversity of the acanthoecid choanoflagellates has been shown to vary substantially between study areas around the globe. A seasonal investigation of acanthoecid species diversity was conducted along the salinity gradient in the Pettaquamscutt River Estuary (PRE), Rhode Island, USA. The taxonomy of the Acanthoecidae is based upon the morphology of a complex basket-like lorica that surrounds the protoplast. Only one previously published study has investigated the diversity of this choanoflagellate family in the western North Atlantic, specifically in the coastal waters of Newfoundland. The Rhode Island survey found that maximum species richness occurred between July and October, and some species exhibited a salinity preference in their distributions, while others had a seasonal shift in occurrence. Acanthocorbis apoda (Leadbeater) Hara and Takahashi, 1984 occurred most consistently throughout the study (55% of samples), while Diaphanoeca grandis Ellis, 1930, Diplotheca costata Valkanov, 1970, Savillea micropora (Norris) Leadbeater, 1975, Stephanoeca cupula (Leadbeater) Thomsen 1988, and Stephanoeca supracostata Hara 1996 were each present in 36-45% of samples. The PRE survey found a four-fold increase in species richness of acanthoecid choanoflagellates over the Canadian study, providing further evidence of the large regional variability in choanoflagellate distributions.
Constipation in childhood

Constipation in children is an often long-lasting pediatric functional gastrointestinal disorder with a worldwide prevalence varying between 0.7% and 29.6%, and estimated health-care costs of US$3.9 billion per year in the USA alone. The pathophysiology of childhood constipation is multifactorial and remains incompletely understood; however, withholding of stools, starting after an experience of a hard, painful, or frightening bowel movement is the most common cause found in children. A thorough medical history and physical examination, including a rectal examination in combination with a bowel diary, is sufficient in the majority of cases to diagnose constipation. The current standard treatment consists of education, toilet training, disimpaction, maintenance therapy and long-term follow-up. In the past decade, well-designed treatment trials in the pediatric population have emerged and long-term outcome studies have been completed. This Review summarizes the current knowledge of the clinical aspects of childhood constipation, including pathogenesis, diagnosis and treatment, with particular emphasis on the latest available data.
Dapped-End Strengthening of Full-Scale Prestressed Double Tee Beams with FRP Composites

The unusual shape of the dapped-end beam develops a severe stress concentration at the re-entrant corner. If suitable reinforcement is not provided close to the re-entrant corner, the diagonal tension crack may grow rapidly and failure may occur with little or no warning. This paper reports the testing of three full-scale prestressed concrete (PC) double tee beams (five tests) in shear at the re-entrant corner. One dapped-end of each beam was reinforced with internal steel reinforcement as a bench mark and the other was strengthened with externally bonded carbon fiber reinforced polymer (CFRP) laminates. Of the two CFRP strengthened dapped-ends one used one-ply externally bonded CFRP reinforcement and the other two-ply externally bonded CFRP reinforcement with a U-anchor. The tests revealed that the reinforcement arrangements have significant influence on the member response. For one of the CFRP cases, the application of the anchor was such that failure by fiber rupture rather than peeling was achieved. R...
The Changing Structure of American Cities: A Study of the Diffusion of Innovation

Using historical and numerical analysis and the five-part schema, this study finds that over the past 50 years structural modifications and adaptations by American cities have generally followed the standard S curve of the diffusion of innovation. In tests of Kaufman's and Hirshman's theories of epochs of change from representativeness to administrative efficiency, this study determines that mayor-council cities have, in a standard innovation diffusion S curve, adopted many of the key features of council-manager cities, increasing their administrative efficiency. At the same time, council-manager cities, again in an S curve, have adopted many of the key features of mayor-council cities, increasing their political responsiveness. Fewer cities are now either distinctly mayor-council or council-manager in form, and most cities are structurally less distinct, constituting a newly merged or hybrid model of local government—the type III city.